VOMITING AND THE OCULOCARDIAC REFLEX IN C HILDREN UNDERGOING STRABISMUS SURGERY - PROPHYLACTIC EFFECTS OF DROPERIDOL AND ATROPINE

Although droperidol is often used to prevent emesis, vomiting is still common in children undergoing strabismus surgery. Methods. One hundre d children aged 3 to 12 years admitted for strabismus surgery were enr olled in a randomised, double-blind study to investigate the influence of the timing of the administration of droperidol (75 mug/kg i.v.) an d the effect of atropine (10 mug/kg i.v.) on postoperative vomiting an d the occurrence of the oculocardiac reflex (OCR). Each child was pros pectively assigned to one of the following groups: Group A: atropine a nd droperidol before the beginning of surgery (n = 25); Group B: atrop ine before the beginning, droperidol after completion of surgery (n = 25); Group C: no atropine, droperidol before the beginning of surgery (n = 25); Group D: no atropine, droperidol after completion of surgery (n = 25). After oral premedication with 0.4 mg/kg midazolam, anaesthe sia was induced via a face mask by inhalation of halothane, nitrous ox ide, and oxygen and 1 mg/kg succinylcholine was given to facilitate tr acheal intubation. Gastric contents were aspirated by a gastric tube a t the end of the operation. Vomiting and retching were recorded for 24 h; recovery from anaesthesia was assessed by a modified Steward score . Results. The four groups were comparable regarding age, sex, body we ight, duration of anaesthesia, and number of repaired eye muscles. Pat ients receiving droperidol before and after the end of surgery had a s imilar incidence of vomiting (groups A and C 60% vs. groups B and D 50 %). There was no significant difference in the number of patients vomi ting between groups A and B (58%) and groups C and D (52%). The incide nce of the OCR was lower in the patients premedicated with atropine (1 8% vs. 60%, P < 0.01). There was no statistical relationship between t he occurrence of the OCR and postoperative emesis. Younger children (3 to 6 years) vomited more often than older ones (7 to 12 years). The i ncidence of the OCR was higher in patients with more than two eye musc les repaired than in others. Recovery scores were slightly lower in pa tients with droperidol after completion of surgery; postoperative reco very times did not differ significantly between the study groups. Conc lusions. The timing of the administration of droperidol (75 mug/kg) ha d no influence on postoperative vomiting. The application of atropine (10 mug/kg) prior to surgery did not influence vomiting after strabism us surgery. Atropine (10 mug/kg) reduced the incidence of the OCR sign ificantly. There was no statistical relationship between the occurrenc e of the OCR and postoperative vomiting.