Anesthesia induction in children: propofol in comparison with thiopental following premedication with midazolam

Propofol provides smooth and rapid induction of anesthesia in adults and guarantees rapid recovery. The use of propofol in adults is frequently associated with pain on injection, but this can be reduced by: (1) injection into the relatively large veins in the forearm or the antecubital fossa: (2) addition of lignocaine to the propofol; or (3) injection of an opioid (alfentanil) before propofol. Compared with experience in adults, there is very little experience with propofol in pediatric anesthesia. The aim of this random prospective study was to compare the induction characteristics of propofol and thiopentone in pediatric anesthesia. Vigilance and behavior in the postoperative period were also compared. METHOD. A total of 75 healthy children aged 3-12 years who were undergoing elective operations were studied. All the children received premedication with 0.5 mg/kg midazolam with 0.02 mg/kg atropine by the rectal route. The children were divided randomly into 3 groups and received: group A, thiopentone 3-6 mg/kg; group B, propofol 1-3 mg/kg mixed with lignocaine (10/200 mg); group C, propofol 1-3 mg/kg, followed 1 min later by alfentanil 0.01 mg/kg. The induction agent was injected over 30 s, if possible into the vein in the forearm or the antecubital fossa. The immediate reaction on vein puncture and any discomfort during the injection were noted. After intubation the anesthesia was maintained with 1 vol% halothane, nitrous oxide and oxygen (2:1). Arterial pressure was measured on arrival in the induction room, immediately after the induction of anesthesia, immediately after intubation and thereafter at 5-min intervals throughout the anesthesia. Heart rate (ECG) and arterial oxygen saturation (saO2) were measured continuously. The existence of any anterograde amnesia was tested (age over 4 years) by means of one of 6 pictures shown to each before operation. The ability to recall the picture shown was recorded 2-5 h postoperatively. The completeness of recovery was assessed at 10-min intervals up to 1 h, and thereafter at 1-h intervals. In the postoperative period a recovery test (postbox test) was performed. The incidence of side effects during the induction of anesthesia and also during recovery and the postoperative period (for 5 h) was recorded. RESULTS. There was no significant difference between the children in the 3 different groups with regard to age, body weight, type of operation, or duration of anesthesia. Among the total of 75 children, 66.7% accepted the vein puncture very well, and 24% well. In some children in each group we observed obstruction of the respiratory tract (group A, 36%; group B, 48%; group C, 64%). Apnea for 20 s was observed only in groups B and C (2 and 3 children respectively). During spontaneous respiration with room air there was a significant decrease of the arterial oxygen saturation about 1 min after induction in all groups. In children ventilated with oxygen by mask, the SaO2 remained nearly constant...