Success and Complications of the Ketamine-Only Intubation Method in the Emergency Department

Abstract

Background: Rapid sequence intubation (RSI), defined as near-simultaneous administration of a sedative and neuromuscular blocking agent, is the most common and successful method of tracheal intubation in the emergency department. However, RSI is sometimes avoided when the physician believes there is a risk of a can't intubate/can't oxygenate scenario or critical hypoxemia because of distorted anatomy or apnea intolerance. Traditionally, topical anesthesia alone or in combination with low-dose sedation are used when physicians deem RSI too risky. Recently, a ketamine-only strategy has been suggested as an alternative approach.

Objective: We compared first attempt success and complications between ketamine-only, topical anesthesia alone or with low-dose sedation, and RSI approaches.

Methods: We analyzed registry data from the National Emergency Airway Registry, comprising emergency department intubation data from 25 centers from January 2016 to December 2018. We excluded pediatric patients (<14 years of age), those in cardiac and respiratory arrest, or those with an alternate pharmacologic approach (i.e., neuromuscular blocking agent only or nonketamine sedative alone). We analyzed first attempt intubation success and adverse events across the 3 intubation approaches. We calculated differences in outcomes between the 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. Unadjusted first attempt success was 61%, 85%, and 90% for the 3 groups, respectively. Hypoxemia (defined as oxygen saturation <90%) occurred in 16%, 13%, and 8% of patients during the first attempt, respectively. At least 1 adverse event occurred in 32%, 19%, and 14% of the courses of intubation for the 3 groups, respectively. In comparing the ketamine-only and topical anesthesia groups, the difference in first pass success was -24% (95% confidence interval -37% to -12%), and the difference in number of cases with ≥1 adverse event was 13% (95% confidence interval 0-25%), both favoring the topical anesthesia group.

Conclusion: Although sometimes advocated, the ketamine-only intubation approach is uncommon and is associated with lower success and higher complications compared with topical anesthesia and RSI approaches.

Keywords: difficult airway; emergency intubation; ketamine; rapid sequence intubation; topical anesthesia.