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Vieira FN, Masy V, LaRue RJ, Laengert SE, De Lannoy CF, Rodrigues A, Sklar MC, Lo N, Petrosoniak A, Rezende-Neto J, Brochard LJ. An Individual Barrier Enclosure Actively Removing Aerosols for Airborne Isolation: A Vacuum Tent. Respir Care 2024; 69:395-406. [PMID: 38538026 PMCID: PMC11108102 DOI: 10.4187/respcare.11094] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2024]
Abstract
BACKGROUND Aerosol barrier enclosure systems have been designed to prevent airborne contamination, but their safety has been questioned. A vacuum tent was designed with active continuous suctioning to minimize risks of aerosol dispersion. We tested its efficacy, risk of rebreathing, and usability on a bench, in healthy volunteers, and in an ergonomic clinical assessment study. METHODS First, a manikin with airway connected to a breathing simulator was placed inside the vacuum tent to generate active breathing, cough, and CO2 production; high-flow nasal cannula (HFNC) was applied in the manikin's nares. Negative pressure was applied in the vacuum tent's apex port using wall suction. Fluorescent microparticles were aerosolized in the vacuum tent for qualitative assessment. To quantify particles inside and around vacuum tent (aerosol retention), an airtight aerosol chamber with aerosolized latex microparticles was used. The vacuum tent was tested on healthy volunteers breathing with and without HFNC. Last, its usability was assessed in 5 subjects by 5 different anesthesiologists for delivery of full anesthesia, including intubation and extubation. RESULTS The vacuum tent was adjusted until no leak was visualized using fluorescent particles. The efficacy in retaining microparticles was confirmed quantitatively. CO2 accumulation inside the vacuum tent showed an inverse correlation with the suction flow in all conditions (normal breathing and HFNC 30 or 60 L/min) in bench and healthy volunteers. Particle removal efficacy and safe breathing conditions (CO2, temperature) were reached when suctioning was at least 60 L/min or 20 L/min > HFNC flow. Five subjects were successfully intubated and anesthetized without ergonomic difficulties and with minimal interference with workflow and an excellent overall assessment by the anesthesiologists. CONCLUSIONS The vacuum tent effectively minimized aerosol dispersion. Its continuous suction system set at a high suction flow was crucial to avoid the spread of aerosol particles and CO2 rebreathing.
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Affiliation(s)
- Fernando N Vieira
- Mr Vieira and Drs Rodrigues, Sklar, and Brochard are affiliated with Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Ontario, Canada; and Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada. Dr Masy is affiliated with Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Ontario, Canada; Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada; and Division of Pediatric Critical Care, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada. Messrs LaRue and Laengert and Dr de Lannoy are affiliated with McMaster University, Center of Excellence in Protective Equipment and Materials, Hamilton, Ontario, Canada; and McMaster University, Department of Chemical Engineering, Hamilton, Ontario, Canada. Dr Lo is affiliated with Department of Anesthesiology and Pain Service, St. Michael's Hospital, Toronto, Ontario, Canada. Dr Petrosoniak is affiliated with Emergency Physician and Trauma Team, St. Michael's and Department of Medicine, University of Toronto, Ontario, Canada. Dr Rezende-Neto is affiliated with Trauma and Acute Care General Surgery, Department of Surgery, St. Michael's Hospital, Toronto, Ontario, Canada
| | - Veronique Masy
- Mr Vieira and Drs Rodrigues, Sklar, and Brochard are affiliated with Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Ontario, Canada; and Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada. Dr Masy is affiliated with Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Ontario, Canada; Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada; and Division of Pediatric Critical Care, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada. Messrs LaRue and Laengert and Dr de Lannoy are affiliated with McMaster University, Center of Excellence in Protective Equipment and Materials, Hamilton, Ontario, Canada; and McMaster University, Department of Chemical Engineering, Hamilton, Ontario, Canada. Dr Lo is affiliated with Department of Anesthesiology and Pain Service, St. Michael's Hospital, Toronto, Ontario, Canada. Dr Petrosoniak is affiliated with Emergency Physician and Trauma Team, St. Michael's and Department of Medicine, University of Toronto, Ontario, Canada. Dr Rezende-Neto is affiliated with Trauma and Acute Care General Surgery, Department of Surgery, St. Michael's Hospital, Toronto, Ontario, Canada
| | - Ryan J LaRue
- Mr Vieira and Drs Rodrigues, Sklar, and Brochard are affiliated with Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Ontario, Canada; and Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada. Dr Masy is affiliated with Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Ontario, Canada; Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada; and Division of Pediatric Critical Care, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada. Messrs LaRue and Laengert and Dr de Lannoy are affiliated with McMaster University, Center of Excellence in Protective Equipment and Materials, Hamilton, Ontario, Canada; and McMaster University, Department of Chemical Engineering, Hamilton, Ontario, Canada. Dr Lo is affiliated with Department of Anesthesiology and Pain Service, St. Michael's Hospital, Toronto, Ontario, Canada. Dr Petrosoniak is affiliated with Emergency Physician and Trauma Team, St. Michael's and Department of Medicine, University of Toronto, Ontario, Canada. Dr Rezende-Neto is affiliated with Trauma and Acute Care General Surgery, Department of Surgery, St. Michael's Hospital, Toronto, Ontario, Canada
| | - Scott E Laengert
- Mr Vieira and Drs Rodrigues, Sklar, and Brochard are affiliated with Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Ontario, Canada; and Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada. Dr Masy is affiliated with Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Ontario, Canada; Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada; and Division of Pediatric Critical Care, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada. Messrs LaRue and Laengert and Dr de Lannoy are affiliated with McMaster University, Center of Excellence in Protective Equipment and Materials, Hamilton, Ontario, Canada; and McMaster University, Department of Chemical Engineering, Hamilton, Ontario, Canada. Dr Lo is affiliated with Department of Anesthesiology and Pain Service, St. Michael's Hospital, Toronto, Ontario, Canada. Dr Petrosoniak is affiliated with Emergency Physician and Trauma Team, St. Michael's and Department of Medicine, University of Toronto, Ontario, Canada. Dr Rezende-Neto is affiliated with Trauma and Acute Care General Surgery, Department of Surgery, St. Michael's Hospital, Toronto, Ontario, Canada
| | - Charles F De Lannoy
- Mr Vieira and Drs Rodrigues, Sklar, and Brochard are affiliated with Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Ontario, Canada; and Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada. Dr Masy is affiliated with Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Ontario, Canada; Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada; and Division of Pediatric Critical Care, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada. Messrs LaRue and Laengert and Dr de Lannoy are affiliated with McMaster University, Center of Excellence in Protective Equipment and Materials, Hamilton, Ontario, Canada; and McMaster University, Department of Chemical Engineering, Hamilton, Ontario, Canada. Dr Lo is affiliated with Department of Anesthesiology and Pain Service, St. Michael's Hospital, Toronto, Ontario, Canada. Dr Petrosoniak is affiliated with Emergency Physician and Trauma Team, St. Michael's and Department of Medicine, University of Toronto, Ontario, Canada. Dr Rezende-Neto is affiliated with Trauma and Acute Care General Surgery, Department of Surgery, St. Michael's Hospital, Toronto, Ontario, Canada
| | - Antenor Rodrigues
- Mr Vieira and Drs Rodrigues, Sklar, and Brochard are affiliated with Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Ontario, Canada; and Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada. Dr Masy is affiliated with Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Ontario, Canada; Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada; and Division of Pediatric Critical Care, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada. Messrs LaRue and Laengert and Dr de Lannoy are affiliated with McMaster University, Center of Excellence in Protective Equipment and Materials, Hamilton, Ontario, Canada; and McMaster University, Department of Chemical Engineering, Hamilton, Ontario, Canada. Dr Lo is affiliated with Department of Anesthesiology and Pain Service, St. Michael's Hospital, Toronto, Ontario, Canada. Dr Petrosoniak is affiliated with Emergency Physician and Trauma Team, St. Michael's and Department of Medicine, University of Toronto, Ontario, Canada. Dr Rezende-Neto is affiliated with Trauma and Acute Care General Surgery, Department of Surgery, St. Michael's Hospital, Toronto, Ontario, Canada
| | - Michael C Sklar
- Mr Vieira and Drs Rodrigues, Sklar, and Brochard are affiliated with Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Ontario, Canada; and Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada. Dr Masy is affiliated with Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Ontario, Canada; Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada; and Division of Pediatric Critical Care, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada. Messrs LaRue and Laengert and Dr de Lannoy are affiliated with McMaster University, Center of Excellence in Protective Equipment and Materials, Hamilton, Ontario, Canada; and McMaster University, Department of Chemical Engineering, Hamilton, Ontario, Canada. Dr Lo is affiliated with Department of Anesthesiology and Pain Service, St. Michael's Hospital, Toronto, Ontario, Canada. Dr Petrosoniak is affiliated with Emergency Physician and Trauma Team, St. Michael's and Department of Medicine, University of Toronto, Ontario, Canada. Dr Rezende-Neto is affiliated with Trauma and Acute Care General Surgery, Department of Surgery, St. Michael's Hospital, Toronto, Ontario, Canada
| | - Nick Lo
- Mr Vieira and Drs Rodrigues, Sklar, and Brochard are affiliated with Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Ontario, Canada; and Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada. Dr Masy is affiliated with Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Ontario, Canada; Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada; and Division of Pediatric Critical Care, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada. Messrs LaRue and Laengert and Dr de Lannoy are affiliated with McMaster University, Center of Excellence in Protective Equipment and Materials, Hamilton, Ontario, Canada; and McMaster University, Department of Chemical Engineering, Hamilton, Ontario, Canada. Dr Lo is affiliated with Department of Anesthesiology and Pain Service, St. Michael's Hospital, Toronto, Ontario, Canada. Dr Petrosoniak is affiliated with Emergency Physician and Trauma Team, St. Michael's and Department of Medicine, University of Toronto, Ontario, Canada. Dr Rezende-Neto is affiliated with Trauma and Acute Care General Surgery, Department of Surgery, St. Michael's Hospital, Toronto, Ontario, Canada
| | - Andrew Petrosoniak
- Mr Vieira and Drs Rodrigues, Sklar, and Brochard are affiliated with Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Ontario, Canada; and Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada. Dr Masy is affiliated with Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Ontario, Canada; Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada; and Division of Pediatric Critical Care, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada. Messrs LaRue and Laengert and Dr de Lannoy are affiliated with McMaster University, Center of Excellence in Protective Equipment and Materials, Hamilton, Ontario, Canada; and McMaster University, Department of Chemical Engineering, Hamilton, Ontario, Canada. Dr Lo is affiliated with Department of Anesthesiology and Pain Service, St. Michael's Hospital, Toronto, Ontario, Canada. Dr Petrosoniak is affiliated with Emergency Physician and Trauma Team, St. Michael's and Department of Medicine, University of Toronto, Ontario, Canada. Dr Rezende-Neto is affiliated with Trauma and Acute Care General Surgery, Department of Surgery, St. Michael's Hospital, Toronto, Ontario, Canada
| | - Joao Rezende-Neto
- Mr Vieira and Drs Rodrigues, Sklar, and Brochard are affiliated with Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Ontario, Canada; and Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada. Dr Masy is affiliated with Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Ontario, Canada; Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada; and Division of Pediatric Critical Care, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada. Messrs LaRue and Laengert and Dr de Lannoy are affiliated with McMaster University, Center of Excellence in Protective Equipment and Materials, Hamilton, Ontario, Canada; and McMaster University, Department of Chemical Engineering, Hamilton, Ontario, Canada. Dr Lo is affiliated with Department of Anesthesiology and Pain Service, St. Michael's Hospital, Toronto, Ontario, Canada. Dr Petrosoniak is affiliated with Emergency Physician and Trauma Team, St. Michael's and Department of Medicine, University of Toronto, Ontario, Canada. Dr Rezende-Neto is affiliated with Trauma and Acute Care General Surgery, Department of Surgery, St. Michael's Hospital, Toronto, Ontario, Canada
| | - Laurent J Brochard
- Mr Vieira and Drs Rodrigues, Sklar, and Brochard are affiliated with Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Ontario, Canada; and Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada. Dr Masy is affiliated with Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Ontario, Canada; Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada; and Division of Pediatric Critical Care, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada. Messrs LaRue and Laengert and Dr de Lannoy are affiliated with McMaster University, Center of Excellence in Protective Equipment and Materials, Hamilton, Ontario, Canada; and McMaster University, Department of Chemical Engineering, Hamilton, Ontario, Canada. Dr Lo is affiliated with Department of Anesthesiology and Pain Service, St. Michael's Hospital, Toronto, Ontario, Canada. Dr Petrosoniak is affiliated with Emergency Physician and Trauma Team, St. Michael's and Department of Medicine, University of Toronto, Ontario, Canada. Dr Rezende-Neto is affiliated with Trauma and Acute Care General Surgery, Department of Surgery, St. Michael's Hospital, Toronto, Ontario, Canada.
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Zhang MX, Lilien TA, van Etten-Jamaludin FS, Fraenkel CJ, Bonn D, Vlaar APJ, Löndahl J, Klompas M, Bem RA. Generation of Aerosols by Noninvasive Respiratory Support Modalities: A Systematic Review and Meta-Analysis. JAMA Netw Open 2023; 6:e2337258. [PMID: 37819660 PMCID: PMC10568354 DOI: 10.1001/jamanetworkopen.2023.37258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 08/29/2023] [Indexed: 10/13/2023] Open
Abstract
Importance Infection control guidelines have historically classified high-flow nasal oxygen and noninvasive ventilation as aerosol-generating procedures that require specialized infection prevention and control measures. Objective To evaluate the current evidence that high-flow nasal oxygen and noninvasive ventilation are associated with pathogen-laden aerosols and aerosol generation. Data Sources A systematic search of EMBASE and PubMed/MEDLINE up to March 15, 2023, and CINAHL and ClinicalTrials.gov up to August 1, 2023, was performed. Study Selection Observational and (quasi-)experimental studies of patients or healthy volunteers supported with high-flow nasal oxygen or noninvasive ventilation were selected. Data Extraction and Synthesis Three reviewers were involved in independent study screening, assessment of risk of bias, and data extraction. Data from observational studies were pooled using a random-effects model at both sample and patient levels. Sensitivity analyses were performed to assess the influence of model choice. Main Outcomes and Measures The main outcomes were the detection of pathogens in air samples and the quantity of aerosol particles. Results Twenty-four studies were included, of which 12 involved measurements in patients and 15 in healthy volunteers. Five observational studies on SARS-CoV-2 detection in a total of 212 air samples during high-flow nasal oxygen in 152 patients with COVID-19 were pooled for meta-analysis. There was no association between high-flow nasal oxygen and pathogen-laden aerosols (odds ratios for positive samples, 0.73 [95% CI, 0.15-3.55] at the sample level and 0.80 [95% CI, 0.14-4.59] at the patient level). Two studies assessed SARS-CoV-2 detection during noninvasive ventilation (84 air samples from 72 patients). There was no association between noninvasive ventilation and pathogen-laden aerosols (odds ratios for positive samples, 0.38 [95% CI, 0.03-4.63] at the sample level and 0.43 [95% CI, 0.01-27.12] at the patient level). None of the studies in healthy volunteers reported clinically relevant increases in aerosol particle production by high-flow nasal oxygen or noninvasive ventilation. Conclusions and Relevance This systematic review and meta-analysis found no association between high-flow nasal oxygen or noninvasive ventilation and increased airborne pathogen detection or aerosol generation. These findings argue against classifying high-flow nasal oxygen or noninvasive ventilation as aerosol-generating procedures or differentiating infection prevention and control practices for patients receiving these modalities.
