A randomised placebo-controlled trial of the effects of midazolam premedication on children's postoperative cognition.

This randomised, placebo-controlled study assessed the effects of midazolam premedication on children's postoperative cognition and physical morbidity. In all, 179 children aged 5-10 years were randomly assigned to receive buccal midazolam (0.2 mg x kg(-1)) or placebo before sevoflurane-nitrous oxide anaesthesia for multiple dental extractions. They performed tests of choice reaction time, attention, psychomotor co-ordination and memory pre-operatively (baseline), before discharge and at 48 h. The reaction time of both groups was significantly slower before discharge compared to baseline, with the midazolam group being significantly slower than placebo. Psychomotor co-ordination was also significantly impaired postoperatively after midazolam. Performance on both tests had recovered to baseline by 48 h. Midazolam was also associated with significant anterograde amnesia, both postoperatively and at 48 h, for information presented in the interval between premedication and surgery. The results show significant short-term impairment of children's cognitive function and amnesia enduring for 48 h after low-dose midazolam premedication.