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Reilly CC, Floyd SV, Raniwalla S, Gall N, Rafferty GF. The clinical utility of the Breathing Pattern Assessment Tool (BPAT) to identify dysfunctional breathing (DB) in individuals living with postural orthostatic tachycardia syndrome (POTS). Auton Neurosci 2023; 248:103104. [PMID: 37393657 DOI: 10.1016/j.autneu.2023.103104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 05/25/2023] [Accepted: 06/16/2023] [Indexed: 07/04/2023]
Abstract
BACKGROUND Dysfunctional breathing (DB) resulting in inappropriate breathlessness is common in individuals living with postural orthostatic tachycardia syndrome (POTS). DB in POTS is complex, multifactorial, and not routinely assessed clinically outside of specialist centres. To date DB in POTS has been identified and diagnosed predominately via cardiopulmonary exercise testing (CPEX), hyperventilation provocation testing and/or specialist respiratory physiotherapy assessment. The Breathing Pattern Assessment Tool (BPAT) is a clinically validated diagnostic tool for DB in Asthma. There are, however, no published data regarding the use of the BPAT in POTS. The aim of this study was therefore to assess the potential clinic utility of the BPAT in the diagnosis of DB in individuals with POTS. METHODS A retrospective observational cohort study of individuals with POTS referred to respiratory physiotherapy for formal assessment of DB. DB was determined by specialist respiratory physiotherapist assessment which included physical assessment of chest wall movement/breathing pattern. The BPAT and Nijgmegen questionnaire were also completed. Receiver operating characteristics (ROC) analysis was used to compare the physiotherapy assessment based diagnosis of DB to the BPAT score. RESULTS Seventy-seven individuals with POTS [mean (sd) age 32 (11) years, 71 (92 %) female] were assessed by a specialist respiratory physiotherapist, with 65 (84 %) being diagnosed with DB. Using the established BPAT cut off of four or more, receiver operating characteristics (ROC) analysis indicated a sensitivity of 87 % and specificity of 75 % for diagnosing DB in individuals with POTS with an area under the curve (AUC) of 0.901 (95 % CI 0.803-0.999), demonstrating excellent discriminatory ability. CONCLUSION BPAT has high sensitivity and moderate specificity for identifying DB in individuals living with POTS.
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Affiliation(s)
- Charles C Reilly
- Department of Physiotherapy, King's College Hospital, Denmark Hill, London, UK; Cicely Saunders Institute of Palliative Care, Policy and Rehabilitation, King's College London, UK.
| | - Sarah V Floyd
- Department of Physiotherapy, King's College Hospital, Denmark Hill, London, UK
| | - Shehnaz Raniwalla
- Department of Physiotherapy, King's College Hospital, Denmark Hill, London, UK
| | - Nicholas Gall
- Department of Cardiology, King's College Hospital, Denmark Hill, London, UK
| | - Gerrard F Rafferty
- Centre for Human & Applied Physiological Sciences, King's College London, UK
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2
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Serna-Pascual M, D'Cruz RF, Volovaya M, Jolley CJ, Hart N, Rafferty GF, Steier J, Aston PJ, Nandi M. Novel breathing pattern analysis: Symmetric Projection Attractor Reconstruction improves identification of impending COPD re-exacerbations - a retrospective cohort analysis. ERJ Open Res 2023; 9:00164-2023. [PMID: 37650090 PMCID: PMC10463025 DOI: 10.1183/23120541.00164-2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 05/05/2023] [Indexed: 09/01/2023] Open
Abstract
Respiratory waveforms can be reduced to simple metrics, such as rate, but this may miss information about waveform shape and whole breathing pattern. A novel analysis method quantifying the whole waveform shape identifies AECOPD earlier. https://bit.ly/3M6uIEB.
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Affiliation(s)
- Miquel Serna-Pascual
- School of Cancer and Pharmaceutical Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
- These authors contributed equally
| | - Rebecca F. D'Cruz
- Lane Fox Clinical Respiratory Physiology Research Unit, Guy's and St Thomas’ NHS Foundation Trust, London, UK
- Centre for Human and Applied Physiological Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
- These authors contributed equally
| | - Maria Volovaya
- School of Cancer and Pharmaceutical Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Caroline J. Jolley
- Centre for Human and Applied Physiological Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Nicholas Hart
- Lane Fox Clinical Respiratory Physiology Research Unit, Guy's and St Thomas’ NHS Foundation Trust, London, UK
- Centre for Human and Applied Physiological Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Gerrard F. Rafferty
- Centre for Human and Applied Physiological Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Joerg Steier
- Lane Fox Clinical Respiratory Physiology Research Unit, Guy's and St Thomas’ NHS Foundation Trust, London, UK
- Centre for Human and Applied Physiological Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Philip J. Aston
- Department of Mathematics, University of Surrey, Guildford, UK
| | - Manasi Nandi
- School of Cancer and Pharmaceutical Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
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3
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Abu-Sultaneh S, Iyer NP, Fernández A, Gaies M, González-Dambrauskas S, Hotz JC, Kneyber MCJ, López-Fernández YM, Rotta AT, Werho DK, Baranwal AK, Blackwood B, Craven HJ, Curley MAQ, Essouri S, Fioretto JR, Hartmann SMM, Jouvet P, Korang SK, Rafferty GF, Ramnarayan P, Rose L, Tume LN, Whipple EC, Wong JJM, Emeriaud G, Mastropietro CW, Napolitano N, Newth CJL, Khemani RG. Executive Summary: International Clinical Practice Guidelines for Pediatric Ventilator Liberation, A Pediatric Acute Lung Injury and Sepsis Investigators (PALISI) Network Document. Am J Respir Crit Care Med 2023; 207:17-28. [PMID: 36583619 PMCID: PMC9952867 DOI: 10.1164/rccm.202204-0795so] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 08/12/2022] [Indexed: 12/31/2022] Open
Abstract
Rationale: Pediatric-specific ventilator liberation guidelines are lacking despite the many studies exploring elements of extubation readiness testing. The lack of clinical practice guidelines has led to significant and unnecessary variation in methods used to assess pediatric patients' readiness for extubation. Methods: Twenty-six international experts comprised a multiprofessional panel to establish pediatrics-specific ventilator liberation clinical practice guidelines, focusing on acutely hospitalized children receiving invasive mechanical ventilation for more than 24 hours. Eleven key questions were identified and first prioritized using the Modified Convergence of Opinion on Recommendations and Evidence. A systematic review was conducted for questions that did not meet an a priori threshold of ⩾80% agreement, with Grading of Recommendations, Assessment, Development, and Evaluation methodologies applied to develop the guidelines. The panel evaluated the evidence and drafted and voted on the recommendations. Measurements and Main Results: Three questions related to systematic screening using an extubation readiness testing bundle and a spontaneous breathing trial as part of the bundle met Modified Convergence of Opinion on Recommendations criteria of ⩾80% agreement. For the remaining eight questions, five systematic reviews yielded 12 recommendations related to the methods and duration of spontaneous breathing trials, measures of respiratory muscle strength, assessment of risk of postextubation upper airway obstruction and its prevention, use of postextubation noninvasive respiratory support, and sedation. Most recommendations were conditional and based on low to very low certainty of evidence. Conclusions: This clinical practice guideline provides a conceptual framework with evidence-based recommendations for best practices related to pediatric ventilator liberation.
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Affiliation(s)
- Samer Abu-Sultaneh
- Division of Pediatric Critical Care, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana
- Riley Hospital for Children at Indiana University Health, Indianapolis, Indiana
| | - Narayan Prabhu Iyer
- Fetal and Neonatal Institute, Division of Neonatology, Department of Pediatrics, Children’s Hospital Los Angeles, Los Angeles, California
- Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Analía Fernández
- Pediatric Critical Care Unit, Acute Care General Hospital “Carlos G. Durand,” Buenos Aires, Argentina
| | - Michael Gaies
- Division of Pediatric Cardiology, Department of Pediatrics, Cincinnati Children’s Hospital Medical Center Heart Institute, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Sebastián González-Dambrauskas
- Red Colaborativa Pediátrica de Latinoamérica (LARed Network), Facultad de Medicina, Unidad de Cuidados Intensivos de Niños del Centro Hospitalario Pereira Rossell, Universidad de la República, Montevideo, Uruguay
| | - Justin Christian Hotz
- Department of Anesthesiology and Critical Care, Children’s Hospital Los Angeles, Los Angeles, California
| | - Martin C. J. Kneyber
- Division of Paediatric Critical Care Medicine, Department of Paediatrics, Beatrix Children’s Hospital, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Yolanda M. López-Fernández
- Department of Pediatrics, Biocruces-Bizkaia Health Research Institute, Cruces University Hospital, Bizkaia, Spain
| | - Alexandre T. Rotta
- Division of Pediatric Critical Care Medicine, Department of Pediatrics, Duke University, Durham, North Carolina
| | - David K. Werho
- Division of Pediatric Cardiology, Cardiothoracic Intensive Care, Rady Children’s Hospital, University of California, San Diego, San Diego, California
| | - Arun Kumar Baranwal
- Department of Pediatrics, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Bronagh Blackwood
- Wellcome-Wolfson Institute for Experimental Medicine, Queen’s University Belfast, Belfast, United Kingdom
| | - Hannah J. Craven
- Ruth Lilly Medical Library, Indiana University School of Medicine, Indianapolis, Indiana
| | - Martha A. Q. Curley
- Family and Community Health, University of Pennsylvania School of Nursing, Philadelphia, Pennsylvania
- Research Institute, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Sandrine Essouri
- Department of Pediatrics, Sainte-Justine Hospital, University of Montreal, Montreal, Quebec, Canada
| | - Jose Roberto Fioretto
- Pediatric Critical Care Division, Department of Pediatrics, Botucatu Medical School, Sao Paulo State University, Botucatu, Sao Paulo, Brazil
| | - Silvia M. M. Hartmann
- Division of Critical Care Medicine, Department of Pediatrics, Seattle Children’s Hospital, University of Washington, Seattle, Washington
| | - Philippe Jouvet
- Department of Pediatrics, Sainte-Justine Hospital, University of Montreal, Montreal, Quebec, Canada
| | - Steven Kwasi Korang
- Department of Anesthesiology and Critical Care, Children’s Hospital Los Angeles, Los Angeles, California
- Copenhagen Trial Unit, Centre for Clinical Intervention Research, Capital Region of Denmark, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Gerrard F. Rafferty
- Centre for Human and Applied Physiological Sciences, Faculty of Life Sciences & Medicine, and
| | - Padmanabhan Ramnarayan
- Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Louise Rose
- Florence Nightingale Faculty of Nursing, Midwifery and Palliative Care, King’s College London, London United Kingdom
| | - Lyvonne N. Tume
- Edge Hill University Health Research Institute, Ormskirk, England
| | - Elizabeth C. Whipple
- Ruth Lilly Medical Library, Indiana University School of Medicine, Indianapolis, Indiana
| | | | - Guillaume Emeriaud
- Department of Pediatrics, Sainte-Justine Hospital, University of Montreal, Montreal, Quebec, Canada
| | - Christopher W. Mastropietro
- Division of Pediatric Critical Care, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana
- Riley Hospital for Children at Indiana University Health, Indianapolis, Indiana
| | | | - Christopher J. L. Newth
- Keck School of Medicine, University of Southern California, Los Angeles, California
- Department of Anesthesiology and Critical Care, Children’s Hospital Los Angeles, Los Angeles, California
| | - Robinder G. Khemani
- Keck School of Medicine, University of Southern California, Los Angeles, California
- Department of Anesthesiology and Critical Care, Children’s Hospital Los Angeles, Los Angeles, California
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Abu-Sultaneh S, Iyer NP, Fernández A, Gaies M, González-Dambrauskas S, Hotz JC, Kneyber MCJ, López-Fernández YM, Rotta AT, Werho DK, Baranwal AK, Blackwood B, Craven HJ, Curley MAQ, Essouri S, Fioretto JR, Hartmann SMM, Jouvet P, Korang SK, Rafferty GF, Ramnarayan P, Rose L, Tume LN, Whipple EC, Wong JJM, Emeriaud G, Mastropietro CW, Napolitano N, Newth CJL, Khemani RG. Operational Definitions Related to Pediatric Ventilator Liberation. Chest 2022; 163:1130-1143. [PMID: 36563873 DOI: 10.1016/j.chest.2022.12.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 11/07/2022] [Accepted: 12/08/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Common, operational definitions are crucial to assess interventions and outcomes related to pediatric mechanical ventilation. These definitions can reduce unnecessary variability among research and quality improvement efforts, to ensure findings are generalizable, and can be pooled to establish best practices. RESEARCH QUESTION Can we establish operational definitions for key elements related to pediatric ventilator liberation using a combination of detailed literature review and consensus-based approaches? STUDY DESIGN AND METHODS A panel of 26 international experts in pediatric ventilator liberation, two methodologists, and two librarians conducted systematic reviews on eight topic areas related to pediatric ventilator liberation. Through a series of virtual meetings, we established draft definitions that were voted upon using an anonymous web-based process. Definitions were revised by incorporating extracted data gathered during the systematic review and discussed in another consensus meeting. A second round of voting was conducted to confirm the final definitions. RESULTS In eight topic areas identified by the experts, 16 preliminary definitions were established. Based on initial discussion and the first round of voting, modifications were suggested for 11 of the 16 definitions. There was significant variability in how these items were defined in the literature reviewed. The final round of voting achieved ≥ 80% agreement for all 16 definitions in the following areas: what constitutes respiratory support (invasive mechanical ventilation and noninvasive respiratory support), liberation and failed attempts to liberate from invasive mechanical ventilation, liberation from respiratory support, duration of noninvasive respiratory support, total duration of invasive mechanical ventilation, spontaneous breathing trials, extubation readiness testing, 28 ventilator-free days, and planned vs rescue use of post-extubation noninvasive respiratory support. INTERPRETATION We propose that these consensus-based definitions for elements of pediatric ventilator liberation, informed by evidence, be used for future quality improvement initiatives and research studies to improve generalizability and facilitate comparison.
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Affiliation(s)
- Samer Abu-Sultaneh
- Division of Pediatric Critical Care, Department of Pediatrics Riley Hospital for Children at Indiana University Health, Indiana University School of Medicine, Indianapolis, IN.
