Capsule Summary
What is already known
It was felt that coronavirus disease 2019 patients needed to be intubated precociously and that is what initial guidelines supported.
What is new in the current study
Current experience suggests that many patients may avoid complications of mechanical ventilation and possibly avoid clinical deterioration by the use of non-invasive ventilatory support.
The 21st century’s first true pandemic has taken the world by storm in the first months of 2020. Originating in Wuhan, China, the severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) virus has spread to all corners of the globe in under 4 months and shows little signs of slowing. The medical community has much to thank the Chinese physicians and health care workers—who were the first hit—for organizing a rapid and focused response which included a huge amount of data collection around prevention, diagnosis and management. From this came invaluable information describing this unique illness [
1-
4]. While most other forms of acute lung injury present with a somewhat similar clinical pattern of respiratory failure, and if severe enough, are often grouped together in a category we have called acute respiratory distress syndrome or acute respiratory distress syndrome (ARDS).
ARDS tends to be a process of lung inflammation resulting in bilateral alveolar infiltrates, lung unit collapse, ventilation and perfusion mismatch and progressive hypoxia and respiratory distress and failure. The physiological pattern is one of low pulmonary compliance. Great strides were made in the management of these entities by the work of Pelosi et al. [
5], Gattinoni et al. [
6], and Gattinoni et al. [
7] in the 1990’s and the advent of the ARDSnet group and the concept of lung protective ventilation, characterized by high positive end expiratory pressure and low tidal volumes. Countless lives were saved using this approach which minimized ventilator-induced lung injury. In the coronavirus disease 2019 (COVID-19) process, however, Gattinoni et al. [
8] recently described a very different pattern with two distinct phenotypes, with only 20% to 30% cases evolving to the classic ARDS-like pattern of lung disease, suggesting they need to be managed differently.
The initial message from the Chinese medical teams was to intubate early, somewhere around a 5-6 liter by nasal prong O2 requirement. This seemed to stem from the accurate observation that many of these patients deteriorated precipitously and that they may be more safely intubated at an earlier stage, particularly given the levels of hypoxia encountered during intubation. Additionally, a high work of breathing generating large swings in intrapleural pressure may result in self-inflicted lung injury and worsen the disease process. There is certainly a rationale for early intubation.
However, this also can come at a cost. Mechanical ventilation is inherently associated with a number of well described and accepted complications such as ventilator associated pneumonia, ventilator-induced lung injury, hemodynamic disturbances, as well as all those related to sedation and immobilization.
Interestingly, it appears that SARS-Cov-2 “runs its course” and seems to “turn off” at some point for survivors, who tend to have a two-week course of mechanical ventilation. Hence an early intubation strategy may result in more ventilated days vs a delayed approach.
It appears fair to say that at the very least, there is clinical equipoise as to whether it is best to intubate early before sudden decompensation occurs, or to assess the patient’s respiratory strain and whether the clinician feels there is substantial risk of self-inflicted lung injury, and to delay intubation by the use of high flow nasal cannulae or non-invasive ventilation.
Another icon of the ventilatory literature Tobin [
9] noted the need for physiological assessment of the COVID-19 respiratory syndromes and a need to understand that “Respiratory rates of 25 to 35 breaths per minute should not be viewed as ipso facto (knee jerk) justification for intubation.”
Additionally, it has become apparent to many clinicians that a significant amount of COVID-19 pneumonia patients present very differently to respiratory failure patients we have been accustomed to see, where the degree of dyspnea correlates relatively well with that of hypoxia. In what has been termed the “happy hypoxic” of SARS-Cov-2, there appears to be an uncoupling of this relationship where the patient is in little or no distress, without tachycardia, yet with profound hypoxia with oxygen saturations often well below 80%. It is these patients where the wisdom of early intubation is being put into question, with several clinicians opting to tolerate lower saturation goals (variable but generally over 80%) in the absence of distress.
