Inadvertent ketamine overdose in children: clinical manifestations and outcome.
OBJECTIVE
We sought to characterize the clinical manifestations, outcome, and etiology of inadvertent ketamine overdose in the emergency department.


METHODS
We investigated cases of inadvertent ketamine overdose in children seen in the ED solicited through electronic mail subscription lists or reported to the Institute for Safe Medication Practices. The clinical manifestations, outcome, and reported cause for each case are described.


RESULTS
We identified 9 cases of inadvertent ketamine overdose in children treated in the ED. Patients received either 5(n=3), 10(n=5), or 100(n=1) times the intended dose, either by the intramuscular (n=5) or intravenous (n=4) route. All 9 experienced prolonged sedation (3 to 24 hours). Four experienced brief respiratory depression shortly after administration, and assisted ventilation was performed in 2. Two children without respiratory difficulty or hypoxemia were intubated by their physicians as a precaution. In 5 children, the dosing error was not discovered until late in the sedation, often when the child was not waking at the expected time. No adverse outcomes were noted, and all children were normal neurologically on discharge and longer-term follow-up if available.


CONCLUSIONS
No adverse outcomes were noted in 9 healthy children treated in the ED who inadvertently received 5 to 100 times the intended dose of ketamine. Toxicity manifested as prolonged sedation in all 9 and brief respiratory depression in 4. The margin of safety in ketamine overdose may be wide, although less common and more serious outcomes cannot be excluded by this small, self-reported sample.
Green
S M
SM
Departments of Emergency Medicine, Loma Linda University Medical Center and Children's Hospital, Loma Linda, CA, USA.
Clark
R
R
Hostetler
M A
MA
Cohen
M
M
Carlson
D
D
Rothrock
S G
SG
D000778:Anesthetics, Dissociative / Q000009:adverse effects; D002648:Child; D002675:Child, Preschool; D062787:Drug Overdose; D004638:Emergency Treatment; D005260:Female; D006801:Humans; D007223:Infant; D007649:Ketamine / Q000009:adverse effects; D008297:Male; D008508:Medication Errors; D014481:United States
D000778:Anesthetics, Dissociative; D007649:Ketamine