Written by Aaron Lacy
Spoon Feed
When forgoing paralytics for perceived difficult airways, there are several options. Intubation with ketamine alone is uncommon, and when compared to topical anesthesia is associated with decreased first pass success and an increased number of adverse events.
Why does this matter?
When there is concern for difficult anatomic or physiologic airways (can’t intubate/oxygenate, critical hypoxemia, distorted anatomy, apnea intolerance), paralytics are sometimes avoided. Traditionally, these airways are approached with topical anesthesia and low-dose sedatives – but what about ketamine? Given it preserves respiratory drive, could ketamine be a better alternative?
The K-hole isn’t the ideal place for RSI
To evaluate the success and complications of ketamine-only intubation in the ED, 12,511 patients from the NEAR database were included in analysis. 80 (0.6%) were intubated with topical anesthesia alone; 102 (0.8%) underwent intubation with ketamine alone; and the rest (12,329; 95%) underwent traditional RSI. First pass success rate for all three groups was 85%, 61%, and 90%, respectively. When comparing ketamine-only vs topical anesthesia-only intubation, there was a 13% greater incidence of ≥1 adverse events (cardiac arrest, dental trauma, airway injury, esophageal intubation, hypoxemia, bleeding, hypotension, laceration) in the ketamine group.
When facing a potentially difficult airway for which paralysis is frightening, a ketamine-only approach doesn’t seem to be the right move at this time. Of course, the study is retrospective, and the sample size is very small compared to overall intubation attempts – but the results are striking. While a prospective randomized control of topical vs ketamine only approach would help answer this question better, this study makes that harder to justify.
Source
Success and Complications of the Ketamine-Only Intubation Method in the Emergency Department. J Emerg Med. 2021 Mar;60(3):265-272. doi: 10.1016/j.jemermed.2020.10.042. Epub 2020 Dec 9.
https://emcrit.org/emcrit/ketamine-only-intubation-paper/
Scott Weingart dicusses some of the pitfalls with drawing these conclusions from registry data, for anyone interested.
Scott raises great points in these podcasts. Registries like NEAR show associations and help raise concerns, questions, and generate hypotheses. They don’t show causation. That said, they are still important, and we can learn important things from them. For this study in particular, I completely agree with Scott. I think there was likely some selection bias as to which patients received ketamine-only intubation which likely confounded the results. The fact is, we just don’t know. What I take away is that there appear to be issues with a ketamine-only approach, and I should be cautious. I would even say that until I had clearer prospective data, I would avoid a ketamine-only approach.