At Santa Cabrini Hospital in Montreal, a scale of respiratory strain is being used (Cabrini Respiratory Strain Scale) to aid in clinical documentation and in an effort to validate it as a marker of severity and potentially a decision tool for progressing to a higher level of ventilatory support. Data should be forthcoming in the upcoming weeks (
Table 1).
Our current ventilatory approach is to delay intubation if it clinically appears safe and feasible [
10]. This requires, ideally, negative pressure rooms and for the patient to be closely monitored in an intensive care unit, given the risk of rapid decompensation, with physicians able to rapidly respond and intubate. We would encourage that other clinicians who are considering this type of management take the time to document cases in an effort to show that, in all likelihood, a proportion of patients can be altogether managed with non-invasive ventilation. Others who fail non-invasive ventilation may still benefit from having potentially a shorter course of mechanical ventilation. This is important data especially in a resource-limited setting as a shorter ventilator course means more ventilators would be available to other patients.
It is important to recognize that this disease is new and that we must find strategies to determine the best course of action as rapidly as possible. The pathophysiology remains unclear, and once intubated, the optimal ventilatory strategy is equally undetermined, with some authors favoring airway pressure release ventilation while others attempt various modes. It is key to keep a keen eye on almost daily developments, understanding that guidelines on COVID-19 are, in these early phases, highly fluid constructs. As clinicians we should try to adhere to the principle of individualizing ventilatory therapy to the patient’s physiology while avoiding iatrogenic injury.
NOTES
-
No potential conflict of interest relevant to this article was reported.
Table 1.Cabrini Respiratory Strain Scale
Table 1.
|
Parameter |
Pointa)
|
|
Respiratory rate |
|
|
< 20 |
0 |
|
20–30 |
1 |
|
31–40 |
2 |
|
> 40 |
4 |
|
Retraction/accessory muscle use |
|
|
None |
0 |
|
Mild |
1 |
|
Moderate |
2 |
|
Severe |
3 |
|
Overall state |
|
|
Relaxed |
0 |
|
Uncomfortable |
1 |
|
Anxious |
2 |
|
Agitated |
3 |
REFERENCES
- 1. Wu C, Chen X, Cai Y, et al. Risk factors associated with acute respiratory distress syndrome and death in patients with coronavirus disease 2019 pneumonia in Wuhan, China. JAMA Intern Med 2020;e200994.
- 2. Wu Z, McGoogan JM. Characteristics of and important lessons from the coronavirus disease 2019 (COVID-19) outbreak in China: summary of a report of 72 314 cases from the Chinese center for disease control and prevention. JAMA 2020;323:1239-42.
- 3. Onder G, Rezza G, Brusaferro S. Case-fatality rate and characteristics of patients dying in relation to COVID-19 in Italy. JAMA 2020;323:1775-6.
- 4. World Health Organization. Report of the WHO-China Joint Mission on Coronavirus Disease 2019 (COVID-19) [Internet]. Geneva: World Health Organization; 2020 [cited 2020 May 4]. Available from: https://www.who.int/docs/default-source/coronaviruse/who-china-joint-mission-on-covid-19-final-report.pdf
- 5. Pelosi P, D’Andrea L, Vitale G, Pesenti A, Gattinoni L. Vertical gradient of regional lung inflation in adult respiratory distress syndrome. Am J Respir Crit Care Med 1994;149:8-13.
- 6. Gattinoni L, Pesenti A, Bombino M, et al. Relationships between lung computed tomographic density, gas exchange, and PEEP in acute respiratory failure. Anesthesiology 1988;69:824-32.
- 7. Gattinoni L, Pesenti A, Avalli L, Rossi F, Bombino M. Pressure-volume curve of total respiratory system in acute respiratory failure: computed tomographic scan study. Am Rev Respir Dis 1987;136:730-6.
