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.
Get full access to this article
View all access options for this article.
References
1.
SharmaA, TiwariS, DebMK, MartyJL. Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2): a global pandemic and treatment strategies. Int J Antimicrob Agents, 2020; 56(2):106054.
2.
Visualizing SARS-Cov-2 transmission routes and mitigation. BMJ, 2021; 375:e065312.
3.
DzinamariraT, MhangoM, DzoboM, NgaraB, ChitungoI, MakandaP, et al. Risk factors for COVID-19 among health care workers. A protocol for a systematic review and meta-analysis. PLoS One, 2021; 16(5):e0250958.
4.
TranK, CimonK, SevernM, Pessoa-SilvaCL, ConlyJ. Aerosol-generating procedures and risk of transmission of acute respiratory infections to health care workers: a systematic review. PLoS One, 2012; 7(4):e35797.
5.
KlompasM, BakerM, RheeC. What is an aerosol-generating procedure?. JAMA Surg, 2021; 156(2):113-114.
CrimiC, PierucciP, RendaT, PisaniL, CarlucciA. High-flow nasal cannula and COVID-19: a clinical review. Respir Care, 2022; 67(2):227-240.
8.
KaurR, WeissTT, PerezA, FinkJB, ChenR, LuoF, et al. Practical strategies to reduce nosocomial transmission to health care professionals providing respiratory care to patients with COVID-19. Crit Care, 2020; 24(1):571.
9.
RanneyLM, GriffethV, JhaKA. Critical supply shortages – The need for ventilators and personal equipment during the COVID-19 pandemic. N Engl J Med, 2020; 382(18):e41.
10.
ElbeddiniA. Sterilization plan of the used metered-dose inhalers (MDI) to avoid wastage amid COVID-19 pandemic drug shortage. J Pharm Policy Pract, 2020; 13(19):19.
11.
DhandR. Mitigating viral dispersion during respiratory support procedures in the ICU. Am J Respir Crit Care Med, 2021; 203(9):1051-1053.
12.
DhandR, LiJ. Coughs and sneezes: their role in transmission of respiratory viral infections, including SARS-CoV-2. Am J Respir Crit Care Med, 2020; 202(5):651-659.
13.
LiJ, EhrmannS. High-flow aerosol-dispersing versus aerosol-generating procedures. Am J Respir Crit Care Med, 2020; 202(8):1069-1071.
ChangAB. The physiology of cough. Paediatr Respir Rev, 2006; 7(1):2-8.
16.
KlompasM, MiltonDK, RheeC, BakerMA, LeekhaS. Current insights into respiratory virus transmission and potential implications for infection control programs: a narrative review. Ann Intern Med, 2021; 174(12):1710-1718.
17.
SomsenGA, van RijnC, KooijS, BemRA, BonnD. Small droplet aerosols in poorly ventilated spaces and SARS-CoV-2 transmission. Lancet Respir Med, 2020; 8(7):658-659.
18.
StadnytskyiV, BaxCE, BaxA, AnfinrudP. The airborne lifetime of small speech droplets and their potential importance in SARS-CoV-2 transmission. Proc Natl Acad Sci U S A, 2020; 117(22):11875-11877.
19.
JayaweeraM, PereraH, GunawardanaB, ManatungeJ. Transmission of COVID-19 virus by droplets and aerosols: a critical review on the unresolved dichotomy. Environ Res, 2020; 188:109819.
20.
LeungNHL. Transmissibility and transmission of respiratory viruses. Nat Rev Microbiol, 2021; 19(8):528-545.
LednickyJA, LauzardM, FanZH, JutlaA, TillyTB, GangwarM, et al. Viable SARS-CoV-2 in the air of a hospital room with COVID-19 patients. Int J Infect Dis, 2020; 100:476-482.
23.
HuiDS, HallSD, ChanMT, ChowBK, NgSS, GinT, SungJJ. Exhaled air dispersion during oxygen delivery via a simple oxygen mask. Chest, 2007; 132(2):540-546.