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Affiliation(s)
- Madeline X. Zhang
- Institute of Physics, Van der Waals-Zeeman Institute, University of Amsterdam, Amsterdam, the Netherlands
| | - Thijs A. Lilien
- Department of Pediatric Intensive Care, Emma Children’s Hospital, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | | | - Carl-Johan Fraenkel
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Daniel Bonn
- Institute of Physics, Van der Waals-Zeeman Institute, University of Amsterdam, Amsterdam, the Netherlands
| | - Alexander P. J. Vlaar
- Department of Intensive Care, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Jakob Löndahl
- Division of Ergonomics and Aerosol Technology, Department of Design Sciences, Lund University, Lund, Sweden
| | - Michael Klompas
- Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts
- Department of Medicine, Brigham and Women’s Hospital, Boston, Massachusetts
| | - Reinout A. Bem
- Department of Pediatric Intensive Care, Emma Children’s Hospital, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
- Amsterdam Reproduction and Development Research Institute, Amsterdam, the Netherlands
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Eain MMG, Nolan K, Murphy B, McCaul C, MacLoughlin R. Exhaled patient derived aerosol dispersion during awake tracheal intubation with concurrent high flow nasal therapy. J Clin Monit Comput 2023; 37:1265-1273. [PMID: 36930390 PMCID: PMC10022553 DOI: 10.1007/s10877-023-00990-x] [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: 10/10/2022] [Accepted: 02/24/2023] [Indexed: 03/18/2023]
Abstract
Awake Tracheal Intubation (ATI) can be performed in cases where there is potential for difficult airway management. It is considered an aerosol generating procedure and is a source of concern to healthcare workers due to the risk of transmission of airborne viral infections, such as SARS-CoV-2. At present, there is a lack of data on the quantities, size distributions and spread of aerosol particles generated during such procedures. This was a volunteer observational study which took place in an operating room of a university teaching hospital. Optical particle sizers were used to provide real time aerosol characterisation during a simulated ATI performed with concurrent high-flow nasal oxygen therapy. The particle sizers were positioned at locations that represented the different locations of clinical staff in an operating room during an ATI. The greatest concentration of patient derived aerosol particles was within 0.5-1.0 m of the subject and along their midline, 2242 #/cm3. As the distance, both radial and longitudinal, from the subject increased, the concentration decreased towards ambient levels, 36.9 ± 5.1 #/cm3. Patient derived aerosol particles < 5 µm in diameter remained entrained in the exhaled aerosol plume and fell to the floor or onto the subject. Patient derived particles > 5 µm in diameter broke away from the exhaled plume and spread radially throughout the operating room. Irrespective of distance and ventilation status, full airborne protective equipment should be worn by all staff when ATI is being performed on patients with suspected viral respiratory infections.
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Affiliation(s)
- Marc Mac Giolla Eain
- Research and Development, Science and Emerging Technologies, Aerogen Ltd, IDA Business Park, Dangan, Galway, H91HE94, Ireland
| | - Kevin Nolan
- School of Mechanical and Materials Engineering, University College Dublin, Dublin, Ireland
| | - Brian Murphy
- Department of Anaesthesia, Rotunda Hospital, Parnell Square, Dublin, Ireland
| | - Conan McCaul
- Department of Anaesthesia, Rotunda Hospital, Parnell Square, Dublin, Ireland
- School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| | - Ronan MacLoughlin
- Research and Development, Science and Emerging Technologies, Aerogen Ltd, IDA Business Park, Dangan, Galway, H91HE94, Ireland.
- School of Pharmacy and Biomolecular Sciences, Royal College of Surgeons, Dublin, Ireland.
- School of Pharmacy and Pharmaceutical Sciences, Trinity College, Dublin, Ireland.
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Lee LYY, Landry SA, Jamriska M, Subedi D, Joosten SA, Barr JJ, Brown R, Kevin K, Schofield R, Monty J, Subbarao K, McGain F. Quantifying the reduction of airborne infectious virus load using a ventilated patient hood. J Hosp Infect 2023; 136:110-117. [PMID: 37105259 PMCID: PMC10125916 DOI: 10.1016/j.jhin.2023.04.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 04/14/2023] [Accepted: 04/14/2023] [Indexed: 04/29/2023]
Abstract
BACKGROUND Healthcare workers treating SARS-CoV-2 patients are at risk of infection by respiratory exposure to patient-emitted, virus-laden aerosols. Source control devices such as ventilated patient isolation hoods have been shown to limit the dissemination of non-infectious airborne particles in laboratory tests, but data on their performance in mitigating the airborne transmission risk of infectious viruses are lacking. AIM We used an infectious airborne virus to quantify the ability of a ventilated hood to reduce infectious virus exposure in indoor environments. METHODS We nebulized 109 plaque forming units (pfu) of bacteriophage PhiX174 virus into a ∼30-m3 room when the hood was active or inactive. The airborne concentration of infectious virus was measured by BioSpot-VIVAS and settle plates using plaque assay quantification on the bacterial host Escherichia coli C. The airborne particle number concentration (PNC) was also monitored continuously using an optical particle sizer. FINDINGS The median airborne viral concentration in the room reached 1.41 × 105 pfu/m3 with the hood inactive. When active, the hood reduced infectious virus concentration in air samples by 374-fold. The deposition of infectious virus on the surface of settle plates was reduced by 87-fold. This was associated with a 109-fold reduction in total airborne particle number escape rate. CONCLUSION A personal ventilation hood significantly reduced airborne particle escape, considerably lowering infectious virus contamination in an indoor environment. Our findings support the further development of source control devices to mitigate nosocomial infection risk among healthcare workers exposed to airborne viruses in clinical settings.
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Affiliation(s)
- L Y Y Lee
- Department of Microbiology and Immunology, University of Melbourne, At the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
| | - S A Landry
- Department of Physiology, School of Biomedical Sciences & Biomedical Discovery Institute, Monash University, Melbourne, VIC, Australia
| | - M Jamriska
- Defence Science and Technology Group, Fishermans Bend, VIC, Australia
| | - D Subedi
- School of Biological Sciences, Monash University, Clayton, VIC, Australia
| | - S A Joosten
- School of Biological Sciences, Monash University, Clayton, VIC, Australia; Monash Lung, Sleep, Allergy and Immunology, Monash Health, Clayton, VIC, Australia; School of Clinical Sciences, Monash University, Melbourne, VIC, Australia; Monash Partners, Epworth, Victoria, VIC, Australia
| | - J J Barr
- School of Biological Sciences, Monash University, Clayton, VIC, Australia
| | - R Brown
- Defence Science and Technology Group, Fishermans Bend, VIC, Australia
| | - K Kevin
- School of Mechanical Engineering, University of Melbourne, Melbourne VIC, Australia
| | - R Schofield
- School of Geography, Earth and Atmospheric Sciences, University of Melbourne, Melbourne, VIC, Australia
| | - J Monty
- School of Mechanical Engineering, University of Melbourne, Melbourne VIC, Australia
| | - K Subbarao
- Department of Microbiology and Immunology, University of Melbourne, At the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia; WHO Collaborating Centre for Reference and Research on Influenza, Victorian Infectious Diseases Reference Laboratory at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
| | - F McGain
- Departments of Anaesthesia and Intensive Care, Western Health, Melbourne, VIC, Australia; Department of Critical Care, University of Melbourne, Melbourne, VIC, Australia; School of Public Health, University of Sydney, Sydney, NSW, Australia.
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Beloncle FM. Is COVID-19 different from other causes of acute respiratory distress syndrome? JOURNAL OF INTENSIVE MEDICINE 2023:S2667-100X(23)00008-7. [PMID: 37362866 PMCID: PMC10085872 DOI: 10.1016/j.jointm.2023.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 01/30/2023] [Accepted: 02/03/2023] [Indexed: 06/28/2023]
Abstract
Coronavirus disease 2019 (COVID-19) pneumonia can lead to acute hypoxemic respiratory failure. When mechanical ventilation is needed, almost all patients with COVID-19 pneumonia meet the criteria for acute respiratory distress syndrome (ARDS). The question of the specificities of COVID-19-associated ARDS compared to other causes of ARDS is of utmost importance, as it may justify changes in ventilatory strategies. This review aims to describe the pathophysiology of COVID-19-associated ARDS and discusses whether specific ventilatory strategies are required in these patients.
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Affiliation(s)
- François M Beloncle
- Medical ICU, University Hospital of Angers, Vent'Lab, University of Angers, Angers 49033, France
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Detection of severe acute respiratory coronavirus virus 2 (SARS-CoV-2) in the air near patients using noninvasive respiratory support devices. Infect Control Hosp Epidemiol 2023; 44:843-845. [PMID: 36919200 DOI: 10.1017/ice.2022.296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
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Harrison S, Davies E, Shelton C. Aerosol-generating procedures: research, guidance and implementation. Anaesthesia 2023; 78:150-154. [PMID: 36196792 DOI: 10.1111/anae.15878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/21/2022] [Indexed: 01/11/2023]
Affiliation(s)
- S Harrison
- North West School of Anaesthesia, Manchester, UK
| | - E Davies
- North West School of Anaesthesia, Manchester, UK
| | - C Shelton
- Department of Anaesthesia, Wythenshawe Hospital, Manchester University NHS Foundation Trust, Manchester, UK.,Lancaster Medical School, Lancaster University, Lancaster, Lancashire, UK
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Frat JP, Marchasson L, Arrivé F, Coudroy R. High-flow nasal cannula oxygen therapy in acute hypoxemic respiratory failure and COVID-19-related respiratory failure. JOURNAL OF INTENSIVE MEDICINE 2023; 3:20-26. [PMID: 36756183 PMCID: PMC9534601 DOI: 10.1016/j.jointm.2022.07.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 06/19/2022] [Accepted: 07/13/2022] [Indexed: 11/17/2022]
Abstract
Although standard oxygen face masks are first-line therapy for patients with acute hypoxemic respiratory failure, high-flow nasal cannula oxygen therapy has gained major popularity in intensive care units. The physiological effects of high-flow oxygen counterbalance the physiological consequences of acute hypoxemic respiratory failure by lessening the deleterious effects of intense and prolonged inspiratory efforts generated by patients. Its simplicity of application for physicians and nurses and its comfort for patients are other arguments for its use in this setting. Although clinical studies have reported a decreased risk of intubation with high-flow oxygen compared with standard oxygen, its survival benefit is uncertain. A more precise definition of acute hypoxemic respiratory failure, including a classification of severity based on oxygenation levels, is needed to better compare the efficiencies of different non-invasive oxygenation support methods (standard oxygen, high-flow oxygen, and non-invasive ventilation). Additionally, the respective role of each non-invasive oxygenation support method needs to be established through further clinical trials in acute hypoxemic respiratory failure, especially in severe forms.
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Affiliation(s)
- Jean-Pierre Frat
- Centre Hospitalier Universitaire de Poitiers, Médecine Intensive Réanimation, Poitiers 86021, France,Centre d'Investigation Clinique 1402 ALIVE, INSERM, Université de Poitiers, Poitiers 86021, France,Corresponding author: Jean-Pierre Frat, Centre Hospitalier Universitaire de Poitiers, Médecine Intensive Réanimation, Poitiers 86021, France
| | - Laura Marchasson
- Centre Hospitalier Universitaire de Poitiers, Médecine Intensive Réanimation, Poitiers 86021, France
| | - François Arrivé
- Centre Hospitalier Universitaire de Poitiers, Médecine Intensive Réanimation, Poitiers 86021, France
| | - Rémi Coudroy
- Centre Hospitalier Universitaire de Poitiers, Médecine Intensive Réanimation, Poitiers 86021, France,Centre d'Investigation Clinique 1402 ALIVE, INSERM, Université de Poitiers, Poitiers 86021, France
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9
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Abstract
Over 2 years have passed since the start of the COVID-19 pandemic, which has claimed millions of lives. Unlike the early days of the pandemic, when management decisions were based on extrapolations from in vitro data, case reports and case series, clinicians are now equipped with an armamentarium of therapies based on high-quality evidence. These treatments are spread across seven main therapeutic categories: anti-inflammatory agents, antivirals, antithrombotics, therapies for acute hypoxaemic respiratory failure, anti-SARS-CoV-2 (neutralizing) antibody therapies, modulators of the renin-angiotensin-aldosterone system and vitamins. For each of these treatments, the patient population characteristics and clinical settings in which they were studied are important considerations. Although few direct comparisons have been performed, the evidence base and magnitude of benefit for anti-inflammatory and antiviral agents clearly outweigh those of other therapeutic approaches such as vitamins. The emergence of novel variants has further complicated the interpretation of much of the available evidence, particularly for antibody therapies. Importantly, patients with acute and chronic kidney disease were under-represented in many of the COVID-19 clinical trials, and outcomes in this population might differ from those reported in the general population. Here, we examine the clinical evidence for these therapies through a kidney medicine lens.