- 8. Gattinoni L, Chiumello D, Caironi P, et al. COVID-19 pneumonia: different respiratory treatments for different phenotypes? Intensive Care Med 2020;Apr; 14; https://doi.org/10.1007/s00134-020-06033-2.
- 9. Tobin MJ. Basing respiratory management of coronavirus on physiological principles. Am J Respir Crit Care Med 2020;201:1319-20.
- 10. Weingart S. ThinkingCC COVID respiratory management webinar [Internet]. [place known]: EMCrit RACC Blog; 2020 Apr 12 [cited 2020 May 4]. Available from: https://emcrit.org/emcrit/covid-respiratory-management/
Citations
Citations to this article as recorded by

- Prehospital respiratory interventions during six waves of COVID-19: results from Israel’s Emergency Medical Services system
Maximilian P. Nerlander, Evan Avraham Alpert, Roman Sonkin, Ziv Dadon, Ari M. Lipsky, Eli Jaffe
BMC Emergency Medicine.2025;[Epub] CrossRef - Acute Respiratory Failure From Early Pandemic COVID-19
Julia M. Fisher, Vignesh Subbian, Patrick Essay, Sarah Pungitore, Edward J. Bedrick, Jarrod M. Mosier
CHEST Critical Care.2024; 2(1): 100030. CrossRef - Association between maternal and perinatal outcomes and histological changes in the placenta of patients with Covid-19: A cohort study
Luiza Rocha de Souza, Melania Maria Ramos Amorim, Alex Sandro Souza, Brena Carvalho Pinto de Melo, Christiane Tiné Cantilino, Maria Alice de Oliveira Saunders, Maria Jucá de Petribú, Luciana Soares Lúcio, Juliana Rodrigues Marinho, Maria Eduarda Virgínia
Medicine.2024; 103(21): e38171. CrossRef - Helmet Ventilation in a Child with COVID‐19 and Acute Respiratory Distress Syndrome
Ke-Yun Chao, Chao-Yu Chen, Xiao-Ru Ji, Shu-Chi Mu, Yu-Hsuan Chien, Vjekoslav Krzelj
Case Reports in Pediatrics.2024;[Epub] CrossRef - The effects of high-flow oxygen therapy on mortality in patients with COVID-19
Mia Bianchi
Journal of the American Association of Nurse Practitioners.2023; 35(3): 183. CrossRef - Invasive versus non-invasive ventilation in patients with COVID-19 pneumonia
Abhijit Nair, Jacob Paul, Ajay Yadav, Khalid Al Sawafi
Journal of Acute Disease.2023; 12(2): 61. CrossRef - Lessons from COVID-19 in the management of acute respiratory failure
Claudia Crimi, Patrick Murphy, Maxime Patout, Javier Sayas, Joao Carlos Winck
Breathe.2023; 19(1): 230035. CrossRef - Association between race and risk of ICU mortality in mechanically ventilated COVID-19 patients at a safety net hospital
Titilope Olanipekun, Temidayo Abe, Timothy Sobukonla, Jothika Tamizharasu, Linda Gamo, Nelson T. Kuete, Nicolas Bakinde, Gloria Westney, Richard H. Snyder
Journal of the National Medical Association.2022; 114(1): 18. CrossRef - Impact of Noninvasive Respiratory Support in Patients With COVID-19 Requiring V-V ECMO
Qamar Ahmad, Adam Green, Abhimanyu Chandel, James Lantry, Mehul Desai, Jikerkhoun Simou, Erik Osborn, Ramesh Singh, Nitin Puri, Patrick Moran, Heidi Dalton, Alan Speir, Christopher King
ASAIO Journal.2022; 68(2): 171. CrossRef - Defining Failure of Noninvasive Ventilation for Acute Respiratory Distress Syndrome: Have We Succeeded?
