(1024) Continuous-Infusion Ketamine Versus Opioids for Primary Analgosedation in Ventilated STICU Patients

Introduction: Ketamine is an opioid-sparing analgosedation agent with increasing use in the ICU due to its unique pharmacologic profile. Growing evidence supports adjunctive ketamine use, but no studies have compared its use for primary analgosedation to the standard of care, opioids. This study evaluated the effectiveness and safety of ketamine vs. opioid infusions for primary analgosedation in ventilated, STICU patients.

Methods: This retrospective, observational cohort study included intubated STICU patients who received either ketamine or opioid infusions for ≥6 consecutive hours between May, 2018 and October, 2022. Exclusions included ketamine use for status epilepticus or receipt of neuromuscular blockade, opioid epidural, or concurrent ketamine and opioid infusions. The primary outcome was percent of time within pain goal (CPOT < 3 or NPS < 4) during analgosedation. Secondary outcomes included percent of time within sedation goal (RASS 0 to -2), morphine milligram equivalent (MME) administered, delirium-free days, vasopressor use, new antipsychotic orders, ventilator days, and ICU length of stay.

Results: 205 patients were included; 99 received ketamine and 106 received an opioid infusion. Baseline characteristics were similar between groups. Ketamine was administered for a median of 1.5 days (IQR 0.8-2.5) at a median rate of 0.25 mg/kg/h. Fentanyl was the most common opioid infusion (n=103), administered for a median of 1.2 days (0.8-2.0) at a median rate of 50 mcg/hr (25-50). The percent of time within pain goal was 52% in the ketamine group and 58% in the opioid group (p=0.33). Patients in the ketamine group spent a greater percentage of time within sedation goal vs. the opioid group (81.1% vs 69.1%, P=0.024). The median total MME administered while mechanically ventilated was significantly lower in the ketamine vs. opioid infusion group (158 MME vs 477 MME, P< 0.001). There were no significant differences in delirium-free days, vasopressor use, new antipsychotic orders, ventilator days, or ICU LOS (p>0.05).

Conclusions: Ketamine infusion for primary analgosedation in intubated STICU patients resulted in at least comparable time at goal pain and sedation scores and was associated with reduced opioid exposure. Prospective studies are warranted.