Extended Duration Ketamine Infusions in Critically Ill Children: A Case Report and Review of the Literature

Ketamine is an N-methyl-D-aspartate receptor antagonist that has been used as an adjunct analgesic and sedative in critically ill children. Previous reports noted that ketamine has been used for a variable duration of 12 to 408 hours for this indication. We report on the use of ketamine infusions for >720 hours as a second-line sedative in addition to an opioid and dexmedetomidine infusion in a 2-month old and 17-month old. The purpose of this case report and review of the literature is to highlight the prolonged ketamine exposure of these two patients and to provide awareness to clinicians on the potential of withdrawal with extended ketamine administration. These children were started on initials doses of 5 and 15 µg/kg/min and titrated to peak doses of 20 and 25 µg/kg/min, respectively. They were continued for a total of 987 and 792 hours, respectively. No adverse events were noted during the ketamine infusions. One patient developed possible withdrawal symptoms 17 hours after ketamine discontinuation despite tapering of the infusion. These symptoms resolved with administration of as needed intravenous opioids and benzodiazepines, and the agitation normalized within 24 hours after ketamine discontinuation. Clinicians should consider tapering ketamine infusions in children receiving >72 hours of a continuous infusion by 5 µg/kg/min every 8 to 12 hours. Patients should be monitored for potential withdrawal symptoms including anxiety, allodynia, hyperalgesia, sweating, and drowsiness.