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Bradley JM, Ferguson K, Bailey A, O’Neill K, McLeese RH, Hill AT, Loebinger MR, Carroll M, Chalmers JD, Gatheral T, Johnson C, De Soyza A, Hurst JR, Downey DG, Elborn JS. Clinimetric Properties of Outcome Measures in Bronchiectasis. Ann Am Thorac Soc 2023; 20:648-659. [PMID: 36548542 PMCID: PMC10174126 DOI: 10.1513/annalsats.202206-493oc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 12/22/2022] [Indexed: 12/24/2022] Open
Abstract
Rationale: There is a lack of outcome measures with robust clinimetric properties in bronchiectasis. Objectives: To determine the clinimetric properties (reliability over 1 year during clinical stability and responsiveness over the course of antibiotics for pulmonary exacerbation) of objective and patient-reported outcome measures. Methods: This multicenter cohort study included adults with bronchiectasis from seven hospitals in the United Kingdom. Participants attended four visits, 4 months apart over 1 year while clinically stable and at the beginning and end of exacerbation and completed lung function (spirometry and multiple breath washout), provided a blood sample for C-reactive protein (CRP) measurement, and completed health-related quality of life (HRQoL) questionnaires (Quality of Life-Bronchiectasis, St. George's Respiratory Questionnaire, and EuroQoL 5-Dimensions 5-Levels). Results: Participants (n = 132) had a mean (standard deviation) age of 66 (11) years, and 64% were female. Lung function parameters (forced expiratory volume in one second [FEV1], standard lung clearance index [LCI2.5]) were reliable over time [coefficient of variation (CV): <10%]). Regarding responsiveness, FEV1 demonstrated better properties than LCI2.5; therefore, a clear justification for the use of LCI2.5 in future trials is needed. CRP was less reliable (CV > 20%) over time than FEV1 and LCI2.5, and whereas CRP had a large mean change between the start and end of an exacerbation, this may have been driven by a small number of patients having a large change in CRP. Reliability of HRQoL questionnaires and questionnaire domains ranged from acceptable (CV: 20-30%) to good (CV: 10-20%), and HRQoL were responsive to treatment of exacerbations. Considering the specific questionnaire domain relevant to the intervention and its associated clinimetric properties is important. Additional statistics will support future power and/or sample size analysis. Conclusions: This information on the clinimetric properties of lung function parameters, CRP, and HRQoL parameters should be used to inform the choice of outcome measures used in future bronchiectasis trials.
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Affiliation(s)
- Judy M. Bradley
- Wellcome-Wolfson Institute for Experimental Medicine and
- Wellcome Trust-Wolfson Northern Ireland Clinical Research Facility, Queen’s University Belfast, Belfast, United Kingdom
| | - Kathryn Ferguson
- Northern Ireland Clinical Research Network, Belfast Health and Social Care Trust, Belfast, United Kingdom
| | | | | | - Rebecca H. McLeese
- Wellcome Trust-Wolfson Northern Ireland Clinical Research Facility, Queen’s University Belfast, Belfast, United Kingdom
| | - Adam T. Hill
- Royal Infirmary of Edinburgh, Edinburgh, United Kingdom
- Department of Respiratory Medicine, Centre for Inflammation Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Michael R. Loebinger
- Host Defence Unit, Royal Brompton Hospital, Imperial College London, London, United Kingdom
| | - Mary Carroll
- University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom
| | | | - Timothy Gatheral
- Department of Respiratory Medicine, University Hospitals of Morecambe Bay NHS Foundation Trust, Kendal, United Kingdom
| | - Christopher Johnson
- Cambridge Centre for Lung Infection, Papworth Hospital, Cambridge, United Kingdom
| | - Anthony De Soyza
- Population and Health Science Institute, National Institute of Health Research Biomedical Research Centre on Ageing, Newcastle University, Newcastle, United Kingdom; and
| | - John R. Hurst
- Department of Respiratory Medicine, University College London, London, United Kingdom
| | | | - J. Stuart Elborn
- Wellcome-Wolfson Institute for Experimental Medicine and
- Host Defence Unit, Royal Brompton Hospital, Imperial College London, London, United Kingdom
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Darquenne C, Theilmann RJ, Fine JM, Verbanck SAB. Nitrogen-based lung clearance index: a valid physiological biomarker for the clinic. J Appl Physiol (1985) 2022; 132:1290-1296. [PMID: 35446597 PMCID: PMC9126222 DOI: 10.1152/japplphysiol.00511.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Multiple breath washout (MBW) testing is increasingly used as a physiological measurement in the clinic, due in part to the availability of commercial equipment and reference values for MBW indices. Commercial N2 washout devices are usually based on indirect measurement of N2 concentration (CN2), by directly measuring either molar mass and O2 and CO2, or molar mass and CO2. We aim to elucidate the role of two potential pitfalls associated with N2-MBW testing that could override its physiological content: indirect N2 measurement and blood-solubility of N2. We performed MBW in 12 healthy adult subjects using a commercial device (MBWindirect) with simultaneous direct gas concentration measurements by mass spectrometry (MBWdirect) and compared CN2 between MBWdirect and MBWindirect. We also measured argon concentration during the same washouts to verify the maximal effect gas solubility can have on N2-based functional residual capacity (FRC) and lung clearance index (LCI). Continuous N2 concentration traces were very similar for MBWindirect and MBWdirect, resulting in comparable breath-by-breath washout plots of expired concentration and in no significant differences in FRCN2, LCIN2, Scond, and Sacin between the two methods. Argon washouts were slightly slower than N2 washouts, as expected for a less diffusive and more soluble gas. Finally, comparison between LCIN2 and LCIAr indicates that the maximum impact from blood-tissue represents less than half a LCI unit in normal subjects. In conclusion, we have demonstrated by direct measurement of N2 and twice as soluble argon, that indirect N2 measurement can be safely used as a meaningful physiological measurement.NEW & NOTEWORTHY The physiological content of N2 multibreath washout testing has been questioned due to N2 indirect measurement accuracy and N2 blood solubility. With direct measurement of N2 and twice as soluble argon, we show that these effects are largely outweighed by ease of use.
