To the Editor:
As intensivists with experience managing patients with coronavirus disease COVID-19 respiratory failure, we read with interest the article by Wong et al.1 describing risk factors for successful emergency airway management in COVID-19 patients. We applaud the impressive size, completeness, and multinational breadth of the dataset compiled by the authors.
We recognize that first-pass success is an important metric for airway management and that COVID patients are challenging, in part due to precautions against disease transmission.2 However, we note that successful intubation may not fully describe the risk involved in difficult airway management, and that even when airway management is ultimately successful, physiologic derangements during the intubation process can be common.3
Patients with COVID-19 may be particularly at risk for physiologic deterioration during airway management. In our hospital we found that aggressive use of noninvasive ventilation allowed many patients to avoid intubation.4 However, those who failed noninvasive ventilation were often exhausted after days of progressive respiratory insufficiency despite maximal use of high-flow nasal cannula, bilevel positive airway pressure, or helmet ventilation. Further, hypovolemia was common due to diuretic therapy to improve oxygenation. In such patients the combination of anesthetic induction, brief apnea, and transition to positive pressure ventilation often resulted in severe refractory hypoxemia and hypotension. Toward the end of our first wave (May 2020), we would not infrequently perform awake fiberoptic intubation in patients failing high-flow nasal cannula to avoid severe cardiorespiratory deterioration associated with even brief apnea and anesthetic induction.
Wong et al. note that their registry did not capture the incidence or severity of hypoxemia or cardiovascular collapse due to airway management. Although we agree that hypoxemia and cardiovascular instability are not normally consequences of airway management, they may complicate physiologically difficult intubation5 and many COVID patients who fail noninvasive ventilation due to progressive disease fall into that category. Existing evidence suggests that first-pass success may not distinguish between anatomical and physiologically difficult airways,6 further limiting the ability of the first-pass success metric to detect cardiorespiratory consequences of COVID-19 airway management.
Wong et al. describe a higher likelihood of first-pass success with rapid sequence intubation. It is unclear, however, whether this finding should be generalized to all patients with COVID-19 respiratory failure. Rapid sequence intubation may be well tolerated early in the course of COVID respiratory failure but markedly less well in those who require intubation after a week of failed noninvasive support. In such late-stage patients, airway managers should integrate physiologic complications of airway management into their decision tree.
Competing Interests
Dr. Tung receives a salary as Critical Care executive section editor for Anesthesia & Analgesia. Dr. Shahul is supported in part by National Institutes of Health (Bethesda, Maryland) grants R01HL148191 and R21HL14848811. Dr. Rubin is the president of DRDR Mobile Health (Chicago, Illinois), a company that creates mobile applications for healthcare, including functional capacity assessment applications. He has engaged in consulting for mobile applications as well. He has not taken any salary or money from the company.
