Objective To compare the effectiveness and safety of ketamine and etomidate for rapid sequential intubation.

Methods Randomized controlled trials and cohort studies with ketamine and etomidate for RSI in patients with acute and critical illnesses published by China National Knowledge Infrastructure, Wanfang Data, VIP Network, PubMed, Embase, Cochrane Library and Clinicaltrials.gov from the date of database creation to May 1, 2023 were searched by computer. The literatures were screened according to inclusion and exclusion criteria, and the data of literatures were also extracted for quality assessment. Meta-analysis was performed by RevMan 5.3 software.

Results A total of 15 literatures with 20 839 patients were included, including 3 RCT studies and 12 cohort studies. Meta-analysis showed that there were no significant differences in the success rate of primary intubation (RR=0.99, 95 %CI, 0.98 to 1.00, P=0.10), incidence of cardiac arrest (RR=1.00, 95 %CI, 0.62 to 1.62, P=0.99), time of mechanical ventilation (MD=0.33, 95 %CI, -0.34 to 1.01, P=0.33), and mortality rate (RR=1.05, 95 %CI, 0.95 to 1.16, P=0.31) between the ketamine group and the etomidate group, but the incidence of adrenal insufficiency (RR=0.54, 95 %CI, 0.41 to 0.70, P < 0.001) and ICU stay (MD=-0.44, 95 %CI, -0.70 to -0.18, P=0.001) in the etomidate group were significantly lower and shorter than those in the ketamine group, while the incidence of hypoxemia was significantly higher in the etomidate group (RR=1.50, 95 %CI, 1.27 to 1.79, P < 0.001).

Conclusion During the process of RSI with sufficient preoxygenation, ketamine is a safe and effective alternative drug, and compared with etomidate, it has a lower incidence of adrenal insufficiency and shorter ICU stay.