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Affiliation(s)
- Chantal Darquenne
- Department of Medicine, University of California, San Diego, California
| | | | - Janelle M Fine
- Department of Medicine, University of California, San Diego, California
| | - Sylvia A B Verbanck
- Respiratory Division, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium
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Sandvik RM, Gustafsson PM, Lindblad A, Buchvald F, Olesen HV, Olsen JH, Skov M, Schmidt MN, Thellefsen MR, Robinson PD, Rubak S, Pressler T, Nielsen KG. Contemporary N 2 and SF 6 multiple breath washout in infants and toddlers with cystic fibrosis. Pediatr Pulmonol 2022; 57:945-955. [PMID: 35029068 DOI: 10.1002/ppul.25830] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 12/20/2021] [Accepted: 01/12/2022] [Indexed: 11/10/2022]
Abstract
INTRODUCTION Multiple breath washout (MBW) is used for early detection of cystic fibrosis (CF) lung disease, with SF6 MBW commonly viewed as the reference method. The use of N2 MBW in infants and toddlers has been questioned for technical and physiological reasons, but a new correction of the N2 signal has minimized the technical part. The present study aimed to assess the remaining differences and the contributing mechanisms for the differences between SF6 and N2 MBW,corrected-such as tidal volume reduction during N2 washout with pure O2 . METHOD This was a longitudinal multicenter cohort study. SF6 MBW and N2 MBW were performed prospectively at three CF centers in the same visits on 154 test occasions across 62 children with CF (mean age: 22.7 months). Offline analysis using identical algorithms to the commercially available program provided outcomes of N2,original and N2,corrected for comparison with SF6 MBW. RESULTS Mean functional residual capacity, FRCN2,corrected was 14.3% lower than FRCN2, original , and 1.0% different from FRCSF6 . Lung clearance index, LCIN2,corrected was 25.2% lower than LCIN2,original , and 7.3% higher than LCISF6 . Mean (SD) tidal volume decreased significantly during N2 MBWcorrected , compared to SF6 MBW (-13.1 ml [-30.7; 4.6], p < 0.0001, equal to -12.0% [-25.7; 1.73]), but this tidal volume reduction did not correlate to the differences between LCIN2,corrected and LCISF6 . The absolute differences in LCI increased significantly with higher LCISF6 (0.63/LCISF6 ) and (0.23/LCISF6 ), respectively, for N2,original and N2,corrected , but the relative differences were stable across disease severity for N2,corrected , but not for N2,original . CONCLUSION Only minor residual differences between FRCN2,corrected and FRCSF6 remained to show that the two methods measure gas volumes very similar in this age range. Small differences in LCI were found. Tidal volume reduction during N2 MBW did not affect differences. The corrected N2 MBW can now be used with confidence in young children with CF, although not interchangeably with SF6 .
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Affiliation(s)
- Rikke M Sandvik
- Danish Paediatric Pulmonary Service, CF Centre Copenhagen, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Per M Gustafsson
- Department of Paediatrics, Central Hospital, Skövde, Sweden.,Institute of Clinical Science, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Anders Lindblad
- Institute of Clinical Science, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Department of Pediatrics, CF Center, Queen Silvia Children's Hospital, Gothenburg, Sweden
| | - Frederik Buchvald
- Danish Paediatric Pulmonary Service, CF Centre Copenhagen, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Hanne V Olesen
- Department of Paediatrics and Adolescent Medicine, Danish Center of Pediatric Pulmonology and Allergology, Cystic Fibrosis Centre Aarhus, Aarhus University Hospital, Aarhus, Denmark
| | - Jørgen H Olsen
- Department of Paediatrics and Adolescent Medicine, Danish Center of Pediatric Pulmonology and Allergology, Cystic Fibrosis Centre Aarhus, Aarhus University Hospital, Aarhus, Denmark
| | - Marianne Skov
- Danish Paediatric Pulmonary Service, CF Centre Copenhagen, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Marika N Schmidt
- Danish Paediatric Pulmonary Service, CF Centre Copenhagen, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Mette R Thellefsen
- Danish Paediatric Pulmonary Service, CF Centre Copenhagen, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Paul D Robinson
- Department of Respiratory Medicine, The Children's Hospital at Westmead, Sydney, New South Wales, Australia
| | - Sune Rubak
- Department of Paediatrics and Adolescent Medicine, Danish Center of Pediatric Pulmonology and Allergology, Cystic Fibrosis Centre Aarhus, Aarhus University Hospital, Aarhus, Denmark
| | - Tacjana Pressler
- Danish Paediatric Pulmonary Service, CF Centre Copenhagen, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Kim G Nielsen
- Danish Paediatric Pulmonary Service, CF Centre Copenhagen, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.,Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
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Wyler F, Oestreich MAH, Frauchiger BS, Ramsey KA, Latzin PT. Correction of sensor crosstalk error in Exhalyzer D multiple-breath washout device significantly impacts outcomes in children with cystic fibrosis. J Appl Physiol (1985) 2021; 131:1148-1156. [PMID: 34351818 DOI: 10.1152/japplphysiol.00338.2021] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
RATIONALE Nitrogen multiple-breath washout is an established technique to assess functional residual capacity and ventilation inhomogeneity in the lung. Accurate measurement of gas concentrations is essential for the appropriate calculation of clinical outcomes. OBJECTIVES We investigated the accuracy of oxygen and carbon dioxide gas sensor measurements used for the indirect calculation of nitrogen concentration in a commercial multiple-breath washout device (Exhalyzer D, Eco Medics AG, Duernten, Switzerland) and its impact on functional residual capacity and lung clearance index. METHODS High precision calibration gas mixtures and mass spectrometry were used to evaluate sensor output. We assessed the impact of corrected signal processing on multiple-breath washout outcomes in a dataset of healthy children and children with cystic fibrosis using custom analysis software. RESULTS We found inadequate correction for the cross sensitivity of the oxygen and carbon dioxide sensors in the Exhalyzer D device. This results in an overestimation of expired nitrogen concentration, and consequently multiple-breath washout outcomes. Breath-by-breath correction of this error reduced the mean (SD) cumulative expired volume by 19.6 (5.0)%, functional residual capacity by 8.9 (2.2)%, and lung clearance index by 11.9 (4.0)%. It also substantially reduced the level of the tissue nitrogen signal at the end of measurements. CONCLUSIONS Inadequate correction for cross sensitivity in the oxygen and carbon dioxide gas sensors of the Exhalyzer D device leads to an overestimation of functional residual capacity and lung clearance index. Correction of this error is possible and could be applied by re-analyzing the measurements in an updated software version.
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Affiliation(s)
- Florian Wyler
- Division of Paediatric Respiratory Medicine and Allergology, Department of Paediatrics, Inselspital, Bern University Hospital, University of Bern, Switzerland
| | - Marc-Alexander H Oestreich
- Division of Paediatric Respiratory Medicine and Allergology, Department of Paediatrics, Inselspital, Bern University Hospital, University of Bern, Switzerland.,Graduate School for Health Sciences, University of Bern, Switzerland
| | - Bettina Sarah Frauchiger
- Division of Paediatric Respiratory Medicine and Allergology, Department of Paediatrics, Inselspital, Bern University Hospital, University of Bern, Switzerland.,Graduate School of Cellular and Biomedical Sciences, University of Bern, Switzerland
| | - Kathryn A Ramsey
- Division of Paediatric Respiratory Medicine and Allergology, Department of Paediatrics, Inselspital, Bern University Hospital, University of Bern, Switzerland
| | - Philipp T Latzin
- Division of Paediatric Respiratory Medicine and Allergology, Department of Paediatrics, Inselspital, Bern University Hospital, University of Bern, Switzerland
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Sandvik R, Gustafsson PM, Lindblad A, Robinson PD, Nielsen K. Improved agreement between N 2 and SF 6 multiple-breath washout in healthy infants and toddlers with improved EXHALYZER D sensor performance. J Appl Physiol (1985) 2021; 131:107-118. [PMID: 34043468 DOI: 10.1152/japplphysiol.00129.2021] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Recent studies indicate limited utility of nitrogen multiple-breath washout (N2MBW) in infancy and advocate for using sulfur hexafluoride (SF6) MBW in this age-group. Modern N2MBW systems, such as EXHALYZER D (ECO MEDICS AG, Duernten, Switzerland), use O2 and CO2 sensors to calculate N2 concentrations (in principle, N2% = 100 - CO2% - O2%). High O2 and CO2 concentrations have now been shown to significantly suppress signal output from the other sensor, raising apparent N2 concentrations. We examined whether improved EXHALYZER D N2 signal, accomplished after thorough examination of this CO2 and O2 interaction on gas sensors and its correction, leads to better agreement between N2MBW and SF6MBW in healthy infants and toddlers. Within the same session, 52 healthy children aged 1-36 mo [mean = 1.30 (SD = 0.72) yr] completed SF6MBW and N2MBW recordings (EXHALYZER D, SPIROWARE version 3.2.1) during supine quiet sleep. SF6 and N2 SPIROWARE files were reanalyzed offline with in-house software using identical algorithms as in SPIROWARE with or without application of the new correction factors for N2MBW provided by ECO MEDICS AG. Applying the improved N2 signal significantly reduced mean [95% confidence interval (CI)] differences between N2MBW and SF6MBW recorded functional residual capacity (FRC) and lung clearance index (LCI): for FRC, from 26.1 (21.0, 31.2) mL, P < 0.0001, to 1.18 (-2.3, 4.5) mL, P = 0.5, and for LCI, from 1.86 (1.68, 2.02), P < 0.001, to 0.44 (0.33, 0.55), P < 0.001. Correction of N2 signal for CO2 and O2 interactions on gas sensors resulted in markedly closer agreement between N2MBW and SF6MBW outcomes in healthy infants and toddlers.NEW & NOTEWORTHY Modern nitrogen multiple-breath washout (N2MBW) systems such as EXHALYZER D use O2 and CO2 sensors to calculate N2 concentrations. New corrections for interactions between high O2 and CO2 concentrations on the gas sensors now provide accurate N2 signals. The correct N2 signal led to much improved agreement between N2MBW and sulfur hexafluoride (SF6) MBW functional residual capacity (FRC) and lung clearance index (LCI) in 52 sleeping healthy infants and toddlers, suggesting a role for N2MBW in this age-group.
