Ketamine Administration: General

Ketamine Administration: General
Dosing and adverse events. The concepts of a continuum
of sedation and dose-dependent adverse events are familiar to
clinicians, given that they are characteristic of
nondissociative sedatives. However, there is strongly
supportive evidence that ketamine does not exhibit any such
dose-related adverse events within the range of clinically
administered doses using standard administration
techniques.2-4,14,18,20,76 A large meta-analysis found no doserelated
adverse events across the standard dosing range, with
only unusually high IV doses (ie, initial dose
2.5 mg/kg or
total dose
5.0 mg/kg) increasing the risk of vomiting and
slightly increasing the risk of apnea and recovery agitation.2,3
Thus, there is no apparent benefit to using 1 mg/kg IV rather
than 2 mg/kg IV or to using 3 mg/kg IM rather than 4 to 5
mg/kg IM, except perhaps a slightly faster recovery with the

lower dose.77 Clinicians should consider simply using the
higher dose because ketamine is less consistently effective
with lower doses.18
Of historical note, during the 1970s anesthesiologists
typically administered much higher ketamine doses (7 to 15
mg/kg IM) than those advocated now, and a systematic review
identified no apparent difference in adverse event profiles
between the higher and more standard dosing.4
In the large meta-analysis, subdissociative ketamine (
3 mg/
kg IM) demonstrated fewer airway and respiratory adverse
effects relative to full dissociative dosing; however, such low
doses are inadequate for most painful procedures and showed a
higher incidence of recovery agitation.2,3 No such association
was found for IV dosing.