24.
HuiDS, ChowBK, LoT, TsangOTY, KoFW, NgSS, et al. Exhaled air dispersion during high-flow nasal cannula therapy versus CPAP via different masks. Eur Respir J, 2019; 53(4):1802339.
25.
TakazonoT, YamamotoK, OkamotoR, MorimotoS, IzumikawaK, MukaeH. Effects of surgical masks on droplet dispersion under various oxygen delivery modalities. Crit Care, 2021; 25(1):89.
26.
DellwegD, KerlJ, GenaAW, AlsaadH, VoelkerC. Exhalation spreading during nasal high-flow therapy at different flow rates. Crit Care Med, 2021; 49(7):e693-e700.
27.
TangJW, SettlesGS. Images in clinical medicine: coughing and aerosols. N Engl J Med, 2008; 359(15):e19.
28.
AnfinrudP, StadnytskyiV, BaxCE, BaxA. Visualizing speech-generated oral fluid droplets with laser light scattering. N Engl J Med, 2020; 382(21):2061-2063.
29.
TangJW, NicolleAD, PantelicJ, JiangM, SekhrC, CheongDK, ThamKW. Qualitative real-time schlieren and shadowgraph imaging of human exhaled airflows: an aid to aerosol infection control. PLoS One, 2011; 6(6):e21392.
30.
HarnoisL, AlolaiwatA, JingG, FinkJB, DhandR, LiJ. Efficacy of various mitigation devices in reducing fugitive emissions from nebulizers. Respir Care, 2022; 67(4):394-403.
31.
LiJ, FinkJB, EhrmannS. High-flow nasal cannula for COVID-19 patients: low risk of bioaerosol dispersion. Eur Respir J, 2020; 55(5):2000892.
32.
GaeckleNT, LeeJ, ParkY, KreykesG, EvansMD, HoganCJJr.. Aerosol generation from the respiratory tract with various modes of oxygen delivery. Am J Respir Crit Care Med, 2020; 202(8):1115-1124.
33.
MillerDC, BeamerP, BillheimerD, SubbianV, SorooshianA, CampbellBS, MosierJM. Aerosol risk with noninvasive respiratory support in patients with COVID-19. J Am Coll Emerg Physicians Open, 2020; 1(4):521-526.
34.
McGainF, HumphriesRS, LeeJH, SchofieldR, FrenchC, KeywoodMD, et al. Aerosol generation related to respiratory interventions and the effectiveness of a personal ventilation hood. Crit Care Resusc, 2020; 22(3):212-220.
35.
HelgesonSA, LeeAS, LimKG, NivenAS, PatelNM. Particulate generation with different oxygen delivery devices. Respir Med, 2021; 181:106386.
36.
WilsonNM, MarksGB, EckhardtA, ClarkeAM, YoungFP, GardenFL, et al. The effect of respiratory activity, noninvasive respiratory support, and facemasks on aerosol generation and its relevance to COVID-19. Anaesthesia, 2021; 76(11):1465-1474.
37.
BemRA, van MourikN, Klein-BlommertR, SpijkermanIJ, KooijS, BonnD, VlaarAP. Risk of aerosol formation during high-flow nasal cannula treatment in critically ill subjects. Respir Care, 2021; 66(6):891-896.
38.
JermyMC, SpenceCJT, KirtonR, O’DonnellJF, KabaliukN, GawS, et al. Assessment of dispersion of airborne particles of oral/nasal fluid by high-flow nasal cannula therapy. PLoS One, 2021; 16(2):e0246123.
39.
HamiltonFW, GregsonFKA, ArnoldDT, SheikhS, WardK, BrownJ, et al. AERATOR Group. Aerosol emission from the respiratory tract: an analysis of aerosol generation from oxygen delivery systems. Thorax 2021. [Epub Ahead of Print], 2022; 77(3):276-282.
40.