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Affiliation(s)
- Rikke Sandvik
- Danish Paediatric Pulmonary Service, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Per M Gustafsson
- Department of Paediatrics, Central Hospital, Skövde, Sweden.,Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Anders Lindblad
- Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Gothenburg CF Centre, Queen Silvia Children's Hospital, Gothenburg, Sweden
| | - Paul D Robinson
- Department of Respiratory Medicine, The Children's Hospital at Westmead, Westmead, New South Wales, Australia.,The Discipline of Paediatrics and Child Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Kim Nielsen
- Danish Paediatric Pulmonary Service, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.,Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
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Right Ventricular Air Embolus. A Physiologic Approach to Management. Ann Am Thorac Soc 2021; 17:892-894. [PMID: 32609027 DOI: 10.1513/annalsats.201911-824cc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Mondéjar-López P, Horsley A, Ratjen F, Bertolo S, de Vicente H, Asensio de la Cruz Ò. A multimodal approach to detect and monitor early lung disease in cystic fibrosis. Expert Rev Respir Med 2021; 15:761-772. [PMID: 33843417 DOI: 10.1080/17476348.2021.1908131] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Introduction: In the early stages, lung involvement in cystic fibrosis (CF) can be silent, with disease progression occurring in the absence of clinical symptoms. Irreversible airway damage is present in the early stages of disease; however, reliable biomarkers of early damage due to inflammation and infection that are universally applicable in day-to-day patient management have yet to be identified.Areas covered: At present, the main methods of detecting and monitoring early lung disease in CF are the lung clearance index (LCI), computed tomography (CT), and magnetic resonance imaging (MRI). LCI can be used to detect patients who may require more intense monitoring, identify exacerbations, and monitor responses to new interventions. High-resolution CT detects structural alterations in the lungs of CF patients with the best resolution of current imaging techniques. MRI is a radiation-free imaging alternative that provides both morphological and functional information. The role of MRI for short-term follow-up and pulmonary exacerbations is currently being investigated.Expert opinion: The roles of LCI and MRI are expected to expand considerably over the next few years. Meanwhile, closer collaboration between pulmonology and radiology specialties is an important goal toward improving care and optimizing outcomes in young patients with CF.
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Affiliation(s)
- Pedro Mondéjar-López
- Pediatric Pulmonologist, Pediatric Pulmonology and Cystic Fibrosis Unit, University Hospital Virgen de la Arrixaca, Murcia, Spain
| | - Alexander Horsley
- Honorary Consultant, Respiratory Research Group, Division of Infection, Immunity & Respiratory Medicine, University of Manchester, Manchester, UK
| | - Felix Ratjen
- Head, Division of Respiratory Medicine, Department of Pediatrics, Translational Medicine, Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Silvia Bertolo
- Radiologist, Department of Radiology, Ca'Foncello Regional Hospital, Treviso, Italy
| | | | - Òscar Asensio de la Cruz
- Pediatric Pulmonologist, Pediatric Unit, University Hospital Parc Taulí de Sabadell, Sabadell, Spain
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Hall GL, Filipow N, Ruppel G, Okitika T, Thompson B, Kirkby J, Steenbruggen I, Cooper BG, Stanojevic S. Official ERS technical standard: Global Lung Function Initiative reference values for static lung volumes in individuals of European ancestry. Eur Respir J 2021; 57:57/3/2000289. [PMID: 33707167 DOI: 10.1183/13993003.00289-2020] [Citation(s) in RCA: 129] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 07/27/2020] [Indexed: 11/05/2022]
Abstract
BACKGROUND Measurement of lung volumes across the life course is critical to the diagnosis and management of lung disease. The aim of the study was to use the Global Lung Function Initiative methodology to develop all-age multi-ethnic reference equations for lung volume indices determined using body plethysmography and gas dilution techniques. METHODS Static lung volume data from body plethysmography and gas dilution techniques from individual, healthy participants were collated. Reference equations were derived using the LMS (lambda-mu-sigma) method and the generalised additive models of location shape and scale programme in R. The impact of measurement technique, equipment type and being overweight or obese on the derived lung volume reference ranges was assessed. RESULTS Data from 17 centres were submitted and reference equations were derived from 7190 observations from participants of European ancestry between the ages of 5 and 80 years. Data from non-European ancestry populations were insufficient to develop multi-ethnic equations. Measurements of functional residual capacity (FRC) collected using plethysmography and dilution techniques showed physiologically insignificant differences and were combined. Sex-specific reference equations including height and age were developed for total lung capacity (TLC), FRC, residual volume (RV), inspiratory capacity, vital capacity, expiratory reserve volume and RV/TLC. The derived equations were similar to previously published equations for FRC and TLC, with closer agreement during childhood and adolescence than in adulthood. CONCLUSIONS Global Lung Function Initiative reference equations for lung volumes provide a generalisable standard for reporting and interpretation of lung volumes measurements in individuals of European ancestry.