| | - Narayan Prabhu Iyer
- Fetal and Neonatal Institute, Division of Neonatology, Children's Hospital Los Angeles, Department of Pediatrics, Keck School of Medicine, University of Southern California, Los Angeles, CA
| | - Analía Fernández
- Pediatric Critical Care Unit, Hospital General de Agudos "C. Durand" Ciudad Autónoma de Buenos Aires, Argentina
| | - Michael Gaies
- Department of Pediatrics, Division of Pediatric Cardiology, University of Cincinnati College of Medicine, and Cincinnati Children's Hospital Medical Center Heart Institute, Cincinnati, OH
| | - Sebastián González-Dambrauskas
- Red Colaborativa Pediátrica de Latinoamérica (LARed Network) and Departamento de Pediatría Unidad de Cuidados Intensivos de Niños del Centro Hospitalario Pereira Rossell, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Justin Christian Hotz
- Department of Anesthesiology and Critical Care, Children's Hospital Los Angeles, Los Angeles, CA
| | - Martin C J Kneyber
- Department of Paediatrics, Division of Paediatric Critical Care Medicine, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Yolanda M López-Fernández
- Department of Pediatrics, Pediatric Critical Care Division, Cruces University Hospital, Biocruces-Bizkaia Health Research Institute, Bizkaia, Spain
| | - Alexandre T Rotta
- Division of Pediatric Critical Care Medicine, Department of Pediatrics, Duke University, Durham, NC
| | - David K Werho
- Division of Pediatric Cardiology, Cardiothoracic Intensive Care, UC San Diego, Rady Children's Hospital, San Diego, CA
| | - Arun Kumar Baranwal
- Department of Pediatrics, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Bronagh Blackwood
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, Northern Ireland, United Kingdom
| | - Hannah J Craven
- Ruth Lilly Medical Library, Indiana University School of Medicine, Indianapolis, IN
| | - Martha A Q Curley
- Family and Community Health, University of Pennsylvania School of Nursing, Philadelphia, PA; Research Institute, Children's Hospital of Philadelphia, Philadelphia, PA
| | - Sandrine Essouri
- Department of Pediatrics, Sainte-Justine Hospital, Université de Montréal, Montreal, QC, Canada
| | - Jose Roberto Fioretto
- Department of Pediatrics, Pediatric Critical Care Division, Botucatu Medical School-UNESP-São Paulo State University, Botucatu, SP, Brazil
| | - Silvia M M Hartmann
- Division of Critical Care Medicine, Department of Pediatrics, Seattle Children's Hospital and University of Washington, Seattle, WA
| | - Philippe Jouvet
- Department of Pediatrics, Sainte-Justine Hospital, Université de Montréal, Montreal, QC, Canada
| | - Steven Kwasi Korang
- Department of Anesthesiology and Critical Care, Children's Hospital Los Angeles, Los Angeles, CA; Copenhagen Trial Unit, Centre for Clinical Intervention Research, The Capital Region of Denmark, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Gerrard F Rafferty
- Centre for Human and Applied Physiological Sciences, Faculty of Life Sciences & Medicine, King's College London, London, England
| | - Padmanabhan Ramnarayan
- Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, England
| | - Louise Rose
- Florence Nightingale Faculty of Nursing, Midwifery and Palliative Care, King's College London, London, England
| | - Lyvonne N Tume
- Edge Hill University Health Research Institute, Ormskirk, England
| | - Elizabeth C Whipple
- Ruth Lilly Medical Library, Indiana University School of Medicine, Indianapolis, IN
| | | | - Guillaume Emeriaud
- Department of Pediatrics, Sainte-Justine Hospital, Université de Montréal, Montreal, QC, Canada
| | - Christopher W Mastropietro
- Division of Pediatric Critical Care, Department of Pediatrics Riley Hospital for Children at Indiana University Health, Indiana University School of Medicine, Indianapolis, IN
| | | | - Christopher J L Newth
- Department of Anesthesiology and Critical Care, Children's Hospital Los Angeles, Los Angeles, CA; Children's Hospital Los Angeles, University of Southern California Keck School of Medicine, Los Angeles, CA
| | - Robinder G Khemani
- Department of Anesthesiology and Critical Care, Children's Hospital Los Angeles, Los Angeles, CA; Children's Hospital Los Angeles, University of Southern California Keck School of Medicine, Los Angeles, CA
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5
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Abu-Sultaneh S, Iyer NP, Fernández A, Gaies M, González-Dambrauskas S, Hotz JC, Kneyber MCJ, López-Fernández YM, Rotta AT, Werho DK, Baranwal AK, Blackwood B, Craven HJ, Curley MAQ, Essouri S, Fioretto JR, Hartmann SM, Jouvet P, Korang SK, Rafferty GF, Ramnarayan P, Rose L, Tume LN, Whipple EC, Wong JJM, Emeriaud G, Mastropietro CW, Napolitano N, Newth CJL, Khemani RG. Executive Summary: International Clinical Practice Guidelines for Pediatric Ventilator Liberation, A PALISI Network Document. Am J Respir Crit Care Med 2022. [PMID: 35969419 DOI: 10.1164/rccm.202204-0795oc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Pediatric specific ventilator liberation guidelines are lacking despite the many studies exploring elements of extubation readiness testing. The lack of clinical practice guidelines has led to significant and unnecessary variation in methods used to assess pediatric patients' readiness for extubation. METHODS Twenty-six international experts comprised a multi-professional panel to establish pediatric specific ventilator liberation clinical practice guidelines, focusing on acutely hospitalized children receiving invasive mechanical ventilation for more than 24 hours. Eleven key questions were identified and first prioritized using the Modified Convergence of Opinion on Recommendations and Evidence. Systematic review was conducted for questions which did not meet an a-priori threshold of ≥80% agreement, with Grading of Recommendations, Assessment, Development, and Evaluation methodologies applied to develop the guidelines. The panel evaluated the evidence, drafted, and voted on the recommendations. MEASUREMENTS AND MAIN RESULTS Three questions related to systematic screening, using an extubation readiness testing bundle and use of a spontaneous breathing trial as part of the bundle met Modified Convergence of Opinion on Recommendations criteria of ≥80% agreement. For the remaining 8 questions, 5 systematic reviews yielded 12 recommendations related to the methods and duration of spontaneous breathing trials; measures of respiratory muscle strength; assessment of risk of post-extubation upper airway obstruction and its prevention; use of post-extubation non-invasive respiratory support; and sedation. Most recommendations were conditional and based on low to very low certainty of evidence. CONCLUSION This clinical practice guideline provides a conceptual framework with evidence-based recommendations for best practices related to pediatric ventilator liberation. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).
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Affiliation(s)
- Samer Abu-Sultaneh
- Indiana University School of Medicine, Department of Pediatrics, Division of Pediatric Critical Care, Indianapolis, Indiana, United States.,Riley Hospital for Children at Indiana University Health, Indianapolis, Indiana, United States;
| | - Narayan Prabhu Iyer
- University of Southern California Keck School of Medicine, Department of Pediatrics, Los Angeles, California, United States.,Children's Hospital of Los Angeles, Fetal and Neonatal Institute, Division of Neonatology, Los Angeles, California, United States
| | - Analía Fernández
- Hospital General de Agudos "C. Durand" Ciudad Autónoma de, Pediatric Critical Care Unit, Buenos Aires, Argentina
| | - Michael Gaies
- University of Cincinnati College of Medicine, Department of pediatrics, Division of pediatric cardiology , Cincinnati, Ohio, United States.,Cincinnati Children's Hospital Medical Center Heart Institute, Cincinnati, Ohio, United States
| | - Sebastián González-Dambrauskas
- Red Colaborativa Pediátrica de Latinoamérica (LARed Network), Montevideo, Uruguay.,Universidad de la República Facultad de Medicina, Unidad de Cuidados Intensivos de Niños del Centro Hospitalario Pereira Rossell (UCIN-CHPR), Montevideo, Montevideo, Uruguay
| | - Justin Christian Hotz
- Children's Hospital of Los Angeles, Department of Anesthesiology and Critical Care, Los Angeles, California, United States
| | - Martin C J Kneyber
- University Medical Centre Groningen Beatrix Childrens Hospital, Department of Paediatrics, Division of Paediatric Critical Care Medicine, Groningen, Netherlands
| | - Yolanda M López-Fernández
- Hospital Universitario Cruces, Department of Pediatrics, Pediatric Intensive Care, Barakaldo, Bizkaia, Spain.,Biocruces Bizkaia Health Research Institute, Barakaldo, Spain
| | - Alexandre T Rotta
- Duke University School of Medicine, Department of Pediatrics, Division of Pediatric Critical Care Medicine, Durham, North Carolina, United States
| | - David K Werho
- University of California San Diego School of Medicine, Department of Pediatrics, Division of Pediatric Cardiology, San Diego, California, United States.,Rady Children's Hospital, Cardiothoracic Intensive Care, San Diego, California, United States
| | - Arun Kumar Baranwal
- Post Graduate Institute of Medical Education and Research, Department of Pediatrics, Chandigarh, India
| | - Bronagh Blackwood
- Queen's University Belfast, Wellcome-Wolfson Institute for Experimental Medicine, Belfast, United Kingdom of Great Britain and Northern Ireland
| | - Hannah J Craven
- Indiana University School of Medicine, Ruth Lilly Medical Library, Indianapolis, Indiana, United States
| | - Martha A Q Curley
- University of Pennsylvania School of Nursing, Family and Community Health, Philadelphia, Pennsylvania, United States.,The Children's Hospital of Philadelphia, Research Institute, Philadelphia, Pennsylvania, United States
| | - Sandrine Essouri
- Université de Montréal, Department of Pediatrics, Montreal, Quebec, Canada.,Saint Justine Hospital, Montreal, Quebec, Canada
| | - Jose Roberto Fioretto
- UNESP - Sao Paulo State University, Botucatu Medical School, Department of Pediatrics, Division of Pediatric Critical Care, Sao Paulo, Botucatu-SP, Brazil
| | - Silvia Mm Hartmann
- University of Washington, Department of Pediatrics, Division of Critical Care Medicine, Seattle, Washington, United States.,Seattle Children's Hospital, Seattle, Washington, United States
| | - Philippe Jouvet
- Université de Montréal, Department of Pediatrics, Montreal, Quebec, Canada.,Saint Justine Hospital, Montreal, Quebec, Canada
| | - Steven Kwasi Korang
- Children's Hospital of Los Angeles, Department of Anesthesiology and Critical Care, Los Angeles, California, United States.,Copenhagen University Hospital, Copenhagen Trial Unit, Centre for Clinical Intervention Research, The Capital Region of Denmark, Rigshospitalet, Copenhagen, Denmark
| | - Gerrard F Rafferty
- King's College London Faculty of Life Sciences and Medicine, Centre for Human and Applied Physiological Sciences (CHAPS), London, United Kingdom of Great Britain and Northern Ireland
| | - Padmanabhan Ramnarayan
- Imperial College London, Department of Surgery and Cancer, Faculty of Medicine, London, United Kingdom of Great Britain and Northern Ireland
| | - Louise Rose
- King's College London, Florence Nightingale Faculty of Nursing, Midwifery and Palliative Care, London, United Kingdom of Great Britain and Northern Ireland
| | - Lyvonne N Tume
- Edge Hill University Health Research Institute, Ormskirk, United Kingdom of Great Britain and Northern Ireland
| | - Elizabeth C Whipple
- Indiana University School of Medicine, Ruth Lilly Medical Library, Indianapolis, Indiana, United States
| | - Judith Ju Ming Wong
- KK Women's and Children's Hospital, Children's Intensive Care Unit, Singapore, Singapore
| | - Guillaume Emeriaud
- Université de Montréal, Department of Pediatrics, Montreal, Quebec, Canada.,Saint Justine Hospital, Montreal, Quebec, Canada
| | - Christopher W Mastropietro
- Indiana University School of Medicine, Department of Pediatrics, Division of Pediatric Critical Care, Indianapolis, Indiana, United States.,Riley Hospital for Children at Indiana University Health, Indianapolis, Indiana, United States
| | - Natalie Napolitano
- The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States
| | - Christopher J L Newth
- University of Southern California Keck School of Medicine, Los Angeles, California, United States.,Children's Hospital of Los Angeles, Department of Anesthesiology and Critical Care, Los Angeles, California, United States
| | - Robinder G Khemani
- University of Southern California Keck School of Medicine, Los Angeles, California, United States.,Children's Hospital of Los Angeles, Department of Anesthesiology and Critical Care, Los Angeles, California, United States
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6
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Tas B, Kalk NJ, Lozano-García M, Rafferty GF, Cho P, Kelleher M, Moxham J, Strang J, Jolley CJ. Undetected Respiratory Depression in People with Opioid Use Disorder. Drug Alcohol Depend 2022; 234:109401. [PMID: 35306391 DOI: 10.1016/j.drugalcdep.2022.109401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 02/16/2022] [Accepted: 03/06/2022] [Indexed: 11/15/2022]
Abstract
BACKGROUND Opioid-related deaths are increasing globally. Respiratory complications of opioid use and underlying respiratory disease in people with Opioid Use Disorder (OUD) are potential contributory factors. Individual variation in susceptibility to overdose is, however, incompletely understood. This study investigated the prevalence of respiratory depression (RD) in OUD treatment and compared this to patients with chronic obstructive pulmonary disease (COPD) of equivalent severity. We also explored the contribution of opioid agonist treatment (OAT) dosage, and type, to the prevalence of RD. METHODS There were four groups of participants: 1) OUD plus COPD ('OUD-COPD', n = 13); 2) OUD without COPD ('OUD', n = 7); 3) opioid-naïve COPD patients ('COPD'n = 13); 4) healthy controls ('HC'n = 7). Physiological indices, including pulse oximetry (SpO2%), end-tidal CO2 (ETCO2), transcutaneous CO2 (TcCO2), respiratory airflow and second intercostal space parasternal muscle electromyography (EMGpara), were recorded continuously over 40 min whilst awake at rest. Significant RD was defined as: SpO2%< 90% for > 10 s, ETCO2 per breath > 6.6 kPa, TcCO2 overall mean > 6 kPa, respiratory pauses > 10 s RESULTS: At least one indicator was observed in every participant with OUD (n = 20). This compared to RD episode occurrence in only 2/7 HC and 2/13 COPD participants (p < 0.05,Fisher's exact test). The occurrence of RD was similar in OUD participants prescribed methadone (n = 6) compared to those prescribed buprenorphine (n = 12). CONCLUSIONS Undetected RD is common in OUD cohorts receiving OAT and is significantly more severe than in opioid-naïve controls. RD can be assessed using simple objective measures. Further studies are required to determine the association between RD and overdose risk.
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Affiliation(s)
- B Tas
- National Addiction Centre, Institute of Psychiatry, Psychology & Neuroscience (IoPPN), Addictions Department, King's College, London SE5 8BB, UK.
| | - N J Kalk
- National Addiction Centre, Institute of Psychiatry, Psychology & Neuroscience (IoPPN), Addictions Department, King's College, London SE5 8BB, UK; South London & Maudsley NHS Foundation Trust, SE5 8AZ, UK
| | - M Lozano-García
- Biomedical Signal Processing and Interpretation group, Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST) & Biomedical Research Networking Centre in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) & Universitat Politècnica de Catalunya (UPC)-Barcelona Tech, Barcelona, Spain
| | - G F Rafferty
- Centre for Human & Applied Physiological Sciences, School of Basic & Medical Biosciences, Faculty of Life Sciences & Medicine, King's College, London SE1 1UL, UK
| | - Psp Cho
- Department of Respiratory Medicine, King's College Hospital NHS Foundation Trust, King's Health Partners, London SE5 9RS, UK
| | - M Kelleher
- National Addiction Centre, Institute of Psychiatry, Psychology & Neuroscience (IoPPN), Addictions Department, King's College, London SE5 8BB, UK; South London & Maudsley NHS Foundation Trust, SE5 8AZ, UK
| | - J Moxham
- Centre for Human & Applied Physiological Sciences, School of Basic & Medical Biosciences, Faculty of Life Sciences & Medicine, King's College, London SE1 1UL, UK
| | - J Strang
- National Addiction Centre, Institute of Psychiatry, Psychology & Neuroscience (IoPPN), Addictions Department, King's College, London SE5 8BB, UK; South London & Maudsley NHS Foundation Trust, SE5 8AZ, UK
| | - C J Jolley
- Centre for Human & Applied Physiological Sciences, School of Basic & Medical Biosciences, Faculty of Life Sciences & Medicine, King's College, London SE1 1UL, UK
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7
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Lozano-Garcia M, Estrada-Petrocelli L, Blanco-Almazan D, Tas B, Cho PSP, Moxham J, Rafferty GF, Torres A, Jane R, Jolley CJ. Noninvasive Assessment of Neuromechanical and Neuroventilatory Coupling in COPD. IEEE J Biomed Health Inform 2022; 26:3385-3396. [PMID: 35404825 DOI: 10.1109/jbhi.2022.3166255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
This study explored the use of parasternal second intercostal space and lower intercostal space surface electromyogram (sEMG) and surface mechanomyogram (sMMG) recordings (sEMGpara and sMMGpara, and sEMGlic and sMMGlic, respectively) to assess neural respiratory drive (NRD), neuromechanical (NMC) and neuroventilatory (NVC) coupling, and mechanical efficiency (MEff) noninvasively in healthy subjects and chronic obstructive pulmonary disease (COPD) patients. sEMGpara, sMMGpara, sEMGlic, sMMGlic, mouth pressure (Pmo), and volume (Vi) were measured at rest, and during an inspiratory loading protocol, in 16 COPD patients (8 moderate and 8 severe) and 9 healthy subjects. Myographic signals were analyzed using fixed sample entropy and normalized to their largest values (fSEsEMGpara%max, fSEsMMGpara%max, fSEsEMGlic%max, and fSEsMMGlic%max). fSEsMMGpara%max, fSEsEMGpara%max, and fSEsEMGlic%max were significantly higher in COPD than in healthy participants at rest. Parasternal intercostal muscle NMC was significantly higher in healthy than in COPD participants at rest, but not during threshold loading. Pmo-derived NMC and MEff ratios were lower in severe patients than in mild patients or healthy subjects during threshold loading, but differences were not consistently significant. During resting breathing and threshold loading, Vi-derived NVC and MEff ratios were significantly lower in severe patients than in mild patients or healthy subjects. sMMG is a potential noninvasive alternative to sEMG for assessing NRD in COPD. The ratios of Pmo and Vi to sMMG and sEMG measurements provide wholly noninvasive NMC, NVC, and MEff indices that are sensitive to impaired respiratory mechanics in COPD and are therefore of potential value to assess disease severity in clinical practice.
