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Etomidate versus Ketamine for RSI

Ketamine versus etomidate for RSI

Rapid sequence intubation (RSI) is a critical procedure for managing the airways of patients who are rapidly deteriorating, utilizing quickly acting induction agents to facilitate intubation. Among the preferred induction agents for RSI, ketamine, etomidate, and propofol are commonly recommended due to their rapid onset of action. However, each of these agents has specific risks and benefits that are important to consider in clinical practice.

Propofol is known for its potential to cause cardiovascular collapse, which can be a significant risk during the procedure. This underscores the need for careful patient selection and monitoring when considering propofol as an induction agent for RSI.

Etomidate, while generally considered to have a more favorable hemodynamic profile, has been associated with adrenal insufficiency. This is due to its inhibition of 11-beta hydroxylase in the adrenal glands, which can have implications for patients requiring long-term critical care. The risk of adrenal suppression poses a concern, especially in critically ill patients who may already have compromised adrenal function.

Ketamine is another commonly used induction agent that has been evaluated for its safety and efficacy in RSI. The agent has favorable hemodynamic effects and lacks the adverse effects exhibited by other agents. It has quick onset and short duration of action, and it preserves respiratory drive and exhibits sympathomimetic properties.

The society of critical care medicine suggests that there is no difference between etomidate and other induction agents administered for RSI with respect to mortality or the incidence of hypotension or vasopressor use in the peri-intubation period and through hospital discharge.[1]

However, a recent Bayesian meta-analysis of seven randomized controlled trials and one propensity-matched study involving a total of 2978 critically ill adult patients found that ketamine might have a slightly lower associated mortality compared to etomidate. The probability that ketamine reduced mortality was 83.2% (RR, 0.93; 95% CrI, 0.79–1.08), which was confirmed by a subgroup analysis excluding studies with a high risk of bias. The was no difference in secondary outcomes including Sequential Organ Failure Assessment (SOFA) score, ventilator-free days, vasopressor-free days, post-induction mean arterial pressure (MAP), and success of intubation on the first attempt.[2]

The study provides insights that surpass the capabilities of a frequentist approach by adopting a Bayesian methodology with low-bias randomized and propensity-matched studies, thereby enhancing statistical power and allowing for more flexible interpretations. However, the study is constrained by heterogeneity in peri-intubation interventions across studies, which introduces potential confounders, and by the predominance of single-centered studies may curtail generalizability.

What is your preferred agent for RSI?

  • 0%Etomidate

  • 0%Ketamine

  • 0%Propofol

  • 0%Midazolam

In conclusion, when choosing an induction agent for RSI in critically ill patients, it is essential to weigh the benefits and risks associated with each option. Propofol, while effective, carries a significant risk of cardiovascular collapse. Etomidate, despite its stable hemodynamic profile, may lead to adrenal insufficiency. Ketamine appears to have a comparatively lower risk of mortality than etomidate, but the evidence is not definitive, and further research is warranted to fully understand its impact.

  1. Guidelines for Rapid Sequence Intubation in the Critically Ill Adult Patient | SCCM Link

  2. Koroki, T., Kotani, Y., Yaguchi, T. et al. Ketamine versus etomidate as an induction agent for tracheal intubation in critically ill adults: a Bayesian meta-analysis. Crit Care 28, 48 (2024) Link

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