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Affiliation(s)
- Graham L Hall
- Children's Lung Health, Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth, Australia .,School of Physiotherapy and Exercise Science, Curtin University, Perth, Australia
| | - Nicole Filipow
- Translational Medicine, Hospital for Sick Children, Toronto, ON, Canada
| | - Gregg Ruppel
- Pulmonary, Critical Care and Sleep Medicine, Saint Louis University School of Medicine, St Louis, MO, USA
| | - Tolu Okitika
- Children's Lung Health, Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth, Australia
| | - Bruce Thompson
- School of Health Sciences, Swinburne University of Technology, Melbourne, Australia
| | - Jane Kirkby
- Respiratory Medicine, Sheffield Children's Hospital NHS Foundation Trust, Sheffield, UK
| | | | - Brendan G Cooper
- Lung Function and Sleep, University Hospital Birmingham and Institute of Clinical Sciences, University of Birmingham, Birmingham, UK
| | - Sanja Stanojevic
- Translational Medicine, Hospital for Sick Children, Toronto, ON, Canada
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Trinkmann F, Maros M, Roth K, Hermanns A, Schäfer J, Gawlitza J, Saur J, Akin I, Borggrefe M, Herth FJF, Ganslandt T. Multiple breath washout (MBW) testing using sulfur hexafluoride: reference values and influence of anthropometric parameters. Thorax 2021; 76:380-386. [PMID: 33593931 DOI: 10.1136/thoraxjnl-2020-214717] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 01/07/2021] [Accepted: 01/20/2021] [Indexed: 11/04/2022]
Abstract
BACKGROUND Multiple breath washout (MBW) using sulfur hexafluoride (SF6) has the potential to reveal ventilation heterogeneity which is frequent in patients with obstructive lung disease and associated small airway dysfunction. However, reference data are scarce for this technique and mostly restricted to younger cohorts. We therefore set out to evaluate the influence of anthropometric parameters on SF6-MBW reference values in pulmonary healthy adults. METHODS We evaluated cross-sectional data from 100 pulmonary healthy never-smokers and smokers (mean 51 (SD 20), range 20-88 years). Lung clearance index (LCI), acinar (Sacin) and conductive (Scond) ventilation heterogeneity were derived from triplicate SF6-MBW measurements. Global ventilation heterogeneity was calculated for the 2.5% (LCI2.5) and 5% (LCI5) stopping points. Upper limit of normal (ULN) was defined as the 95th percentile. RESULTS Age was the only meaningful parameter influencing SF6-MBW parameters, explaining 47% (CI 33% to 59%) of the variance in LCI, 32% (CI 18% to 47%) in Sacin and 10% (CI 2% to 22%) in Scond. Mean LCI increases from 6.3 (ULN 7.4) to 8.8 (ULN 9.9) in subjects between 20 and 90 years. Smoking accounted for 2% (CI 0% to 8%) of the variability in LCI, 4% (CI 0% to 13%) in Sacin and 3% (CI 0% to 13%) in Scond. CONCLUSION SF6-MBW outcome parameters showed an age-dependent increase from early adulthood to old age. The effect was most pronounced for global and acinar ventilation heterogeneity and smaller for conductive ventilation heterogeneity. No influence of height, weight and sex was seen. Reference values can now be provided for all important SF6-MBW outcome parameters over the whole age range. TRIAL REGISTRATION NUMBER NCT04099225.
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Affiliation(s)
- Frederik Trinkmann
- 1st Department of Medicine, University Medical Centre Mannheim, Mannheim, Baden-Württemberg, Germany .,Department of Pneumology and Critical Care Medicine, Thoraxklinik at University Hospital Heidelberg, Translational Lung Research Centre Heidelberg (TLRC), Member of German Centre for Lung Research (DZL), Heidelberg, Baden-Württemberg, Germany.,Department of Biomedical Informatics, Centre for Preventive Medicine & Digital Health Baden-Württemberg, University Medical Centre Mannheim, Mannheim, Germany
| | - Máté Maros
- Department of Biomedical Informatics, Centre for Preventive Medicine & Digital Health Baden-Württemberg, University Medical Centre Mannheim, Mannheim, Germany.,Department of Neuroradiology, University Medical Centre Mannheim, Mannheim, Germany
| | - Katharina Roth
- 1st Department of Medicine, University Medical Centre Mannheim, Mannheim, Baden-Württemberg, Germany
| | - Arne Hermanns
- 1st Department of Medicine, University Medical Centre Mannheim, Mannheim, Baden-Württemberg, Germany
| | - Julia Schäfer
- 1st Department of Medicine, University Medical Centre Mannheim, Mannheim, Baden-Württemberg, Germany
| | - Joshua Gawlitza
- Institute for Clinical Radiology and Nuclear Medicine, University Medical Centre Mannheim, Mannheim, Germany
| | - Joachim Saur
- 1st Department of Medicine, University Medical Centre Mannheim, Mannheim, Baden-Württemberg, Germany
| | - Ibrahim Akin
- 1st Department of Medicine, University Medical Centre Mannheim, Mannheim, Baden-Württemberg, Germany.,DZHK (German Centre for Cardiovascular Research), Mannheim, Germany
| | - Martin Borggrefe
- 1st Department of Medicine, University Medical Centre Mannheim, Mannheim, Baden-Württemberg, Germany.,DZHK (German Centre for Cardiovascular Research), Mannheim, Germany
| | - Felix J F Herth
- Department of Pneumology and Critical Care Medicine, Thoraxklinik at University Hospital Heidelberg, Translational Lung Research Centre Heidelberg (TLRC), Member of German Centre for Lung Research (DZL), Heidelberg, Baden-Württemberg, Germany
| | - Thomas Ganslandt
- Department of Biomedical Informatics, Centre for Preventive Medicine & Digital Health Baden-Württemberg, University Medical Centre Mannheim, Mannheim, Germany
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Isaac SM, Jensen R, Anagnostopoulou P, Davies JC, Gappa M, Latzin P, Saunders C, Short C, Singer F, Stanojevic S, Zwitserloot A, Ratjen F. Evaluation of a multiple breath nitrogen washout system in children. Pediatr Pulmonol 2020; 55:2108-2114. [PMID: 32437013 DOI: 10.1002/ppul.24862] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 05/13/2020] [Indexed: 11/10/2022]
Abstract
INTRODUCTION The multiple breath nitrogen washout (MBW) test offers a sensitive measure of airway function. In this study we aim to (a) assess the validity of the EasyOne Pro LAB (MBWndd ) in an in vitro lung model, (b) assess the feasibility, repeatability, and reproducibility of MBWndd and (c) compare outcomes with the Exhalyzer D (MBWEM ) and body plethysmography. METHODS In vitro, functional residual capacity (FRC) measurements were assessed using a lung model under quasi-physiological conditions and compared to measured FRC. In vivo plethysmography and MBW were performed in a prospective study of children at two visits (n = 45 healthy; n = 41 cystic fibrosis [CF]). Bland-Altman plots were used to compare agreement between FRC and lung clearance index (LCI) measurements. RESULTS In vitro FRCndd measurements were repeatable but lung volumes were underestimated (mean relative difference -5.4% (limits of agreement [LA] -9.6%; -1.1%), 95% confidence interval (CI) -6.27; -4.45). In vivo, compared to plethysmography, FRCndd was consistently lower (-19.3% [-40.5; 1.9], 95% CI [-23.9; -14.7]), and showed a volume dependency. LCIndd values were also higher in children with smaller lung volumes. The within-test coefficient of variation of the FRCndd and LCIndd were 4.9% in health, and 5.6% and 6.9% in CF respectively. LCIndd was reproducible between-visits (mean relative difference [LA] -3.7% [-14.8, -7.5; 95% CI -6.6; -0.73] in health [n = 17] and 0.34% [-13.2, 22.8; 95% CI -5.0; 5.69] in CF [n = 23]). When calculated using the same algorithm, LCIndd was similar to LCIEM in health. CONCLUSIONS MBWndd measurements are feasible, repeatable, and reproducible, however, MBW-derived outcomes are not interchangeable with MBWEM .
