Efficacy of Continuous Infusion Ketamine for Analgosedation in the Medical Intensive Care Unit: A Propensity-Weighted Analysis

Abstract

Background: Few randomized controlled trials have evaluated the use of ketamine vs opiate-based analgosedation. Methods: A retrospective cohort analysis of 169 mechanically ventilated patients admitted to the medical intensive care unit (MICU) at an academic medical center was conducted to evaluate efficacy of ketamine vs opiate-based analgosedation by comparing the percentage of time within target sedation range. The primary outcome was percentage of time within target sedation range (RASS -1 to +1) within first 72 hours of primary sedation initiation. Secondary outcomes including percentage of time under-sedated, over-sedated, and in coma; use of concomitant analgesic, sedative, and antipsychotic agents; presence of delirium; percentage of CPOT scores at goal; and hemodynamic effects were also evaluated. Results: After weighting, the mean percentage of time at RASS goal for ketamine patients was 43.0% compared to 41.4% for opiate-based sedation patients. Ketamine was not significantly non-inferior to opiate-based sedation for the mean percentage of time at RASS goal (P = .11). The median percentage of CPOT scores at goal was 13.3% higher in the ketamine group (P = .042). Patients in the ketamine group received significantly less additional sedative agents than the patients in the opiate-based sedation group. Conclusion: A similar percent of time at RASS goal was found for the ketamine analgosedation group compared to the opiate-based sedation group, although this did not reach statistical signicance for non-inferiority due to lack of statistical power. This study found a higher percentage of CPOT scores within goal with less additional sedative agents required compared to an opiate-based sedation regimen.