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10
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Asymptomatic screening for severe acute respiratory coronavirus virus 2 (SARS-CoV-2) as an infection prevention measure in healthcare facilities: Challenges and considerations. Infect Control Hosp Epidemiol 2023; 44:2-7. [PMID: 36539917 DOI: 10.1017/ice.2022.295] [Citation(s) in RCA: 24] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Testing of asymptomatic patients for severe acute respiratory coronavirus virus 2 (SARS-CoV-2) (ie, "asymptomatic screening) to attempt to reduce the risk of nosocomial transmission has been extensive and resource intensive, and such testing is of unclear benefit when added to other layers of infection prevention mitigation controls. In addition, the logistic challenges and costs related to screening program implementation, data noting the lack of substantial aerosol generation with elective controlled intubation, extubation, and other procedures, and the adverse patient and facility consequences of asymptomatic screening call into question the utility of this infection prevention intervention. Consequently, the Society for Healthcare Epidemiology of America (SHEA) recommends against routine universal use of asymptomatic screening for SARS-CoV-2 in healthcare facilities. Specifically, preprocedure asymptomatic screening is unlikely to provide incremental benefit in preventing SARS-CoV-2 transmission in the procedural and perioperative environment when other infection prevention strategies are in place, and it should not be considered a requirement for all patients. Admission screening may be beneficial during times of increased virus transmission in some settings where other layers of controls are limited (eg, behavioral health, congregate care, or shared patient rooms), but widespread routine use of admission asymptomatic screening is not recommended over strengthening other infection prevention controls. In this commentary, we outline the challenges surrounding the use of asymptomatic screening, including logistics and costs of implementing a screening program, and adverse patient and facility consequences. We review data pertaining to the lack of substantial aerosol generation during elective controlled intubation, extubation, and other procedures, and we provide guidance for when asymptomatic screening for SARS-CoV-2 may be considered in a limited scope.
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11
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Li J. Optimizing Respiratory Care for Patients While Protecting Ourselves. Respir Care 2023; 68:167-168. [PMID: 36566027 PMCID: PMC9993505 DOI: 10.4187/respcare.10680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Jie Li
- Department of Cardiopulmonary SciencesDivision of Respiratory CareRush UniversityChicago, Illinois
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12
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Ramsey ME, Faugno AJ, Puryear WB, Lee BC, Foss AD, Lambert LH, Nargi FE, Bopp GP, Lee LP, Rudzinski CM, Ervin BL, Runstadler JA, Hill NS. Characterization of SARS-CoV-2 Aerosols Dispersed During Noninvasive Respiratory Support of Patients With COVID-19. Respir Care 2023; 68:8-17. [PMID: 36566031 PMCID: PMC9993517 DOI: 10.4187/respcare.10340] [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] [Indexed: 12/26/2022]
Abstract
BACKGROUND In the midst of the COVID-19 pandemic, noninvasive respiratory support (NRS) therapies such as high-flow nasal cannula (HFNC) and noninvasive ventilation (NIV) were central to respiratory care. The extent to which these treatments increase the generation and dispersion of infectious respiratory aerosols is not fully understood. The objective of this study was to characterize SARS-CoV-2 aerosol dispersion from subjects with COVID-19 undergoing NRS therapy. METHODS Several different aerosol sampling devices were used to collect air samples in the vicinity of 31 subjects with COVID-19, most of whom were receiving NRS therapy, primarily HFNC. Aerosols were collected onto filters and analyzed for the presence of SARS-CoV-2 RNA. Additional measurements were collected in an aerosol chamber with healthy adult subjects using respiratory therapy devices under controlled and reproducible conditions. RESULTS Fifty aerosol samples were collected from subjects receiving HFNC or NIV therapy, whereas 6 samples were collected from subjects not receiving NRS. Only 4 of the 56 aerosol samples were positive for SARS-CoV-2 RNA, and all positive samples were collected using a high air flow scavenger mask collection device placed in close proximity to the subject. The chamber measurements with healthy subjects did not show any significant increase in aerosol dispersion caused by the respiratory therapy devices compared to baseline. CONCLUSIONS Our findings demonstrate very limited detection of SARS-CoV-2-containing aerosols in the vicinity of subjects with COVID-19 receiving NRS therapies in the clinical setting. These results, combined with controlled chamber measurements showing that HFNC and NIV device usage was not associated with increased aerosol dispersion, suggest that NRS therapies do not result in increased dispersal of aerosols in the clinical setting.
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Affiliation(s)
- Meghan E Ramsey
- Biotechnology and Human Systems Division, Massachusetts Institute of Technology, Lincoln Laboratory, Lexington, Massachusetts
| | - Anthony J Faugno
- Critical Care and Sleep Division, Tufts Medical Center, Boston, Massachusetts
| | - Wendy B Puryear
- Cummings School of Veterinary Medicine, Tufts University, Grafton, Massachusetts
| | - Brian C Lee
- Biotechnology and Human Systems Division, Massachusetts Institute of Technology, Lincoln Laboratory, Lexington, Massachusetts
| | - Alexa D Foss
- Cummings School of Veterinary Medicine, Tufts University, Grafton, Massachusetts
| | - Lester H Lambert
- Critical Care and Sleep Division, Tufts Medical Center, Boston, Massachusetts
| | - Frances E Nargi
- Biotechnology and Human Systems Division, Massachusetts Institute of Technology, Lincoln Laboratory, Lexington, Massachusetts
| | - Gregory P Bopp
- Biotechnology and Human Systems Division, Massachusetts Institute of Technology, Lincoln Laboratory, Lexington, Massachusetts
| | - Lauren P Lee
- Biotechnology and Human Systems Division, Massachusetts Institute of Technology, Lincoln Laboratory, Lexington, Massachusetts
| | - Christina M Rudzinski
- Biotechnology and Human Systems Division, Massachusetts Institute of Technology, Lincoln Laboratory, Lexington, Massachusetts
| | - Benjamin L Ervin
- Biotechnology and Human Systems Division, Massachusetts Institute of Technology, Lincoln Laboratory, Lexington, Massachusetts
| | | | - Nicholas S Hill
- Critical Care and Sleep Division, Tufts Medical Center, Boston, Massachusetts.
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13
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Mehmood R, Mansoor Z, Atanasov GP, Cheian A, Davletova A, Patel A, Ahmed D. High-Flow Nasal Oxygenation and Its Applicability in COVID Patients. SN COMPREHENSIVE CLINICAL MEDICINE 2022; 4:49. [PMID: 35128319 PMCID: PMC8801314 DOI: 10.1007/s42399-022-01132-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Accepted: 01/26/2022] [Indexed: 11/24/2022]
Abstract
High-flow nasal oxygenation (HFNO) is a type of oxygen therapy that provides humidified and heated oxygen through a nasal cannula at much higher flow rates than standard oxygen therapy, while also allowing control over the fraction of inspired oxygen (FIO2). Compared to standard oxygen therapy, it is much more comfortable for the patient and seems to alleviate most of the problems associated with standard oxygen therapy, such as dry nose, dry throat and nasal pain. It also provides a variety of benefits that can reduce the incidence of escalating treatment and initiating mechanical ventilation in COVID patients with acute hypoxemic respiratory failure (AHRF). This article provides an overview of HFNO and its current applications in COVID patients during the pandemic.
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Affiliation(s)
- Raafay Mehmood
- First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Zainab Mansoor
- First Faculty of Medicine, Charles University, Prague, Czech Republic
| | | | - Alexei Cheian
- First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Alina Davletova
- First Faculty of Medicine, Charles University, Prague, Czech Republic
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14
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McGrath JA, O’Sullivan A, Joyce M, Byrne MA, Li J, Fink JB, MacLoughlin R. In vitro model for investigating aerosol dispersion in a simulated COVID-19 patient during high-flow nasal cannula treatment. Front Med (Lausanne) 2022; 9:1002659. [PMID: 36530866 PMCID: PMC9751314 DOI: 10.3389/fmed.2022.1002659] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 11/14/2022] [Indexed: 08/05/2023] Open
Abstract
The use of high-flow nasal cannula in the treatment of COVID-19 infected patients has proven to be a valuable treatment option to improve oxygenation. Early in the pandemic, there were concerns for the degree of risk of disease transmission to health care workers utilizing these treatments that are considered aerosol generating procedures. This study developed an in vitro model to examine the release of simulated patient-derived bioaerosol with and without high-flow nasal cannula at gas flow rates of 30 and 50 L/min. Aerosol dispersion was evaluated at 30 and 90 cm distances. Reduction of transmission risk was assessed using a surgical facemask on the manikin. Results indicated that the use of a facemask facilitated a 94-95% reduction in exhaled aerosol concentration at 30 cm and 22-60% reduction for 90 cm distance across both gas flow rates. This bench study confirms that this in vitro model can be used as a tool to assess the risk of disease transmission during aerosol generating procedures in a simulated patient and to test factors to mitigate the risk.
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Affiliation(s)
- James A. McGrath
- Department of Physics, School of Natural Science, Ryan Institute’s Centre for Climate & Air Pollution Studies, University of Galway, Galway, Ireland
| | - Andrew O’Sullivan
- Research & Development, Science & Emerging Technologies, Aerogen Limited, Galway, Ireland
| | - Mary Joyce
- Research & Development, Science & Emerging Technologies, Aerogen Limited, Galway, Ireland
| | - Miriam A. Byrne
- Department of Physics, School of Natural Science, Ryan Institute’s Centre for Climate & Air Pollution Studies, University of Galway, Galway, Ireland
| | - Jie Li
- Division of Respiratory Care, Department of Cardiopulmonary Sciences, Rush University Medical Center, Chicago, IL, United States
| | - James B. Fink
- Aerogen Pharma Corporation, San Mateo, CA, United States
| | - Ronan MacLoughlin
- Research & Development, Science & Emerging Technologies, Aerogen Limited, Galway, Ireland
- School of Pharmacy and Biomolecular Sciences, Royal College of Surgeons in Ireland, Dublin, Ireland
- School of Pharmacy and Pharmaceutical Sciences, Trinity College Dublin, Dublin, Ireland
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15
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Silvers A, Brewster DJ, Ford A, Licina A, Andrews C, Adams M. Re-evaluating our language when reducing risk of SARS-CoV-2 transmission to healthcare workers: Time to rethink the term, “aerosol-generating procedures”. Virol J 2022; 19:189. [PMCID: PMC9672604 DOI: 10.1186/s12985-022-01910-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 10/22/2022] [Indexed: 11/19/2022] Open
Abstract
AbstractThe term, "aerosol-generating procedures” (AGPs), was proposed during the prior SARS-CoV-1 epidemic in order to maximise healthcare worker and patient protection. The concept of AGPs has since expanded to include routine therapeutic processes such as various modes of oxygen delivery and non-invasive ventilation modalities. Evidence gained during the SARS-CoV-2 pandemic has brought into question the concept of AGPs with regard to intubation, airway management, non-invasive ventilation and high flow nasal oxygen delivery. Although encounters where these procedures occur may still be associated with increased risk of infectious transmission, this is a function of the clinical context and not because the procedure itself is aerosol-generating.
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16
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Sánchez-Ayllón F, Segura-Alba O, Dos Santos-Bezerril M, Rojo-Rojo A, Melendreras-Ruiz R, Alcázar-Artero M, José Pujalte-Jesús M, Luis Díaz-Agea J. Safety Assessment of Low-Flow Oxygenation Device: Quasi-Experimental Study. Clin Nurs Res 2022; 31:1431-1437. [PMID: 35996872 DOI: 10.1177/10547738221112745] [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: 01/27/2023]
Abstract
The objective of this study was to verify the feasibility of using an Oxygenation Device with Reservoir and Positive End-Expiratory Pressure (ODRPEEP; DORPEEP in Spanish) and to analyze its safety with respect to mask leaks and carbon dioxide retention measured upon expiration. A quasi-experimental pilot study was designed with eight volunteers in two experiments to determine the degree of leaks from the device, according to the observation of water vapor particle diffusion, on the one hand, and of thermal images on the other. The results from this study showed that the mask from the DORPEEP© device at is tightest fit provided an adequate seal, although not fully airtight. In the thermal images and in the experiment with water vapor in our study, dispersions were mainly observed in the lower area in individuals with a beard. The DORPEEP© device was shown to have only slight leaks.
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17
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Shrimpton AJ, Pickering AE. Aerosols: time to clear the air? Anaesthesia 2022; 77:1193-1196. [DOI: 10.1111/anae.15864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/25/2022] [Indexed: 11/30/2022]
Affiliation(s)
- A. J. Shrimpton
- Anaesthesia, Pain and Critical Care Sciences, School of Physiology, Pharmacology and Neuroscience University of Bristol UK
| | - A. E. Pickering
- Anaesthesia, Pain and Critical Care Sciences, School of Physiology, Pharmacology and Neuroscience University of Bristol UK
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18
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Koyauchi T, Suzuki Y, Inoue Y, Hozumi H, Karayama M, Furuhashi K, Fujisawa T, Enomoto N, Inui N, Suda T. Clinical practice of high-flow nasal cannula therapy in COVID-19 pandemic era: a cross-sectional survey of respiratory physicians. Respir Investig 2022; 60:779-786. [PMID: 36153288 PMCID: PMC9464591 DOI: 10.1016/j.resinv.2022.08.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Revised: 08/01/2022] [Accepted: 08/22/2022] [Indexed: 12/03/2022]
Abstract
Background Despite the rapid widespread use of a high-flow nasal cannula (HFNC) during the COVID-19 pandemic, its indications and appropriate use as perceived by physicians remain poorly known. Methods In September 2021, we sent a questionnaire to each respiratory physician from 15 institutions in Shizuoka prefecture, Japan. In this survey, we compared the perceptions of HFNC indications and interventions during implementation to those of non-invasive ventilation (NIV) and invasive mechanical ventilation (IMV). Furthermore, this study examined concerns about SARS-CoV-2 infection spread and psychological distress experienced among respondents. Results Of the 140 respiratory physicians contacted, 87 (62.1%) completed the survey. The results indicate that 96.5% of the respondents agreed with the indication of HFNC for COVID-19, whereas only 13.7% agreed with NIV. The physicians reported that patients with HFNC had a lower frequency of sustained sedation, physical restraint, and implementation in the ICU than that of patients with NIV and IMV. The HFNC was introduced as a respiratory modality following conventional oxygen therapy (COT) in patients with COVID-19, regardless of full or do-not-intubate codes. Additionally, they reported that patients with COVID-19 switched from COT to HFNC significantly earlier than those without COVID-19. Simultaneously, this survey revealed persistent concerns of SARS-CoV-2 infection spread and psychological distress (47.1% and 53.3%, respectively) among respiratory physicians during HFNC use. Conclusion Clinically, HFNC is considered useful for COVID-19 patients by most respiratory physicians. However, HFNC remains a concern for COVID-19 spread and psychological distress among several respiratory physicians, indicating the need for urgent action.
