(947) Variations in Institutional Ketamine Use for Acute Pain

Introduction: Ketamine remains an option and common therapy for treatment in sickle cell patients who experience refractory pain and demonstrate a tolerance to opioids. Ketamine has expanded its analgesic indications, including use in chronic pain, in the perioperative setting and in the emergency department (ED) for patients experiencing acute pain or pain-associated agitation. A lack of consensus remains for ketamine-specific dosing recommendations and standard monitoring parameters indicated for broadened analgesic uses. The purpose of this study was to assess the safety and efficacy of institutional ketamine use for analgesia.

Methods: This was a retrospective analysis of patients treated with intravenous ketamine for analgesia at an academic health system. Patients were identified via the electronic medical record and use of ketamine-specific order sets that auto-populate based on patient location. Patients were divided into cohorts based on selected route and ordered dose of ketamine. Patient safety monitoring included blood pressure, heart rate, and SpO2 at baseline, followed by 15 minutes, 30 minutes, and 1-hour post-ketamine initiation or administration. Efficacy was assessed by evaluating pain scale reports at baseline, 1 hour, and 2 hours post-ketamine initiation or administration.

Results: A total of 100 patients were included (n=55 IV push [IVP] ketamine; n=45 continuous IV infusion [CIVI] ketamine). The mean dose of IVP ketamine in the ED was 0.25 mg/kg vs 0.6 mg/kg in psychiatric emergency services. The mean CIVI ketamine dose was 2.8 mcg/kg/min in post-operative patients vs 8.4 mcg/kg/min in ICU patients. Systolic blood pressure changes >10 mmHg occurred in 43 patients, of which 24 (56%) recovered to baseline within 1 hour of ketamine administration. Heart rate changes >10 bpm occurred in 31 patients, of which 9 (29%) recovered to baseline within 1 hour of ketamine administration. SpO2 changes >5% occurred in 12 patients. Pain scale scores decreased in 24% of all patients.

Conclusions: Ketamine remains a reasonable option for inpatient management of analgesia. The ideal safety monitoring standard for ketamine when used for analgesia remains debated and potential utilization of ketamine in hospital units without the necessary capabilities for safety monitoring is not recommended.