Continuous Ketamine Infusion for Treatment of Refractory Headache in the Inpatient Setting (P11-12.008)

Abstract

<h3>Objective:</h3> The aim of this retrospective case series is to describe our experience using continuous ketamine infusion for treatment of refractory headache in the inpatient setting. We report the efficacy of intravenous (IV) ketamine in a small patient cohort. <h3>Background:</h3> Refractory headaches can be challenging to manage. Ketamine has been proposed for use in intractable headaches. There is limited information available on administering IV ketamine in the inpatient setting for refractory headache, and a protocol has not been established. <h3>Design/Methods:</h3> Four patients ≥ 18 years of age were admitted with refractory headaches and treated with IV ketamine during the study timeframe of January 2020 and December 2021. Demographic and clinical characteristics are reported. <h3>Results:</h3> All four patients were female, with an average age of 48.3+4.9 years (range: 44–53 years). Each experienced headaches despite treatment with an average of 5.8 + 2.5 IV medications. Mean pain score (0–10 scale) prior to ketamine administration was 9.3+1.0 and was significantly lower, 1.8+1.3 post-ketamine (mean difference = 7.5+2.1, p=0.006). All patients achieved target pain (defined as &gt;50% reduction in headache). Ketamine infusion was started at 0.1 mg/kg/hr for three patients and at 0.2 mg/kg/hr for one patient. Average peak rate of ketamine infusion was 0.48+0.17 mg/kg/hr (range 0.3–0.7 mg/kg/hr). Average total time of ketamine infusion administration was 51.9+6.6 hours (range 44.5–60.0 hours). Few transient adverse events were reported, including dysarthria and somnolence, which resolved spontaneously. <h3>Conclusions:</h3> Target pain levels were achieved while on continuous ketamine for all four patients with refractory headache in our case series. It was well tolerated. Larger randomized trials are needed to investigate the safety and efficacy of ketamine infusion for refractory headache in the inpatient setting. <b>Disclosure:</b> Dr. Kim has nothing to disclose. Dr. Park has nothing to disclose. Dr. Shemme has nothing to disclose. Tracy J. Koehler has nothing to disclose. Dr. Phillips has nothing to disclose.