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8
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Suh ES, D'Cruz RF, Ramsay M, Steier J, Jolley CJ, Reilly CC, Hart N, Moxham J, Murphy PB, Rafferty GF. Second intercostal space electromyography as a measure of neural respiratory drive: Clinical utility and validity. Respir Physiol Neurobiol 2021; 290:103683. [PMID: 33971312 DOI: 10.1016/j.resp.2021.103683] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 05/05/2021] [Indexed: 11/19/2022]
Affiliation(s)
- Eui-Sik Suh
- Lane Fox Clinical Respiratory Physiology Research Centre, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Rebecca F D'Cruz
- Lane Fox Clinical Respiratory Physiology Research Centre, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Michelle Ramsay
- Lane Fox Clinical Respiratory Physiology Research Centre, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Joerg Steier
- Lane Fox Clinical Respiratory Physiology Research Centre, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Caroline J Jolley
- Centre for Human & Applied Physiological Sciences, King's College London, London, UK; King's College Hospital NHS Foundation Trust, London, UK
| | - Charles C Reilly
- Centre for Human & Applied Physiological Sciences, King's College London, London, UK; King's College Hospital NHS Foundation Trust, London, UK
| | - Nicholas Hart
- Lane Fox Clinical Respiratory Physiology Research Centre, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - John Moxham
- Centre for Human & Applied Physiological Sciences, King's College London, London, UK; King's College Hospital NHS Foundation Trust, London, UK
| | - Patrick B Murphy
- Lane Fox Clinical Respiratory Physiology Research Centre, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Gerrard F Rafferty
- Centre for Human & Applied Physiological Sciences, King's College London, London, UK.
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9
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Lozano-Garcia M, Davidson CM, Prieto-Ramon C, Moxham J, Rafferty GF, Jolley CJ, Jane R. Spatial Distribution of Normal Lung Sounds in Healthy Individuals under Varied Inspiratory Load and Flow Conditions. Annu Int Conf IEEE Eng Med Biol Soc 2020; 2020:2744-2747. [PMID: 33018574 DOI: 10.1109/embc44109.2020.9175992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Respiratory sounds yield pertinent information about respiratory function in both health and disease. Normal lung sound intensity is a characteristic that correlates well with airflow and it can therefore be used to quantify the airflow changes and limitations imposed by respiratory diseases. The dual aims of this study are firstly to establish whether previously reported asymmetries in normal lung sound intensity are affected by varying the inspiratory threshold load or the airflow of respiration, and secondly to investigate whether fixed sample entropy can be used as a valid measure of lung sound intensity. Respiratory sounds were acquired from twelve healthy individuals using four contact microphones on the posterior skin surface during an inspiratory threshold loading protocol and a varying airflow protocol. The spatial distribution of the normal lung sounds intensity was examined. During the protocols explored here the normal lung sound intensity in the left and right lungs in healthy populations was found to be similar, with asymmetries of less than 3 dB. This agrees with values reported in other studies. The fixed sample entropy of the respiratory sound signal was also calculated and compared with the gold standard root mean square representation of lung sound intensity showing good agreement.
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10
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Lozano-Garcia M, Nuhic J, Moxham J, Rafferty GF, Jolley CJ, Jane R. Performance Evaluation of Fixed Sample Entropy for Lung Sound Intensity Estimation. Annu Int Conf IEEE Eng Med Biol Soc 2020; 2020:2740-2743. [PMID: 33018573 DOI: 10.1109/embc44109.2020.9176215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Lung sound (LS) signals are often contaminated by impulsive artifacts that complicate the estimation of lung sound intensity (LSI) using conventional amplitude estimators. Fixed sample entropy (fSampEn) has proven to be robust to cardiac artifacts in myographic respiratory signals. Similarly, fSampEn is expected to be robust to artifacts in LS signals, thus providing accurate LSI estimates. However, the choice of fSampEn parameters depends on the application and fSampEn has not previously been applied to LS signals. This study aimed to perform an evaluation of the performance of the most relevant fSampEn parameters on LS signals, and to propose optimal fSampEn parameters for LSI estimation. Different combinations of fSampEn parameters were analyzed in LS signals recorded in a heterogeneous population of healthy subjects and chronic obstructive pulmonary disease patients during loaded breathing. The performance of fSampEn was assessed by means of its cross-covariance with flow signals, and optimal fSampEn parameters for LSI estimation were proposed.
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11
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Hadfield DJ, Rose L, Reid F, Cornelius V, Hart N, Finney C, Penhaligon B, Molai J, Harris C, Saha S, Noble H, Clarey E, Thompson L, Smith J, Johnson L, Hopkins PA, Rafferty GF. Neurally adjusted ventilatory assist versus pressure support ventilation: a randomized controlled feasibility trial performed in patients at risk of prolonged mechanical ventilation. Crit Care 2020; 24:220. [PMID: 32408883 PMCID: PMC7224141 DOI: 10.1186/s13054-020-02923-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 04/24/2020] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND The clinical effectiveness of neurally adjusted ventilatory assist (NAVA) has yet to be demonstrated, and preliminary studies are required. The study aim was to assess the feasibility of a randomized controlled trial (RCT) of NAVA versus pressure support ventilation (PSV) in critically ill adults at risk of prolonged mechanical ventilation (MV). METHODS An open-label, parallel, feasibility RCT (n = 78) in four ICUs of one university-affiliated hospital. The primary outcome was mode adherence (percentage of time adherent to assigned mode), and protocol compliance (binary-≥ 65% mode adherence). Secondary exploratory outcomes included ventilator-free days (VFDs), sedation, and mortality. RESULTS In the 72 participants who commenced weaning, median (95% CI) mode adherence was 83.1% (64.0-97.1%) and 100% (100-100%), and protocol compliance was 66.7% (50.3-80.0%) and 100% (89.0-100.0%) in the NAVA and PSV groups respectively. Secondary outcomes indicated more VFDs to D28 (median difference 3.0 days, 95% CI 0.0-11.0; p = 0.04) and fewer in-hospital deaths (relative risk 0.5, 95% CI 0.2-0.9; p = 0.032) for NAVA. Although overall sedation was similar, Richmond Agitation and Sedation Scale (RASS) scores were closer to zero in NAVA compared to PSV (p = 0.020). No significant differences were observed in duration of MV, ICU or hospital stay, or ICU, D28, and D90 mortality. CONCLUSIONS This feasibility trial demonstrated good adherence to assigned ventilation mode and the ability to meet a priori protocol compliance criteria. Exploratory outcomes suggest some clinical benefit for NAVA compared to PSV. Clinical effectiveness trials of NAVA are potentially feasible and warranted. TRIAL REGISTRATION ClinicalTrials.gov, NCT01826890. Registered 9 April 2013.
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Affiliation(s)
- Daniel J Hadfield
- Critical Care, King's College Hospital, London, UK.
- Centre for Human and Applied Physiological Sciences, King's College London, London, UK.
| | - Louise Rose
- Florence Nightingale Faculty of Nursing, Midwifery & Palliative Care, King's College London, London, UK
- Sunnybrook Health Sciences Centre and Sunnybrook Research Institute, Toronto, Canada
| | - Fiona Reid
- School of Population Health and Environmental Sciences, King's College London, London, UK
| | - Victoria Cornelius
- Faculty of Medicine, School of Public Health, Imperial College, London, UK
| | - Nicholas Hart
- Centre for Human and Applied Physiological Sciences, King's College London, London, UK
- Lane Fox Unit, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Clare Finney
- Critical Care, King's College Hospital, London, UK
| | | | | | - Clair Harris
- Critical Care, King's College Hospital, London, UK
| | - Sian Saha
- Critical Care, King's College Hospital, London, UK
| | | | - Emma Clarey
- Critical Care, King's College Hospital, London, UK
| | | | - John Smith
- Critical Care, King's College Hospital, London, UK
| | - Lucy Johnson
- Critical Care, King's College Hospital, London, UK
| | | | - Gerrard F Rafferty
- Centre for Human and Applied Physiological Sciences, King's College London, London, UK
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12
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Jacunski M, Rafferty GF. The effects of hypoxia and fatigue on skeletal muscle electromechanical delay. Exp Physiol 2020; 105:842-851. [PMID: 32134528 DOI: 10.1113/ep088180] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 03/02/2020] [Indexed: 12/20/2022]
Abstract
NEW FINDINGS What is the central question of this study? What are the mechanisms underlying impaired muscular endurance and accelerated fatigue during acute hypoxia? What is the main finding and its importance? Hypoxia had no effect on the electrochemical latency associated with muscle contraction elicited by supramaximal electrical motor nerve stimulation in vivo. This provides greater insight into the effects of hypoxia and fatigue on the mechanisms of muscle contraction in vivo. ABSTRACT Acute hypoxia impairs muscle endurance and accelerates fatigue, but the underlying mechanisms, including any effects on muscle electrical activation, are incompletely understood. Electromyographic, mechanomyographic and force signals, elicited by common fibular nerve stimulation, were used to determine electromechanical delay (EMDTOT ) of the tibialis anterior muscle in normoxia and hypoxia ( F I O 2 0.125) at rest and following fatiguing ankle dorsiflexor exercise (60% maximum voluntary contraction, 5 s on, 3 s off) in 12 healthy participants (mean (SD) age 27.4 (9.0) years). EMDTOT was determined from electromyographic to force signal onset, electrical activation latency from electromyographic to mechanomyographic (EMDE-M ) and mechanical latency from mechanomyographic to force (EMDM-F ). Twitch force fell significantly following fatiguing exercise in normoxia (46.8 (14.7) vs. 20.6 (14.3) N, P = 0.0002) and hypoxia (52.9 (15.4) vs. 28.8 (15.2) N, P = 0.0006). No effect of hypoxia on twitch force at rest was observed. Fatiguing exercise resulted in significant increases in mean (SD) EMDTOT in normoxia (Δ 4.7 (4.57) ms P = 0.0152) and hypoxia (Δ 3.7 (4.06) ms P = 0.0384) resulting from increased mean (SD) EMDM-F only (normoxia Δ 4.1 (4.1) ms P = 0.0391, hypoxia Δ 3.4 (3.6) ms P = 0.0303). Mean (SD) EMDE-M remained unchanged during normoxic (Δ 0.6 (1.08) ms) and hypoxic (Δ 0.25 (0.75) ms) fatiguing exercise. No differences in percentage change from baseline for twitch force, EMDTOT , EMDE-M and EMDM-F between normoxic and hypoxic fatigue conditions were observed. Hypoxia in isolation or in combination with fatigue had no effect on the electrochemical latency associated with electrically evoked muscle contraction.
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Affiliation(s)
- Mark Jacunski
- Guy's, King's & St Thomas' School of Medical Education, Faculty of Life Sciences & Medicine, King's College London, London, UK
| | - Gerrard F Rafferty
- Centre for Human & Applied Physiological Sciences, School of Basic & Medical Biosciences, Faculty of Life Sciences & Medicine, King's College London, London, UK
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13
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Reilly CC, Floyd SV, Lee K, Warwick G, James S, Gall N, Rafferty GF. Breathlessness and dysfunctional breathing in patients with postural orthostatic tachycardia syndrome (POTS): The impact of a physiotherapy intervention. Auton Neurosci 2019; 223:102601. [PMID: 31743851 DOI: 10.1016/j.autneu.2019.102601] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 11/11/2019] [Accepted: 11/11/2019] [Indexed: 12/22/2022]
Abstract
Postural orthostatic tachycardia syndrome (POTS) is a chronic, multifactorial syndrome with complex symptoms of orthostatic intolerance. Breathlessness is a prevalent symptom, however little is known about the aetiology. Anecdotal evidence suggests that breathless POTS patients commonly demonstrate dysfunctional breathing/hyperventilation syndrome (DB/HVS). There are, however, no published data regarding DB/HVS in POTS, and whether physiotherapy/breathing retraining may improve patients' breathing pattern and symptoms. The aim of this study was to explore the potential impact of a physiotherapy intervention involving education and breathing control on DB/HVS in POTS. A retrospective observational cohort study of all patients with POTS referred to respiratory physiotherapy for treatment of DB/HVS over a 20-month period was undertaken. 100 patients (99 female, mean (standard deviation) age 31 (12) years) with a clinical diagnosis of DB/HV were referred, of which data was available for 66 patients pre - post intervention. Significant improvements in Nijmegen score, respiratory rate and breath hold time (seconds) were observed following treatment. These data provide a testable hypothesis that breathing retraining may provide breathless POTS patients with some symptomatic relief, thus improving their health-related quality of life. The intervention can be easily protocolised to ensure treatment fidelity. Our preliminary findings provide a platform for a subsequent randomised controlled trial of breathing retraining in POTS.
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Affiliation(s)
- Charles C Reilly
- Department of Physiotherapy, King's College Hospital NHS Foundation Trust, United Kingdom of Great Britain and Northern Ireland.
| | - Sarah V Floyd
- Department of Physiotherapy, King's College Hospital NHS Foundation Trust, United Kingdom of Great Britain and Northern Ireland
| | - Kai Lee
- Department of Respiratory Medicine, King's College Hospital NHS Foundation Trust, United Kingdom of Great Britain and Northern Ireland
| | - Geoffrey Warwick
- Department of Respiratory Medicine, King's College Hospital NHS Foundation Trust, United Kingdom of Great Britain and Northern Ireland
| | - Stephen James
- Department of Anaesthesia, King's College Hospital NHS Foundation Trust, United Kingdom of Great Britain and Northern Ireland
| | - Nicholas Gall
- Department of Cardiology, King's College Hospital NHS Foundation Trust, United Kingdom of Great Britain and Northern Ireland
| | - Gerrard F Rafferty
- King's College London, Centre for Human and Aerospace Physiological Sciences, United Kingdom of Great Britain and Northern Ireland
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14
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Cook H, Reilly CC, Rafferty GF. A home-based lower limb-specific resistance training programme for patients with COPD: an explorative feasibility study. ERJ Open Res 2019; 5:00126-2018. [PMID: 31205928 PMCID: PMC6556558 DOI: 10.1183/23120541.00126-2018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 05/01/2019] [Indexed: 11/20/2022] Open
Abstract
Peripheral muscle weakness leading to poor exercise tolerance is a significant problem in patients with chronic obstructive pulmonary disease (COPD). Increased lower limb strength following pulmonary rehabilitation (PR) has been shown to be associated with positive outcomes [1]. Despite this, access to and completion of PR remains problematic and alternative exercise interventions are sought. Elastic band resistance training has recently been shown to be as effective as conventional outpatient free-weight exercise training [2–4]. Elastic band resistance training may, therefore, provide an alternative home-based exercise intervention for patients with COPD who are unable or unwilling to participate in PR due to significant symptom burden or anxiety in attending group classes It is feasible and acceptable to deliver a home-based lower limb-specific resistance training (LLSRT) programme to patients with COPD. Individual patient improvements in walking distance and breathlessness severity were observed post-LLSRT intervention.http://bit.ly/30xYpWI
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Affiliation(s)
- Hannah Cook
- King's College London, Centre for Human and Aerospace Physiological Sciences, London, UK.,These authors contributed equally to this work
| | - Charles C Reilly
- Dept of Physiotherapy, Kings College Hospital NHS Foundation Trust, London, UK.,These authors contributed equally to this work
| | - Gerrard F Rafferty
- King's College London, Centre for Human and Aerospace Physiological Sciences, London, UK
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15
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Charles E, Hunt KA, Rafferty GF, Peacock JL, Greenough A. Work of breathing during HHHFN and synchronised NIPPV following extubation Eur J Pediatr 2019;178:105-110, doi: 10.1007/s00431-018-3254-3. Response to: How can we provide true synchronization in synchronized NIPPV. Corresponding Author: Kadir Şerafettin Tekgündüz; doi: 10.1007/s00431-019-03353-4. Eur J Pediatr 2019; 178:781-782. [PMID: 30903307 DOI: 10.1007/s00431-019-03354-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 02/19/2019] [Indexed: 11/25/2022]
Affiliation(s)
- Elinor Charles
- The Asthma UK Centre for Allergic Mechanisms in Asthma, King's College London, London, UK
- Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Katie A Hunt
- The Asthma UK Centre for Allergic Mechanisms in Asthma, King's College London, London, UK
- Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Gerrard F Rafferty
- Centre for Human and Aerospace Physiological Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Janet L Peacock
- School of Population Health and Environmental Sciences, King's College London, London, UK
- National Institute for Health Research (NIHR) Biomedical Research Centre based at Guy's and St Thomas' NHS Foundation Trust and King's College London, London, UK
| | - Anne Greenough
- The Asthma UK Centre for Allergic Mechanisms in Asthma, King's College London, London, UK.
- Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK.