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Affiliation(s)
- Takafumi Koyauchi
- Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, Shizuoka, 431-3192, Japan.
| | - Yuzo Suzuki
- Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, Shizuoka, 431-3192, Japan
| | - Yusuke Inoue
- Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, Shizuoka, 431-3192, Japan
| | - Hironao Hozumi
- Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, Shizuoka, 431-3192, Japan
| | - Masato Karayama
- Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, Shizuoka, 431-3192, Japan
| | - Kazuki Furuhashi
- Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, Shizuoka, 431-3192, Japan
| | - Tomoyuki Fujisawa
- Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, Shizuoka, 431-3192, Japan
| | - Noriyuki Enomoto
- Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, Shizuoka, 431-3192, Japan
| | - Naoki Inui
- Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, Shizuoka, 431-3192, Japan
| | - Takafumi Suda
- Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, Shizuoka, 431-3192, Japan
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19
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Application of High-Flow Nasal Cannula in COVID-19: A Narrative Review. Life (Basel) 2022; 12:life12091419. [PMID: 36143455 PMCID: PMC9505799 DOI: 10.3390/life12091419] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 09/09/2022] [Accepted: 09/09/2022] [Indexed: 02/07/2023] Open
Abstract
Background: During the first wave of COVID-19, the large influx of severely ill patients led to insufficient availability of beds in intensive care units and a shortage of ventilators. The shortage of ventilators, high mortality of intubated patients, and high risk of infections among healthcare workers involved in intubation were the main factors that led to the prevalence of noninvasive respiratory support during the pandemic. The high-flow nasal cannula (HFNC) is a commonly used, popular form of noninvasive respiratory support. Due to its unique physiological effects, HFNC can provide a high fraction of humidified oxygen and is satisfactorily comfortable for patients with COVID-19. However, before the COVID-19 era, there was little evidence on the application of HFNC in patients with acute respiratory failure caused by viral infection. Aim: This narrative review provides an overview of recent studies on the use of HFNC in patients with COVID-19-related acute hypoxemic respiratory failure. The main topics discussed include the probability of successful use of HFNC in these patients, whether late intubation increases mortality, the availability of convenient and accurate monitoring tools, comparison of HFNC with other types of noninvasive respiratory support, whether HFNC combined with the prone position is more clinically useful, and strategies to further reduce the infection risk associated with HFNC. The implication of this study is to identify some of the limitations and research gaps of the current literature and to give some advice for future research.
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20
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Joan TV, Kristiyan SA, Ernest SL, Nuria TP, Herme GB, Josep MB. Efficiency and sensitivity optimization of a protocol to quantify indoor airborne SARS-CoV-2 levels. J Hosp Infect 2022; 130:44-51. [PMID: 36100140 PMCID: PMC9465472 DOI: 10.1016/j.jhin.2022.08.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 08/24/2022] [Accepted: 08/26/2022] [Indexed: 11/29/2022]
Abstract
Background Development of methodologies to quantify airborne micro-organisms is needed for the prevention and control of infections. It is difficult to conclude which is the most efficient and sensitive strategy to assess airborne SARS-CoV-2 RNA levels due to the disparity of results reported in clinical settings. Aim To improve our previously reported protocol of measuring SARS-CoV-2 RNA levels, which was based on bioaerosol collection with a liquid impinger and RNA quantification with droplet digital polymerase chain reaction (ddPCR). Methods Air samples were collected in COVID-19 patient rooms to assess efficiency and/or sensitivity of different air samplers, liquid collection media, and reverse transcriptases (RT). Findings Mineral oil retains airborne RNA better than does hydrophilic media without impairing integrity. SARS-CoV-2 ORF1ab target was detected in 80% of the air samples using BioSampler with mineral oil. No significant differences in effectiveness were obtained with MD8 sampler equipped with gelatine membrane filters, but the SARS-CoV-2 copies/m3 air obtained with the latter were lower (28.4 ± 6.1 vs 9 ± 1.7). SuperScript II RT allows the detection of a single SARS-CoV-2 genome RNA molecule by ddPCR with high efficiency. This was the only RT that allowed the detection of SARS-CoV-2 N1 target in air samples. Conclusion The collection efficiency and detection sensivity of a protocol to quantify SARS-CoV-2 RNA levels in indoor air has been improved in the present study. Such optimization is important to improve our understanding of the microbiological safety of indoor air.
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Affiliation(s)
- Truyols-Vives Joan
- Molecular Biology and One Health Research Group (MolONE), Universitat de Les Illes Balears (UIB), Palma, Spain
| | | | - Sala-Llinàs Ernest
- Molecular Biology and One Health Research Group (MolONE), Universitat de Les Illes Balears (UIB), Palma, Spain; Health Research Institute of the Balearic Islands (IdISBa), Balearic Islands, Spain; Department of Pulmonary Medicine, Hospital Universitari Son Espases (HUSE), Balearic Islands, Spain; Biomedical Research Networking Center on Respiratory Diseases (CIBERES), Madrid, Spain
| | - Toledo-Pons Nuria
- Health Research Institute of the Balearic Islands (IdISBa), Balearic Islands, Spain; Department of Pulmonary Medicine, Hospital Universitari Son Espases (HUSE), Balearic Islands, Spain
| | - G Baldoví Herme
- Department of Chemistry, Universitat Politècnica de València (UPV)
| | - Mercader-Barceló Josep
- Molecular Biology and One Health Research Group (MolONE), Universitat de Les Illes Balears (UIB), Palma, Spain; Health Research Institute of the Balearic Islands (IdISBa), Balearic Islands, Spain.
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21
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Noninvasive Ventilation in Treatment of Respiratory Failure-Related COVID-19 Infection: Review of the Literature. Can Respir J 2022; 2022:9914081. [PMID: 36091330 PMCID: PMC9453089 DOI: 10.1155/2022/9914081] [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: 03/23/2021] [Revised: 10/22/2021] [Accepted: 06/14/2022] [Indexed: 11/18/2022] Open
Abstract
The recently diagnosed coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in December 2019 commonly affects the respiratory system. The incidence of acute hypoxic respiratory failure varied among epidemiological studies with high percentage of patients requiring mechanical ventilation with a high mortality. Noninvasive ventilation is an alternative tool for ventilatory support instead of invasive mechanical ventilation, especially with scarce resources and intensive care beds. Initially, there were concerns by the national societies regarding utilization of noninvasive ventilation in acute respiratory failure. Recent publications reflect the gained experience with the safe utilization of noninvasive mechanical ventilation. Noninvasive ventilation has beneficiary role in treatment of acute hypoxic respiratory failure with proper indications, setting, monitoring, and timely escalation of therapy. Patients should be monitored frequently for signs of improvement or deterioration in the clinical status. Awareness of indications, contraindications, and parameters reflecting either success or failure of noninvasive ventilation in the management of acute respiratory failure secondary to COVID-19 is essential for improvement of outcomes.
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22
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Borg BM, Osadnik C, Adam K, Chapman DG, Farrow CE, Glavas V, Hancock K, Lanteri CJ, Morris EG, Romeo N, Schneider‐Futschik EK, Selvadurai H. Pulmonary function testing during
SARS‐CoV
‐2: An
ANZSRS
/
TSANZ
position statement. Respirology 2022; 27:688-719. [PMID: 35981737 PMCID: PMC9539179 DOI: 10.1111/resp.14340] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 06/30/2022] [Indexed: 11/30/2022]
Affiliation(s)
- Brigitte M. Borg
- Respiratory Medicine The Alfred Melbourne Victoria Australia
- School of Public Health and Preventive Medicine Monash University Melbourne Victoria Australia
| | - Christian Osadnik
- Department of Physiotherapy Monash University Frankston Victoria Australia
- Monash Lung Sleep Allergy & Immunology Monash Health Clayton Victoria Australia
| | - Keith Adam
- Sonic HealthPlus Osborne Park Western Australia Australia
| | - David G. Chapman
- Respiratory Investigation Unit, Department of Respiratory Medicine Royal North Shore Hospital St Leonards New South Wales Australia
- Airway Physiology & Imaging Group, Woolcock Institute of Medical Research The University of Sydney Glebe New South Wales Australia
- Discipline of Medical Science, School of Life Sciences, Faculty of Science University of Technology Sydney Ultimo New South Wales Australia
| | - Catherine E. Farrow
- Airway Physiology & Imaging Group, Woolcock Institute of Medical Research The University of Sydney Glebe New South Wales Australia
- Respiratory Function Laboratory, Department of Respiratory and Sleep Medicine Westmead Hospital Westmead New South Wales Australia
- Westmead Clinical School, Sydney Medical School, Faculty of Medicine and Health Sciences The University of Sydney Sydney New South Wales Australia
| | - Vanda Glavas
- Respiratory SA Kent Town South Australia Australia
| | - Kerry Hancock
- Chandlers Hill Surgery Happy Valley South Australia Australia
| | - Celia J. Lanteri
- Department of Respiratory & Sleep Medicine Austin Health Heidelberg Victoria Australia
- Institute for Breathing and Sleep Austin Health Heidelberg Victoria Australia
| | - Ewan G. Morris
- Department of Respiratory Medicine Waitematā District Health Board Auckland New Zealand
| | - Nicholas Romeo
- Department of Respiratory Medicine Northern Health Epping Victoria Australia
| | - Elena K. Schneider‐Futschik
- Cystic Fibrosis Pharmacology Laboratory, Department of Biochemistry & Pharmacology University of Melbourne Parkville Victoria Australia
- School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences University of Melbourne Parkville Victoria Australia
| | - Hiran Selvadurai
- Department of Respiratory Medicine The Children's Hospital, Westmead, Sydney Childrens Hospital Network Sydney NSW Australia
- Discipline of Child and Adolescent Health Sydney Medical School, The University of Sydney Sydney NSW Australia
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23
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Abstract
During the early phase of the COVID-19 pandemic, many respiratory therapies were classified as aerosol-generating procedures. This categorization resulted in a broad range of clinical concerns and a shortage of essential medical resources for some patients. In the past 2 years, many studies have assessed the transmission risk posed by various respiratory care procedures. These studies are discussed in this narrative review, with recommendations for mitigating transmission risk based on the current evidence.
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Affiliation(s)
- Jie Li
- Department of Cardiopulmonary Sciences, Division of Respiratory Care, Rush University, Chicago, Illinois
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24
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Prevention of SARS-CoV-2 and respiratory viral infections in healthcare settings: current and emerging concepts. Curr Opin Infect Dis 2022; 35:353-362. [PMID: 35849526 DOI: 10.1097/qco.0000000000000839] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
PURPOSE OF REVIEW COVID-19 has catalyzed a wealth of new data on the science of respiratory pathogen transmission and revealed opportunities to enhance infection prevention practices in healthcare settings. RECENT FINDINGS New data refute the traditional division between droplet vs airborne transmission and clarify the central role of aerosols in spreading all respiratory viruses, including Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), even in the absence of so-called 'aerosol-generating procedures' (AGPs). Indeed, most AGPs generate fewer aerosols than talking, labored breathing, or coughing. Risk factors for transmission include high viral loads, symptoms, proximity, prolonged exposure, lack of masking, and poor ventilation. Testing all patients on admission and thereafter can identify early occult infections and prevent hospital-based clusters. Additional prevention strategies include universal masking, encouraging universal vaccination, preferential use of N95 respirators when community rates are high, improving native ventilation, utilizing portable high-efficiency particulate air filters when ventilation is limited, and minimizing room sharing when possible. SUMMARY Multifaceted infection prevention programs that include universal testing, masking, vaccination, and enhanced ventilation can minimize nosocomial SARS-CoV-2 infections in patients and workplace infections in healthcare personnel. Extending these insights to other respiratory viruses may further increase the safety of healthcare and ready hospitals for novel respiratory viruses that may emerge in the future.
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Oxygénothérapie à haut débit nasal dans l’insuffisance respiratoire aiguë hypoxémique. Rev Mal Respir 2022; 39:607-617. [DOI: 10.1016/j.rmr.2022.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 05/24/2022] [Indexed: 11/18/2022]
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Survey of coronavirus disease 2019 (COVID-19) infection control policies at leading US academic hospitals in the context of the initial pandemic surge of the severe acute respiratory coronavirus virus 2 (SARS-CoV-2) omicron variant. Infect Control Hosp Epidemiol 2022; 44:597-603. [PMID: 35705223 PMCID: PMC9253430 DOI: 10.1017/ice.2022.155] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVE To assess coronavirus disease 2019 (COVID-19) infection policies at leading US medical centers in the context of the initial wave of the severe acute respiratory coronavirus virus 2 (SARS-CoV-2) omicron variant. DESIGN Electronic survey study eliciting hospital policies on masking, personal protective equipment, cohorting, airborne-infection isolation rooms (AIIRs), portable HEPA filters, and patient and employee testing. SETTING AND PARTICIPANTS "Hospital epidemiologists from U.S. News top 20 hospitals and 10 hospitals in the CDC Prevention Epicenters program." As it is currently written, it implies all 30 hospitals are from the CDC Prevention Epicenters program, but that only applies to 10 hospitals. Alternatively, we could just say "Hospital epidemiologists from 30 leading US hospitals." METHODS Survey results were reported using descriptive statistics. RESULTS Of 30 hospital epidemiologists surveyed, 23 (77%) completed the survey between February 15 and March 3, 2022. Among the responding hospitals, 18 (78%) used medical masks for universal masking and 5 (22%) used N95 respirators. 16 hospitals (70%) required universal eye protection. 22 hospitals (96%) used N95s for routine COVID-19 care and 1 (4%) reserved N95s for aerosol-generating procedures. 2 responding hospitals (9%) utilized dedicated COVID-19 wards; 8 (35%) used mixed COVID-19 and non-COVID-19 units; and 13 (57%) used both dedicated and mixed units. 4 hospitals (17%) used AIIRs for all COVID-19 patients, 10 (43%) prioritized AIIRs for aerosol-generating procedures, 3 (13%) used alternate risk-stratification criteria (not based on aerosol-generating procedures), and 6 (26%) did not routinely use AIIRs. 9 hospitals (39%) did not use portable HEPA filters, but 14 (61%) used them for various indications, most commonly as substitutes for AIIRs when unavailable or for specific high-risk areas or situations. 21 hospitals (91%) tested asymptomatic patients on admission, but postadmission testing strategies and preferred specimen sites varied substantially. 5 hospitals (22%) required regular testing of unvaccinated employees and 1 hospital (4%) reported mandatory weekly testing even for vaccinated employees during the SARS-CoV-2 omicron surge. CONCLUSIONS COVID-19 infection control practices in leading hospitals vary substantially. Clearer public health guidance and transparency around hospital policies may facilitate more consistent national standards.