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Affiliation(s)
- Sarah M Isaac
- Translational Medicine, Research Institute, Hospital for Sick Children, Toronto, Canada
| | - Renee Jensen
- Translational Medicine, Research Institute, Hospital for Sick Children, Toronto, Canada
| | - Pinelopi Anagnostopoulou
- Division of Respiratory Medicine, Department of Pediatrics, University Children's Hospital of Bern, University of Bern, Bern, Switzerland.,Institute of Anatomy, University of Bern, Bern, Switzerland
| | - Jane C Davies
- National Heart & Lung Institute, Imperial College London and Royal Brompton Hospital, London, UK
| | - Monika Gappa
- Evangelisches Krankenhaus Düsseldorf, Formerly Marienhospital Wesel, Germany
| | - Philipp Latzin
- Division of Respiratory Medicine, Department of Pediatrics, University Children's Hospital of Bern, University of Bern, Bern, Switzerland
| | - Clare Saunders
- National Heart & Lung Institute, Imperial College London and Royal Brompton Hospital, London, UK
| | - Christopher Short
- National Heart & Lung Institute, Imperial College London and Royal Brompton Hospital, London, UK
| | - Florian Singer
- Division of Respiratory Medicine, Department of Pediatrics, University Children's Hospital of Bern, University of Bern, Bern, Switzerland
| | - Sanja Stanojevic
- Translational Medicine, Research Institute, Hospital for Sick Children, Toronto, Canada.,University of Toronto, Toronto, Ontario, Canada
| | - Annelies Zwitserloot
- University Medical Centre Groningen, Beatrix Children's Hospital, The Netherlands
| | - Felix Ratjen
- Translational Medicine, Research Institute, Hospital for Sick Children, Toronto, Canada.,University of Toronto, Toronto, Ontario, Canada.,Division of Respiratory Medicine, Hospital for Sick Children, Toronto, Ontario, Canada
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11
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Horsley AR, Alrumuh A, Bianco B, Bayfield K, Tomlinson J, Jones A, Maitra A, Cunningham S, Smith J, Fullwood C, Pandyan A, Gilchrist FJ. Lung clearance index in healthy volunteers, measured using a novel portable system with a closed circuit wash-in. PLoS One 2020; 15:e0229300. [PMID: 32097445 PMCID: PMC7041809 DOI: 10.1371/journal.pone.0229300] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 02/03/2020] [Indexed: 11/18/2022] Open
Abstract
Introduction Lung clearance index (LCI) is a sensitive measure of early lung disease, but adoption into clinical practice has been slow. Challenges include the time taken to perform each test. We recently described a closed-circuit inert gas wash-in method that reduces overall testing time by decreasing the time to equilibration. The aim of this study was to define a normative range of LCI in healthy adults and children derived using this method. We were also interested in the feasibility of using this system to measure LCI in a community setting. Methods LCI was assessed in healthy volunteers at three hospital sites and in two local primary schools. Volunteers completed three washout repeats at a single visit using the closed circuit wash-in method (0.2% SF6 wash-in tracer gas to equilibrium, room air washout). Results 160 adult and paediatric subjects successfully completed LCI assessment (95%) (100 in hospital, 60 in primary schools). Median coefficient of variation was 3.4% for LCI repeats and 4.3% for FRC. Mean (SD) LCI for the analysis cohort (n = 53, age 5–39 years) was 6.10 (0.42), making the upper limit of normal LCI 6.8. There was no relationship between LCI and multiple demographic variables. Median (interquartile range) total test time was 18.7 (16.0–22.5) minutes. Conclusion The closed circuit method of LCI measurement can be successfully and reproducibly measured in healthy volunteers, including in out-of-hospital settings. Normal range appears stable up to 39 years. With few subjects older than 40 years, further work is required to define the normal limits above this age.
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Affiliation(s)
- Alex R. Horsley
- Division of Infection, Immunity & Respiratory Medicine, Faculty of Biology Medicine and Health, University of Manchester, Manchester, United Kingdom
- Manchester Adult CF Centre, Manchester University NHS Foundation Trust, Manchester, United Kingdom
- * E-mail:
| | - Amnah Alrumuh
- Institute of Applied Clinical Science, Keele University, Newcastle-under-Lyme, United Kingdom
- Royal Stoke University Hospital, University Hospitals of North Midlands NHS Trust, Stoke-on-Trent, United Kingdom
| | - Brooke Bianco
- Manchester Adult CF Centre, Manchester University NHS Foundation Trust, Manchester, United Kingdom
- NIHR Manchester Clinical Research Facility, Manchester, United Kingdom
| | - Katie Bayfield
- NIHR Manchester Clinical Research Facility, Manchester, United Kingdom
| | - Joanne Tomlinson
- Royal Stoke University Hospital, University Hospitals of North Midlands NHS Trust, Stoke-on-Trent, United Kingdom
| | - Andrew Jones
- Division of Infection, Immunity & Respiratory Medicine, Faculty of Biology Medicine and Health, University of Manchester, Manchester, United Kingdom
- Manchester Adult CF Centre, Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | - Anirban Maitra
- Royal Manchester Children’s Hospital, Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | - Steve Cunningham
- Centre for Inflammation Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Jaclyn Smith
- Division of Infection, Immunity & Respiratory Medicine, Faculty of Biology Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Catherine Fullwood
- Research and Innovation, Manchester University NHS Foundation Trust, Manchester, United Kingdom
- Centre for Biostatistics, Faculty of Biology Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Anand Pandyan
- Institute of Applied Clinical Science, Keele University, Newcastle-under-Lyme, United Kingdom
| | - Francis J. Gilchrist
- Institute of Applied Clinical Science, Keele University, Newcastle-under-Lyme, United Kingdom
- Royal Stoke University Hospital, University Hospitals of North Midlands NHS Trust, Stoke-on-Trent, United Kingdom
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12
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Trinkmann F, Lenz SA, Schäfer J, Gawlitza J, Schroeter M, Gradinger T, Akin I, Borggrefe M, Ganslandt T, Saur J. Feasibility and clinical applications of multiple breath wash-out (MBW) testing using sulphur hexafluoride in adults with bronchial asthma. Sci Rep 2020; 10:1527. [PMID: 32001782 PMCID: PMC6992773 DOI: 10.1038/s41598-020-58538-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 01/15/2020] [Indexed: 11/17/2022] Open
Abstract
Ventilation heterogeneity is frequent in bronchial asthma and can be assessed using multiple breath wash-out testing (MBW). Most data is available in paediatric patients and using nitrogen as a tracer gas. We aimed to evaluate sulphur hexafluoride (SF6) MBW in adult asthmatics. Spirometry, whole-body plethysmography, impulse oscillometry and SF6-MBW were prospectively performed. MBW parameters reflecting global (lung clearance index, LCI), acinar (Sacin) and conductive (Scond) ventilation heterogeneity were derived from three consecutive wash-outs. LCI was calculated for the traditional 2.5% and an earlier 5% stopping point that has the potential to reduce wash-out times. 91 asthmatics (66%) and 47 non-asthmatic controls (34%) were included in final analysis. LCI2.5 and LCI5 were higher in asthmatics (p < 0.001). Likewise, Sacin and Scond were elevated (p < 0.001 and p < 0.01). Coefficient of variation was 3.4% for LCI2.5 and 3.5% for LCI5 in asthmatics. Forty-one asthmatic patients had normal spirometry. ROC analysis revealed an AUC of 0.906 for the differentiation from non-asthmatic controls exceeding diagnostic performance of individual and conventional parameters (AUC = 0.819, p < 0.05). SF6-MBW is feasible and reproducible in adult asthmatics. Ventilation heterogeneity is increased as compared to non-asthmatic controls persisting in asthmatic patients with normal spirometry. Diagnostic performance is not affected using an earlier LCI stopping point while reducing wash-out duration considerably.
