[Premedication using intrarectal midazolam. Study of effective dosage in pediatric anesthesia]

The object of this study was to determine the optimal dose of midazolam given per rectum which would produce sedation adequate for inducing inhalational anaesthesia in paediatric practice. Five doses were studied: 0.15, 0.25, 0.30, 0.35 and 0.40 mg X kg-1. The criteria used to appreciate the effectiveness of the sedation at 30 min were the change in the child's behaviour, with a scale of 6 levels, and the acceptance of the mask and anaesthetic vapours. There was a significant correlation between the dose administered and the degree of sedation, as well as between the dose administered and the lack of reaction to the mask. Significantly better results were found with the higher doses of 0.35 and 0.40 mg X kg-1, when compared with the children who had received 0.15 and 0.25 mg X kg-1. Only in the groups who received 0.35 and 0.40 mg X kg-1 were the degrees of sedation and acceptance of induction considered as adequate. The dose of 0.35 mg X kg-1 seemed to be the best dose for adequately premedicating a child.