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Abstract
PURPOSE OF REVIEW Apneic oxygenation is increasingly used in pediatric anesthesia. Its benefit for specific applications depends on the effect of apneic oxygenation on safe apnea time and carbon dioxide (CO2) elimination, on differences between low and high flow oxygen delivery, and on possible adverse effects. The present review summarizes current evidence on these pathophysiological aspects of apneic oxygenation as well as its applications in pediatric anesthesia. RECENT FINDINGS Apneic oxygenation with both low flow and high flow nasal oxygen increases the safe apnea time, but does not lead to increased CO2 elimination. Airway pressures and adverse effects like atelectasis formation, oxidative stress and aerosol generation under apneic oxygenation are not well studied in pediatric anesthesia. Data from adults suggest no important effect on airway pressures when the mouth is open, and no significant formation of atelectasis, oxidative stress or aerosol generation with high flow nasal oxygen. SUMMARY Apneic oxygenation in pediatric anesthesia is mainly used during standard and difficult airway management. It is sometimes used for airway interventions, but CO2 accumulation remains a major limiting factor in this setting. Reports highlight the use of high flow nasal oxygen in spontaneously breathing rather than in apneic children for airway interventions.
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Shrimpton AJ, Brown JM, Cook TM, Penfold CM, Reid JP, Pickering AE. Quantitative evaluation of aerosol generation from upper airway suctioning assessed during tracheal intubation and extubation sequences in anaesthetized patients. J Hosp Infect 2022; 124:13-21. [PMID: 35276282 PMCID: PMC9172909 DOI: 10.1016/j.jhin.2022.02.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 02/17/2022] [Accepted: 02/28/2022] [Indexed: 12/14/2022]
Abstract
BACKGROUND Open respiratory suctioning is defined as an aerosol generating procedure (AGP). Laryngopharyngeal suctioning, used to clear secretions during anaesthesia, is widely managed as an AGP. However, it is uncertain whether upper airway suctioning should be designated as an AGP due to the lack of both aerosol and epidemiological evidence. AIM To assess the relative risk of aerosol generation by upper airway suctioning during tracheal intubation and extubation in anaesthetized patients. METHODS This prospective environmental monitoring study was undertaken in an ultraclean operating theatre setting to assay aerosol concentrations during intubation and extubation sequences, including upper airway suctioning, for patients undergoing surgery (N=19). An optical particle sizer (particle size 0.3-10 μm) sampled aerosol 20 cm above the patient's mouth. Baseline recordings (background, tidal breathing and volitional coughs) were followed by intravenous induction of anaesthesia with neuromuscular blockade. Four periods of laryngopharyngeal suctioning were performed with a Yankauer sucker: pre-laryngoscopy, post-intubation, pre-extubation and post-extubation. FINDINGS Aerosol was reliably detected {median 65 [interquartile range (IQR) 39-259] particles/L} above background [median 4.8 (IQR 1-7) particles/L, P<0.0001] when sampling in close proximity to the patient's mouth during tidal breathing. Upper airway suctioning was associated with a much lower average aerosol concentration than breathing [median 6.0 (IQR 0-12) particles/L, P=0.0007], and was indistinguishable from background (P>0.99). Peak aerosol concentrations recorded during suctioning [median 45 (IQR 30-75) particles/L] were much lower than during volitional coughs [median 1520 (IQR 600-4363) particles/L, P<0.0001] and tidal breathing [median 540 (IQR 300-1826) particles/L, P<0.0001]. CONCLUSION Upper airway suctioning during airway management was not associated with a higher aerosol concentration compared with background, and was associated with a much lower aerosol concentration compared with breathing and coughing. Upper airway suctioning should not be designated as a high-risk AGP.
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Affiliation(s)
- A J Shrimpton
- Anaesthesia, Pain and Critical Care, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK.
| | - J M Brown
- Department of Anaesthesia and Intensive Care Medicine, North Bristol NHS Trust, Bristol, UK
| | - T M Cook
- Department of Anaesthesia and Intensive Care Medicine, Royal United Hospital NHS Trust, Bath, UK
| | - C M Penfold
- Bristol Biomedical Research Centre, University of Bristol NHS Foundation Trust and University of Bristol, Bristol, UK
| | - J P Reid
- School of Chemistry, University of Bristol, Bristol, UK
| | - A E Pickering
- Anaesthesia, Pain and Critical Care, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
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Gregson FKA, Shrimpton AJ, Hamilton F, Cook TM, Reid JP, Pickering AE, Pournaras DJ, Bzdek BR, Brown J. Identification of the source events for aerosol generation during oesophago-gastro-duodenoscopy. Gut 2022; 71:871-878. [PMID: 34187844 PMCID: PMC8245282 DOI: 10.1136/gutjnl-2021-324588] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 06/16/2021] [Indexed: 12/17/2022]
Abstract
OBJECTIVE To determine if oesophago-gastro-duodenoscopy (OGD) generates increased levels of aerosol in conscious patients and identify the source events. DESIGN A prospective, environmental aerosol monitoring study, undertaken in an ultraclean environment, on patients undergoing OGD. Sampling was performed 20 cm away from the patient's mouth using an optical particle sizer. Aerosol levels during OGD were compared with tidal breathing and voluntary coughs within subject. RESULTS Patients undergoing bariatric surgical assessment were recruited (mean body mass index 44 and mean age 40 years, n=15). A low background particle concentration in theatres (3 L-1) enabled detection of aerosol generation by tidal breathing (mean particle concentration 118 L-1). Aerosol recording during OGD showed an average particle number concentration of 595 L-1 with a wide range (3-4320 L-1). Bioaerosol-generating events, namely, coughing or burping, were common. Coughing was evoked in 60% of the endoscopies, with a greater peak concentration and a greater total number of sampled particles than the patient's reference voluntary coughs (11 710 vs 2320 L-1 and 780 vs 191 particles, n=9 and p=0.008). Endoscopies with coughs generated a higher level of aerosol than tidal breathing, whereas those without coughs were not different to the background. Burps also generated increased aerosol concentration, similar to those recorded during voluntary coughs. The insertion and removal of the endoscope were not aerosol generating unless a cough was triggered. CONCLUSION Coughing evoked during OGD is the main source of the increased aerosol levels, and therefore, OGD should be regarded as a procedure with high risk of producing respiratory aerosols. OGD should be conducted with airborne personal protective equipment and appropriate precautions in those patients who are at risk of having COVID-19 or other respiratory pathogens.
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Affiliation(s)
| | - Andrew J Shrimpton
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
- Department of Anaesthesia and Intensive Care Medicine, North Bristol NHS Trust, Bristol, UK
| | - Fergus Hamilton
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Tim M Cook
- Department of Anaesthesia and Intensive Care Medicine, Royal United Hospitals NHS Trust, Bath, and Bristol Medical School, University of Bristol, Bristol, UK
| | | | - Anthony E Pickering
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
- Bristol Anaesthesia, Pain and Critical Care Sciences, Translational Health Sciences, Bristol Medical School, Bristol, UK
| | - Dimitri J Pournaras
- Department of Upper Gastrointestinal and Bariatric/Metabolic Surgery, North Bristol NHS Trust, Bristol, UK
| | - Bryan R Bzdek
- School of Chemistry, University of Bristol, Bristol, UK
| | - Jules Brown
- Department of Anaesthesia and Intensive Care Medicine, North Bristol NHS Trust, Bristol, UK
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Chao KY, Wang JS, Liu WL. Role of helmet ventilation during the 2019 coronavirus disease pandemic. Sci Prog 2022; 105:368504221092891. [PMID: 35404163 PMCID: PMC9006090 DOI: 10.1177/00368504221092891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Coronavirus disease 2019 (COVID-19) has been declared a pandemic by the World Health Organization; it has affected millions of people and caused hundreds of thousands of deaths. Patients with COVID-19 pneumonia may develop acute hypoxia respiratory failure and require noninvasive respiratory support or invasive respiratory management. Healthcare workers have a high risk of contracting COVID-19 while fitting respiratory devices. Recently, European experts have suggested that the use of helmet continuous positive airway pressure should be the first choice for acute hypoxia respiratory failure caused by COVID-19 because it reduces the spread of the virus in the ambient air. By contrast, in the United States, helmets were restricted for respiratory care before the COVID-19 pandemic until the Food and Drug Administration provided the ‘Umbrella Emergency Use Authorization for Ventilators and Ventilator Accessories’. This narrative review provides an evidence-based overview of the use of helmet ventilation for patients with respiratory failure.
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Affiliation(s)
- Ke-Yun Chao
- Department of Respiratory Therapy, Fu Jen Catholic University Hospital, Fu Jen Catholic University, New Taipei City, Taiwan
- School of Physical Therapy, Graduate Institute of Rehabilitation Sciences, Chang Gung University, Taoyuan, Taiwan
| | - Jong-Shyan Wang
- Department of Physical Medicine and Rehabilitation, Keelung Chang Gung Memorial Hospital, Keelung, Taiwan
- Department of Physical Therapy, College of Medicine, Graduate Institute of Rehabilitation Science, Chang Gung University, Taoyuan, Taiwan
- Research Center for Chinese Herbal Medicine, College of Human Ecology, Chang Gung University of Science and Technology, Taoyuan, Taiwan
| | - Wei-Lun Liu
- Department of Emergency and Critical Care Medicine, Fu Jen Catholic University Hospital, Fu Jen Catholic University, New Taipei City, Taiwan
- Data Science Center, College of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan
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Frat JP, Le Pape S, Coudroy R, Thille AW. Noninvasive Oxygenation in Patients with Acute Respiratory Failure: Current Perspectives. Int J Gen Med 2022; 15:3121-3132. [PMID: 35418775 PMCID: PMC9000535 DOI: 10.2147/ijgm.s294906] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 02/22/2022] [Indexed: 01/16/2023] Open
Abstract
Purpose of Review High-flow nasal oxygen and noninvasive ventilation are two alternative strategies to standard oxygen in the management of acute respiratory failure. Discussion Although high-flow nasal oxygen has gained major popularity in ICUs due to its simplicity of application, good comfort for patients, efficiency in improving oxygenation and promising results in patients with acute hypoxemic respiratory failure, further large clinical trials are needed to confirm its superiority over standard oxygen. Non-invasive ventilation may have deleterious effects, especially in patients exerting strong inspiratory efforts, and no current recommendations support its use in this setting. Protective non-invasive ventilation using higher levels of positive-end expiratory pressure, more prolonged sessions and other interfaces such as the helmet may have beneficial physiological effects leading to it being proposed as alternative to high-flow nasal oxygen in acute hypoxemic respiratory failure. By contrast, non-invasive ventilation is the first-line strategy of oxygenation in patients with acute exacerbation of chronic lung disease, while high-flow nasal oxygen could be an alternative to non-invasive ventilation after partial reversal of respiratory acidosis. Questions remain about the target populations and non-invasive oxygen strategy representing the best alternative to standard oxygen in acute hypoxemic respiratory failure. As concerns acute on-chronic-respiratory failure, the place of high-flow nasal oxygen remains to be evaluated.
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Affiliation(s)
- Jean-Pierre Frat
- Centre Hospitalier Universitaire de Poitiers, Médecine Intensive Réanimation, Poitiers, France
- Centre d’Investigation Clinique 1402 ALIVE, INSERM, Université de Poitiers, Poitiers, France
| | - Sylvain Le Pape
- Centre Hospitalier Universitaire de Poitiers, Médecine Intensive Réanimation, Poitiers, France
| | - Rémi Coudroy
- Centre Hospitalier Universitaire de Poitiers, Médecine Intensive Réanimation, Poitiers, France
- Centre d’Investigation Clinique 1402 ALIVE, INSERM, Université de Poitiers, Poitiers, France
| | - Arnaud W Thille
- Centre Hospitalier Universitaire de Poitiers, Médecine Intensive Réanimation, Poitiers, France
- Centre d’Investigation Clinique 1402 ALIVE, INSERM, Université de Poitiers, Poitiers, France
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Li J, A Alolaiwat A, J Harnois L, Fink JB, Dhand R. Mitigating Fugitive Aerosols During Aerosol Delivery via High-Flow Nasal Cannula Devices. Respir Care 2022; 67:404-414. [PMID: 34789564 PMCID: PMC9994017 DOI: 10.4187/respcare.09589] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Aerosol delivery via high-flow nasal cannula (HFNC) has attracted clinical interest in recent years. However, both HFNC and nebulization are categorized as aerosol-generating procedures (AGPs). In vitro studies raised concerns that AGPs had high transmission risk. Very few in vivo studies examined fugitive aerosols with nebulization via HFNC, and effective methods to mitigate aerosol dispersion are unknown. METHODS Two HFNC devices (Airvo 2 and Vapotherm) with or without a vibrating mesh nebulizer were compared; HFNC alone, surgical mask over HFNC interface, and HFNC with face tent scavenger were used in a random order for 9 healthy volunteers. Fugitive aerosol concentrations at sizes of 0.3-10.0 μm were continuously measured by particle sizers placed at 1 and 3 ft from participants. On a different day, 6 of the 9 participants received 6 additional nebulizer treatments via vibrating mesh nebulizer or small-volume nebulizer (SVN) with a face mask or a mouthpiece with/without an expiratory filter. In vitro simulation was employed to quantify inhaled dose of albuterol with vibrating mesh nebulizer via Airvo 2 and Vapotherm. RESULTS Compared to baseline, neither HFNC device generated higher aerosol concentrations. Compared to HFNC alone, vibrating mesh nebulizer via Airvo 2 generated higher 0.3-1.0 μm particles (all P < .05), but vibrating mesh nebulizer via Vapotherm did not. Concentrations of 1.0-3.0 μm particles with vibrating mesh nebulizer via Airvo 2 were similar with vibrating mesh nebulizer and a mouthpiece/face mask but less than SVN with a mouthpiece/face mask (all P < .05). Placing a surgical mask over HFNC during nebulization reduced 0.5-1.0 μm particles (all P < .05) to levels similar to the use of a nebulizer with mouthpiece and expiratory filter. In vitro the inhaled dose of albuterol with vibrating mesh nebulizer via Airvo 2 was ≥ 6 times higher than vibrating mesh nebulizer via Vapotherm. CONCLUSIONS During aerosol delivery via HFNC, Airvo 2 generated higher inhaled dose and consequently higher fugitive aerosols than Vapotherm. Simple measures, such as placing a surgical mask over nasal cannula during nebulization via HFNC, could effectively reduce fugitive aerosol concentrations.