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Affiliation(s)
- Frederik Trinkmann
- 1st Department of Medicine (Cardiology, Angiology, Pulmonary and Intensive Care), University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany. .,Department of Biomedical Informatics of the Heinrich-Lanz-Centre, University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany.
| | - Steffi A Lenz
- 1st Department of Medicine (Cardiology, Angiology, Pulmonary and Intensive Care), University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Julia Schäfer
- 1st Department of Medicine (Cardiology, Angiology, Pulmonary and Intensive Care), University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Joshua Gawlitza
- Institute of Clinical Radiology and Nuclear Medicine, University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Michele Schroeter
- 1st Department of Medicine (Cardiology, Angiology, Pulmonary and Intensive Care), University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Tobias Gradinger
- Department of Biomedical Informatics of the Heinrich-Lanz-Centre, University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Ibrahim Akin
- 1st Department of Medicine (Cardiology, Angiology, Pulmonary and Intensive Care), University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Mannheim, University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Martin Borggrefe
- 1st Department of Medicine (Cardiology, Angiology, Pulmonary and Intensive Care), University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Mannheim, University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Thomas Ganslandt
- Department of Biomedical Informatics of the Heinrich-Lanz-Centre, University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Joachim Saur
- 1st Department of Medicine (Cardiology, Angiology, Pulmonary and Intensive Care), University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
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13
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Nielsen JG. Nitrogen offset in N 2 multiple washout method. ERJ Open Res 2020; 6:00335-2019. [PMID: 32201687 PMCID: PMC7073414 DOI: 10.1183/23120541.00335-2019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 12/04/2019] [Indexed: 11/18/2022] Open
Abstract
In a recent study of the nitrogen multiple breath washout (MBW) method to measure lung clearance index (LCI) using the Exhalyzer device (Eco Medics AG, Dürnten, Switzerland), Bayfieldet al. [1] reported an N2 offset signal of ∼1.4%, slightly higher than reported in several previous studies. There was no similar offset using sulfur hexafluoride as the tracer gas measured with the Innocor device (Innovision ApS, Glamsbjerg, Denmark), a finding that is in line with previous reports. The results of this and other studies are extremely important as the Exhalyzer is the device that is currently used in ≥100 cystic fibrosis centres in the European Cystic Fibrosis Society Clinical Trial Network and the Cystic Fibrosis Foundation Therapeutics Development Network in various drug trials [2]. An offset in the nitrogen signal significantly affects LCI measured by the N2 MBW methodhttp://bit.ly/35hwOuH
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14
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Nuttall AGL, Velásquez W, Beardsmore CS, Gaillard EA. Lung clearance index: assessment and utility in children with asthma. Eur Respir Rev 2019; 28:28/154/190046. [PMID: 31748419 DOI: 10.1183/16000617.0046-2019] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 07/26/2019] [Indexed: 11/05/2022] Open
Abstract
There is increasing evidence that ventilation heterogeneity and small airway disease are significant factors in asthma, with evidence suggesting that the small airways are involved from an early stage in childhood asthma. Spirometry is commonly used to monitor lung function in asthmatics; however, it is not sensitive to small airway disease. There has been renewed interest in multibreath washout (MBW) tests, with recognition of the lung clearance index (LCI) as a global index of abnormality in gas mixing of the lungs that therefore also reflects small airway disease. This review summarises the technical and practical aspects of the MBW/LCI in children, and the differences between commercially available equipment. Children with severe asthma are more likely to have an abnormal LCI, whereas most children with mild-to-moderate asthma have an LCI within the normal range, but slightly higher than age-matched healthy controls. Monitoring children with asthma with MBW alongside standard spirometry may provide useful additional information.
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Affiliation(s)
- Amy G L Nuttall
- Institute for Lung Health, NIHR Leicester Respiratory Biomedical Research Unit and Dept of Infection Immunity and Inflammation, University of Leicester, Leicester, UK.,Children's Hospital, University Hospitals Leicester, Leicester, UK
| | - Werner Velásquez
- Hospital de Especialidades Rodolfo Robles, Quetzaltenango, Guatemala
| | - Caroline S Beardsmore
- Institute for Lung Health, NIHR Leicester Respiratory Biomedical Research Unit and Dept of Infection Immunity and Inflammation, University of Leicester, Leicester, UK.,Children's Hospital, University Hospitals Leicester, Leicester, UK
| | - Erol A Gaillard
- Institute for Lung Health, NIHR Leicester Respiratory Biomedical Research Unit and Dept of Infection Immunity and Inflammation, University of Leicester, Leicester, UK .,Children's Hospital, University Hospitals Leicester, Leicester, UK
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15
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Bayfield KJ, Horsley A, Alton E, Irving S, Bush A, Davies JC. Simultaneous sulfur hexafluoride and nitrogen multiple-breath washout (MBW) to examine inherent differences in MBW outcomes. ERJ Open Res 2019; 5:00234-2018. [PMID: 31720295 PMCID: PMC6826248 DOI: 10.1183/23120541.00234-2018] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 08/27/2019] [Indexed: 11/10/2022] Open
Abstract
Multiple-breath washout (MBW) can be performed with different gases (sulfur hexafluoride (SF6) and nitrogen (N2)) and different devices, all of which give discrepant results. This study aimed to confirm previously reported differences and explore factors influencing discrepant results; equipment factors or the physical properties of gases used. Inherent differences in simultaneous SF6 and N2 washout on the mass spectrometer show why results are never comparablehttp://bit.ly/34k52Oo
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Affiliation(s)
- Katie J Bayfield
- Imperial College London, London, UK.,Royal Brompton and Harefield NHS Foundation Trust, London, UK.,European Cystic Fibrosis Society Clinical Trials Network, Lung Clearance Index Core Facility, London, UK.,The Children's Hospital at Westmead, Sydney, Australia
| | - Alex Horsley
- Institute of Inflammation and repair, Education and Research centre, University of Manchester, University Hospital of South Manchester, Manchester, UK
| | - Eric Alton
- Imperial College London, London, UK.,Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - Samantha Irving
- Imperial College London, London, UK.,Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - Andrew Bush
- Imperial College London, London, UK.,Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - Jane C Davies
- Imperial College London, London, UK.,Royal Brompton and Harefield NHS Foundation Trust, London, UK.,European Cystic Fibrosis Society Clinical Trials Network, Lung Clearance Index Core Facility, London, UK
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16
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Robinson PD, Latzin P, Ramsey KA, Stanojevic S, Aurora P, Davis SD, Gappa M, Hall GL, Horsley A, Jensen R, Lum S, Milla C, Nielsen KG, Pittman JE, Rosenfeld M, Singer F, Subbarao P, Gustafsson PM, Ratjen F. Preschool Multiple-Breath Washout Testing. An Official American Thoracic Society Technical Statement. Am J Respir Crit Care Med 2019; 197:e1-e19. [PMID: 29493315 DOI: 10.1164/rccm.201801-0074st] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Obstructive airway disease is nonuniformly distributed throughout the bronchial tree, although the extent to which this occurs can vary among conditions. The multiple-breath washout (MBW) test offers important insights into pediatric lung disease, not available through spirometry or resistance measurements. The European Respiratory Society/American Thoracic Society inert gas washout consensus statement led to the emergence of validated commercial equipment for the age group 6 years and above; specific recommendations for preschool children were beyond the scope of the document. Subsequently, the focus has shifted to MBW applications within preschool subjects (aged 2-6 yr), where a "window of opportunity" exists for early diagnosis of obstructive lung disease and intervention. METHODS This preschool-specific technical standards document was developed by an international group of experts, with expertise in both custom-built and commercial MBW equipment. A comprehensive review of published evidence was performed. RESULTS Recommendations were devised across areas that place specific age-related demands on MBW systems. Citing evidence where available in the literature, recommendations are made regarding procedures that should be used to achieve robust MBW results in the preschool age range. The present work also highlights the important unanswered questions that need to be addressed in future work. CONCLUSIONS Consensus recommendations are outlined to direct interested groups of manufacturers, researchers, and clinicians in preschool device design, test performance, and data analysis for the MBW technique.
