Ketamine infusions as an adjunct for sedation in critically ill children.

OBJECTIVE: Limited reports have described ketamine's role as an adjunct sedative. The purpose was to describe ketamine's role as an adjunct to achieve goal sedation in mechanically ventilated children. DESIGN: Retrospective, descriptive study. SETTING: Thirteen-bed pediatric intensive care unit (ICU) and 12-bed pediatric cardiovascular ICU. PARTICIPANTS: Seventy-three ketamine courses were included, representing 62 mechanically ventilated children <18 years receiving ketamine for ≥12 hours. MAIN OUTCOME MEASURE(S): The primary outcome was to determine the median dose and time to achieve goal sedation (80 percent of State Behavioral Scale scores between 0 and -1) based on ketamine's place in therapy as an adjunct in the sedation regimen. Secondary outcomes included a comparison of sedative dosing pre- and post-ketamine initiation between place in therapy groups and paralyzed/nonparalyzed patients, and identification of ketamine-attributed adverse drug event (ADEs) or iatrogenic withdrawal syndrome (IWS). RESULTS: The median age was 1.0 years (interquartile range: 0.4-4.9). Ketamine was initiated as first-line (n = 7; 9.6 percent), second-line (n = 39; 53.4 percent), third-line (n = 26; 35.6 percent), or fourth-line (n = 1; 1.4 percent) sedation. The median initial and peak doses were 0.6 mg/kg/h (0.3-0.6) and 0.9 mg/kg/h (0.9-1.2), respectively. The median dose and time to achieve goal sedation was 0.8 mg/kg/h (0.6-1.1) and 2 hours (1-7), respectively. ADEs were noted during three courses (4.1 percent) and IWS after discontinuation of one course (1.4 percent). CONCLUSIONS: The majority were initiated on ketamine as a second- or third-line adjunct sedative. The median initial dose was 0.6 and dose to achieve goal sedation was 0.8 mg/kg/h. Ketamine-attributed ADEs and IWS episodes were rare.

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.