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Affiliation(s)
- Jie Li
- Department of Cardiopulmonary Sciences, Division of Respiratory Care, Rush University, Chicago, Illinois.
| | - Amnah A Alolaiwat
- Department of Cardiopulmonary Sciences, Division of Respiratory Care, Rush University, Chicago, Illinois
| | - Lauren J Harnois
- Department of Cardiopulmonary Sciences, Division of Respiratory Care, Rush University, Chicago, Illinois
| | - James B Fink
- Department of Cardiopulmonary Sciences, Division of Respiratory Care, Rush University, Chicago, Illinois; and Aerogen Pharma Corp, San Mateo, California
| | - Rajiv Dhand
- Department of Medicine, University of Tennessee Graduate School of Medicine, Knoxville, Tennessee
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33
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Hamilton FW, Gregson FKA, Arnold DT, Sheikh S, Ward K, Brown J, Moran E, White C, Morley AJ, Bzdek BR, Reid JP, Maskell NA, Dodd JW. Aerosol emission from the respiratory tract: an analysis of aerosol generation from oxygen delivery systems. Thorax 2022. [PMID: 34737195 DOI: 10.1101/2021.01.29.21250552] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
INTRODUCTION continuous positive airway pressure (CPAP) and high-flow nasal oxygen (HFNO) provide enhanced oxygen delivery and respiratory support for patients with severe COVID-19. CPAP and HFNO are currently designated as aerosol-generating procedures despite limited high-quality experimental data. We aimed to characterise aerosol emission from HFNO and CPAP and compare with breathing, speaking and coughing. MATERIALS AND METHODS Healthy volunteers were recruited to breathe, speak and cough in ultra-clean, laminar flow theatres followed by using CPAP and HFNO. Aerosol emission was measured using two discrete methodologies, simultaneously. Hospitalised patients with COVID-19 had cough recorded using the same methodology on the infectious diseases ward. RESULTS In healthy volunteers (n=25 subjects; 531 measures), CPAP (with exhalation port filter) produced less aerosol than breathing, speaking and coughing (even with large >50 L/min face mask leaks). Coughing was associated with the highest aerosol emissions of any recorded activity. HFNO was associated with aerosol emission, however, this was from the machine. Generated particles were small (<1 µm), passing from the machine through the patient and to the detector without coalescence with respiratory aerosol, thereby unlikely to carry viral particles. More aerosol was generated in cough from patients with COVID-19 (n=8) than volunteers. CONCLUSIONS In healthy volunteers, standard non-humidified CPAP is associated with less aerosol emission than breathing, speaking or coughing. Aerosol emission from the respiratory tract does not appear to be increased by HFNO. Although direct comparisons are complex, cough appears to be the main aerosol-generating risk out of all measured activities.
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Affiliation(s)
- Fergus W Hamilton
- Infection Science, North Bristol NHS Trust, Westbury on Trym, UK
- MRC Integrative Epidemiology Unit, Bristol, UK
| | - Florence K A Gregson
- Bristol Aerosol Research Centre, School of Chemistry, University of Bristol, Bristol, UK
| | - David T Arnold
- Academic Respiratory Unit, North Bristol NHS Trust, Westbury on Trym, UK
| | - Sadiyah Sheikh
- Bristol Aerosol Research Centre, School of Chemistry, University of Bristol, Bristol, UK
| | - Kirsty Ward
- Physiotherapy Department, North Bristol NHS Trust, Westbury on Trym, UK
| | - Jules Brown
- Anaesthetics and Intensive Care Department, North Bristol NHS Trust, Westbury on Trym, UK
| | - Ed Moran
- Infectious Diseases, North Bristol NHS Trust, Bristol, UK
| | - Carrie White
- Research and Development, North Bristol NHS Trust, Westbury on Trym, UK
| | - Anna J Morley
- Academic Respiratory Unit, North Bristol NHS Trust, Westbury on Trym, UK
| | - Bryan R Bzdek
- Bristol Aerosol Research Centre, School of Chemistry, University of Bristol, Bristol, UK
| | - Jonathan P Reid
- Bristol Aerosol Research Centre, School of Chemistry, University of Bristol, Bristol, UK
| | - Nicholas A Maskell
- Academic Respiratory Unit, North Bristol NHS Trust, Westbury on Trym, UK
| | - James William Dodd
- MRC Integrative Epidemiology Unit, Bristol, UK
- Academic Respiratory Unit, North Bristol NHS Trust, Westbury on Trym, UK
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Airborne SARS-CoV-2 RNA excretion by patients with COVID-19 on different oxygen delivery systems: a prospective observational study. J Hosp Infect 2022; 123:87-91. [PMID: 35288255 PMCID: PMC8917005 DOI: 10.1016/j.jhin.2022.03.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 02/23/2022] [Accepted: 03/06/2022] [Indexed: 12/23/2022]
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Urbina T, Elabbadi A, Gabarre P, Bigé N, Turpin M, Bonny V, Desnos C, Baudel JL, Lavillegrand JR, Hariri G, Fartoukh M, Guidet B, Maury E, Dumas G, Voiriot G, Ait-Oufella H. Endotracheal intubation rate is lower in critically-ill SARS-CoV-2 patients requiring high-flow nasal oxygen receiving additional face-mask noninvasive ventilation: a retrospective bicentric cohort with propensity score analysis. Minerva Anestesiol 2022; 88:580-587. [PMID: 35191641 DOI: 10.23736/s0375-9393.22.16094-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND SARS-CoV-2 pneumonia is responsible for unprecedented numbers of acute respiratory failure requiring invasive mechanical ventilation (IMV). This work aimed to assess whether adding face-mask noninvasive ventilation (NIV) to high-flow nasal oxygen (HFNO) was associated with a reduced need for endotracheal intubation. METHODS This retrospective cohort study was conducted from July 2020 to January 2021 in two tertiary care intensive care units (ICUs) in Paris, France. Patients admitted for laboratory confirmed SARS-CoV-2 infection with acute hypoxemic respiratory failure requiring HFNO with or without NIV were included. The primary outcome was the rate of endotracheal intubation. Secondary outcomes included day-28 mortality, day-28 respiratory support and IMV free days, ICU and hospital length-of-stay. Sensitivity analyses with both propensity score matching and overlap weighting were used. RESULTS 128 patients were included, 88 (69%) received HFNO alone and 40 (31%) received additional NIV. Additional NIV was associated with a reduced rate of endotracheal intubation in multivariate analysis (53 (60%) vs 15 (38%), HR=0.46 (95%CI, 0.23-0.95), p=0.04). Sensitivity analyses by propensity score matching (HR=0.45 (95%IC, 0.24-0.84), p=0.01) and overlap weighting (HR=0.52 (95% CI, 0.28-0.94), p=0.03) were consistent. Day-28 mortality was 25 (28%) in the HFNO group and 8 (20%) in the NIV group (HR=0.75 (95%CI, 0.15-3.82), p=0.72). NIV was associated with higher IMV free days (20 (0-28) vs 28 (14-28), p=0.015). All sensitivity analyses were consistent regarding secondary outcomes. CONCLUSION Need for endotracheal intubation was lower in critically-ill SARS-CoV-2 patients receiving face-mask noninvasive mechanical ventilation in addition to high-flow oxygen therapy.
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Affiliation(s)
- Tomas Urbina
- Intensive Care Unit, Saint-Antoine hospital, Assistance Publique-Hôpitaux de Paris, Paris, France - .,Sorbonne Université, Pierre et Marie-Curie university, Paris, France -
| | - Alexandre Elabbadi
- Sorbonne Université, Pierre et Marie-Curie university, Paris, France.,Intensive Care Unit, Tenon hospital, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Paul Gabarre
- Intensive Care Unit, Saint-Antoine hospital, Assistance Publique-Hôpitaux de Paris, Paris, France.,Sorbonne Université, Pierre et Marie-Curie university, Paris, France
| | - Naike Bigé
- Intensive Care Unit, Saint-Antoine hospital, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Matthieu Turpin
- Sorbonne Université, Pierre et Marie-Curie university, Paris, France.,Intensive Care Unit, Tenon hospital, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Vincent Bonny
- Intensive Care Unit, Saint-Antoine hospital, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Cyrielle Desnos
- Intensive Care Unit, Tenon hospital, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Jean-Luc Baudel
- Intensive Care Unit, Saint-Antoine hospital, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Jean-Remi Lavillegrand
- Intensive Care Unit, Saint-Antoine hospital, Assistance Publique-Hôpitaux de Paris, Paris, France.,Sorbonne Université, Pierre et Marie-Curie university, Paris, France
| | - Geoffroy Hariri
- Intensive Care Unit, Saint-Antoine hospital, Assistance Publique-Hôpitaux de Paris, Paris, France.,Sorbonne Université, Pierre et Marie-Curie university, Paris, France
| | - Muriel Fartoukh
- Sorbonne Université, Pierre et Marie-Curie university, Paris, France.,Intensive Care Unit, Tenon hospital, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Bertrand Guidet
- Intensive Care Unit, Saint-Antoine hospital, Assistance Publique-Hôpitaux de Paris, Paris, France.,Sorbonne Université, Pierre et Marie-Curie university, Paris, France
| | - Eric Maury
- Intensive Care Unit, Saint-Antoine hospital, Assistance Publique-Hôpitaux de Paris, Paris, France.,Sorbonne Université, Pierre et Marie-Curie university, Paris, France
| | - Guillaume Dumas
- Intensive Care Unit, Saint-Louis hospital, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Guillaume Voiriot
- Sorbonne Université, Pierre et Marie-Curie university, Paris, France.,Intensive Care Unit, Tenon hospital, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Hafid Ait-Oufella
- Intensive Care Unit, Saint-Antoine hospital, Assistance Publique-Hôpitaux de Paris, Paris, France.,Sorbonne Université, Pierre et Marie-Curie university, Paris, France.,Inserm U970, Cardiovascular research center, Université de Paris, Paris, France
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Sequera-Ramos L, Garcia-Marcinkiewicz A, Riva T, Fuchs A. Noninvasive ventilation in children: A review for the pediatric anesthesiologist. Paediatr Anaesth 2022; 32:262-272. [PMID: 34877751 DOI: 10.1111/pan.14364] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 12/01/2021] [Accepted: 12/02/2021] [Indexed: 01/19/2023]
Abstract
Preserving adequate respiratory function is essential in the perioperative period. Mechanical ventilation with endotracheal intubation is widely used for this purpose. In select patients, noninvasive ventilation (NIV) may be an alternative to invasive ventilation or may complement respiratory management. NIV is used to provide ventilatory support and increase gas exchange at the alveolar level without the use of an invasive artificial airway such as an endotracheal tube or tracheostomy. NIV includes both continuous positive airway pressure (CPAP) and noninvasive positive pressure ventilation. Indications for NIV range from acute hypoxic respiratory failure in the intensive care unit or the emergency department, to chronic respiratory failure in patients with neuromuscular disease with nocturnal hypoventilation. In the perioperative setting, NIV is commonly applied as CPAP, and bilevel positive airway pressure (BPAP). There are limited data on the role of NIV in children in the perioperative setting, and there are no clear guidelines regarding optimal timing of use and pressure settings of perioperative NIV. Contraindications to the use of NIV include reduced level of consciousness, apnea, severe respiratory distress, and inability to maintain upper airway patency or airway protective reflexes. Common problems encountered during NIV involve airway leaks and asynchrony with auto-triggering. High-flow nasal oxygen (HFNO) has emerged as an alternative to NIV when trying to decrease the work of breathing and improve oxygenation in children. HFNO delivers humidified and heated oxygen at rates between 2 and 70 L/min using specific nasal cannulas, and flows are determined by the patient's weight and clinical needs. HFNO can be useful as a method for preoxygenation in infants and children by prolonging apnea time before desaturation, yet in children with decreased minute ventilation or apnea HFNO does not improve alveolar gas exchange. Clinicians experienced with these devices, such as pediatric intensivists and pulmonary medicine specialists, can be useful resources for the pediatric anesthesiologist caring for complex patients on NIV.
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Affiliation(s)
- Luis Sequera-Ramos
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Annery Garcia-Marcinkiewicz
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Thomas Riva
- Department of Anaesthesiology and Pain Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.,Unit for Research & Innovation in Anaesthesia, Department of Paediatric Anaesthesia, Istituto Giannina Gaslini, Genoa, Italy
| | - Alexander Fuchs
- Department of Anaesthesiology and Pain Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
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Crimi C, Pierucci P, Renda T, Pisani L, Carlucci A. High-Flow Nasal Cannula and COVID-19: A Clinical Review. Respir Care 2022; 67:227-240. [PMID: 34521762 PMCID: PMC9993935 DOI: 10.4187/respcare.09056] [Citation(s) in RCA: 48] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
During the coronavirus disease 2019 (COVID-19) pandemic, noninvasive respiratory support has played a central role in managing patients affected by moderate-to-severe acute hypoxemic respiratory failure, despite inadequate scientific evidence to support its usage. High-flow nasal cannula (HFNC) treatment has gained popularity because of its effectiveness in delivering a high fraction of humidified oxygen, which improves ventilatory efficiency and the respiratory pattern, as well as its reported high tolerability, ease of use, and application outside of ICUs. Nevertheless, the risk of infection transmission to health-care workers has raised some concerns about its use in the first wave of the pandemic outbreak, with controversial recommendations provided by different scientific societies. This narrative review provides an overview of the recent evidence on the physiologic rationale, risks, and benefits of using HFNC instead of conventional oxygen therapy and other types of noninvasive respiratory support devices, such as continuous positive airway pressure and noninvasive ventilation in patients affected by COVID-19 pneumonia with associated acute hypoxemic respiratory failure. It also summarizes the available evidence with regard to the clinical use of HFNC during the current pandemic and its reported outcomes, and highlights the risks of bioaerosol dispersion associated with HFNC use.
