What is the nature of the emergence phenomenon when using intravenous or intramuscular ketamine for paediatric procedural sedation?

Emerg Med Australas. 2009 Aug;21(4):315-22. doi: 10.1111/j.1742-6723.2009.01203.x.


Objective: Ketamine has become the drug most favoured by emergency physicians for sedation of children in the ED. Some emergency physicians do not use ketamine for paediatric procedural sedation (PPS) because of concern about emergence delirium on recovery. The present study set out to determine the true incidence and nature of this phenomenon.

Methods: Prospective data relating to any emergence agitation, crying, hallucinations, dreams, altered perceptions, delirium and necessary interventions were recorded in consecutive cases of ketamine PPS from March 2002 to June 2007, and analysed. Standard inclusion and exclusion criteria for the use of ketamine were followed.

Results: A total of 745 prospective data collection records were available for analysis over the 5 year period. Of all, 93 (12.5%) children cried on awakening when recovering from PPS, 291 (39%) experienced pleasant altered perceptions and 16 (2.1%) experienced what was called 'emergence delirium'. None required any active treatment and all except one settled within 20 min. There was no evidence of an increased rate of nightmares on telephone follow up in the weeks post procedure.

Conclusion: The belief that ketamine, in the doses used for ED PPS, causes frequent emergence delirium is flawed. A pleasant emergence phenomenon is common, but is not distressing for the child, and has no long-term (up to 30 days) negative sequelae. Rarely, there is anxiety or distress on awakening from ketamine sedation, which settles spontaneously. This should not deter emergency physicians from using ketamine for PPS.

MeSH terms

  • Adolescent
  • Anesthesia Recovery Period
  • Anesthetics, Dissociative / administration & dosage
  • Anesthetics, Dissociative / adverse effects*
  • Australia
  • Child
  • Child, Preschool
  • Conscious Sedation / methods*
  • Delirium / chemically induced
  • Delirium / prevention & control*
  • Humans
  • Infant
  • Injections, Intramuscular
  • Injections, Intravenous
  • Ketamine / administration & dosage
  • Ketamine / adverse effects*
  • Male
  • Treatment Outcome


  • Anesthetics, Dissociative
  • Ketamine