Coadministered Benzodiazepines

Coadministered Benzodiazepines
As with anticholinergics, the prophylactic coadministration of
benzodiazepines has been traditionally recommended with the
intent of preventing or reducing recovery reactions.4,12,15,16 A
single controlled trial in ED adults found that midazolam
pretreatment (0.03 mg/kg IV) significantly reduced the
incidence of recovery agitation by 17% (number needed to
benefit6).28 Unfortunately, this study failed to describe the
nature or severity of these reactions, and so it remains unclear
how many of the events were clinically important and how
many were minor and transient. Nevertheless, midazolam
prophylaxis appears a reasonable but nonmandatory option in
adults.
In children, however, 2 controlled trials82,83 and a large
meta-analysis3 have failed to note even a trend toward benefit
from such prophylaxis. Children have far fewer recovery
reactions than adults, and thus the routine pretreatment of such
patients is not supported by the evidence.
When unpleasant ketamine-associated recovery reactions do
rarely occur, they can be rapidly and reliably diminished with
titrated benzodiazepines.4,12,16,19,20,36,71,83,84
Coadministered Antiemetics
A controlled trial in ED children has shown that
prophylactic ondansetron significantly decreases the rate of
emesis in children by 8% (number needed to benefit13).85
Given this modest effect, such therapy cannot be considered
mandatory. Early adolescence is the peak age for vomiting, and
one option would be to target these children at highest risk for
whom the number needed to benefit is 9.3 The literature is
silent on antiemetic prophylaxis in adults.