Bruno L. Ferreyro, Jose Dianti, Laveena Munshi
Annals of the American Thoracic Society.2022; 19(2): 167. CrossRef - Helmet Ventilation for Pediatric Patients During the COVID-19 Pandemic: A Narrative Review
Shu-Chi Mu, Yu-Hsuan Chien, Pin-Zhen Lai, Ke-Yun Chao
Frontiers in Pediatrics.2022;[Epub] CrossRef - Comparison of Early and Late Intubation in COVID-19 and Its Effect on Mortality
Benjamin McKay, Matthew Meyers, Leah Rivard, Holly Stankewicz, Jill C. Stoltzfus, Guhan Rammohan
International Journal of Environmental Research and Public Health.2022; 19(5): 3075. CrossRef - Posición prono en respiración espontánea: una lección más del COVID-19
Diana Borre-Naranjo, Amilkar Almanza, Dairo Rodelo, Leydis Lora, Wilfrido Coronell, Carmelo Dueñas-Castell
Acta Colombiana de Cuidado Intensivo.2022; 22: S71. CrossRef - An Imaging Overview of COVID-19 ARDS in ICU Patients and Its Complications: A Pictorial Review
Nicolò Brandi, Federica Ciccarese, Maria Rita Rimondi, Caterina Balacchi, Cecilia Modolon, Camilla Sportoletti, Matteo Renzulli, Francesca Coppola, Rita Golfieri
Diagnostics.2022; 12(4): 846. CrossRef - Role of helmet ventilation during the 2019 coronavirus disease pandemic
Ke-Yun Chao, Jong-Shyan Wang, Wei-Lun Liu
Science Progress.2022;[Epub] CrossRef - Early intubation and decreased in-hospital mortality in patients with coronavirus disease 2019
Ryo Yamamoto, Daiki Kaito, Koichiro Homma, Akira Endo, Takashi Tagami, Morio Suzuki, Naoyuki Umetani, Masayuki Yagi, Eisaku Nashiki, Tomohiro Suhara, Hiromasa Nagata, Hiroki Kabata, Koichi Fukunaga, Kazuma Yamakawa, Mineji Hayakawa, Takayuki Ogura, Atsush
Critical Care.2022;[Epub] CrossRef - Clinical and laboratory characteristics of intensive care patients of the first and second waves of the COVID-19 pandemic
M.V. Bychinin, T.V. Klypa, T.V. Mandel, D.I. Korshunov, N.A. Kolyshkina, R.A. Dzheliev
Anesteziologiya i reanimatologiya.2022; (4): 57. CrossRef - Does the intubation timeline affect the in-hospital mortality of COVID-19 patients? A retrospective cohort study
Shazia Rehman, Muhammad Ali Shahiman, Mundher A. Khaleel, Ondřej Holý
Frontiers in Medicine.2022;[Epub] CrossRef - Respiratory Physiology of COVID-19 and Influenza Associated Acute Respiratory Distress Syndrome
Niklas Kronibus, Frederik Seiler, Guy Danziger, Ralf Muellenbach, Christian Reyher, André Becker, Maren Kamphorst, Torben Rixecker, Carlos Metz, Robert Bals, Philipp Lepper, Sebastian Mang
Journal of Clinical Medicine.2022; 11(21): 6237. CrossRef - Impact of COVID‐19 on emergency medicine resident procedure performance
Tony W. Bruno, Rohan Janwadkar, Lisa M. Clayton, Patrick G. Hughes, Joshua J. Solano, Richard D. Shih, Leslie A. Bilello, Mary J. Hughes, Scott M. Alter
AEM Education and Training.2022;[Epub] CrossRef - High-Flow Nasal Cannula Therapy in COVID-19: Using the ROX Index to Predict Success
Abhimanyu Chandel, Saloni Patolia, A Whitney Brown, A Claire Collins, Dhwani Sahjwani, Vikramjit Khangoora, Paula C Cameron, Mehul Desai, Aditya Kasarabada, Jack K Kilcullen, Steven D Nathan, Christopher S King