- National Institute for Health Research (NIHR) Biomedical Research Centre based at Guy's and St Thomas' NHS Foundation Trust and King's College London, London, UK.
- NICU, 4th Floor Golden Jubilee Wing, King's College Hospital, Denmark Hill, London, SE5 9RS, UK.
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16
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Williams S, Porter M, Westbrook J, Rafferty GF, MacBean V. The influence of posture on parasternal intercostal muscle activity in healthy young adults. Physiol Meas 2019; 40:01NT03. [DOI: 10.1088/1361-6579/aafefd] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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17
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Charles E, Hunt KA, Rafferty GF, Peacock JL, Greenough A. Work of breathing during HHHFNC and synchronised NIPPV following extubation. Eur J Pediatr 2019; 178:105-110. [PMID: 30374754 DOI: 10.1007/s00431-018-3254-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 09/07/2018] [Accepted: 09/12/2018] [Indexed: 10/28/2022]
Abstract
Our aim was to compare the work of breathing (WOB) during synchronised nasal intermittent positive pressure ventilation (SNIPPV) and heated humidified high flow nasal cannula (HHHFNC) when used as post-extubation support in preterm infants. A randomised crossover study was undertaken of nine infants with a median gestational age of 27 (range 24-31) weeks and post-natal age of 7 (range 2-50) days. Infants were randomised to either SNIPPV or HHHFNC immediately following extubation. They were studied for 2 h on one mode and then switched to the other modality and studied for a further 2-h period. The work of breathing, assessed by measuring the pressure time product of the diaphragm (PTPdi), and thoracoabdominal asynchrony (TAA) were determined at the end of each 2-h period. The infants' inspired oxygen requirement, oxygen saturation, heart rate and respiratory rate were also recorded. The median PTPdi was lower on SNIPPV than on HHHFNC (232 (range 130-352) versus 365 (range 136-449) cmH2O s/min, p = 0.0077), and there was less thoracoabdominal asynchrony (13.4 (range 8.5-41.6) versus 36.1 (range 4.3-50.4) degrees, p = 0.038).Conclusion: In prematurely born infants, SNIPPV compared to HHHFNC post-extubation reduced the work of breathing and thoracoabdominal asynchrony. What is Known: • The work of breathing and extubation failure are not significantly different in prematurely-born infants supported by HHHFNC or nCPAP. • SNIPPV reduces inspiratory effort and increases tidal volume and carbon dioxide exchange compared to nCPAP in prematurely born infants. What is New: • SNIPPV, as compared to HHHFNC, reduced the work of breathing in prematurely-born infants studied post-extubation. • SNIPPV, as compared to HHHFNC, reduced thoracoabdominal asynchrony in prematurely born infants studied post-extubation.
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Affiliation(s)
- Elinor Charles
- MRC & Asthma UK Centre for Allergic Mechanisms in Asthma, King's College London, NICU, 4th Floor Golden Jubilee Wing, King's College Hospital, Denmark Hill, London, SE5 9RS, UK. .,Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK.
| | - Katie A Hunt
- MRC & Asthma UK Centre for Allergic Mechanisms in Asthma, King's College London, NICU, 4th Floor Golden Jubilee Wing, King's College Hospital, Denmark Hill, London, SE5 9RS, UK. .,Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK.
| | - Gerrard F Rafferty
- Centre for Human and Aerospace Physiological Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Janet L Peacock
- School of Population Health and Environmental Sciences, King's College London, London, UK.,National Institute for Health Research (NIHR) Biomedical Research Centre based at Guy's and St Thomas' NHS Foundation Trust and King's College London, London, UK
| | - Anne Greenough
- MRC & Asthma UK Centre for Allergic Mechanisms in Asthma, King's College London, NICU, 4th Floor Golden Jubilee Wing, King's College Hospital, Denmark Hill, London, SE5 9RS, UK. .,Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK. .,National Institute for Health Research (NIHR) Biomedical Research Centre based at Guy's and St Thomas' NHS Foundation Trust and King's College London, London, UK.
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18
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Lozano-Garcia M, Sarlabous L, Moxham J, Rafferty GF, Torres A, Jolley CJ, Jane R. Assessment of Inspiratory Muscle Activation using Surface Diaphragm Mechanomyography and Crural Diaphragm Electromyography. Annu Int Conf IEEE Eng Med Biol Soc 2018; 2018:3342-3345. [PMID: 30441104 DOI: 10.1109/embc.2018.8513046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The relationship between surface diaphragm mechanomyography (sMMGdi), as a noninvasive measure of inspiratory muscle mechanical activation, and crural diaphragm electromyography (oesEMGdi), as the invasive gold standard measure of diaphragm electrical activation, had not previously been examined. To investigate this relationship, oesEMGdi and sMMGdi were measured simultaneously in 6 healthy subjects during an incremental inspiratory threshold loading protocol, and analyzed using fixed sample entropy (fSampEn). A positive curvilinear relationship was observed between mean fSampEn sMMGdi and oesEMGdi (r = 0.67). Accordingly, an increasing electromechanical ratio was also observed with increasing inspiratory load. These findings suggest that sMMGdi could provide useful noninvasive measures of inspiratory muscle mechanical activation.
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Lozano-García M, Sarlabous L, Moxham J, Rafferty GF, Torres A, Jané R, Jolley CJ. Surface mechanomyography and electromyography provide non-invasive indices of inspiratory muscle force and activation in healthy subjects. Sci Rep 2018; 8:16921. [PMID: 30446712 PMCID: PMC6240075 DOI: 10.1038/s41598-018-35024-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 10/28/2018] [Indexed: 11/30/2022] Open
Abstract
The current gold standard assessment of human inspiratory muscle function involves using invasive measures of transdiaphragmatic pressure (Pdi) or crural diaphragm electromyography (oesEMGdi). Mechanomyography is a non-invasive measure of muscle vibration associated with muscle contraction. Surface electromyogram and mechanomyogram, recorded transcutaneously using sensors placed over the lower intercostal spaces (sEMGlic and sMMGlic respectively), have been proposed to provide non-invasive indices of inspiratory muscle activation, but have not been directly compared to gold standard Pdi and oesEMGdi measures during voluntary respiratory manoeuvres. To validate the non-invasive techniques, the relationships between Pdi and sMMGlic, and between oesEMGdi and sEMGlic were measured simultaneously in 12 healthy subjects during an incremental inspiratory threshold loading protocol. Myographic signals were analysed using fixed sample entropy (fSampEn), which is less influenced by cardiac artefacts than conventional root mean square. Strong correlations were observed between: mean Pdi and mean fSampEn |sMMGlic| (left, 0.76; right, 0.81), the time-integrals of the Pdi and fSampEn |sMMGlic| (left, 0.78; right, 0.83), and mean fSampEn oesEMGdi and mean fSampEn sEMGlic (left, 0.84; right, 0.83). These findings suggest that sMMGlic and sEMGlic could provide useful non-invasive alternatives to Pdi and oesEMGdi for the assessment of inspiratory muscle function in health and disease.
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Affiliation(s)
- Manuel Lozano-García
- Biomedical Signal Processing and Interpretation group, Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain.
- Biomedical Research Networking Centre in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Barcelona, Spain.
- Department of Automatic Control (ESAII), Universitat Politècnica de Catalunya (UPC)-Barcelona Tech, Barcelona, Spain.
| | - Leonardo Sarlabous
- Biomedical Signal Processing and Interpretation group, Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Biomedical Research Networking Centre in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Barcelona, Spain
- Department of Automatic Control (ESAII), Universitat Politècnica de Catalunya (UPC)-Barcelona Tech, Barcelona, Spain
| | - John Moxham
- Faculty of Life Sciences & Medicine, King's College London, King's Health Partners, London, United Kingdom
| | - Gerrard F Rafferty
- King's College Hospital NHS Foundation Trust, King's Health Partners, London, United Kingdom
- Centre for Human & Applied Physiological Sciences, School of Basic & Medical Biosciences, Faculty of Life Sciences & Medicine, King's College London, King's Health Partners, London, United Kingdom
| | - Abel Torres
- Biomedical Signal Processing and Interpretation group, Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Biomedical Research Networking Centre in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Barcelona, Spain
- Department of Automatic Control (ESAII), Universitat Politècnica de Catalunya (UPC)-Barcelona Tech, Barcelona, Spain
| | - Raimon Jané
- Biomedical Signal Processing and Interpretation group, Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Biomedical Research Networking Centre in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Barcelona, Spain
- Department of Automatic Control (ESAII), Universitat Politècnica de Catalunya (UPC)-Barcelona Tech, Barcelona, Spain
| | - Caroline J Jolley
- King's College Hospital NHS Foundation Trust, King's Health Partners, London, United Kingdom
- Centre for Human & Applied Physiological Sciences, School of Basic & Medical Biosciences, Faculty of Life Sciences & Medicine, King's College London, King's Health Partners, London, United Kingdom
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MacBean V, Lunt A, Drysdale SB, Yarzi MN, Rafferty GF, Greenough A. Predicting healthcare outcomes in prematurely born infants using cluster analysis. Pediatr Pulmonol 2018; 53:1067-1072. [PMID: 29790677 DOI: 10.1002/ppul.24050] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 04/25/2018] [Indexed: 11/10/2022]
Abstract
AIMS Prematurely born infants are at high risk of respiratory morbidity following neonatal unit discharge, though prediction of outcomes is challenging. We have tested the hypothesis that cluster analysis would identify discrete groups of prematurely born infants with differing respiratory outcomes during infancy. METHODS A total of 168 infants (median (IQR) gestational age 33 (31-34) weeks) were recruited in the neonatal period from consecutive births in a tertiary neonatal unit. The baseline characteristics of the infants were used to classify them into hierarchical agglomerative clusters. Rates of viral lower respiratory tract infections (LRTIs) were recorded for 151 infants in the first year after birth. RESULTS Infants could be classified according to birth weight and duration of neonatal invasive mechanical ventilation (MV) into three clusters. Cluster one (MV ≤5 days) had few LRTIs. Clusters two and three (both MV ≥6 days, but BW ≥or <882 g respectively), had significantly higher LRTI rates. Cluster two had a higher proportion of infants experiencing respiratory syncytial virus LRTIs (P = 0.01) and cluster three a higher proportion of rhinovirus LRTIs (P < 0.001) CONCLUSIONS: Readily available clinical data allowed classification of prematurely born infants into one of three distinct groups with differing subsequent respiratory morbidity in infancy.
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Affiliation(s)
- Victoria MacBean
- Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom
| | - Alan Lunt
- MRC and Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London, United Kingdom.,Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom
| | - Simon B Drysdale
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, London, United Kingdom
| | - Muska N Yarzi
- Cellular and Molecular Medicine, University of Bristol, London, United Kingdom
| | - Gerrard F Rafferty
- Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom
| | - Anne Greenough
- MRC and Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London, United Kingdom.,Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom.,NIHR Biomedical Research Centre based at Guy's and St Thomas' NHS Foundation Trust and King's College London, London, United Kingdom
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21
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Rossor T, Bhat R, Ali K, Peacock J, Rafferty GF, Greenough A. The effect of caffeine on the ventilatory response to hypercarbia in preterm infants. Pediatr Res 2018; 83:1152-1157. [PMID: 29790869 DOI: 10.1038/pr.2018.48] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 02/15/2018] [Indexed: 11/09/2022]
Abstract
BackgroundWe tested the hypotheses that caffeine therapy would increase the ventilatory response to hypercarbia in infants above the effect of maturation and those with a weaker ventilatory response to hypercarbia would be more likely to subsequently develop apnea that required treatment.MethodsInfants born at less than 34 weeks of gestation underwent a steady-state hypercarbic challenge using 0, 2, and 4% carbon dioxide soon after birth that was repeated at weekly intervals. The results of the initial study were compared between infants who did or did not subsequently develop apnea requiring treatment with caffeine.ResultsTwenty-six infants born at a median gestation of 32 (range 31-33) weeks were assessed. Caffeine administration was associated with an increase in CO2 sensitivity, and the mean increase was 15.3 (95% CI: 1-30) ml/kg/min/% CO2. Fourteen infants subsequently developed apnea treated with caffeine. After controlling for gestational age and birth weight, they had significantly lower carbon dioxide sensitivity at their initial study compared with those who did not require treatment.ConclusionCaffeine administration was associated with an increase in the ventilatory response to hypercarbia. An initial weaker ventilatory response to hypercarbia was associated with the subsequent development of apnea requiring treatment with caffeine.
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Affiliation(s)
- Thomas Rossor
- Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Ravindra Bhat
- Neonatal Intensive Care Centre, King's College Hospital NHS Foundation Trust, London, UK
| | - Kamal Ali
- Neonatal Intensive Care Centre, King's College Hospital NHS Foundation Trust, London, UK
| | - Janet Peacock
- School of Population Sciences, School of Population Sciences and Health Services Research, King's College London, London, UK
| | - Gerrard F Rafferty
- Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Anne Greenough
- Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
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22
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Connolly B, Maddocks M, MacBean V, Bernal W, Hart N, Hopkins P, Rafferty GF. Nonvolitional assessment of tibialis anterior force and architecture during critical illness. Muscle Nerve 2018; 57:964-972. [PMID: 29266337 DOI: 10.1002/mus.26049] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 12/02/2017] [Accepted: 12/10/2017] [Indexed: 12/29/2022]
Abstract
INTRODUCTION Contemporaneous measures of muscle architecture and force have not previously been conducted during critical illness to examine their relationship with intensive care unit (ICU)-acquired weakness. METHODS Ankle dorsiflexor muscle force (ADMF) with high-frequency electrical peroneal nerve stimulation and skeletal muscle architecture via ultrasound were measured in 21 adult, critically ill patients, 16 at ICU admission. RESULTS Thirteen patients were measured on 2 occasions. Among these, 10 who were measured at ICU admission demonstrated muscle weakness. Despite significant reductions in tibialis anterior (Δ = -88.5 ± 78.8 mm2 , P = 0.002) and rectus femoris (Δ = -126.1 ± 129.1 mm2 , P = 0.006) cross-sectional areas between occasions, ADMF did not change (100-HZ ankle dorsiflexor force 9.8 [IQR, 8.0-14.4] kg vs. 8.6 (IQR, 6.7-19.2) kg, P = 0.9). DISCUSSION Muscle weakness was evident at ICU admission. No additional decrements were observed 7 days later despite significant reductions in muscle size. These data suggest that not all ICU weakness is truly "acquired" and questions our understanding of muscle function during critical illness. Muscle Nerve 57: 964-972, 2018.
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Affiliation(s)
- Bronwen Connolly
- King's College London, Division of Asthma, Allergy and Lung Biology, Department of Respiratory Medicine, UK
| | - Matthew Maddocks
- King's College London, Department of Palliative Care, Cicely Saunders Institute, UK
| | - Victoria MacBean
- King's College London, Division of Asthma, Allergy and Lung Biology, Department of Respiratory Medicine, UK
| | - William Bernal
- Institute of Liver Studies, King's College Hospital, London, UK
| | - Nicholas Hart
- Lane Fox Respiratory Unit, Guy's & St.Thomas' NHS Foundation Trust, London, UK
| | - Philip Hopkins
- Department of Critical Care, King's College Hospital, London, UK
| | - Gerrard F Rafferty
- King's College London, Division of Asthma, Allergy and Lung Biology, Department of Respiratory Medicine, UK
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MacBean V, Drysdale SB, Yarzi MN, Peacock JL, Rafferty GF, Greenough A. Respiratory viral infections in infancy and school age respiratory outcomes and healthcare costs. Pediatr Pulmonol 2018; 53:342-348. [PMID: 29314779 DOI: 10.1002/ppul.23937] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 12/02/2017] [Indexed: 11/06/2022]
Abstract
OBJECTIVES To determine the impact of viral lower respiratory tract infections (LRTIs) in infancy including rhinovirus (RV) and infancy respiratory syncytial virus (RSV), on school age pulmonary function and healthcare utilization in prematurely born children. WORKING HYPOTHESIS School age respiratory outcomes would be worse and healthcare utilization greater in children who had viral LRTIs in infancy. STUDY DESIGN Prospective study. SUBJECT SELECTION A cohort of prematurely born children who had symptomatic LRTIs during infancy documented, was recalled. METHODS Pulmonary function was assessed at 5 to 7 years of age and health related costs of care from aged one to follow-up determined. RESULTS Fifty-one children, median gestational age 33+6 weeks, were assessed at a median (IQR) age 7.03 (6.37-7.26) years. Twenty-one children had no LRTI, 14 RV LRTI, 10 RSV LRTI, and 6 another viral LRTI (other LRTI). Compared to the no LRTI group, the RV group had a lower FEV1 (P = 0.033) and the other LRTI group a lower FVC (P = 0.006). Non-respiratory medication costs were higher in the RV (P = 0.018) and RSV (P = 0.013) groups. Overall respiratory healthcare costs in the RV (£153/year) and RSV (£27/year) groups did not differ significantly from the no LRTI group (£56/year); the other LRTI group (£431/year) had higher respiratory healthcare costs (P = 0.042). CONCLUSIONS In moderately prematurely born children, RV and RSV LRTIs in infancy were not associated with higher respiratory healthcare costs after infancy. Children who experienced LRTIs caused by other respiratory viruses (including RV) had higher respiratory healthcare costs and greater pulmonary function impairment.