Strand-AmundsenR, TronstadC, ElvebakkO, MartinsenT, DybwadM, LingaasE, TønnessenTI. Quantification of aerosol dispersal from suspected aerosol-generating procedures. ERJ Open Res, 2021; 7(4):00206-2021.
41.
LiJ, FinkJB, ElshafeiAA, StewartLM, BarbianHJ, MirzaSH, et al. Placing a mask on COVID-19 patients during high-flow nasal cannula therapy reduces aerosol particle dispersion. ERJ Open Res, 2021; 7(1):00519-2020.
42.
LeungCCH, JoyntGM, GomersallCD, WongWT, LeeA, LingL, et al. Comparison of high-flow nasal cannula versus oxygen face mask for environmental bacterial contamination in critically ill pneumonia patients: a randomized controlled crossover trial. J Hosp Infect, 2019; 101(1):84-87.
43.
LebreilAL, GreuxV, GlenetM, HugueninA, N'GuyenY, BerriF, et al. Surfaces and air contamination by SARS-CoV-2 using high-flow nasal oxygenation or assisted mechanical ventilation system in ICU rooms of COVID-19 patients. J Infect Dis, 2022; 225(3):385-391.
44.
RocaO, PachecoA, RodonJ, AntónA, Vergara-AlertJ, ArmadansL, et al. Nasal high-flow oxygen therapy in COVID-19 patients does not cause environmental surface contamination. J Hosp Infect, 2021; 116:103-105.
45.
WestaferLM, SoaresWE3rd, SalvadorD, MedarametlaV, SchoenfeldEM. No evidence of increasing COVID-19 in health care workers after implementation of high-flow nasal cannula: a safety evaluation. Am J Emerg Med, 2021; 39:158-161.
46.
MontielV, RobertA, RobertA, NabaouiA, MarieT, MestreNM, et al. Surgical mask on top of high-flow nasal cannula improves oxygenation in critically ill COVID-19 patients with hypoxemic respiratory failure. Ann Intensive Care, 2020; 10(1):125.
47.
SimondsAK, HanakA, ChatwinM, MorrellM, HallA, ParkerKH, et al. Evaluation of droplet dispersion during noninvasive ventilation, oxygen therapy, nebulizer treatment, and chest physiotherapy in clinical practice: implications for management of pandemic influenza and other airborne infections. Health Technol Assess, 2010; 14(46):131-172.
48.
HuiDS, ChowBK, NgSS, ChuLCY, HallSD, GinT, et al. Exhaled air dispersion distances during noninvasive ventilation via different Respironics face masks. Chest, 2009; 136(4):998-1005.
49.
HuiDS, ChowBK, LoT, NgSS, KoFW, GinT, ChanMTV. Exhaled air dispersion during noninvasive ventilation via helmets and a total face mask. Chest, 2015; 147(5):1336-1343.
50.
AvariH, HiebertRJ, RyzynskiAA, LevyA, NardiJ, Kanji-JafferH, et al. Quantitative assessment of viral dispersion associated with respiratory support devices in a simulated critical care environment. Am J Respir Crit Care Med, 2021; 203(9):1112-1118.
51.
WinslowRL, ZhouJ, WindleEF, NurI, LallR, JiC, et al. SARS-CoV-2 environmental contamination from hospitalized patients with COVID-19 receiving aerosol-generating procedures. Thorax, 2022; 77(3):259-267.
52.
ThuressonS, FraenkelCJ, SasinovichS, SoldemyrJ, WidellA, MedstrandP, et al. Airborne SARS-CoV-2 in hospitals - effects of aerosol-generating procedures, HEPA filtration units, patient viral load, and physical distance. Clin Infect Dis, 2022 Feb 28:ciac161.
LavoriniF, UsmaniOS, DhandR. Aerosol delivery systems for treating obstructive airway diseases during the SARS-CoV-2 pandemic. Intern Emerg Med, 2021; 16(8):2035-2039.
55.
