Comparison of midazolam (Ro 21-3981) and diazepam as complement of ketamine-air anesthesia in children

A single-blind, randomized, prospective, comparative clinical trial was performed in 90 (30 X 3) pediatric patients, comparing a new water-soluble benzodiazepine, midazolam (Ro 21-3931) and ketamine-air (8 mg . kg-1) by intramuscular or intravenous routes at equipotent dose (0.2 mg . kg-1) with the standard anesthesia technique with diazepam (0.3 mg . kg-1) as an intravenous complement, during anesthesia for diagnostic urological procedures on an out-patient basis. Comparison between the three series of the mean values of maximal variation of hemodynamic parameters (systolic and diastolic blood pressures, and heart rate) during maintenance of anesthesia revealed no statistical significant difference in their values. Apnea was not observed in any patient. Local tolerance was excellent after i.v. administration, while good in the ketamine-midazolam i.m. series, 5 patients reported slight pain under pressure at the site of injection 24 hours after the end of anesthesia. No serious adverse reactions were observed in this clinical trial. We concluded that the efficacy of midazolam (Ro 21-3981) was excellent and comparable to that of the standard drug (diazepam), with the added advantage of better tolerance after both the intramuscular and intravenous administration, due to the rapid intramuscular absorption of midazolam, which starts simultaneously with that of ketamine.