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Affiliation(s)
- Victoria MacBean
- Faculty of Life Sciences & Medicine, School of Basic & Medical Biosciences, King's College London, London, United Kingdom
| | - Simon B Drysdale
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, United Kingdom
| | - Muska N Yarzi
- Cellular & Molecular Medicine, University of Bristol, Bristol, United Kingdom
| | - Janet L Peacock
- School of Population Health & Environmental Sciences, King's College London, London, United Kingdom.,NIHR Biomedical Research Centre, Guy's and St Thomas' NHS Foundation Trust, King's College London, London, United Kingdom
| | - Gerrard F Rafferty
- Faculty of Life Sciences & Medicine, School of Basic & Medical Biosciences, King's College London, London, United Kingdom
| | - Anne Greenough
- Faculty of Life Sciences & Medicine, School of Basic & Medical Biosciences, King's College London, London, United Kingdom.,NIHR Biomedical Research Centre, Guy's and St Thomas' NHS Foundation Trust, King's College London, London, United Kingdom
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Lee KK, Matos S, Ward K, Rafferty GF, Moxham J, Evans DH, Birring SS. Sound: a non-invasive measure of cough intensity. BMJ Open Respir Res 2017; 4:e000178. [PMID: 28725446 PMCID: PMC5501240 DOI: 10.1136/bmjresp-2017-000178] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Revised: 03/28/2017] [Accepted: 03/29/2017] [Indexed: 11/30/2022] Open
Abstract
Introduction Cough intensity is an important determinant of cough severity reported by patients. Cough sound analysis has been widely validated for the measurement of cough frequency but few studies have validated its use in the assessment of cough strength. We investigated the relationship between cough sound and physiological measures of cough strength. Methods 32 patients with chronic cough and controls underwent contemporaneous measurements of voluntary cough sound, flow and oesophageal pressure. Sound power, peak energy, rise-time, duration, peak-frequency, bandwidth and centroid-frequency were assessed and compared with physiological measures. The relationship between sound and subjective cough strength Visual Analogue Score (VAS), the repeatability of cough sounds and the effect of microphone position were also assessed. Results Sound power and energy correlated strongly with cough flow (median Spearman’s r=0.87–0.88) and oesophageal pressure (median Spearman’s r=0.89). Sound power and energy correlated strongly with cough strength VAS (median Spearman’s r=0.84–0.86) and were highly repeatable (intraclass correlation coefficient=0.93–0.94) but both were affected by change in microphone position. Conclusions Cough sound power and energy correlate strongly with physiological measures and subjective perception of cough strength. Power and energy are highly repeatable measures but the microphone position should be standardised. Our findings support the use of cough sound as an index of cough strength.
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Affiliation(s)
- Kai K Lee
- Division of Asthma, Allergy and Lung Biology, King's College London, London, UK.,Department of Respiratory Medicine, King's College Hospital NHS Foundation Trust, London, UK
| | - Sergio Matos
- Institute of Electronics and Telematics Engineering, University of Aveiro, Aveiro, Portugal
| | - Katie Ward
- Division of Asthma, Allergy and Lung Biology, King's College London, London, UK
| | - Gerrard F Rafferty
- Division of Asthma, Allergy and Lung Biology, King's College London, London, UK
| | - John Moxham
- Division of Asthma, Allergy and Lung Biology, King's College London, London, UK.,Department of Respiratory Medicine, King's College Hospital NHS Foundation Trust, London, UK
| | - David H Evans
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | - Surinder S Birring
- Division of Asthma, Allergy and Lung Biology, King's College London, London, UK.,Department of Respiratory Medicine, King's College Hospital NHS Foundation Trust, London, UK
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Ali K, Rosser T, Bhat R, Wolff K, Hannam S, Rafferty GF, Greenough A. Antenatal smoking and substance-misuse, infant and newborn response to hypoxia. Pediatr Pulmonol 2017; 52:650-655. [PMID: 27723956 DOI: 10.1002/ppul.23620] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 09/22/2016] [Accepted: 09/27/2016] [Indexed: 11/10/2022]
Abstract
OBJECTIVES To determine at the peak age for sudden infant death syndrome (SIDS) the ventilatory response to hypoxia of infants whose mothers substance misused in pregnancy (SM infants), or smoked during pregnancy (S mothers) and controls whose mothers neither substance misused or smoked. In addition, we compared the ventilatory response to hypoxia during the neonatal period and peak age of SIDS. WORKING HYPOTHESIS Infants of S or SM mothers compared to control infants would have a poorer ventilatory response to hypoxia at the peak age of SIDS. STUDY DESIGN Prospective, observational study. PATIENT-SUBJECT SELECTION Twelve S; 12 SM and 11 control infants were assessed at 6-12 weeks of age and in the neonatal period. METHODOLOGY Changes in minute volume, oxygen saturation, heart rate, and end tidal carbon dioxide levels on switching from breathing room air to 15% oxygen were assessed. Maternal and infant urine samples were tested for cotinine, cannabinoids, opiates, amphetamines, methadone, cocaine, and benzodiazepines. RESULTS The S and SM infants had a greater decline in minute volume (P = 0.037, P = 0.016, respectively) and oxygen saturation (P = 0.031) compared to controls. In all groups, the magnitude of decline in minute volume in response to hypoxia was higher in the neonatal period compared to at 6-12 weeks (P < 0.001). CONCLUSIONS Both maternal substance misuse and smoking were associated with an impaired response to a hypoxic challenge at the peak age for SIDS. The hypoxic ventilatory decline was more marked in the neonatal period compared to the peak age for SIDS indicating a maturational effect. Pediatr Pulmonol. 2017;52:650-655. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Kamal Ali
- Neonatal Intensive Care Unit, King's College Hospital NHS Foundation Trust, London, United Kingdom
| | - Thomas Rosser
- Division of Asthma, Allergy and Lung Biology, MRC & Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London, United Kingdom
| | - Ravindra Bhat
- Neonatal Intensive Care Unit, King's College Hospital NHS Foundation Trust, London, United Kingdom
| | - Kim Wolff
- Addiction Sciences Unit, King's College London, London, United Kingdom
| | - Simon Hannam
- Division of Asthma, Allergy and Lung Biology, MRC & Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London, United Kingdom
| | - Gerrard F Rafferty
- Division of Asthma, Allergy and Lung Biology, MRC & Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London, United Kingdom
| | - Anne Greenough
- Neonatal Intensive Care Unit, King's College Hospital NHS Foundation Trust, London, United Kingdom.,Division of Asthma, Allergy and Lung Biology, MRC & Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London, United Kingdom.,National Institute for Health Research (NIHR) Biomedical Research Centre based at Guy's and St Thomas' NHS Foundation Trust and King's College London, London, United Kingdom
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26
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MacBean V, Pringle CL, Lunt AC, Sharp KD, Ali A, Greenough A, Moxham J, Rafferty GF. Parasternal intercostal muscle activity during methacholine-induced bronchoconstriction. Exp Physiol 2017; 102:475-484. [PMID: 28194830 DOI: 10.1113/ep086120] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 02/08/2017] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? The parasternal intercostal electromyogram (EMGpara) is known to provide an accurate, non-invasive index of respiratory load-capacity balance. Although relationships between EMGpara and both airflow obstruction and hyperinflation have been shown, the independent contribution of each factor has not been examined. What is the main finding and its importance? Reductions in airway calibre and inspiratory capacity along with increases in EMGpara were induced via methacholine challenge. A strong inverse relationship was observed between EMGpara and airway obstruction, with no influence of inspiratory capacity. These data suggest that EMGpara is more strongly influenced by airway calibre than by changes in end-expiratory lung volume during airway challenge testing. Neural respiratory drive, measured via the parasternal intercostal electromyogram (EMGpara), provides a non-invasive index of the load-capacity balance of the respiratory muscle pump. Previous studies in patients with obstructive lung disease have shown strong relationships between EMGpara and the extent of both airflow obstruction and hyperinflation. The relative influence of the two factors has not, however, been described. Airflow obstruction was induced via methacholine challenge testing in 25 adult humans. Forced expiratory volume in 1 s (FEV1 ) and surface EMGpara during tidal breathing were measured after each dose, with 20 of the participants also undergoing measurements of inspiratory capacity (IC) at each stage. Linear mixed model analysis was used to assess dose-wise changes in FEV1 and EMGpara, and thereafter to determine the influence of changes in FEV1 and IC on change in EMGpara. Median (interquartile range) FEV1 decreased significantly [from 96.00 (80.00-122.30) to 67.80 (37.98-92.27)% predicted, P < 0.0001] and EMGpara increased significantly [from 5.37 (2.25-8.92) to 6.27 (3.37-19.60) μV, P < 0.0001] from baseline to end of test. Linear mixed model analysis showed a significant interaction between methacholine dose and induced change in EMGpara, with an increase in EMGpara of 0.24 (95% confidence interval 0.11-0.37) μV per methacholine dose2 . Change in FEV1 further influenced this relationship [increase in slope of 0.002 (0.004-0.001) μV dose-2 per % predicted fall in FEV1 , P = 0.011], but not with change in IC. These data suggest that bronchoconstriction exerts a more potent influence on levels of EMGpara than changes in end-expiratory lung volume during methacholine challenge.
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Affiliation(s)
- Victoria MacBean
- Division of Asthma, Allergy and Lung Biology, King's College London, London, UK
| | - Claire L Pringle
- Division of Asthma, Allergy and Lung Biology, King's College London, London, UK
| | - Alan C Lunt
- Division of Asthma, Allergy and Lung Biology, King's College London, London, UK
| | - Keith D Sharp
- Division of Asthma, Allergy and Lung Biology, King's College London, London, UK
| | - Ashraf Ali
- Department of Respiratory Medicine, King's College Hospital NHS Foundation Trust, London, UK
| | - Anne Greenough
- Division of Asthma, Allergy and Lung Biology, King's College London, London, UK.,National Institute for Health Research (NIHR) Biomedical Research Centre based at Guy's and St Thomas' NHS Foundation Trust and King's College London, London, UK
| | - John Moxham
- Division of Asthma, Allergy and Lung Biology, King's College London, London, UK
| | - Gerrard F Rafferty
- Division of Asthma, Allergy and Lung Biology, King's College London, London, UK
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27
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Reed KI, Pengo MF, Xiao S, Ratneswaran C, Shah N, Chen T, Douiri A, Hart N, Luo Y, Rafferty GF, Rossi GP, Williams A, Polkey MI, Moxham J, Steier J. S26 Feasibility and patient tolerability of transcutaneous electrical stimulation in obstructive sleep apnoea. Thorax 2016. [DOI: 10.1136/thoraxjnl-2016-209333.32] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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28
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Smith L, Reilly CC, MacBean V, Jolley CJ, Elston C, Moxham J, Rafferty GF. Physiological markers of exercise capacity and lung disease severity in cystic fibrosis. Respirology 2016; 22:714-720. [PMID: 27882640 DOI: 10.1111/resp.12954] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 09/21/2016] [Accepted: 09/24/2016] [Indexed: 11/29/2022]
Abstract
BACKGROUND AND OBJECTIVE Peak aerobic capacity (VO2 peak) is an important outcome measure in cystic fibrosis (CF), but measurement is not widely available and can be influenced by patient motivation, pain and fatigue. Alternative markers of disease severity would be helpful. Neural respiratory drive, measured using parasternal intercostal muscle electromyography (EMGpara), reflects the load to capacity balance of the respiratory system and provides a composite measure of pulmonary function impairment in CF. The aim of the study was to investigate the relationship between exercise capacity, EMGpara and established measures of pulmonary function in clinically stable adult CF patients. METHODS Twenty CF patients (12 males, median (range) age: 22.3 (17.0-43.1) years) performed the 10-m incremental shuttle walk test (ISWT) maximally with contemporaneous measures of aerobic metabolism. EMGpara was recorded from second intercostal space at rest and normalized using peak electromyogram activity obtained during maximum respiratory manoeuvres and expressed as EMGpara%max (EMGpara expressed as a percentage of maximum). RESULTS VO2 peak was strongly correlated with ISWT distance (r = 0.864, P < 0.0001). Lung gas transfer (TL CO) % predicted was best correlated with VO2 peak (r = 0.842, P < 0.0001) and ISWT distance (r = 0.788, P < 0.0001). EMGpara%max also correlated with VO2 peak (-0.757, P < 0.0001), while the relationships between exercise outcome measures and forced expiratory volume in 1 s (FEV1 ) % predicted and forced vital capacity (FVC) % predicted were less strong. A TL CO% predicted of <70.5% was the strongest predictor of VO2 peak <32 mL/min/kg (area under the curve (AUC): 0.96, 100% sensitivity, 83.3% specificity). ISWT distance and EMGpara%max also performed well, with other pulmonary function variables demonstrating poorer predictive ability. CONCLUSION TL CO% predicted and EMGpara%max relate strongly to exercise performance markers in CF and may provide alternative predictors of lung disease progression.
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Affiliation(s)
- Laurie Smith
- Division of Asthma, Allergy and Lung Biology, Department of Respiratory Medicine (Chest Unit), King's College London, London, UK
| | - Charles C Reilly
- Division of Asthma, Allergy and Lung Biology, Department of Respiratory Medicine (Chest Unit), King's College London, London, UK.,King's College Hospital NHS Foundation Trust, London, UK
| | - Victoria MacBean
- Division of Asthma, Allergy and Lung Biology, Department of Respiratory Medicine (Chest Unit), King's College London, London, UK
| | - Caroline J Jolley
- Division of Asthma, Allergy and Lung Biology, Department of Respiratory Medicine (Chest Unit), King's College London, London, UK.,Centre for Human and Aerospace Physiological Sciences, King's College London, London, UK
| | | | - John Moxham
- Division of Asthma, Allergy and Lung Biology, Department of Respiratory Medicine (Chest Unit), King's College London, London, UK
| | - Gerrard F Rafferty
- Division of Asthma, Allergy and Lung Biology, Department of Respiratory Medicine (Chest Unit), King's College London, London, UK
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MacBean V, Hughes C, Nicol G, Reilly CC, Rafferty GF. Measurement of neural respiratory drive via parasternal intercostal electromyography in healthy adult subjects. Physiol Meas 2016; 37:2050-2063. [PMID: 27779132 DOI: 10.1088/0967-3334/37/11/2050] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Neural respiratory drive, quantified by the parasternal intercostal muscle electromyogram (EMGpara), provides a sensitive measure of respiratory system load-capacity balance. Reference values for EMGpara-based measures are lacking and the influence of individual anthropometric characteristics is not known. EMGpara is conventionally expressed as a percentage of that obtained during a maximal inspiratory effort (EMGpara%max), leading to difficulty in applying the technique in subjects unable to reliably perform such manoeuvres. To measure EMGpara in a large, unselected cohort of healthy adult subjects in order to evaluate relevant technical and anthropometric factors. Surface second intercostal space EMGpara was measured during resting breathing and maximal inspiratory efforts in 63 healthy adult subjects, median (IQR) age 31.0 (25.0-47.0) years, 28 males. Detailed anthropometry, spirometry and respiratory muscle strength were also recorded. Median (IQR EMGpara was 4.95 (3.35-6.93) µV, EMGpara%max 4.95 (3.39-8.65)% and neural respiratory drive index (NRDI, the product of EMGpara%max and respiratory rate) was 73.62 (46.41-143.92) %.breath/min. EMGpara increased significantly to 6.28 (4.26-9.93) µV (p < 0.001) with a mouthpiece, noseclip and pneumotachograph in situ. Median (IQR) EMGpara was higher in female subjects (5.79 (4.42-7.98) µV versus 3.56 (2.81-5.35) µV, p = 0.003); after controlling for sex neither EMGpara, EMGpara%max or NRDI were significantly related to anthropometrics, age or respiratory muscle strength. In subjects undergoing repeat measurements within the same testing session (n = 48) or on a separate occasion (n = 19) similar repeatability was observed for both EMGpara and EMGpara%max. EMGpara is higher in female subjects than males, without influence of other anthropometric characteristics. Reference values are provided for EMGpara-derived measures. Expressing EMGpara as a percentage of maximum confers no advantage with respect to measurement repeatability, expanding the potential application of the technique. Raw EMGpara is a useful marker of respiratory system load-capacity balance.