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17
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Small Airway Disease in Pulmonary Hypertension-Additional Diagnostic Value of Multiple Breath Washout and Impulse Oscillometry. J Clin Med 2018; 7:jcm7120532. [PMID: 30544842 PMCID: PMC6306708 DOI: 10.3390/jcm7120532] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 11/28/2018] [Accepted: 12/07/2018] [Indexed: 11/29/2022] Open
Abstract
Airways obstruction is frequent in patients with pulmonary hypertension (PH). Small airway disease (SAD) was identified as a major contributor to resistance and symptoms. However, it is easily missed using current diagnostic approaches. We aimed to evaluate more elaborate diagnostic tests such as impulse oscillometry (IOS) and SF6-multiple-breath-washout (MBW) for the assessment of SAD in PH. Twenty-five PH patients undergoing body-plethysmography, IOS and MBW testing were prospectively included and equally matched to pulmonary healthy and non-healthy controls. Lung clearance index (LCI) and acinar ventilation heterogeneity (Sacin) differed significantly between PH, healthy and non-healthy controls. Likewise, differences were found for all IOS parameters between PH and healthy, but not non-healthy controls. Transfer factor corrected for ventilated alveolar volume (TLCO/VA), frequency dependency of resistance (D5-20), resonance frequency (Fres) and Sacin allowed complete differentiation between PH and healthy controls (AUC (area under the curve) = 1.0). Likewise, PH patients were separated from non-healthy controls (AUC 0.762) by D5-20, LCI and conductive ventilation heterogeneity (Scond). Maximal expiratory flow (MEF) values were not associated with additional diagnostic values. MBW and IOS are feasible in PH patients both providing additional information. This can be used to discriminate PH from healthy and non-healthy controls. Therefore, further research targeting SAD in PH and evaluation of therapeutic implications is justified.
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18
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Comparison of lung clearance index determined by washout of N 2 and SF 6 in infants and preschool children with cystic fibrosis. J Cyst Fibros 2018; 18:399-406. [PMID: 30420236 DOI: 10.1016/j.jcf.2018.11.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 10/30/2018] [Accepted: 11/02/2018] [Indexed: 12/29/2022]
Abstract
BACKGROUND Multiple-breath washout (MBW) has been shown to detect early impairment of lung function in children with cystic fibrosis (CF). Nitrogen (N2) or sulfur hexafluoride (SF6) can be used as tracer gas for MBW. Recent data indicated higher lung clearance index (LCI) values measured with N2-MBW than concurrent SF6-MBW in older children and adults, however, a comparison in infants and younger children, as well as to other outcome measures of CF lung disease is pending. METHODS N2- and SF6-MBW were performed consecutively in 31 sedated infants and preschool children with CF (mean age, 2.3 ± 0.8 years) and 20 controls (mean age, 2.3 ± 1.1 years) using the Exhalyzer D system. Children with CF also underwent chest magnetic resonance imaging (MRI). RESULTS Mean difference (95% CI) in LCI between N2- and SF6-MBW was 1.1 ± 0.4 (0.9 to 1.3) in controls and 2.1 ± 1.9 (1.4 to 2.8) in CF. Agreement between N2- and SF6-LCI was poor in children with CF. N2-LCI and SF6-LCI correlated with MRI, however N2-LCI showed a higher concordance with MRI than SF6-LCI. The absolute difference between N2- and SF6-LCI values increased with the severity of CF lung disease as determined by MRI scores. CONCLUSION N2-LCI values were higher than SF6-LCI values in infants and preschool children with CF and controls. Better concordance of N2-LCI than SF6-LCI with chest MRI scores point towards of a higher sensitivity of N2-LCI to detect early lung disease in children with CF.
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19
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Guglani L, Kasi A, Starks M, Pedersen KE, Nielsen JG, Weiner DJ. Difference between SF6 and N2 multiple breath washout kinetics is due to N2 back diffusion and error in N2 offset. J Appl Physiol (1985) 2018; 125:1257-1265. [DOI: 10.1152/japplphysiol.00326.2018] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Measurement of lung clearance index (LCI) by multiple breath washout (MBW) is a sensitive method for monitoring lung disease in patients with cystic fibrosis (CF). To compare nitrogen MBW (N2-MBW) and sulfur hexafluoride MBW (SF6-MBW), we connected these two gas analysis systems in series to obtain truly simultaneous measurements, with no differences other than the gas used. Nonsmoking healthy controls (HC) and subjects with CF were recruited at two institutions. The Exhalyzer-D (for N2-MBW measurement) was connected in series with the Innocor (for SF6-MBW measurement). Subjects washed in SF6 from a Douglas bag with tidal breathing and washed out SF6 and nitrogen with 100% oxygen provided as bias flow. Washout of both gases was continued past the LCI point (1/40th of equilibration concentration) in triplicate. N2-MBW resulted in higher cumulative exhaled volume, functional residual capacity (FRC), and LCI when compared with SF6-derived parameters in HC subjects ( P < 0.0001 for all comparisons). All N2-MBW parameters were also significantly higher than SF6-MBW parameters in subjects with CF ( P < 0.01 for all comparisons). After recalculation with a common FRC, N2-MBW LCI was higher than SF6-MBW LCI in subjects with CF (19.73 vs. 11.39; P < 0.0001) and in HC (8.12 vs. 6.78; P < 0.0001). Adjusting for N2 back diffusion and an offset error in the nitrogen measurement resulted in near complete agreement between the two methodologies. We found significant differences in LCI and FRC measurements using two different gases for MBW. This may have significant implications for the future use and interpretation of LCI data in clinical trials and routine clinical care. NEW & NOTEWORTHY This study provides important insights into the differences between the two techniques used for measuring lung clearance index (LCI): N2 and SF6 multiple breath washout. Differences between measurements made by these two methods in subjects with cystic fibrosis and healthy controls could be explained by nitrogen back diffusion and N2 offset error. This is important for use and interpretation of LCI data as an outcome measure for clinical trials and in routine clinical care.
