Written by Aaron Lacy


This meta-analysis did not find a difference in peri-intubation hypotension with ketamine vs. other induction agents, even after removing studies at high risk for bias and analyzing subgroups.

Ketamine vs. all… again… and again
Peri-intubation hypotension is lumped into the list of major adverse events that occur during rapid sequence intubation, with an incidence as high as one in five. The question of which induction agent is more strongly associated with peri-intubation hypotension has been investigated many times and in many ways. The authors highlight this, noting significant heterogeneity in the 27 studies (6 RCTs) in this systematic review and meta-analysis. This study differentiates itself from others in that it compares ketamine to other induction agents besides etomidate (fentanyl, midazolam, and propofol).

There was no difference in the odds of peri-intubation hypotension when ketamine (n=8,472) was used compared to other induction agents (n=23,484) (OR 1.10, 95%CI 0.78-1.56). The lack of statistical significance held when studies at high risk for bias were removed from the analysis.

Specifically, when comparing the age-old question of ketamine vs. etomidate, there was almost a significant difference (OR 1.38, 95%CI 0.99-1.94, p=0.58). The authors note that not all studies reported ketamine dose, and in those that did, doses ranged from 0.5 mg/kg to 2.0 mg/kg.

How will this change my practice?
I rarely use midazolam as an induction agent (status epilepticus) and don’t use fentanyl or propofol in the ED for RSI. As we discussed in a post from last month, the evidence supports either etomidate or ketamine as an induction agent at this time, and my selection is based on specific patient factors. There is an ongoing RCT comparing ketamine and etomidate, which is slated to finish enrollment in 2025 that may add clarity – or further muddy the waters – as to which induction agent should be used for specific patients.

Source
Incidence of post-induction hypotension following emergency rapid sequence induction with ketamine: a systematic review and meta-analysis. Scand J Trauma Resusc Emerg Med. 2025 May 1;33(1):71. doi: 10.1186/s13049-025-01374-7. PMID: 40312726