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Affiliation(s)
- V MacBean
- Division of Asthma, Allergy and Lung Biology, King's College London, London, UK
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Bhat P, Peacock JL, Rafferty GF, Hannam S, Greenough A. Prediction of infant extubation outcomes using the tension-time index. Arch Dis Child Fetal Neonatal Ed 2016; 101:F444-7. [PMID: 26802111 DOI: 10.1136/archdischild-2015-309264] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 12/27/2015] [Indexed: 11/03/2022]
Abstract
OBJECTIVE The tension-time index of the diaphragm (TTdi) is a composite assessment of the load on and the capacity of the diaphragm. TTmus is a non-invasive tension-time index of the respiratory muscles. Our aim was to determine whether TTdi or TTmus predicted extubation outcome and performed better than respiratory muscle strength (Pimax, Pdimax), respiratory drive (P0.1) and work of breathing (transdiaphragmatic pressure-time product (PTPdi)) or routinely available clinical data. DESIGN Prospective study. SETTING Tertiary neonatal intensive care unit. PATIENTS Sixty infants, median gestation age 35 (range 23-42) weeks and postnatal age of 55 (range 1-115) days. INTERVENTIONS Airway occlusions were performed to measure Pimax, Pdimax and P0.1. TTdi and PTPdi were derived from measurements of transdiaphragmatic pressure. TTmus was derived from airway pressure measurements. Measurements were made within 6 h of extubation. MAIN OUTCOME MEASURES Extubation failure defined as reintubation within 48 h of extubation. RESULTS Twelve infants failed extubation. The infants who failed extubation were significantly more immature (medians 25 vs 37 weeks) and of greater postnatal age (23 vs 5 days) and had higher TTdi (0.15 vs 0.04) and TTmus (0.17 vs 0.08). TTdi and TTmus were only significantly better predictors than the peak inflation pressure immediately prior to extubation and did not perform significantly better than gestational age or birth weight. CONCLUSIONS Assessment of TTdi and TTmus cannot be recommended for use in routine clinical practice.
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Affiliation(s)
- Prashanth Bhat
- Division of Asthma, Allergy and Lung Biology, MRC-Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London, UK
| | - Janet L Peacock
- Division of Health and Social Care Research, King's College London, London, UK National Institute for Health Research (NIHR) Biomedical Research Centre, Guy's and St Thomas' NHS Foundation Trust and King's College London, London, UK
| | - Gerrard F Rafferty
- Division of Asthma, Allergy and Lung Biology, MRC-Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London, UK
| | - Simon Hannam
- Division of Asthma, Allergy and Lung Biology, MRC-Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London, UK
| | - Anne Greenough
- Division of Asthma, Allergy and Lung Biology, MRC-Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London, UK National Institute for Health Research (NIHR) Biomedical Research Centre, Guy's and St Thomas' NHS Foundation Trust and King's College London, London, UK
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Shetty S, Hickey A, Rafferty GF, Peacock JL, Greenough A. Work of breathing during CPAP and heated humidified high-flow nasal cannula. Arch Dis Child Fetal Neonatal Ed 2016; 101:F404-7. [PMID: 26769758 DOI: 10.1136/archdischild-2015-309310] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 12/07/2015] [Indexed: 11/03/2022]
Abstract
OBJECTIVE To determine whether continuous positive airway pressure (CPAP) compared with heated humidified, high-flow nasal cannula (HHFNC) in infants with evolving or established bronchopulmonary dysplasia (BPD) reduced the work of breathing (WOB) and thoracoabdominal asynchrony (TAA) and improved oxygen saturation (SaO2). DESIGN Randomised crossover study. SETTING Tertiary neonatal unit. PATIENTS 20 infants (median gestational age of 27.6 weeks (range 24.6-31.9 weeks)) were studied at a median postnatal age of 30.9 weeks (range 28.1-39.1 weeks). INTERVENTIONS Infants were studied on 2 consecutive days. On the first study day, they were randomised to either CPAP or HHFNC each for 2 h, the order being reversed on the second day. MAIN OUTCOME MEASURES The WOB was assessed by measuring the pressure time product of the diaphragm (PTPdi). PTPdi, TAA and SaO2 were assessed during the final 5 min of each 2 h period and the results on the two study days were meaned. RESULTS There were no significant differences in the results on CPAP versus HHFNC: mean PTPdi 226 (range 126-294) versus 224 cm H2O/s/min (95% CI for difference: -27 to 22; p=0.85) (range 170-318) (p=0.82), mean TAA 13.4° (range 4.51°-23.32°) versus 14.01° (range 4.25°-23.86°) (95% CI for difference: -3.9 to 2.8: p=0.73) (p=0.63) and mean SaO2 95% (range 93%-100%) versus 95% (94%-99%), (95% CI for difference -1.8 to 0.5; p=0.25) (p=0.45). CONCLUSION In infants with evolving or established BPD, CPAP compared with HHFNC offered no significant advantage with regard to the WOB, degree of asynchrony or oxygen saturation.
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Affiliation(s)
- Sandeep Shetty
- Neonatal Intensive Care Centre, King's College Hospital, London, UK Division of Asthma, Allergy and Lung Biology, MRC Centre for Allergic Mechanisms in Asthma, King's College London, London, UK
| | - Ann Hickey
- Neonatal Intensive Care Centre, King's College Hospital, London, UK
| | - Gerrard F Rafferty
- Division of Asthma, Allergy and Lung Biology, MRC Centre for Allergic Mechanisms in Asthma, King's College London, London, UK
| | - Janet L Peacock
- Division of Health and Social Care Research, King's College London, London, UK NIHR Biomedical Research Centre at Guy's and St Thomas' NHS Foundation Trust and King's College London, London, UK
| | - Anne Greenough
- Division of Asthma, Allergy and Lung Biology, MRC Centre for Allergic Mechanisms in Asthma, King's College London, London, UK NIHR Biomedical Research Centre at Guy's and St Thomas' NHS Foundation Trust and King's College London, London, UK
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Pengo MF, Xiao S, Ratneswaran C, Reed K, Shah N, Chen T, Douiri A, Hart N, Luo Y, Rafferty GF, Rossi GP, Williams A, Polkey MI, Moxham J, Steier J. Randomised sham-controlled trial of transcutaneous electrical stimulation in obstructive sleep apnoea. Thorax 2016; 71:923-31. [PMID: 27435610 PMCID: PMC5036236 DOI: 10.1136/thoraxjnl-2016-208691] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Accepted: 06/23/2016] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Obstructive sleep apnoea (OSA) is characterised by a loss of neuromuscular tone of the upper airway dilator muscles while asleep. This study investigated the effectiveness of transcutaneous electrical stimulation in patients with OSA. PATIENTS AND METHODS This was a randomised, sham-controlled crossover trial using transcutaneous electrical stimulation of the upper airway dilator muscles in patients with confirmed OSA. Patients were randomly assigned to one night of sham stimulation and one night of active treatment. The primary outcome was the 4% oxygen desaturation index, responders were defined as patients with a reduction >25% in the oxygen desaturation index when compared with sham stimulation and/or with an index <5/hour in the active treatment night. RESULTS In 36 patients (age mean 50.8 (SD 11.2) years, male/female 30/6, body mass index median 29.6 (IQR 26.9-34.9) kg/m(2), Epworth Sleepiness Scale 10.5 (4.6) points, oxygen desaturation index median 25.7 (16.0-49.1)/hour, apnoea-hypopnoea index median 28.1 (19.0-57.0)/hour) the primary outcome measure improved when comparing sham stimulation (median 26.9 (17.5-39.5)/hour) with active treatment (median 19.5 (11.6-40.0)/hour; p=0.026), a modest reduction of the mean by 4.1 (95% CI -0.6 to 8.9)/hour. Secondary outcome parameters of patients' perception indicated that stimulation was well tolerated. Responders (47.2%) were predominantly from the mild-to-moderate OSA category. In this subgroup, the oxygen desaturation index was reduced by 10.0 (95% CI 3.9 to 16.0)/hour (p<0.001) and the apnoea-hypopnoea index was reduced by 9.1 (95% CI 2.0 to 16.2)/hour (p=0.004). CONCLUSION Transcutaneous electrical stimulation of the pharyngeal dilators during a single night in patients with OSA improves upper airway obstruction and is well tolerated. TRIAL REGISTRATION NUMBER NCT01661712.
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Affiliation(s)
- Martino F Pengo
- Faculty of Life Sciences and Medicine, King's College London, London, UK Guy's and St Thomas' NHS Foundation Trust, Lane Fox Respiratory Unit/Sleep Disorders Centre, London, UK Department of Medicine (DIMED), University of Padua, Padua, Italy
| | - Sichang Xiao
- Faculty of Life Sciences and Medicine, King's College London, London, UK State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Culadeeban Ratneswaran
- Faculty of Life Sciences and Medicine, King's College London, London, UK Guy's and St Thomas' NHS Foundation Trust, Lane Fox Respiratory Unit/Sleep Disorders Centre, London, UK
| | - Kate Reed
- Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Nimish Shah
- Faculty of Life Sciences and Medicine, King's College London, London, UK Guy's and St Thomas' NHS Foundation Trust, Lane Fox Respiratory Unit/Sleep Disorders Centre, London, UK
| | - Tao Chen
- Division of Health and Social Care, King's College London, London, UK
| | - Abdel Douiri
- Division of Health and Social Care, King's College London, London, UK
| | - Nicholas Hart
- Faculty of Life Sciences and Medicine, King's College London, London, UK Guy's and St Thomas' NHS Foundation Trust, Lane Fox Respiratory Unit/Sleep Disorders Centre, London, UK
| | - Yuanming Luo
- Department of Medicine (DIMED), University of Padua, Padua, Italy
| | - Gerrard F Rafferty
- Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Gian Paolo Rossi
- Department of Medicine (DIMED), University of Padua, Padua, Italy
| | - Adrian Williams
- Faculty of Life Sciences and Medicine, King's College London, London, UK Guy's and St Thomas' NHS Foundation Trust, Lane Fox Respiratory Unit/Sleep Disorders Centre, London, UK
| | - Michael I Polkey
- NIHR Respiratory Biomedical Research Unit, The Royal Brompton and Harefield NHS Foundation Trust and Imperial College, London, UK
| | - John Moxham
- Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Joerg Steier
- Faculty of Life Sciences and Medicine, King's College London, London, UK Guy's and St Thomas' NHS Foundation Trust, Lane Fox Respiratory Unit/Sleep Disorders Centre, London, UK
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Chowdhury O, Bhat P, Rafferty GF, Hannam S, Milner AD, Greenough A. In vitro assessment of the effect of proportional assist ventilation on the work of breathing. Eur J Pediatr 2016; 175:639-43. [PMID: 26746416 DOI: 10.1007/s00431-015-2673-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 11/16/2015] [Accepted: 11/19/2015] [Indexed: 11/25/2022]
Abstract
UNLABELLED During proportional assist ventilation, elastic and resistive unloading can be delivered to reduce the work of breathing (WOB). Our aim was to determine the effects of different levels of elastic and resistive unloading on the WOB in lung models designed to mimic certain neonatal respiratory disorders. Two dynamic lung models were used, one with a compliance of 0.4 ml/cm H2O to mimic an infant with respiratory distress syndrome and one with a resistance of 300 cm H2O/l/s to mimic an infant with bronchopulmonary dypslasia. Pressure volume curves were constructed at each unloading level. Elastic unloading in the low compliance model was highly effective in reducing the WOB measured in the lung model; the effective compliance increased from 0.4 ml/cm H2O at baseline to 4.1 ml/cm H2O at maximum possible elastic unloading (2.0 cm H2O/ml). Maximum possible resistive unloading (200 cm H2O/l/s) in the high-resistance model only reduced the effective resistance from 300 to 204 cm H2O/l/s. At maximum resistive unloading, oscillations appeared in the airway pressure waveform. CONCLUSION Our results suggest that elastic unloading will be helpful in respiratory conditions characterised by a low compliance, but resistive unloading as currently delivered is unlikely to be of major clinical benefit. WHAT IS KNOWN • During PAV, the ventilator can provide elastic and resistive unloading. What is New: • Elastic unloading was highly effective in reducing the work of breathing. • Maximum resistive unloading only partially reduced the effective resistance.
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Affiliation(s)
- Olie Chowdhury
- Division of Asthma, Allergy and Lung Biology, MRC and Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London, SE5 9RS, UK
| | - Prashanth Bhat
- Division of Asthma, Allergy and Lung Biology, MRC and Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London, SE5 9RS, UK
| | - Gerrard F Rafferty
- Division of Asthma, Allergy and Lung Biology, MRC and Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London, SE5 9RS, UK
| | - Simon Hannam
- Division of Asthma, Allergy and Lung Biology, MRC and Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London, SE5 9RS, UK
| | - Anthony D Milner
- Division of Asthma, Allergy and Lung Biology, MRC and Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London, SE5 9RS, UK
| | - Anne Greenough
- Division of Asthma, Allergy and Lung Biology, MRC and Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London, SE5 9RS, UK.
- NIHR Biomedical Research Centre at Guy's and St Thomas' NHS Foundation Trust and King's College London, London, UK.
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Maddocks M, Nolan C, Man WDC, Polkey M, Hart N, Gao W, Rafferty GF, Moxham J, Higginson IJ. Neuromuscular electrical stimulation to improve exercise capacity in patients with severe COPD - Authors' reply. Lancet Respir Med 2016; 4:e16. [PMID: 27304371 DOI: 10.1016/s2213-2600(16)00093-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 02/25/2016] [Accepted: 02/26/2016] [Indexed: 11/15/2022]
Affiliation(s)
- Matthew Maddocks
- King's College London, Cicely Saunders Institute, Division of Palliative Care, Policy & Rehabilitation, London SE5 9PJ, UK.
