Safety and feasibility of continuous ketamine infusion for analgosedation in medical and cardiac ICU patients who received mechanical ventilation support: A retrospective cohort study.

Abstract

PurposeTo assess the effect of continuous ketamine administration in patients admitted to medical and cardiac intensive care units (ICUs) and received mechanical ventilation support.MethodsWe conducted a retrospective cohort study between March 2012 and June 2020 at an academy-affiliated tertiary hospital. Adult patients who received mechanical ventilation support for over 24 h and continuous ketamine infusion for at least 8 h were included. The primary outcome was immediate hemodynamic safety after continuous ketamine infusion. The secondary outcomes included immediate delirium, pain, and use of sedation.ResultsOf all 12,534 medical and cardiac ICU patients, 564 were eligible for the analysis. Ketamine was used for 33.3 (19.0–67.5) h and the median continuous infusion dose was 0.11 (0.06–0.23) mcg/kg/h. Of all patients, 469 (83.2%) received continuous ketamine infusion concomitant with analgosedation. Blood pressure and vasopressor inotropic scores did not change after continuous ketamine infusion. Heart rate decreased significantly from 106.9 (91.4–120.9) at 8 h before ketamine initiation to 99.8% (83.9–114.4) at 24 h after ketamine initiation. In addition, the respiratory rate decreased from 21.7 (18.6–25.4) at 8 h before ketamine initiation to 20.1 (17.0–23.0) at 24 h after ketamine initiation. Overall opioid usage was significantly reduced: 3.0 (0.0–6.0) mcg/kg/h as fentanyl equivalent dose at 8 h before ketamine initiation to 1.0 (0.0–4.1) mcg/kg/h as fentanyl equivalent dose at 24 h post-ketamine initiation. However, the use of sedatives and antipsychotic medications did not decrease. In addition, ketamine did not increase the incidence of delirium within 24 h after ketamine infusion.ConclusionKetamine may be a safe and feasible analgesic for medical and cardiac ICU patients who received mechanical ventilation support as an opioid-sparing agent without adverse hemodynamic effects.