Adjunctive Ketamine for Sedation in Critically Ill Mechanically Ventilated Patients: An Active-Controlled, Pilot, Feasibility Clinical Trial

Abstract Objective Ketamine has been shown to decrease sedative requirements in intensive care unit (ICU). Randomized trials are limited on patient-centered outcomes. We designed this pilot clinical trial to evaluate the feasibility of using ketamine as an adjunct analgosedative compared with standard of care (SOC) alone and determine preliminary effect size on 28-day mechanical ventilation (MV) duration and ventilator-free days (VFDs). Design Pilot, single-center, active-controlled, open-label, randomized clinical trial. Setting Medical, surgical, and transplant ICUs at King Faisal Specialist Hospital and Research Center, Saudi Arabia. Patients and Methods Adult patients who were intubated within 24 hours, expected to require MV for the next calendar day, and had institutional pain and sedation protocol initiated. Intervention Adjunct ketamine infusion 1-2 μg/kg/min for 48 hours versus SOC. Measurements and Main Results Total of 83 patients (43 in SOC and 40 in ketamine) were included. Demographics were balanced between groups. Median MV duration was 7 (interquartile range [IQR] 3-9.25 days) in ketamine and 5 (IQR 2-8 days) in SOC, p= 0.15. Median VFDs was 19 (IQR 0-24.75 days) in ketamine and 19 (IQR 0-24 days) in the SOC (p=0.70). More patients attained goal RASS score at 24 and 48 hours in ketamine (67.5% and 73.5%, respectively) compared with SOC (52.4% and 66.7%, respectively). Sedatives and vasopressors cumulative doses, and hemodynamic changes were similar. ICU length-of-stay was 12.5 (IQR 6-21.2 days) in ketamine, compared with 12 (IQR 5.5-23 days) in SOC, p=0.89. Consent and protocol adherence rate were adequate. No serious adverse events were observed in either group. Conclusions Use of ketamine as an adjunct analgosedative agent appeared to be feasible and safe with no negative impact on outcomes, including hemodynamics. The protocol of this pilot trial could be improved by modifying ketamine dosing regimen. These findings provide a basis for future, adequately powered, multicenter trial to investigate its association with patient-centered outcomes further.