Respiratory Care.2021; 66(6): 909. CrossRef - Oxygenation Strategies in Critically Ill Patients With COVID-19
Julianne M. Evers, Sarah J. Pehlke, Lauren L. Jones, Michelle G. Urquhart
Dimensions of Critical Care Nursing.2021; 40(2): 75. CrossRef - Emergency Department Management of Severe Hypoxemic Respiratory Failure in Adults With COVID-19
Susan R. Wilcox, Anna Condella
The Journal of Emergency Medicine.2021; 60(6): 729. CrossRef - High-flow nasal oxygen in patients with COVID-19-associated acute respiratory failure
Ricard Mellado-Artigas, Bruno L. Ferreyro, Federico Angriman, María Hernández-Sanz, Egoitz Arruti, Antoni Torres, Jesús Villar, Laurent Brochard, Carlos Ferrando
Critical Care.2021;[Epub] CrossRef - Safety of air medical transport of patients with COVID‐19 by personnel using routine personal protective equipment
Darren Braude, Michael Lauria, Margaret O'Donnell, Jodine Shelly, Michael Berve, Mike Torres, Dave Olvera, Sean Jarboe, Anna Mazon, Douglas Dixon
JACEP Open.2021; 2(2): e12389. CrossRef - Neurologic Emergencies during the Coronavirus Disease 2019 Pandemic
Julie G. Shulman, Thomas Ford, Anna M. Cervantes-Arslanian
Neurologic Clinics.2021; 39(2): 671. CrossRef - Early Intubation and Increased Coronavirus Disease 2019 Mortality: A Propensity Score–Matched Retrospective Cohort Study
Austin J. Parish, Jason R. West, Nicholas D. Caputo, Trevor M. Janus, Denley Yuan, John Zhang, Daniel J. Singer
Critical Care Explorations.2021; 3(6): e0452. CrossRef - The role of ROX and mROX indices in predicting intubation in COVID 19 patients treated with high flow nasal oxygen in Intensive Care Unit
İlkay Ceylan, Halil Erkan Sayan, Korgün Ökmen, Umut Öylevi
Journal of Clinical Medicine of Kazakhstan.2021; 18(3): 18. CrossRef - What we learned in the past year in managing our COVID-19 patients in intensive care units?
Jain Nitesh, Rahul Kashyap, Salim R Surani
World Journal of Critical Care Medicine.2021; 10(4): 81. CrossRef - Oxygen Economics: The Use of Heated High-Flow Nasal Oxygen in Air Medical Transport of the Adult Patient
Jon C. Inkrott, Jason R. White
Air Medical Journal.2021; 40(6): 380. CrossRef - Integrated oxygen therapy consisting of non invasive ventilation and nasal cannulae in respiratory failure secondary to COVID-19 pneumonia: Case series
Anshul Singh, Suman Choudhary, Ashok Kumar Saxena
Indian Journal of Clinical Anaesthesia.2021; 8(4): 45. CrossRef - A Year of Critical Care: The Changing Face of the ICU During COVID-19
Atiya Dhala, Deepa Gotur, Steven Huan-Ling Hsu, Aditya Uppalapati, Marco Hernandez, Jefferson Alegria, Faisal Masud
Methodist DeBakey Cardiovascular Journal.2021; 17(5): 31. CrossRef - COVID-19: challenges and opportunities
Adam J Singer, Bettina C Fries
Clinical and Experimental Emergency Medicine.2020; 7(3): 141. CrossRef - Timing of Intubation and Its Implications on Outcomes in Critically Ill Patients With Coronavirus Disease 2019 Infection
Atul Matta, Siddique Chaudhary, Kevin Bryan Lo, Robert DeJoy, Fahad Gul, Ricardo Torres, Neal Chaisson, Gabriel Patarroyo-Aponte
Critical Care Explorations.2020; 2(10): e0262. CrossRef