| | - Claire Nolan
- NIHR Respiratory Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust and Imperial College, London, UK; Harefield Pulmonary Rehabilitation Team, Harefield Hospital, UK
| | - William D C Man
- NIHR Respiratory Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust and Imperial College, London, UK; Harefield Pulmonary Rehabilitation Team, Harefield Hospital, UK
| | - Michael Polkey
- NIHR Respiratory Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust and Imperial College, London, UK
| | - Nicholas Hart
- Lane Fox Unit, Guy's & St Thomas' NHS Foundation Trust, London, UK; King's College London, Respiratory Medicine, Division of Asthma, Allergy & Lung Biology, London, UK
| | - Wei Gao
- King's College London, Cicely Saunders Institute, Division of Palliative Care, Policy & Rehabilitation, London SE5 9PJ, UK
| | - Gerrard F Rafferty
- King's College London, Respiratory Medicine, Division of Asthma, Allergy & Lung Biology, London, UK
| | - John Moxham
- King's College London, Respiratory Medicine, Division of Asthma, Allergy & Lung Biology, London, UK
| | - Irene J Higginson
- King's College London, Cicely Saunders Institute, Division of Palliative Care, Policy & Rehabilitation, London SE5 9PJ, UK
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Reilly CC, Jolley CJ, Elston C, Moxham J, Rafferty GF. Blunted perception of neural respiratory drive and breathlessness in patients with cystic fibrosis. ERJ Open Res 2016; 2:00057-2015. [PMID: 27730171 PMCID: PMC5005154 DOI: 10.1183/23120541.00057-2015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 01/17/2016] [Indexed: 12/16/2022] Open
Abstract
The electromyogram recorded from the diaphragm (EMGdi) and parasternal intercostal muscle using surface electrodes (sEMGpara) provides a measure of neural respiratory drive (NRD), the magnitude of which reflects lung disease severity in stable cystic fibrosis. The aim of this study was to explore perception of NRD and breathlessness in both healthy individuals and patients with cystic fibrosis. Given chronic respiratory loading and increased NRD in cystic fibrosis, often in the absence of breathlessness at rest, we hypothesised that patients with cystic fibrosis would be able to tolerate higher levels of NRD for a given level of breathlessness compared to healthy individuals during exercise. 15 cystic fibrosis patients (mean forced expiratory volume in 1 s (FEV1) 53.5% predicted) and 15 age-matched, healthy controls were studied. Spirometry was measured in all subjects and lung volumes measured in the cystic fibrosis patients. EMGdi and sEMGpara were recorded at rest and during incremental cycle exercise to exhaustion and expressed as a percentage of maximum (% max) obtained from maximum respiratory manoeuvres. Borg breathlessness scores were recorded at rest and during each minute of exercise. EMGdi % max and sEMGpara % max and associated Borg breathlessness scores differed significantly between healthy subjects and cystic fibrosis patients at rest and during exercise. The relationship between EMGdi % max and sEMGpara % max and Borg score was shifted to the right in the cystic fibrosis patients, such that at comparable levels of EMGdi % max and sEMGpara % max the cystic fibrosis patients reported significantly lower Borg breathlessness scores compared to the healthy individuals. At Borg score 1 (clinically significant increase in breathlessness from baseline) corresponding levels of EMGdi % max (20.2±12% versus 32.15±15%, p=0.02) and sEMGpara % max (18.9±8% versus 29.2±15%, p=0.04) were lower in the healthy individuals compared to the cystic fibrosis patients. In the cystic fibrosis patients EMGdi % max at Borg score 1 was related to the degree of airways obstruction (FEV1) (r=−0.664, p=0.007) and hyperinflation (residual volume/total lung capacity) (r=0.710, p=0.03). This relationship was not observed for sEMGpara % max. These data suggest that compared to healthy individuals, patients with cystic fibrosis can tolerate much higher levels of NRD before increases in breathlessness from baseline become clinically significant. EMGdi % max and sEMGpara % max provide physiological tools with which to elucidate factors underlying inter-individual differences in breathlessness perception. Patients with CF can tolerate higher levels of NRD before breathlessness becomes clinically significanthttp://ow.ly/Xp2q3
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Affiliation(s)
- Charles C Reilly
- King's College London, Faculty of Life Sciences and Medicine, London, UK; King's College Hospital, Physiotherapy, London, UK
| | - Caroline J Jolley
- King's College London, Faculty of Life Sciences and Medicine, London, UK
| | | | - John Moxham
- King's College London, Faculty of Life Sciences and Medicine, London, UK
| | - Gerrard F Rafferty
- King's College London, Faculty of Life Sciences and Medicine, London, UK
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Ali K, Rossor T, Bhat R, Wolff K, Hannam S, Rafferty GF, Peacock JL, Greenough A. Antenatal substance misuse and smoking and newborn hypoxic challenge response. Arch Dis Child Fetal Neonatal Ed 2016; 101:F143-8. [PMID: 26290480 DOI: 10.1136/archdischild-2015-308491] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 07/28/2015] [Indexed: 11/04/2022]
Abstract
OBJECTIVES Infants of smoking (S) and substance misusing (SM) mothers have an increased risk of sudden infant death syndrome. The aim of this study was to test the hypothesis that infants of SM or S mothers compared with infants of non-SM, non-smoking mothers (controls) would have a poorer ventilatory response to hypoxia, which was particularly marked in the SM infants. DESIGN Physiological study. SETTING Tertiary perinatal centre. PATIENTS 21 SM; 21 S and 19 control infants. Infants were assessed before maternity/neonatal unit discharge. INTERVENTIONS Maternal and infant urine samples were tested for cotinine, cannabinoids, opiates, amphetamines, methadone, cocaine and benzodiazepines. MAIN OUTCOME MEASURES During quiet sleep, the infants were switched from breathing room air to 15% oxygen and changes in minute volume were assessed. RESULTS The SM infants had a greater mean increase (p=0.028, p=0.034, respectively) and a greater magnitude of decline (p<0.001, p=0.018, respectively) in minute volume than the S infants and the controls. The rate of decline in minute volume was greater in the SM infants (p=0.008) and the S infants (p=0.011) compared with the controls. CONCLUSIONS Antenatal substance misuse and smoking affect the infant's ventilatory response to a hypoxic challenge.
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Affiliation(s)
- Kamal Ali
- Division of Asthma, Allergy and Lung Biology, MRC & Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London, UK
| | - Thomas Rossor
- Division of Asthma, Allergy and Lung Biology, MRC & Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London, UK
| | - Ravindra Bhat
- Division of Asthma, Allergy and Lung Biology, MRC & Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London, UK
| | - Kim Wolff
- Addiction Sciences Unit, King's College London, London, UK
| | - Simon Hannam
- Division of Asthma, Allergy and Lung Biology, MRC & Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London, UK
| | - Gerrard F Rafferty
- Division of Asthma, Allergy and Lung Biology, MRC & Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London, UK
| | - Janet L Peacock
- National Institute for Health Research (NIHR) Biomedical Research Centre based at Guy's and St Thomas' NHS Foundation Trust and King's College London, London, UK Division of Health and Social Care Research, King's College London, London, UK
| | - Anne Greenough
- Division of Asthma, Allergy and Lung Biology, MRC & Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London, UK National Institute for Health Research (NIHR) Biomedical Research Centre based at Guy's and St Thomas' NHS Foundation Trust and King's College London, London, UK
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Abstract
BACKGROUND The intensity of cough is an important determinant of cough severity. Few studies have quantified cough intensity in patients with chronic cough with objective measures. We investigated the intensity of voluntary, induced, and spontaneous cough in patients with chronic cough and healthy control subjects. METHODS Patients with chronic cough and control subjects underwent physiologic assessment of the intensity of maximum voluntary, capsaicin-induced, and spontaneous cough. Assessments included measurement of gastric pressure (Pga) and esophageal pressure (Pes) during cough, peak cough flow (PCF), expiratory muscle strength (twitch gastric pressure [TwPga]), and cough compression phase duration (CPD). Subjective perception of cough intensity was assessed using a visual analog scale (VAS). RESULTS Pes, Pga, and PCF during maximum voluntary cough were significantly greater in patients with chronic cough compared with control subjects (P = .003-.042). There was no difference in TwPga between patients and control subjects. CPD was increased in female patients compared with control subjects (mean ± SD, 0.50 ± 0.22 s vs 0.28 ± 0.17 s; P = .007). Mean ± SD Pes during spontaneous cough was comparable to induced cough (128 ± 28 cm H2O vs 122 ± 37 cm H2O, P = .686) but less than maximum voluntary cough (170 ± 46 cm H2O, P = .020). Median within-subject correlation coefficients between cough intensity VAS and Pes, Pga, and PCF were r = 0.82 to 0.86. CONCLUSIONS Maximum voluntary cough intensity was increased in patients with chronic cough compared with control subjects. There was no significant difference in expiratory muscle contractility. Further studies should evaluate the compressive phase of cough in more detail. Physiologic measures of cough intensity correlated strongly with subjective perception of intensity in patients with chronic cough and may be relevant objective outcome measures for clinical studies.
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Affiliation(s)
- Kai K Lee
- Division of Asthma, Allergy and Lung Biology, King's College London, King's Health Partners, London, England
| | - Katie Ward
- Division of Asthma, Allergy and Lung Biology, King's College London, King's Health Partners, London, England
| | - Gerrard F Rafferty
- Division of Asthma, Allergy and Lung Biology, King's College London, King's Health Partners, London, England
| | - John Moxham
- Division of Asthma, Allergy and Lung Biology, King's College London, King's Health Partners, London, England
| | - Surinder S Birring
- Division of Asthma, Allergy and Lung Biology, King's College London, King's Health Partners, London, England.
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Sinha A, Lee KK, Rafferty GF, Yousaf N, Pavord ID, Galloway J, Birring SS. Predictors of objective cough frequency in pulmonary sarcoidosis. Eur Respir J 2016; 47:1461-71. [PMID: 26846840 DOI: 10.1183/13993003.01369-2015] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 12/01/2015] [Indexed: 12/30/2022]
Abstract
Cough is a common symptom of pulmonary sarcoidosis. This study aimed to quantify cough frequency, and investigate its relationship with cough reflex sensitivity, pulmonary function and health status.32 patients with pulmonary sarcoidosis were compared with 40 healthy controls. Cough reflex sensitivity to capsaicin, objective 24-h cough counts, cough-specific health status, cough severity and cough triggers were measured. The predictors of cough frequency in sarcoidosis were determined in a multivariate analysis.Objective cough frequency was significantly raised in patients with sarcoidosis compared with healthy controls (p<0.001) and patients with cough had an impaired health status. Patients with pulmonary sarcoidosis had a heightened cough reflex sensitivity compared with healthy controls (p<0.001). Only cough reflex sensitivity was significantly associated with objective cough frequency in multivariate analysis, explaining 42% of the variance (p<0.001). There was no association between cough frequency, lung function, number of organs involved, chest radiograph stage or serum angiotensin-converting enzyme levels.Cough is a common and significant symptom in patients with sarcoidosis. Ambulatory objective cough monitoring provides novel insights into the determinants of cough in sarcoidosis, suggesting that cough reflex sensitivity may be more important than lung function and other measures of disease severity, and this should be investigated further.
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Affiliation(s)
- Aish Sinha
- Division of Asthma, Allergy and Lung Biology, King's College London, King's Health Partners, London, UK
| | - Kai K Lee
- Division of Asthma, Allergy and Lung Biology, King's College London, King's Health Partners, London, UK
| | - Gerrard F Rafferty
- Child Health, School of Medicine, King's College London, King's Health Partners, London, UK
| | - Nadia Yousaf
- Dept of Oncology, St George's University Hospital Foundation Trust, London, UK
| | - Ian D Pavord
- Dept of Respiratory Medicine, Nuffield Dept of Medicine, University of Oxford, Oxford, UK
| | - James Galloway
- Division of Rheumatology, King's College London, King's Health Partners, London, UK
| | - Surinder S Birring
- Division of Asthma, Allergy and Lung Biology, King's College London, King's Health Partners, London, UK
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Lunt A, Ahmed N, Rafferty GF, Dick M, Rees D, Height S, Thein SL, Greenough A. Airway and alveolar nitric oxide production, lung function, and pulmonary blood flow in sickle cell disease. Pediatr Res 2016; 79:313-7. [PMID: 26492287 DOI: 10.1038/pr.2015.217] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 08/04/2015] [Indexed: 01/25/2023]
Abstract
BACKGROUND Children with sickle cell disease (SCD) often have obstructive lung function abnormalities which could be due to asthma or increased pulmonary blood volume; it is important to determine the underlying mechanism to direct appropriate treatment. In asthmatics, exhaled nitric oxide (FeNO) is elevated. FeNO, however, can also be raised due to increased alveolar production. Our aim, therefore, was to determine if airway or alveolar NO production differed between SCD children and ethnic and age-matched controls. METHODS Lung function, airway NO flux and alveolar NO production, and effective pulmonary blood flow were assessed in 18 SCD children and 18 ethnic and age-matched controls. RESULTS The SCD children compared to the controls had a higher respiratory system resistance (P = 0.0008), alveolar NO production (P = 0.0224), and pulmonary blood flow (P < 0.0001), but not airway NO flux. There was no significant correlation between FeNO and respiratory system resistance in either group, but in the SCD children, there were correlations between alveolar NO production (P = 0.0006) and concentration (P < 0.0001) and pulmonary blood flow. CONCLUSION Airway NO flux was not elevated in the SCD children nor correlated with airways obstruction, suggesting that airways obstruction, at least in some SCD children, is not due to asthma.
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Affiliation(s)
- Alan Lunt
- Division of Asthma, Allergy and Lung Biology, MRC Centre for Allergic Mechanisms in Asthma, King's College London, London, UK.,National Institute for Health Research Biomedical Research Centre based at Guy's and St Thomas' NHS Foundation Trust and King's College London, London, UK
| | - Na'eem Ahmed
- Division of Asthma, Allergy and Lung Biology, MRC Centre for Allergic Mechanisms in Asthma, King's College London, London, UK
| | - Gerrard F Rafferty
- Division of Asthma, Allergy and Lung Biology, MRC Centre for Allergic Mechanisms in Asthma, King's College London, London, UK
| | - Moira Dick
- Department of Haematology, King's College Hospital NHS Foundation Trust, London, UK
| | - David Rees
- Department of Haematology, King's College Hospital NHS Foundation Trust, London, UK.,Division of Cancer Studies, King's College London, London, UK
| | - Sue Height
- Department of Haematology, King's College Hospital NHS Foundation Trust, London, UK
| | - Swee Lay Thein
- Department of Haematology, King's College Hospital NHS Foundation Trust, London, UK.,Division of Cancer Studies, King's College London, London, UK
| | - Anne Greenough
- Division of Asthma, Allergy and Lung Biology, MRC Centre for Allergic Mechanisms in Asthma, King's College London, London, UK.,National Institute for Health Research Biomedical Research Centre based at Guy's and St Thomas' NHS Foundation Trust and King's College London, London, UK
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Kulnik ST, Birring SS, Hodsoll J, Moxham J, Rafferty GF, Kalra L. Higher cough flow is associated with lower risk of pneumonia in acute stroke. Thorax 2016; 71:474-5. [PMID: 26834183 DOI: 10.1136/thoraxjnl-2015-207810] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Accepted: 01/14/2016] [Indexed: 11/04/2022]
Abstract
UNLABELLED There is little available evidence to demonstrate how cough strength mediates the risk of aspiration-related pneumonia in acute stroke. Our secondary analysis of trial data indicates that risk of pneumonia reduces with increasing peak cough flow (PCF) of voluntary cough (OR 0.994 for each 1 L/min increase in PCF, 95% CI 0.988 to 1.0, p=0.035); and to a lesser degree with increasing PCF of reflex cough (OR 0.998 for each 1 L/min increase in PCF, 95% CI 0.992 to 1.004, p=0.475). These data serve hypothesis generation. Further studies are needed to confirm these findings and validate their clinical utility. CLINICAL TRIAL REGISTRATION NUMBER ISRCTN40298220 (post-results).
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Affiliation(s)
- Stefan T Kulnik
- Faculty of Health, Social Care and Education, St George's, University of London, London, UK
| | - Surinder S Birring
- Division of Asthma, Allergy & Lung Biology, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - John Hodsoll
- Department of Biostatistics, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - John Moxham
- Division of Asthma, Allergy & Lung Biology, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Gerrard F Rafferty
- Division of Asthma, Allergy & Lung Biology, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Lalit Kalra
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
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Lee KK, Ward K, Rafferty GF, Moxham J, Birring SS. Response. Chest 2016; 149:286-7. [PMID: 26757294 DOI: 10.1016/j.chest.2015.09.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 09/29/2015] [Indexed: 10/22/2022] Open
Affiliation(s)
- Kai K Lee
- King's College London, Division of Asthma, Allergy and Lung Biology, King's Health Partners, London, England
| | - Katie Ward
- King's College London, Division of Asthma, Allergy and Lung Biology, King's Health Partners, London, England
| | - Gerrard F Rafferty
- King's College London, Division of Asthma, Allergy and Lung Biology, King's Health Partners, London, England
| | - John Moxham
- King's College London, Division of Asthma, Allergy and Lung Biology, King's Health Partners, London, England
| | - Surinder S Birring
- King's College London, Division of Asthma, Allergy and Lung Biology, King's Health Partners, London, England.
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Maddocks M, Nolan CM, Man WDC, Polkey MI, Hart N, Gao W, Rafferty GF, Moxham J, Higginson IJ. Neuromuscular electrical stimulation to improve exercise capacity in patients with severe COPD: a randomised double-blind, placebo-controlled trial. Lancet Respir Med 2016; 4:27-36. [PMID: 26701362 DOI: 10.1016/s2213-2600(15)00503-2] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 11/24/2015] [Accepted: 11/24/2015] [Indexed: 12/14/2022]
Abstract
BACKGROUND Skeletal muscle dysfunction and exercise intolerance are common in severe chronic obstructive pulmonary disease (COPD). We assessed the effectiveness of neuromuscular electrical stimulation (NMES) as a home-based exercise therapy. METHODS In this double-blind, placebo-controlled trial, undertaken across three UK National Health Service sites, we randomly assigned (1:1) adults with COPD, a forced expiratory volume in 1 s (FEV1) less than 50% predicted, and incapacitating breathlessness (Medical Research Council dyspnoea scale ≥4) to receive active or placebo NMES, daily over a 6-week period. Randomisation was by an independent system using minimisation to balance age, GOLD stage, and quadriceps strength. Participants and outcome assessors were masked to group allocation. The primary endpoint was change in 6-min walk test (6MWT) distance at 6 weeks. Analysis was by intention to treat. The trial was registered as ISRCTN15985261 and is now closed. FINDINGS Between June 29, 2012, and July 4, 2014, we enrolled 73 participants, of whom 52 participants were randomly assigned; 25 to receive active NMES and 27 to placebo NMES. Change in 6MWT distance was greater in the active NMES group (mean 29·9 [95% CI 8·9 to 51·0]) compared with in the placebo group (-5·7 [-19·9 to 8·4]; mean difference at 6 weeks 35·7 m [95% CI 10·5 to 60·9]; p=0·005). Sensitivity analyses for complete-cases and adjustment for baseline values showed similar results. 6 weeks after stopping the intervention the effect waned (7·3 m [95% CI -32·5 to 47·0]; p=0·50). The proportion of participants who had adverse events was similar between groups (five [20%] in the active NMES group and nine [33%] in the placebo group). Two participants, one from each group, reported persistent erythema, which was considered to be possibly related to NMES and the use of adhesive electrodes. INTERPRETATION NMES improves functional exercise capacity in patients with severe COPD by enhancing quadriceps muscle mass and function. These data support the use of NMES in the management of patients unable to engage with conventional pulmonary rehabilitation. More work is needed to study how to maintain the effect. FUNDING National Institute for Health Research.