O'NeilCA, LiJ, LeaveyA, WangY, HinkM, WallaceM, et al. Centers for Disease Control and Prevention Epicenters Program. Characterization of aerosols generated during patient care activities. Clin Infect Dis, 2017; 65(8):1335-1341.
56.
McGrathJA, O’SullivanA, BennettG, O’TooleC, JoyceM, ByrneMA, et al. Investigation of the quantity of exhaled aerosols released into the environment during nebulization. Pharmaceutics, 2019; 11(2):75.
57.
HuiDS, ChowBK, ChuLCY, NgSS, HallSD, GinT, ChanMTV. Exhaled air and aerosolized droplet dispersion during application of a jet nebulizer. Chest, 2009; 135(3):648-654.
58.
TangJW, KalliomakiP, VarilaTM, WarisM, KoskelaH. Nebulizers as a potential source of airborne virus. J Infect, 2020; 81(4):647-679.
59.
ChanVW, NgHH, RahmanL, TangA, TangKP, MokA, et al. Transmission of severe acute respiratory syndrome coronavirus 1 and severe acute respiratory syndrome coronavirus 2 during aerosol-generating procedures in critical care: a systematic review and meta-analysis of observational studies. Crit Care Med, 2021; 49(7):1159-1168.
60.
LoebM, McGeerA, HenryB, OfnerM, RoseD, HlywkaT, et al. SARS among critical care nurses, Toronto. Emerg Infect Dis, 2004; 10(2):251-255.
61.
FinkJB, EhrmannS, LiJ, DaileyP, McKiernanP, DarquenneC, et al. Reducing aerosol-related risk of transmission in the era of COVID-19: an interim guidance endorsed by the International Society of Aerosols in Medicine. J Aerosol Med Pulm Drug Deliv, 2020; 33(6):300-304.
62.
SwansonCS, DhandR, CaoL, FerrisJ, ElderCS, HeQ. Microbiome-based source identification of microbial contamination in nebulizers used by in-patients. J Hosp Infect, 2022; 122:157-161.
63.
SwansonCS, DhandR, CaoL, FerrisJ, ElderCS, HeQ. Microbiome profiles of nebulizers in hospital use. J Aerosol Med Pulm Drug Deliv, 2022. [Epub ahead of print].
64.
WoodsJA. Evidence-based treatment during the SARS-CoV-2 pandemic: identifying the knowns and unknowns of nebulization. J Am Pharm Assoc, 2021; 61(2):e55-e56.
65.
LiJ, AlolaiwatA, HarnoisL, FinkJB, DhandR. Mitigating fugitive aerosols during aerosol delivery via high-flow nasal cannula devices. Respir Care, 2022; 67(4):404-414. [Epub ahead of print].
66.
WilsonJ, CarsonG, FitzgeraldS, LlewelynMJ, JenkinsD, ParkerS, et al. members of the Independent High Risk AGP Review Panel. Are medical procedures that induce coughing or involve respiratory suctioning associated with increased generation of aerosols and risk of SARS-CoV-2 infection? A rapid systematic review. J Hosp Infect, 2021; 116:37-46.
67.
LingL, GomersallCD. Potential aerosol generation by bronchoscopy and intubation: another piece in the puzzle. Chest, 2020; 158(6):2251-2252.
68.
HeinzerlingA, StuckeyMJ, ScheuerT, XuK, PerkinsKM, RessegerH, et al. Transmission of COVID-19 to health care personnel during exposures to a hospitalized patient - Solano County, California, February 2020. MMWR Morb Mortal Wkly Rep, 2020; 69(15):472-476.
69.
DoggettN, ChowC, MubarekaS. Characterization of experimental and clinical bioaerosol generation during potential aerosol-generating procedures. Chest, 2020; 158(6):2467-2473.
70.
BrownJ, GregsonFKA, ShrimptonA, CookTM, BzdekBR, ReidJP, PickeringAE. A quantitative evaluation of aerosol generation during tracheal intubation and extubation. Anaesthesia, 2021; 76(2):174-181.
