Effects of Pre-Operative Administration of Ranitidine and Bromazepam for Premedication in Children

Abstract

Effects of pre-operative administration of ranitidine on pH and volume of gastric juice were evaluated in 54 children (mean age: 5.4±1.0 yr) who underwent elective surgery under general anesthesia. Simultaneously, bromazepam suppository was evaluated as a premedication agent for pediatric patients. Patients were randomly divided into four groups, and premedication agents were given 2 hr prior to induction of anesthesia. Patients in group A received diazepam syrup (0.5 mg/kg p. o.) and those in group B received bromazepam suppository (3 mg). Patients in groups C and D received ranitidine (1 mg or 2 mg/kg i. m.) together with bromazepam suppository (3 mg). Following induction of anesthesia, a gastric tube (10 Fr. or 12 Fr.) was passed and stomach contents were collected and analyzed for volume and pH, which was repeated every hr until the end of the operation. The gastric pH at the induction of anesthesia was observed to be 2. 5 or less in 70% of the patients of groups A and B, 13% of group C, and 0% of group D. The volume of gastric contents was less than 0.4 ml/kg in 87% of ranitidine-treated patients (groups C and D), in 29% of group A, and in 60% of group B. It was then concluded that pre-operative administration of ranitidine caused a significant reduction of both acidity and volume of gastric contents, which will contribute to preventing or reducing aspiration pneumonitis during general anesthesia. Plasma ranitidine concentrations measured by high-performance liquid chromatography revealed 228±32ng/ml in group C and 487±59ng/ml in group D at the induction of anesthesia. Sedation at the induction of anesthesia was evaluated utilizing our original pediatric premedication score, which consists of 3 check points: quietness (very good, 3; good, 2; fair, 1; bad, 0) ; crying (no, 2; a little, 1; yes, 0) ; and i. v. root (under local anesthesia, 1; following induction of anesthesia, 0). The averaged scores were 4.5±0.4 in group A, 4.2±1.9 in group B, 4.1 ±0.6 in group C, and 4.8±0.5 in group D, respectively. There was no significant difference in the score in 4 groups. A plasma bromazepam level was 414±49 ng/ml at the induction of anesthesia. Our results showed that bromazepam suppository is as effective as diazepam syrup for premedication in children. © 1989, The Japanese Society of Clinical Pharmacology and Therapeutics. All rights reserved.