Awake Flexible Scope Intubation in Critically Ill Patients With Physiologically Difficult Airways: A Prospective, Observational Case Series

IMPORTANCE AND OBJECTIVES: Asleep tracheal intubation is a potentially dangerous intervention in critically ill patients. Patients at high-risk of severe hypoxemia or hemodynamic collapse have a "physiologically difficult airway." This study aimed to evaluate the procedural success and maintenance of physiologic stability associated with awake flexible scope intubation in these patients. DESIGN: Prospective single-center observational case series. SETTING: Tertiary critical care unit. PARTICIPANTS: Adults 18 years old or older requiring intubation who were considered to have a "physiologically difficult airway." MAIN OUTCOMES AND MEASURES: All patients underwent awake intubation under topical anesthesia. The primary outcome was a composite endpoint consisting of first-pass success and the absence of serious physiologic events, defined as severe hypoxemia (pulse oximetry saturation [Spo2] < 80%), hypotension (mean arterial pressure [MAP] < 60 mm Hg), hypertension (MAP > 120 mm Hg), new arrhythmia, or cardiac arrest. Continuous recording of the bedside monitor, time points during intubation, and six aspects of cooperation were documented. RESULTS: All 39 patients had successful intubation on first attempt (100%). Of those fully studied, 25 of 36 (69.4%) met the composite endpoint: intubation plus physiologic stability. There were no arrhythmias or arrests. Spo2 decreased from baseline of 98% to 95% (p < 0.001) with one patient recording a Spo2 less than 80%. Peak heart rate increased from baseline of 95-105 beats/min (p < 0.001). MAP changed from baseline 87 mm Hg to lowest, 72 mm Hg (p < 0.001) and highest, 98 mm Hg (p < 0.001). Four patients had a recorded MAP less than 60 mm Hg (11%), and six patients had a MAP greater than 120 mm Hg (17%), but nine of the ten of these hemodynamic events lasted less than 30 seconds. CONCLUSIONS AND RELEVANCE: In critically ill patients with a physiologically difficult airway requiring intubation, awake flexible scope intubation may be an alternative to asleep tracheal intubation to help preserve hemodynamics. Further studies are needed to validate these findings.