The impact of ketamine on outcomes in critically ill patients: a systematic review with meta-analysis and trial sequential analysis of randomized controlled trials

Abstract

Background This meta-analysis aims to evaluate the effects of ketamine in critically ill intensive care unit (ICU) patients. Methods The search for randomized controlled trials (RCTs) in PubMed, Scopus, and the Cochrane Library was performed initially in January but was repeated in December 2023. Included studies compared ketamine with other traditional agents used in the ICU. We synthesized evidence using RevMan v5.4, presenting the results as forest plots, and used trial sequential analysis (TSA) software v. 0.9.5.10 Beta, presenting results as TSA plots. Our outcomes were mortality, pain, opioid and midazolam requirements, delirium rates, and ICU length of stay. Results Twelve RCTs involving 805 ICU patients (ketamine group, 398; control group, 407) were included in the meta-analysis. The ketamine group was not superior to the control group in terms of mortality, pain, mean and cumulative opioid consumption, midazolam consumption, and ICU length of stay. However, the model favored the ketamine group over the control group in delirium rate. This result is significant in terms of conventional boundaries (alpha=5%) but is not robust in TSA. The applicability of the findings is limited by the small number of patients pooled for each outcome. Conclusions No differences were found between ketamine and control groups regarding any outcome except delirium rate, where the model favored the ketamine group over the control group. However, this result is not robust as sensitivity analysis and trial sequential analysis suggest that more RCTs should be conducted in the future.

Keywords

• critical care
• critical illness
• intensive care unit
• ketamine
• pain management