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Affiliation(s)
- Matthew Maddocks
- King's College London, Cicely Saunders Institute, Division of Palliative Care, Policy & Rehabilitation, London, UK.
| | - Claire M Nolan
- NIHR Respiratory Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust and Imperial College, London, UK; Harefield Pulmonary Rehabilitation Team, Harefield Hospital, Harefield, Middlesex, UK
| | - William D-C Man
- NIHR Respiratory Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust and Imperial College, London, UK; Harefield Pulmonary Rehabilitation Team, Harefield Hospital, Harefield, Middlesex, UK
| | - Michael I Polkey
- NIHR Respiratory Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust and Imperial College, London, UK
| | - Nicholas Hart
- Lane Fox Unit, Guy's & St Thomas' NHS Foundation Trust, London, UK; King's College London, Respiratory Medicine, Division of Asthma, Allergy & Lung Biology, London, UK
| | - Wei Gao
- King's College London, Cicely Saunders Institute, Division of Palliative Care, Policy & Rehabilitation, London, UK
| | - Gerrard F Rafferty
- King's College London, Respiratory Medicine, Division of Asthma, Allergy & Lung Biology, London, UK
| | - John Moxham
- King's College London, Respiratory Medicine, Division of Asthma, Allergy & Lung Biology, London, UK
| | - Irene J Higginson
- King's College London, Cicely Saunders Institute, Division of Palliative Care, Policy & Rehabilitation, London, UK
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Jolley CJ, Bell J, Rafferty GF, Moxham J, Strang J. S50 Understanding Heroin Overdose: A Study of the Acute Respiratory Depressant Effects of Injected Pharmaceutical Heroin. Thorax 2015. [DOI: 10.1136/thoraxjnl-2015-207770.56] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Jolley CJ, Bell J, Rafferty GF, Moxham J, Strang J. Understanding Heroin Overdose: A Study of the Acute Respiratory Depressant Effects of Injected Pharmaceutical Heroin. PLoS One 2015; 10:e0140995. [PMID: 26495843 PMCID: PMC4619694 DOI: 10.1371/journal.pone.0140995] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 10/02/2015] [Indexed: 11/18/2022] Open
Abstract
Opioids are respiratory depressants and heroin/opioid overdose is a major contributor to the excess mortality of heroin addicts. The individual and situational variability of respiratory depression caused by intravenous heroin is poorly understood. This study used advanced respiratory monitoring to follow the time course and severity of acute opioid-induced respiratory depression. 10 patients (9/10 with chronic airflow obstruction) undergoing supervised injectable opioid treatment for heroin addiction received their usual prescribed dose of injectable opioid (diamorphine or methadone) (IOT), and their usual prescribed dose of oral opioid (methadone or sustained release oral morphine) after 30 minutes. The main outcome measures were pulse oximetry (SpO2%), end-tidal CO2% (ETCO2%) and neural respiratory drive (NRD) (quantified using parasternal intercostal muscle electromyography). Significant respiratory depression was defined as absence of inspiratory airflow >10s, SpO2% < 90% for >10s and ETCO2% per breath >6.5%. Increases in ETCO2% indicated significant respiratory depression following IOT in 8/10 patients at 30 minutes. In contrast, SpO2% indicated significant respiratory depression in only 4/10 patients, with small absolute changes in SpO2% at 30 minutes. A decline in NRD from baseline to 30 minutes post IOT was also observed, but was not statistically significant. Baseline NRD and opioid-induced drop in SpO2% were inversely related. We conclude that significant acute respiratory depression is commonly induced by opioid drugs prescribed to treat opioid addiction. Hypoventilation is reliably detected by capnography, but not by SpO2% alone. Chronic suppression of NRD in the presence of underlying lung disease may be a risk factor for acute opioid-induced respiratory depression.
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Affiliation(s)
- Caroline J. Jolley
- Division of Asthma, Allergy and Lung Biology, Faculty of Life Sciences and Medicine, King’s College London, King’s Health Partners, Denmark Hill, London, United Kingdom
| | - James Bell
- National Addiction Centre, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, King’s Health Partners, Denmark Hill, London, United Kingdom
- Addictions Services, South London & Maudsley NHS Foundation Trust, King’s Health Partners, Denmark Hill, London, United Kingdom
| | - Gerrard F. Rafferty
- Division of Asthma, Allergy and Lung Biology, Faculty of Life Sciences and Medicine, King’s College London, King’s Health Partners, Denmark Hill, London, United Kingdom
| | - John Moxham
- Division of Asthma, Allergy and Lung Biology, Faculty of Life Sciences and Medicine, King’s College London, King’s Health Partners, Denmark Hill, London, United Kingdom
| | - John Strang
- National Addiction Centre, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, King’s Health Partners, Denmark Hill, London, United Kingdom
- Addictions Services, South London & Maudsley NHS Foundation Trust, King’s Health Partners, Denmark Hill, London, United Kingdom
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46
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Kassim Z, Moxham J, Davenport M, Nicolaides K, Greenough A, Rafferty GF. Respiratory muscle strength in healthy infants and those with surgically correctable anomalies. Pediatr Pulmonol 2015; 50:71-8. [PMID: 24574153 DOI: 10.1002/ppul.23007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 12/10/2013] [Accepted: 01/14/2014] [Indexed: 12/11/2022]
Abstract
Assessment of respiratory muscle strength provides important diagnostic and prognostic information. Normative data in healthy, term infants is, however, limited. Surgically correctable birth defects, congenital diaphragmatic hernia (CDH) and abdominal wall defects (AWD), commonly have impaired diaphragm function. The study aims were to obtain normative data for respiratory muscle strength in healthy, term born infants at birth and at 6 weeks postnatal age (PNA) and to investigate the influence of growth and maturation on inspiratory muscle strength in CDH/AWD infants. Maximal inspiratory (cPimax) and expiratory (cPemax) pressures during crying were measured at birth in 67 healthy, term born infants (mean (SD) gestational age (GA) 39.4 (1.7) weeks) and reassessed in 27 at 6 weeks PNA. cPimax and functional residual capacity (FRC) (22.3 (4.2) ml/kg) were also measured in 23 infants with AWD/CDH (mean (SD) GA 36.9 (2.1) weeks) and reassessed in 16 at median (range) 6.5 (1.5-15) months PNA. In healthy infants, mean (SD) cPimax was 88.8 (19.33) cmH2 O and cPemax 61.8 (13.5) cmH2 O at birth, increasing significantly at followup to 100.9 (15.2) cmH2 O (P < 0.05) and 82.6 (19.4) cmH2 O (P < 0.001) respectively. Mean (SD) cPimax was significantly lower (47.5 (22.4) cmH2 O, P < 0.0001) in AWD/CDH infants compared to healthy infants at birth but had increased significantly to 88.1 (27.6) cmH2 O (P < 0.0001) at followup which correlated significantly with increases in FRC (r(2) = 0.33, P = 0.0263). Infants with AWD and CDH have significantly reduced inspiratory muscle strength compared to healthy term born infants but strength increases markedly in early life.
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Affiliation(s)
- Zainab Kassim
- King's College London, Division of Asthma Allergy and Lung Biology, Department of Child Health and Kings College Hospital NHS Foundation, London, UK
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Bhat P, Patel DS, Hannam S, Rafferty GF, Peacock JL, Milner AD, Greenough A. Crossover study of proportional assist versus assist control ventilation. Arch Dis Child Fetal Neonatal Ed 2015; 100:F35-8. [PMID: 25512446 DOI: 10.1136/archdischild-2013-305817] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVE To test the hypothesis that in very prematurely born infants remaining ventilated beyond the first week, proportional assist ventilation (PAV) compared with assist control ventilation (ACV) would be associated with reduced work of breathing, increased respiratory muscle strength and less ventilator-infant asynchrony which would be associated with improved oxygenation. DESIGN Randomised crossover study. SETTING Tertiary neonatal unit. PATIENTS 12 infants with a median gestational age of 25 (range 24-26) weeks were studied at a median of 43 (range 8-86) days. INTERVENTIONS Infants were studied for 1 h each on PAV and ACV in random order. MAIN OUTCOME MEASURES At the end of each hour, the work of breathing (assessed by measuring the diaphragmatic pressure time product), thoracoabdominal asynchrony and respiratory muscle strength (maximal inspiratory pressure, maximal expiratory pressure (Pemax) and maximal transdiaphragmatic pressure (Pdimax)) were assessed. Blood gas analysis was performed and the oxygenation index (OI) calculated. RESULTS After 1 h on PAV compared with 1 h on ACV, the median OI (5.55 (range 5-11) vs 10.10 (range 7-16), p=0.002) and PTP levels were lower (217 (range 59-556) cm H2O.s/min vs 309 (range 55-544) cm H2O.s/min, p=0.005), while Pdimax (44.26 (range 21-66) cm H2O vs 37.9 (range 19-45) cm H2O, p=0.002) and Pemax (25.6 (range 6.5-42) cm H2O vs 15.9 (range 3-35) cm H2O levels p=0.010) were higher. CONCLUSIONS These results suggest that PAV compared with ACV may have physiological advantages for prematurely born infants who remain ventilated after the first week after birth.
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Affiliation(s)
- Prashanth Bhat
- Division of Asthma, Allergy and Lung Biology, MRC Centre for Allergic Mechanisms in Asthma, King's College London, London, UK
| | - Deena-Shefali Patel
- Division of Asthma, Allergy and Lung Biology, MRC Centre for Allergic Mechanisms in Asthma, King's College London, London, UK
| | - Simon Hannam
- Division of Asthma, Allergy and Lung Biology, MRC Centre for Allergic Mechanisms in Asthma, King's College London, London, UK
| | - Gerrard F Rafferty
- Division of Asthma, Allergy and Lung Biology, MRC Centre for Allergic Mechanisms in Asthma, King's College London, London, UK
| | - Janet L Peacock
- Division of Health and Social Care Research, King's College London, London, UK NIHR Biomedical Research Centre at Guy's and St Thomas' NHS Foundation Trust and King's College London, London, UK
| | - Anthony D Milner
- Division of Asthma, Allergy and Lung Biology, MRC Centre for Allergic Mechanisms in Asthma, King's College London, London, UK
| | - Anne Greenough
- Division of Asthma, Allergy and Lung Biology, MRC Centre for Allergic Mechanisms in Asthma, King's College London, London, UK NIHR Biomedical Research Centre at Guy's and St Thomas' NHS Foundation Trust and King's College London, London, UK
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Drysdale SB, Lo J, Prendergast M, Alcazar M, Wilson T, Zuckerman M, Smith M, Broughton S, Rafferty GF, Peacock JL, Johnston SL, Greenough A. Lung function of preterm infants before and after viral infections. Eur J Pediatr 2014; 173:1497-504. [PMID: 24898777 DOI: 10.1007/s00431-014-2343-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 05/20/2014] [Accepted: 05/21/2014] [Indexed: 11/28/2022]
Abstract
UNLABELLED Our aim was to determine whether viral lower respiratory tract infections (LRTIs) adversely affect prematurely born infants' lung function at follow up. Seventy infants, median gestational age 34 (range, 24-35) weeks were prospectively followed; 32 had an RSV (n = 14) or another respiratory viral (n = 18) LRTI (viral LRTI group) and 38 had no LRTI (no LRTI group). Six of the viral LRTI and five of the no LRTI group had been hospitalised. Nasopharyngeal aspirates (NPAs) obtained whenever the infants had an LRTI. Lung function (functional residual capacity [FRCHe], compliance [Crs] and resistance [Rrs] of the respiratory system) was measured at 36 weeks postmenstrual age (PMA) and 1 year corrected. At 1 year, lung volume (FRCpleth) and airways resistance (Raw) were also assessed. There were no significant differences in the lung function of the two groups at 36 weeks PMA but at 1 year, the viral LRTI compared to the no LRTI group had a higher mean Raw (23 versus 17 cm H2O/l/s, p = 0.0068), the differences remained significant after adjustment. CONCLUSION These results suggest viral LRTIs, regardless of whether hospitalisation is required, adversely affect prematurely born infants' airway resistance at follow up.
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Affiliation(s)
- Simon B Drysdale
- Division of Asthma, Allergy and Lung Biology, King's College London, London, UK,
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Abstract
The aim of this study was to test the hypothesis that neural respiratory drive, measured using diaphragm electromyogram (EMGdi) activity expressed as a percentage of maximum (EMGdi%max), is closely related to breathlessness in chronic obstructive pulmonary disease. We also investigated whether neuroventilatory uncoupling contributes significantly to breathlessness intensity over an awareness of levels of neural respiratory drive alone. EMGdi and ventilation were measured continuously during incremental cycle and treadmill exercise in 12 chronic obstructive pulmonary disease patients (forced expiratory volume in 1 s±sd was 38.7±14.5 % pred). EMGdi was expressed both as EMGdi%max and relative to tidal volume expressed as a percentage of predicted vital capacity to quantify neuroventilatory uncoupling. EMGdi%max was closely related to Borg breathlessness in both cycle (r=0.98, p=0.0001) and treadmill exercise (r=0.94, p=0.005), this relationship being similar to that between neuroventilatory uncoupling and breathlessness (cycling r=0.94, p=0.005; treadmill r=0.91, p=0.01). The relationship between breathlessness and ventilation was poor when expansion of tidal volume became limited. In chronic obstructive pulmonary disease the intensity of exertional breathlessness is closely related to EMGdi%max. These data suggest that breathlessness in chronic obstructive pulmonary disease can be largely explained by an awareness of levels of neural respiratory drive, rather than the degree of neuroventilatory uncoupling. EMGdi%max could provide a useful physiological biomarker for breathlessness in chronic obstructive pulmonary disease.
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Affiliation(s)
- Caroline J Jolley
- King's College London Division of Asthma, Allergy and Lung Biology, King's College London School of Medicine, King's Health Partners, London, UK.
| | - Yuanming M Luo
- State Key Laboratory of Respiratory Disease, Guangzhou Medical College, Guangzhou, China
| | - Joerg Steier
- King's College London Division of Asthma, Allergy and Lung Biology, King's College London School of Medicine, King's Health Partners, London, UK. Lane Fox Respiratory Unit/Sleep Disorders Centre, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Gerrard F Rafferty
- King's College London Division of Asthma, Allergy and Lung Biology, King's College London School of Medicine, King's Health Partners, London, UK
| | - Michael I Polkey
- NIHR Respiratory Biomedical Research Unit, Royal Brompton and Harefield NHS Foundation Trust and Imperial College, London, UK
| | - John Moxham
- King's College London Division of Asthma, Allergy and Lung Biology, King's College London School of Medicine, King's Health Partners, London, UK
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Campbell R, Gordon P, Ward K, Reilly C, Scott DL, Rafferty GF. Nonvolitional assessment of muscle endurance in idiopathic inflammatory myopathies: There is no relationship between patient-reported fatigue and muscle fatigability. Muscle Nerve 2014; 50:401-6. [DOI: 10.1002/mus.24148] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 11/10/2013] [Accepted: 12/02/2013] [Indexed: 11/08/2022]
Affiliation(s)
- Richard Campbell
- Department of Academic Rheumatology; King's College London, Weston Education Centre; Cutcombe Road, London SE5 9RJ UK
| | - Patrick Gordon
- Department of Academic Rheumatology; King's College London, Weston Education Centre; Cutcombe Road, London SE5 9RJ UK
| | - Katie Ward
- Department of Respiratory Medicine; Kings College; London UK
| | - Charles Reilly
- Department of Respiratory Medicine; Kings College; London UK
| | - David L. Scott
- Department of Academic Rheumatology; King's College London, Weston Education Centre; Cutcombe Road, London SE5 9RJ UK
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