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Affiliation(s)
- Claudia Crimi
- Respiratory Medicine Unit, "Policlinico-Vittorio Emanuele-San Marco," University Hospital, Catania, Italy.
| | - Paola Pierucci
- Respiratory Medicine Unit, Policlinico "Aldo Moro" University Hospital, Bari, Italy
| | - Teresa Renda
- Respiratory and Critical Care Unit, Cardio-thoracic and Vascular Department, Careggi Teaching Hospital, Florence, Italy
| | - Lara Pisani
- Respiratory and Critical Care Unit, IRCCS Azienda Ospedaliero Universitaria di Bologna, University Hospital Sant'Orsola-Malpighi, Bologna, Italy
- Department of Clinical, Integrated and Experimental Medicine, Alma Mater Studiorum University, Bologna, Italy
| | - Annalisa Carlucci
- Department of Medicine and Surgery, Università Insubria, Varese-Como, Italy
- Pulmonary Rehabilitation Unit, Istituti Clinici Scientifici Maugeri, Pavia, Italy
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38
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Crowley C, Murphy B, McCaul C, Cahill R, Nolan KP. Airborne particle dispersion by high flow nasal oxygen: An experimental and CFD analysis. PLoS One 2022; 17:e0262547. [PMID: 35061806 PMCID: PMC8782405 DOI: 10.1371/journal.pone.0262547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 12/28/2021] [Indexed: 12/15/2022] Open
Abstract
High Flow Nasal Oxygen (HFNO) therapy offers a proven means of delivering respiratory support to critically ill patients suffering from viral illness such as COVID-19. However, the therapy has the potential to modify aerosol generation and dispersion patterns during exhalation and thereby put healthcare workers at increased risk of disease transmission. Fundamentally, a gap exists in the literature with regards to the effect of the therapy on the fluid dynamics of the exhalation jet which is essential in understanding the dispersion of aerosols and hence quantifying the disease transmission risk posed by the therapy. In this paper, a multi-faceted approach was taken to studying the aerosol-laden exhalation jet. Schlieren imaging was used to visualise the flow field for a range of expiratory activities for three healthy human volunteers receiving HFNO therapy at flow rates of 0-60 L/min. A RANS turbulence model was implemented using the CFD software OpenFOAM and used to perform a parametric study on the influence of exhalation velocity and duration on the dispersion patterns of non-evaporating droplets in a room environment. A dramatic increase in the turbulence of the exhalation jet was observed when HFNO was applied. Quantitative analysis indicated that the mean exhalation velocity was increased by 2.2-3.9 and 2.3-3 times that for unassisted breathing and coughing, respectively. A 1-2 second increase was found in the exhalation duration. The CFD model showed that small droplets (10-40 μm) were most greatly affected, where a 1 m/s increase in velocity and 1 s increase in duration caused an 80% increase in axial travel distance.
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Affiliation(s)
- Caroline Crowley
- School of Mechanical and Material Engineering, University College Dublin, Dublin, Ireland
| | - Brian Murphy
- Department of Anaesthesia, The Rotunda Hospital, Dublin, Ireland
- Department of Anaesthesia, Mater Misericordiae Hospital, Dublin, Ireland
| | - Conan McCaul
- Department of Anaesthesia, The Rotunda Hospital, Dublin, Ireland
- Department of Anaesthesia, Mater Misericordiae Hospital, Dublin, Ireland
- School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| | - Ronan Cahill
- School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
- Centre for Precision Surgery, Section of Surgery and Surgical Specialities, School of Medicine, University College Dublin, Dublin, Ireland
| | - Kevin Patrick Nolan
- School of Mechanical and Material Engineering, University College Dublin, Dublin, Ireland
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Klompas M. New Insights into the Prevention of Hospital-Acquired Pneumonia/Ventilator-Associated Pneumonia Caused by Viruses. Semin Respir Crit Care Med 2022; 43:295-303. [PMID: 35042261 DOI: 10.1055/s-0041-1740582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
A fifth or more of hospital-acquired pneumonias may be attributable to respiratory viruses. The SARS-CoV-2 pandemic has clearly demonstrated the potential morbidity and mortality of respiratory viruses and the constant threat of nosocomial transmission and hospital-based clusters. Data from before the pandemic suggest the same can be true of influenza, respiratory syncytial virus, and other respiratory viruses. The pandemic has also helped clarify the primary mechanisms and risk factors for viral transmission. Respiratory viruses are primarily transmitted by respiratory aerosols that are routinely emitted when people exhale, talk, and cough. Labored breathing and coughing increase aerosol generation to a much greater extent than intubation, extubation, positive pressure ventilation, and other so-called aerosol-generating procedures. Transmission risk is proportional to the amount of viral exposure. Most transmissions take place over short distances because respiratory emissions are densest immediately adjacent to the source but then rapidly dilute and diffuse with distance leading to less viral exposure. The primary risk factors for transmission then are high viral loads, proximity, sustained exposure, and poor ventilation as these all increase net viral exposure. Poor ventilation increases the risk of long-distance transmission by allowing aerosol-borne viruses to accumulate over time leading to higher levels of exposure throughout an enclosed space. Surgical and procedural masks reduce viral exposure but do not eradicate it and thus lower but do not eliminate transmission risk. Most hospital-based clusters have been attributed to delayed diagnoses, transmission between roommates, and staff-to-patient infections. Strategies to prevent nosocomial respiratory viral infections include testing all patients upon admission, preventing healthcare providers from working while sick, assuring adequate ventilation, universal masking, and vaccinating both patients and healthcare workers.
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Affiliation(s)
- Michael Klompas
- Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Healthcare Institute, Boston, Massachusetts.,Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts
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40
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Kerai S, Singh R, Saxena KN, Desai SD, Bhalotra AR. A Retrospective Study on Experience of High-flow Nasal Cannula Oxygen in Critically Ill COVID-19 Adult Patients Admitted to Intensive Care Unit. Indian J Crit Care Med 2022; 26:62-66. [PMID: 35110846 PMCID: PMC8783255 DOI: 10.5005/jp-journals-10071-24097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Affiliation(s)
- Sukhyanti Kerai
- Department of Anaesthesiology and Critical Care, Maulana Azad Medical College, New Delhi, India
| | - Rahil Singh
- Department of Anaesthesiology and Critical Care, Maulana Azad Medical College, New Delhi, India
- Rahil Singh, Department of Anaesthesiology and Critical Care, Maulana Azad Medical College, New Delhi, India, Phone: +91 9810719025, e-mail:
| | - Kirti N Saxena
- Department of Anaesthesiology and Critical Care, Maulana Azad Medical College, New Delhi, India
| | - Suraj D Desai
- Department of Anaesthesiology and Critical Care, Maulana Azad Medical College, New Delhi, India
| | - Anju R Bhalotra
- Department of Anaesthesiology and Critical Care, Maulana Azad Medical College, New Delhi, India
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41
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Peddle MB, Avari H, Smith JA, Ryzynski AA, Pinto R, Plenderleith SW, Fowler RA, Tien H, Mubareka S. A Quantitative Study of Particle Dispersion due to Respiratory Support Modalities in PC-12 Aircraft: Prehospital Patient Transport. Air Med J 2022; 41:109-113. [PMID: 35248328 DOI: 10.1016/j.amj.2021.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 10/13/2021] [Indexed: 11/30/2022]
Abstract
OBJECTIVE It is unclear whether supplemental oxygen and noninvasive ventilation respiratory support devices increase the dispersion of potentially infectious bioaerosols in a pressurized air medical cabin. This study quantitatively compared particle dispersion from respiratory support modalities in an air medical cabin during flight. METHODS Dispersion was measured in a fixed wing air ambulance during flight with a breathing medical mannequin simulator exhaling nebulized saline from the lower respiratory tract with the following respiratory support modalities: a nasal cannula with a surgical mask, high-flow nasal oxygen (HFNO) with a surgical mask, and noninvasive bilevel positive airway pressure (BiPAP) ventilation. RESULTS Nasal cannula oxygen with a surgical mask was associated with the highest particle concentrations. In the absence of mask seal leaks, BiPAP was associated with 1 order of magnitude lower particle concentration compared with a nasal cannula with a surgical mask. Particle concentrations associated with HFNO with a surgical mask were lower than a nasal cannula with a surgical mask but higher than BiPAP. CONCLUSIONS Particle dispersion associated with the use of BiPAP and HFNO with a surgical mask is lower than nasal cannula oxygen with a surgical mask. These findings may assist air medical organizations with operational decisions where little data exist about respiratory particle dispersion.
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Affiliation(s)
- Michael B Peddle
- Ornge, Mississauga, Ontario, Canada; Division of Emergency Medicine, Western University, Victoria Hospital, London, Ontario, Canada.
| | - Hamed Avari
- Sunnybrook Research Institute, Toronto, Ontario, Canada
| | | | - Agnes A Ryzynski
- Practice Based Research and Innovation, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
| | - Ruxandra Pinto
- Department of Critical Care Medicine, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
| | | | - Robert A Fowler
- Department of Critical Care Medicine, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
| | - Homer Tien
- Ornge, Mississauga, Ontario, Canada; Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Samira Mubareka
- Sunnybrook Research Institute, Toronto, Ontario, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
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Affiliation(s)
- Hasan M Al-Dorzi
- College of Medicine, King Saud bin Abdulaziz University for Health Sciences, King Abdullah International Medical Research Center and Intensive Care Department, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, ICU2, Mail Code 1425, PO Box 22490, Riyadh 11426, Saudi Arabia
| | - John Kress
- Section of Pulmonary and Critical Care, Medical ICU, University of Chicago, 5841 South Maryland Avenue, MC 6026, Chicago, IL 60637, USA
| | - Yaseen M Arabi
- College of Medicine, King Saud bin Abdulaziz University for Health Sciences, King Abdullah International Medical Research Center and Intensive Care Department, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, ICU2, Mail Code 1425, PO Box 22490, Riyadh 11426, Saudi Arabia.
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Mu SC, Chien YH, Lai PZ, Chao KY. Helmet Ventilation for Pediatric Patients During the COVID-19 Pandemic: A Narrative Review. Front Pediatr 2022; 10:839476. [PMID: 35186812 PMCID: PMC8847782 DOI: 10.3389/fped.2022.839476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 01/11/2022] [Indexed: 12/15/2022] Open
Abstract
The air dispersion of exhaled droplets from patients is currently considered a major route of coronavirus disease 2019 (COVID-19) transmission, the use of non-invasive ventilation (NIV) should be more cautiously employed during the COVID-19 pandemic. Recently, helmet ventilation has been identified as the optimal treatment for acute hypoxia respiratory failure caused by COVID-19 due to its ability to deliver NIV respiratory support with high tolerability, low air leakage, and improved seal integrity. In the present review, we provide an evidence-based overview of the use of helmet ventilation in children with respiratory failure.
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Affiliation(s)
- Shu-Chi Mu
- Department of Pediatrics, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan.,School of Medicine, College of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Yu-Hsuan Chien
- Department of Pediatrics, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan.,Department of Pediatrics, Fu Jen Catholic University Hospital, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Pin-Zhen Lai
- Department of Respiratory Therapy, Fu Jen Catholic University Hospital, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Ke-Yun Chao
- Department of Respiratory Therapy, Fu Jen Catholic University Hospital, Fu Jen Catholic University, New Taipei City, Taiwan.,School of Physical Therapy, Graduate Institute of Rehabilitation Sciences, Chang Gung University, Taoyuan, Taiwan
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44
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Shrimpton AJ, Brown JM, Gregson FKA, Cook TM, Scott DA, McGain F, Humphries RS, Dhillon RS, Reid JP, Hamilton F, Bzdek BR, Pickering AE. Quantitative evaluation of aerosol generation during manual facemask ventilation. Anaesthesia 2022; 77:22-27. [PMID: 34700360 PMCID: PMC8653000 DOI: 10.1111/anae.15599] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/21/2021] [Indexed: 01/13/2023]
Abstract
Manual facemask ventilation, a core component of elective and emergency airway management, is classified as an aerosol-generating procedure. This designation is based on one epidemiological study suggesting an association between facemask ventilation and transmission during the SARS-CoV-1 outbreak in 2003. There is no direct evidence to indicate whether facemask ventilation is a high-risk procedure for aerosol generation. We conducted aerosol monitoring during routine facemask ventilation and facemask ventilation with an intentionally generated leak in anaesthetised patients. Recordings were made in ultraclean operating theatres and compared against the aerosol generated by tidal breathing and cough manoeuvres. Respiratory aerosol from tidal breathing in 11 patients was reliably detected above the very low background particle concentrations with median [IQR (range)] particle counts of 191 (77-486 [4-1313]) and 2 (1-5 [0-13]) particles.l-1 , respectively, p = 0.002. The median (IQR [range]) aerosol concentration detected during facemask ventilation without a leak (3 (0-9 [0-43]) particles.l-1 ) and with an intentional leak (11 (7-26 [1-62]) particles.l-1 ) was 64-fold (p = 0.001) and 17-fold (p = 0.002) lower than that of tidal breathing, respectively. Median (IQR [range]) peak particle concentration during facemask ventilation both without a leak (60 (0-60 [0-120]) particles.l-1 ) and with a leak (120 (60-180 [60-480]) particles.l-1 ) were 20-fold (p = 0.002) and 10-fold (0.001) lower than a cough (1260 (800-3242 [100-3682]) particles.l-1 ), respectively. This study demonstrates that facemask ventilation, even when performed with an intentional leak, does not generate high levels of bioaerosol. On the basis of this evidence, we argue facemask ventilation should not be considered an aerosol-generating procedure.
