[Better acceptance of measures for induction of anesthesia after rectal premedication with midazolam in children. Comparison of results of an open and placebo-controlled study].

The rectal administration of midazolam for premedication of children before induction of anesthesia by mask was investigated in two clinical studies. In 62 children aged between 2 and 10 years, midazolam was given by open design at various dosages (0.15 mg.kg-1, 0.25 mg.kg-1, 0.30 mg.kg-1, 0.35 mg.kg-1, 0.40 mg.kg-1) to evaluate the most effective dose for optimal acceptance of the mask and gas mixture. An additional 40 children between 3 and 9 years received 0.2 mg midazolam.kg-1 body weight or placebo in a double-blind design to estimate the lower limit of efficacy of midazolam. All children were classified as ASA I and had to undergo a surgical procedure. Within the two studies the children were not different with respect to their general data, age, weight, and sex. In both studies more boys than girls were included. Parameters of efficacy were the degree of sedation before and at 10, 20, and 30 min after midazolam as well as acceptance of the mask and the gas mixture at induction of anesthesia. In all groups, including placebo, a sedative and tranquilizing effect of the premedication was found. The rectal administration of 0.35-0.4 mg midazolam.kg-1 is most suitable for the preoperative medication of children between 2 and 10 years. Due to the degree of sedation and the relief of anxiety toward the surroundings and the operation, the induction of anesthesia is optimally accepted by the child. In contrast, the effect of a dose around 0.2 mg midazolam.kg-1 body weight is not much different from that of placebo and is not sufficient for effective premedication.