Use of ketamine at induction followed by reduced propofol
infusion rate for maintenance is associated with shorter recovery times for
children undergoing magnetic resonance imaging with deep sedation, according to
a study published online in Pediatric

Achim Schmitz, MD, from the University Children’s Hospital
in Zurich, and colleagues randomly assigned 347 children aged 3 months to 10
years scheduled as outpatients for elective magnetic resonance imaging with
deep sedation to receive either 1 mg/kg ketamine at induction followed by a
propofol infusion rate of 5 mg/kg/hour or a propofol infusion rate of 10
mg/kg/hour without ketamine. The primary outcome was time to full recovery.

The researchers found that the ketamine-propofol group
experienced significantly shorter recovery times (38 versus 54 minutes; median
difference, 14 minutes; P < 0.001), as well as better quality of induction and higher blood pressure. But, the incidence of movement requiring additional sedative drugs was higher in the ketamine-propofol group. Respiratory side effects, cardiovascular compromise, emergence delirium, and postoperative nausea and vomiting did not differ significantly between the groups.

“Both sedation concepts proved to be reliable with a
low incidence of side effects,” the authors write. “Ketamine at
induction with a reduced propofol infusion rate leads to faster post-anaesthetic


Reference: Schmitz
 A, et al. Sedation for magnetic
resonance imaging using propofol with or without ketamine at induction in
pediatrics—A prospective randomized double-blinded study. Pediatric Anesthesia. Published online 27 January 2018.