Premedication for ambulatory surgery in preschool children: a comparison of oral midazolam and rectal thiopentone.

Seventy five ASA 1 and 2 children, aged between six months and five years were randomized to receive oral midazolam 0.5 mg.kg-1, rectal thiopentone 35 mg.kg-1 or no premedication to compare the safety and efficacy of, and parental attitudes to, both premedicants. Cardio-respiratory variables were from the time of premedication to awakening from anaesthesia. In addition, anxiety and sedation scores and patients' acceptance of both premedicant and mask at induction, were all recorded using four-point rating scales. Times to recovery and discharge, and parental satisfaction with the premedication their child had received were also recorded. Children receiving rectal thiopentone had higher sedation scores and were more accepting of the mask than were the other two groups (P < 0.001). Their acceptance of the premedication was similar to that of the midazolam group. Times to spontaneous eye opening and discharge were longer in the thiopentone group (P < 0.005). Parental preoperative satisfaction rating was higher for thiopentone, but not midazolam, than no premedication (P < 0.05). When asked their premedication preferences for subsequent general anaesthetics, a higher proportion of parents whose children were not premedicated requested an alternative regimen (P < 0.01). In conclusion the study found that premedication with rectal thiopentone provided superior induction characteristics to oral midazolam, but with a longer recovery period.