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Affiliation(s)
- A. J. Shrimpton
- Anaesthesia, Pain and Critical Care Sciences, School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolUK
| | - J. M. Brown
- Department of Anaesthesia and Intensive Care MedicineNorth Bristol NHS TrustBristolUK
| | | | - T. M. Cook
- Department of Anaesthesia and Intensive Care MedicineRoyal United Hospital NHS TrustBathUK
| | - D. A. Scott
- Department of Critical CareUniversity of Melbourne; St. Vincent's Hospital MelbourneAustralia
| | - F. McGain
- Western HealthFootscrayVictoriaAustralia
| | - R. S. Humphries
- Climate Science CentreCSIRO Oceans and AtmosphereAspendaleVictoriaAustralia
| | - R. S. Dhillon
- Department of NeurosurgerySt Vincent's Hospital MelbourneFitzroyVictoriaAustralia
| | - J. P. Reid
- School of ChemistryUniversity of BristolBristolUK
| | - F. Hamilton
- Department of Population Health SciencesUniversity of BristolBristolUK
| | - B. R. Bzdek
- School of ChemistryUniversity of BristolBristolUK
| | - A. E. Pickering
- Anaesthesia, Pain and Critical Care Sciences, School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolUK
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Dhala A, Gotur D, Hsu SHL, Uppalapati A, Hernandez M, Alegria J, Masud F. A Year of Critical Care: The Changing Face of the ICU During COVID-19. Methodist Debakey Cardiovasc J 2021; 17:31-42. [PMID: 35855452 PMCID: PMC9244858 DOI: 10.14797/mdcvj.1041] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 09/17/2021] [Indexed: 11/10/2022] Open
Abstract
During the SARS-CoV-2 pandemic, admissions to hospital intensive care units (ICUs) surged, exerting unprecedented stress on ICU resources and operations. The novelty of the highly infectious coronavirus disease 2019 (COVID-19) required significant changes to the way critically ill patients were managed. Houston Methodist’s incident command center team navigated this health crisis by ramping up its bed capacity, streamlining treatment algorithms, and optimizing ICU staffing while ensuring adequate supplies of personal protective equipment (PPE), ventilators, and other ICU essentials. A tele–critical-care program and its infrastructure were deployed to meet the demands of the pandemic. Community hospitals played a vital role in creating a collaborative ecosystem for the treatment and referral of critically ill patients. Overall, the healthcare industry’s response to COVID-19 forced ICUs to become more efficient and dynamic, with improved patient safety and better resource utilization. This article provides an experiential account of Houston Methodist’s response to the pandemic and discusses the resulting impact on the function of ICUs.
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Affiliation(s)
- Atiya Dhala
- Houston Methodist Hospital, Houston, Texas, US
| | - Deepa Gotur
- Houston Methodist DeBakey Heart & Vascular Center, Houston Methodist Hospital, Houston, Texas, US
| | - Steven Huan-Ling Hsu
- Houston Methodist DeBakey Heart & Vascular Center, Houston Methodist Hospital, Houston, Texas, US
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Strand-Amundsen R, Tronstad C, Elvebakk O, Martinsen T, Dybwad M, Lingaas E, Tønnessen TI. Quantification of aerosol dispersal from suspected aerosol-generating procedures. ERJ Open Res 2021; 7:00206-2021. [PMID: 34877350 PMCID: PMC8474485 DOI: 10.1183/23120541.00206-2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 09/11/2021] [Indexed: 11/18/2022] Open
Abstract
Background Oxygen-delivering modalities like humidified high-flow nasal cannula (HFNC) and noninvasive positive-pressure ventilation (NIV) are suspected of generating aerosols that may contribute to transmission of disease such as coronavirus disease 2019. We sought to assess if these modalities lead to increased aerosol dispersal compared to the use of non-humidified low-flow nasal cannula oxygen treatment (LFNC). Methods Aerosol dispersal from 20 healthy volunteers using HFNC, LFNC and NIV oxygen treatment was measured in a controlled chamber. We investigated effects related to coughing and using a surgical face mask in combination with the oxygen delivering modalities. An aerodynamic particle sizer measured aerosol particles (APS3321, 0.3–20 µm) directly in front of the subjects, while a mesh of smaller particle sensors (SPS30, 0.3–10 µm) was distributed in the test chamber. Results Non-productive coughing led to significant increases in particle dispersal close to the face when using LFNC and HFNC but not when using NIV. HFNC or NIV did not lead to a statistically significant increase in aerosol dispersal compared to LFNC. With non-productive cough in a room without air changes, there was a significant drop in particle levels between 100 cm and 180 cm from the subjects. Conclusions Our results indicate that using HFNC and NIV does not lead to increased aerosol dispersal compared to low-flow oxygen treatment, except in rare cases. For a subject with non-productive cough, NIV with double-limb circuit and non-vented mask may be a favourable choice to reduce the risk for aerosol spread. High-flow nasal cannula or NIV oxygen treatment does not lead to an increase in aerosol dispersal compared to the use of low-flow nasal cannula oxygen. For a coughing patient, using dual-limb NIV may reduce the risk of aerosol spread.https://bit.ly/3AnoyJu
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Affiliation(s)
| | - Christian Tronstad
- Dept of Clinical and Biomedical Engineering, Oslo University Hospital, Oslo, Norway
| | - Ole Elvebakk
- Dept of Clinical and Biomedical Engineering, Oslo University Hospital, Oslo, Norway
| | - Tormod Martinsen
- Dept of Clinical and Biomedical Engineering, Oslo University Hospital, Oslo, Norway
| | - Marius Dybwad
- Norwegian Defence Research Establishment (FFI), Kjeller, Norway
| | - Egil Lingaas
- Dept of Infection Prevention, Oslo University Hospital - Rikshospitalet, Oslo, Norway
| | - Tor Inge Tønnessen
- Dept of Anaesthesiology, Division of Emergencies and Critical Care, Oslo University Hospital, Oslo, Norway.,Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
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Munsif M, McDonald C, Goh N, Smallwood N. Nasal high flow oxygen therapy during acute admissions or periods of worsening symptoms. Curr Opin Support Palliat Care 2021; 15:205-213. [PMID: 34545856 DOI: 10.1097/spc.0000000000000566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW Nasal high flow therapy (NHF) is increasingly used in acute care settings. In this review, we consider recent advances in the utilization of NHF in chronic obstructive pulmonary disease (COPD), terminal cancer and symptom management. Considerations around NHF use during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic are also discussed. RECENT FINDINGS NHF enables humidification and high flows to be provided together with titrated, supplemental oxygen therapy. Compared to conventional oxygen therapy, NHF improves respiratory physiology by reducing workload, enhancing muco-ciliary clearance and improving dead space washout. Some studies suggest that early use of NHF in people being cared for in the emergency department leads to lower rates of invasive ventilation and noninvasive ventilation. There is also emerging evidence for NHF use in people with COPD and chronic respiratory failure, and in palliative care. NHF is comfortable, well-tolerated and safe for use in the management of breathlessness in people with cancer. NHF can be delivered by face mask to patients with SARS-CoV-2 infection, to ease the burden on critical care resources. SUMMARY The evidence base for NHF is rapidly growing and offers promise in relieving troublesome symptoms and for people receiving palliative care.
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Affiliation(s)
- Maitri Munsif
- Department of Respiratory and Sleep Medicine
- Institute for Breathing and Sleep, Austin Health
| | - Christine McDonald
- Department of Respiratory and Sleep Medicine
- Institute for Breathing and Sleep, Austin Health
- University of Melbourne
| | - Nicole Goh
- Department of Respiratory and Sleep Medicine
- Institute for Breathing and Sleep, Austin Health
- University of Melbourne
| | - Natasha Smallwood
- Department of Respiratory Medicine, The Alfred Hospital
- Department of Immunology and Pathology, Central Clinical School, Alfred Centre, Monash University, Melbourne, Victoria, Australia
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48
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Klompas M, Milton DK, Rhee C, Baker MA, Leekha S. Current Insights Into Respiratory Virus Transmission and Potential Implications for Infection Control Programs : A Narrative Review. Ann Intern Med 2021; 174:1710-1718. [PMID: 34748374 DOI: 10.7326/m21-2780] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Policies to prevent respiratory virus transmission in health care settings have traditionally divided organisms into Droplet versus Airborne categories. Droplet organisms (for example, influenza) are said to be transmitted via large respiratory secretions that rapidly fall to the ground within 1 to 2 meters and are adequately blocked by surgical masks. Airborne pathogens (for example, measles), by contrast, are transmitted by aerosols that are small enough and light enough to carry beyond 2 meters and to penetrate the gaps between masks and faces; health care workers are advised to wear N95 respirators and to place these patients in negative-pressure rooms. Respirators and negative-pressure rooms are also recommended when caring for patients with influenza or SARS-CoV-2 who are undergoing "aerosol-generating procedures," such as intubation. An increasing body of evidence, however, questions this framework. People routinely emit respiratory particles in a range of sizes, but most are aerosols, and most procedures do not generate meaningfully more aerosols than ordinary breathing, and far fewer than coughing, exercise, or labored breathing. Most transmission nonetheless occurs at close range because virus-laden aerosols are most concentrated at the source; they then diffuse and dilute with distance, making long-distance transmission rare in well-ventilated spaces. The primary risk factors for nosocomial transmission are community incidence rates, viral load, symptoms, proximity, duration of exposure, and poor ventilation. Failure to appreciate these factors may lead to underappreciation of some risks (for example, overestimation of the protection provided by medical masks, insufficient attention to ventilation) or misallocation of limited resources (for example, reserving N95 respirators and negative-pressure rooms only for aerosol-generating procedures or requiring negative-pressure rooms for all patients with SARS-CoV-2 infection regardless of stage of illness). Enhanced understanding of the factors governing respiratory pathogen transmission may inform the development of more effective policies to prevent nosocomial transmission of respiratory pathogens.
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Affiliation(s)
- Michael Klompas
- Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, and Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts (M.K., C.R., M.A.B.)
| | - Donald K Milton
- Maryland Institute for Applied Environmental Health, School of Public Health, University of Maryland, College Park, Maryland (D.K.M.)
| | - Chanu Rhee
- Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, and Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts (M.K., C.R., M.A.B.)
| | - Meghan A Baker
- Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, and Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts (M.K., C.R., M.A.B.)
| | - Surbhi Leekha
- Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, Maryland (S.L.)
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Arnold DT, Hamilton FW, Moran E. Coughs and sneezes spread diseases: but do 'aerosol generating' procedures? Thorax 2021; 77:216-217. [PMID: 34759027 DOI: 10.1136/thoraxjnl-2021-218133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/28/2021] [Indexed: 12/29/2022]
Affiliation(s)
- David T Arnold
- Academic Respiratory Unit, University of Bristol, Bristol, UK
| | - Fergus W Hamilton
- MRC-IEU, University of Bristol, Bristol, UK.,Microbiology, North Bristol NHS Trust, Westbury on Trym, UK
| | - Ed Moran
- Department of Infectious Disease, North Bristol NHS Trust, Bristol, UK
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de Man P, Ortiz M, Bluyssen PM, de Man SJ, Rentmeester MJ, van der Vliet M, Wils EJ, Ong DSY. Airborne SARS-CoV-2 in home- and hospital environment investigated with a high-powered air sampler. J Hosp Infect 2021; 119:126-131. [PMID: 34752804 PMCID: PMC8572039 DOI: 10.1016/j.jhin.2021.10.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 10/19/2021] [Accepted: 10/20/2021] [Indexed: 12/14/2022]
Abstract
Background The initial aim was to study the effects of face masks worn by recently infected individuals on the airborne spread of SARS-CoV-2, but findings motivated us to proceed with comparing the presence of SARS-CoV-2 in air samples near infected individuals at home with those near infected intensive care unit (ICU) patients. Aim To assess the presence of SARS-CoV-2 in the air of homes of infected individuals and in ICU rooms of critically ill patients with COVID-19 who were undergoing different forms of potential aerosol-generating medical procedures. Methods A high-volume air sampler method was developed that used a household vacuum cleaner with surgical face masks serving as sample filters. SARS-CoV-2 RNA was harvested from these filters and analysed by polymerase chain reaction. Fog experiments were performed to visualize the airflow around the air sampler. Air samples were acquired in close proximity of infected individuals, with or without wearing face masks, in their homes. Environmental air samples remote from these infected individuals were also obtained, plus samples near patients in the ICU undergoing potential aerosol-generating medical procedures. Findings Wearing a face mask resulted in a delayed and reduced flow of the fog into the air sampler. Face masks worn by infected individuals were found to contain SARS-CoV-2 RNA in 71% of cases. SARS-CoV-2 was detected in air samples regardless of mask experiments. The proportion of positive air samples was higher in the homes (29/41; 70.7%) than in the ICU (4/17; 23.5%) (P < 0.01). Conclusion SARS-CoV-2 RNA could be detected in air samples by using a vacuum cleaner based air sampler method. Air samples in the home environment of recently infected individuals contained SARS-CoV-2 RNA nearly three times more frequently by comparison with those obtained in ICU rooms during potential aerosol-generating medical procedures.
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Affiliation(s)
- Peter de Man
- Department of Medical Microbiology and Infection Control, Franciscus Gasthuis & Vlietland, Rotterdam, The Netherlands
| | - Marco Ortiz
- Indoor Environment, Faculty of Architecture and the Built Environment, Delft University of Technology, Delft, The Netherlands
| | - Philomena M Bluyssen
- Indoor Environment, Faculty of Architecture and the Built Environment, Delft University of Technology, Delft, The Netherlands
| | - Stijn J de Man
- Department of Medical Microbiology and Infection Control, Franciscus Gasthuis & Vlietland, Rotterdam, The Netherlands
| | - Marie-Jozé Rentmeester
- Department of Medical Microbiology and Infection Control, Franciscus Gasthuis & Vlietland, Rotterdam, The Netherlands
| | - Marijke van der Vliet
- Department of Medical Microbiology and Infection Control, Franciscus Gasthuis & Vlietland, Rotterdam, The Netherlands
| | - Evert-Jan Wils
- Department of Intensive Care Medicine, Franciscus Gasthuis & Vlietland, Rotterdam, The Netherlands
| | - David S Y Ong
- Department of Medical Microbiology and Infection Control, Franciscus Gasthuis & Vlietland, Rotterdam, The Netherlands; Department of Epidemiology, Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
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