The Daily Dose • Sunday, March 20, 2022
Airway Emergencies in the ICU: Identifying and Mitigating Adverse Events
Anesthesiologists are frequently called on to perform emergent intubations in the non-operating room setting. An engaging and relevant SOCCA Panel entitled, “Evidence-Based Emergency Airway Management: Past the Tipping Point?,” given on Saturday, March 19, at the IARS 2022 Annual Meeting, discussed important considerations for performing these high-risk procedures. Intensivists Mary Jarzebowski, MD, Rachel Kadar, MD, R. Alok Gupta, MD, FCCP, FASA, and Craig Jabaley, MD, FCCM, reviewed patient factors associated with major adverse events in the peri-intubation period, best practices for optimizing preoxygenation before endotracheal intubation, and current evidence for selecting specific induction agents to minimize hypotension.
During her presentation entitled, “Emergency Airway Management: Why Aren’t Outcomes Improving?,” Mary Jarzebowski, MD, Clinical Assistant Professor of Anesthesiology at the University of Michigan and critical care anesthesiologist at the VA Ann Arbor Healthcare System, wagered that “intubating critically ill patients is the riskiest procedure that we as anesthesiologists do.” She presented evidence of a high incidence of adverse events like severe hypoxemia and severe hypotension occurring during or after intubation of patients in the ICU (Nolan and Kelly 2011, Russotto 2021). She identified key risk factors for peri-intubation cardiac arrest to be obesity, older age, a lack of preoxygenation, hypoxemia, and hypotension (De Jong, et al. 2018). She concluded her talk by affirming that we still need to apply better methods of preventing and mitigating hypoxemia and hemodynamic instability when intubating critically ill patients.
Rachel Kadar, MD, Assistant Professor of Anesthesiology at the McGaw Medical Center of Northwestern University, then presented “Beating the Clock: How to Extend Apnea Time in Critically Ill Patients.” Dr. Kadar emphasized that preoxygenation is even more important in emergency airway management than under routine conditions since critically ill patients desaturate 25 times more quickly than healthy ones.
She then shared several clinical pearls for optimizing preoxygenation and apneic oxygenation before intubation. First, increasing mean airway pressure by using CPAP, BiPAP, high-flow nasal cannula (HFNC), or the PEEP valve with bag-mask ventilation promotes alveolar recruitment and has been shown to improve preoxygenation compared to conventional oxygen therapy (Fong 2019). Second, apneic oxygenation with HFNC or a regular nasal cannula has been shown to be noninferior to the standard of care and may also reduce the risk of peri-intubation hypoxia (Pavlov 2017, Jhou 2020, Casey 2019). Third, Dr. Kadar referenced Scott Weingart, MD’s work in suggesting “delayed sequence intubation” (“DSI”) as a superior approach to rapid sequence intubation in managing the airways of critically ill patients (Weingart 2015). DSI incorporates the use of ketamine (or other sedative agent) before intubation to optimize preoxygenation of patients who might not tolerate conventional preoxygenation techniques. Finally, recent recommendations from the Society for Airway Management included mention of the various methods mentioned above (Kornas 2021).
In “Pushing the Poison: Choice of Induction Agent in Critically Ill Patients,” R. Alok Gupta, MD, FCCP, FASA, Assistant Professor of Anesthesiology at Northwestern Memorial Hospital, focused on ways to mitigate peri-intubation hypotension, with an emphasis on choice of induction agent. He began his talk by highlighting some helpful guidelines published in the UK (Higgs 2018). These guidelines recommended ketamine as the induction agent of choice, proactive use of vasoactive agents (in bolus or infusion form) to prevent or treat hypotension, the likely avoidance of etomidate due to the risk of adrenal suppression, and the avoidance of aggressive positive-pressure ventilation after successful intubation. Dr. Gupta discussed the significant controversy surrounding the clinical significance of using a single dose of etomidate for induction (Jabre 2009, Bruder 2015, Albert 2021, Wan 2021). He also explained that any induction agent could cause hypotension by decreasing a critically ill patient’s sympathetic drive, which might be keeping the patient alive during periods of extreme physiological stress. Dr. Gupta raised the possibility of mitigating hypotension by focusing less on the actual drug and more on moderating the dose or rate of administration of a chosen induction agent. He also encouraged fluid administration to optimize preload in patients who might be hypovolemic prior to induction. Finally, he encouraged the audience to recall that in emergencies, keeping patients alive takes priority over ensuring their level of sedation. Conditions of extreme hemodynamic instability are unlikely to require significant doses of induction agents.
Craig Jabaley, MD, FCCM, Associate Professor, Anesthesiology at Emory University School of Medicine, concluded the panel by summarizing the panelists’ key points and encouraging the tailoring of clinical management according to each patient’s anatomy, physiology, and environment. Proactive planning and swift management of adverse events are essential for peri-intubation success.