Abstract:

Background and Objectives: Rapid sequence intubation (RSI), defined as near-simultaneous administration of a sedative and neuromuscular blocking agent (NMBA), is the most common and successful method of tracheal intubation in the ED. However the risk of a can’t intubate-can’t oxygenate scenario may limit the utility of RSI in patients with distorted anatomy or apnea intolerance. Traditionally, topical anesthesia alone +/- low dose sedation has been used when RSI is deemed too risky. Recently, a ketamine-only strategy has been suggested as an alternative approach. We compared first attempt success and complications between ketamine-only, topical anesthesia, and RSI approaches.

Methods: We analyzed prospectively-collected data from the National Emergency Airway Registry (NEAR), comprising ED intubation data from 25 centers from January 2016 to December 2018. We excluded pediatric patients (age <15), those in cardiac and respiratory arrest, or those with an alternate pharmacologic approach (i.e. NMBA only or non-ketamine sedative alone). We analyzed outcomes, stratified by the three intubation approaches. Study outcomes included first attempt success, hypoxemia (defined as an oxygen saturation < 90%), and adverse events during the course of intubation. We calculated differences in outcomes between ketamine-only and topical anesthesia groups.

Results: During the study period, 12,511 of 19,071 intubation encounters met inclusion criteria, including 102 (0.8%) intubated with ketamine alone, 80 (0.6%) who had intubation facilitated by topical anesthesia, and 12,329 (98.5%) who underwent RSI. The median dose of ketamine in the ketamine-only group was 100 mg (IQR 70-150 mg). Unadjusted first attempt success was 61%, 85%, and 90% for the three groups, respectively. Hypoxemia occurred in 16%, 13%, and 8% of patients during the first attempt, respectively. At least one adverse event occurred in 32%, 19%, and 14% of the courses of intubation for the three groups, respectively. In comparing the ketamine-only and topical anesthesia groups, the difference in first pass success was -24% (95% CI, -37% to -12%), and the difference in number of cases with at least one adverse event was 13% (95% CI, 0% to 25%).

Conclusion: The ketamine-only intubation approach is uncommonly used in the ED. It is associated with lower success and higher complications compared with topical anesthesia and RSI approaches.