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Affiliation(s)
- Lokesh Guglani
- Center for Cystic Fibrosis and Airways Disease Research, Emory University, Atlanta, Georgia
| | - Ajay Kasi
- Center for Cystic Fibrosis and Airways Disease Research, Emory University, Atlanta, Georgia
| | - Miah Starks
- Center for Cystic Fibrosis and Airways Disease Research, Emory University, Atlanta, Georgia
| | | | | | - Daniel J. Weiner
- Division of Pulmonary Medicine, Allergy & Immunology, Department of Pediatrics, University of Pittsburgh, Pittsburgh, Pennsylvania
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20
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Bell AS, Lawrence PJ, Singh D, Horsley A. Feasibility and challenges of using multiple breath washout in COPD. Int J Chron Obstruct Pulmon Dis 2018; 13:2113-2119. [PMID: 30022817 PMCID: PMC6044337 DOI: 10.2147/copd.s164285] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Background Lung clearance index (LCI), derived from multiple-breath washout (MBW), is a well-established assessment of ventilation inhomogeneity in cystic fibrosis but has not been widely applied in other conditions characterized by heterogeneous airways disease, such as COPD. The aim of this study was to evaluate the sensitivity, repeatability, and practicality of LCI in patients with COPD. Methods Fifty-four COPD patients completed MBW using nitrogen as the washout tracer gas (MBWN2, measured using an Exhalyzer™ device), spirometry, and plethysmography. Twenty patients repeated MBWN2, MBWSF6 (using a separate Innocor™ gas analyzer to measure washout of the exogenous trace sulphur hexafluoride), and spirometry at a second visit ≥24 hours later. Results Mean (SD) COPD LCI measured by nitrogen washout (LCIN2) was 12.1 (2.2); mean (SD) LCI Z-score 5.8 (2.0). LCIN2 increased across Global Initiative for Obstructive Lung Disease stages 1 to 3 and was abnormal (Z-score >1.65) in all COPD patients, including those with forced expiratory volume in 1 second (FEV1) ≥80% predicted. LCI was repeatable (median intra-test coefficient of variation 4.1%) and reproducible (limits of agreement -1.8 to 1.6) after mean of 16 days. Functional residual capacity (FRC) measurements were significantly greater using nitrogen than SF6 or plethysmography: mean FRC measured by nitrogen washout (FRCN2) 139% predicted versus FRC measured by plethysmography 125% predicted, p<0.0001. Conclusion LCI is most suitable as a measure of early airways disease in COPD in those with well-preserved FEV1, with similar repeatability and limitations to that observed in cystic fibrosis. Using the Exhalyzer system to perform MBWN2, however, appeared to substantially over-read FRC. This discrepancy needs addressing before FRCN2 measurements made using this device can be reliably deployed.
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Affiliation(s)
- Alan S Bell
- The Medicines Evaluation Unit, Wythenshawe Hospital, Manchester, UK.,Division of Infection Immunity and Respiratory Medicine, Faculty of Biology Medicine and Health, University of Manchester, Manchester, UK,
| | | | - Dave Singh
- The Medicines Evaluation Unit, Wythenshawe Hospital, Manchester, UK.,Division of Infection Immunity and Respiratory Medicine, Faculty of Biology Medicine and Health, University of Manchester, Manchester, UK, .,Manchester Academic Health Science Centre, Manchester, UK,
| | - Alexander Horsley
- Division of Infection Immunity and Respiratory Medicine, Faculty of Biology Medicine and Health, University of Manchester, Manchester, UK, .,Manchester Academic Health Science Centre, Manchester, UK, .,Manchester Adult Cystic Fibrosis Centre, Manchester University NHS Foundation Trust, Manchester, UK,
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O’Neill K, Saunders C. New directions on lung clearance index variability and feasibility. J Cyst Fibros 2018; 17:137-139. [DOI: 10.1016/j.jcf.2018.02.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/28/2018] [Indexed: 01/20/2023]
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Trinkmann F, Götzmann J, Saur D, Schroeter M, Roth K, Stach K, Borggrefe M, Saur J, Akin I, Michels JD. Multiple breath washout testing in adults with pulmonary disease and healthy controls - can fewer measurements eventually be more? BMC Pulm Med 2017; 17:185. [PMID: 29228942 PMCID: PMC5725793 DOI: 10.1186/s12890-017-0543-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 11/29/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Multiple breath washout (MBW) became a valuable research tool assessing ventilation heterogeneity. However, routine clinical application still faces several challenges. Deriving MBW parameters from three technically acceptable measurements according to current recommendations prolongs test times. We therefore aimed to evaluate reporting only duplicate measurements in healthy adults and pulmonary disease. METHODS One hundred and fifty-three subjects prospectively underwent conventional lung function testing and closed-circuit SF6-MBW. Three technically acceptable MBW-measurements were obtained in 103 subjects. RESULTS Lung clearance index (LCI) differed significantly among 19 controls (7.4 ± 0.8), 19 patients with sarcoidosis (8.1 ± 1.2), 32 with bronchial asthma (9.2 ± 1.9) and 33 with COPD (10.8 ± 2.2, p < 0.001). Within-test repeatability was high (coefficient of variation between 2.5% in controls and 3.6% in COPD) and remained unchanged when only including the first two measurements. Likewise, LCI remained stable with mean absolute changes ranging from 0.9 ± 0.8% in controls to 1.5 ± 0.9% in COPD (p = 0.1). Mean test time reduction differed significantly between groups reaching 200 s in COPD (p = 0.01). CONCLUSIONS Duplicate SF6-MBW-measurements are sufficient in adult patients with pulmonary disease and healthy controls. LCI values and intra-test repeatability are not affected reducing total test time statistically significant. Our findings have the potential to further facilitate application of MBW in research and clinical routine. TRIAL REGISTRATION NCT03176745 , June 2, 2017 retrospectively registered.
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Affiliation(s)
- Frederik Trinkmann
- 1st Department of Medicine (Cardiology, Angiology, Pulmonary and Intensive Care), University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany.
| | - Johannes Götzmann
- 1st Department of Medicine (Cardiology, Angiology, Pulmonary and Intensive Care), University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Daniel Saur
- 1st Department of Medicine (Cardiology, Angiology, Pulmonary and Intensive Care), University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Michele Schroeter
- 1st Department of Medicine (Cardiology, Angiology, Pulmonary and Intensive Care), University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Katharina Roth
- 1st Department of Medicine (Cardiology, Angiology, Pulmonary and Intensive Care), University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Ksenija Stach
- 1st Department of Medicine (Cardiology, Angiology, Pulmonary and Intensive Care), University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Mannheim, University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Martin Borggrefe
- 1st Department of Medicine (Cardiology, Angiology, Pulmonary and Intensive Care), University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Mannheim, University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Joachim Saur
- 1st Department of Medicine (Cardiology, Angiology, Pulmonary and Intensive Care), University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Ibrahim Akin
- 1st Department of Medicine (Cardiology, Angiology, Pulmonary and Intensive Care), University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Mannheim, University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Julia D Michels
- 1st Department of Medicine (Cardiology, Angiology, Pulmonary and Intensive Care), University Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
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