71.
DhillonRS, RowinWA, HumphriesRS, KevinK, WardJD, PhanTD, et al. Clinical Aerosolization Study Group. Aerosolization during tracheal intubation and extubation in an operating theater setting. Anaesthesia, 2021; 76(2):182-188.
ChanMTV, ChowBK, LoT, KoFW, NgSS, GinT, HuiDS. Exhaled air dispersion during bag-mask ventilation and sputum suctioning - Implications for infection control. Sci Rep, 2018; 8(1):198.
74.
BegleyJL, LaveryKE, NicksonCP, BrewsterDJ. The aerosol box for intubation in coronavirus disease 2019 patients: an in situ simulation crossover study. Anaesthesia, 2020; 75(8):1014-1021.
75.
FongS, LiE, ViolatoE, ReidA, GuY. Impact of aerosol box on intubation during COVID-19: a simulation study of normal and difficult airways. Can J Anaesth, 2021; 68(4):496-504.
76.
NestorCC, WangS, IrwinMG. Are tracheal intubation and extubation aerosol-generating procedures?. Anaesthesia, 2021; 76(2):151-155.
77.
BergesAJ, LinaIA, OspinoR, TsaiHW, BrennerMJ, PandianV, et al. Quantifying viral particle aerosolization risk during tracheostomy surgery and tracheostomy care. JAMA Otolaryngol Head Neck Surg, 2021; 147(9):797-803.
78.
LiJ, SchoenrockC, FinkJB. Aerosol particle concentrations with different oxygen devices and interfaces for spontaneous breathing patients with tracheostomy: a randomized crossover trial. ERJ Open Res, 2021; 7(4):00486-2021.
79.
HullJH, LloydJK, CooperBG. Lung function testing in the COVID-19 endemic. Lancet Respir Med, 2020; 8(7):666-667.
80.
WilsonKC, KaminskyDA, MichaudG, SharmaS, NiciL, FolzRJ, et al. Restoring pulmonary and sleep services as the COVID-19 pandemic lessens. From an Association of Pulmonary, Critical Care, and Sleep Division directors and American Thoracic Society–coordinated task force. Ann Am Thorac Soc, 2020; 17(11):1343-1351.
81.
SheikhS, HamiltonFW, NavaGW, GregsonFK, ArnoldDT, RileyC, et al. AERATOR Group. Are aerosol generated during lung function testing in patients and healthy volunteers? Results from the AERATOR study. Thorax, 2022; 77(3):292-294.
82.
LiJ, JingG, FinkJB, PorszaszJ, MoranEM, KiourkasRD, et al. Airborne particulate concentrations during and after pulmonary function testing. Chest, 2021; 159(4):1570-1574.
83.
HelgesonSA, LimKG, LeeAS, NivenAS, PatelNM. Aerosol generation during spirometry. Ann Am Thorac Soc, 2020; 17(12):1637-1639.
84.
TomisaG, HorváthA, FarkasÁ, NagyA, KisE, TamásiL. Real-life measurement of size-fractionated aerosol concentration in a plethysmography box during the COVID-19 pandemic and estimation of the associated viral load. J Hosp Infect, 2021; 118:7-14.
85.
SajgalikP, Garzona-NavasA, CsécsI, AskewJW, Lopez-JimenezF, NivenAS, et al. Characterization of aerosol generation during various intensities of exercise. Chest, 2021; 160(4):1377-1387.
86.
HelgesonSA, LeeAS, PatelNM, TaylorBJ, LimKG, NivenAS. Cardiopulmonary exercise and the risk of aerosol generation while wearing a surgical mask. Chest, 2021; 159(4):1567-1569.
Garzona-NavasA, SajgalikP, CsécsI, AskewJW, Lopez-JimenezF, NivenAS, et al. Mitigation of aerosols generated during exercise testing with a portable high-efficiency particulate air filter with fume hood. Chest, 2021; 160(4):1388-1396.