[Emesis and the oculocardiac reflex. Drug prophylaxis with droperidol and atropine in children undergoing strabismus surgery].

Although droperidol is often used to prevent emesis, vomiting is still common in children undergoing strabismus surgery. METHODS. One hundred children aged 3 to 12 years admitted for strabismus surgery were enrolled in a randomised, double-blind study to investigate the influence of the timing of the administration of droperidol (75 micrograms/kg i.v.) and the effect of atropine (10 micrograms/kg i.v.) on postoperative vomiting and the occurrence of the oculocardiac reflex (OCR). Each child was prospectively assigned to one of the following groups: Group A: atropine and droperidol before the beginning of surgery (n = 25); Group B: atropine 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, anaesthesia was induced via a face mask by inhalation of halothane, nitrous oxide, and oxygen and 1 mg/kg succinylcholine was given to facilitate tracheal intubation. Gastric contents were aspirated by a gastric tube at 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 weight, duration of anaesthesia, and number of repaired eye muscles. Patients receiving droperidol before and after the end of surgery had a similar incidence of vomiting (groups A and C 60% vs. groups B and D 50%). There was no significant difference in the number of patients vomiting between groups A and B (58%) and groups C and D (52%). The incidence of the OCR was lower in the patients premedicated with atropine (18% vs. 60%, P < 0.01). There was no statistical relationship between the occurrence of the OCR and post-operative emesis. Younger children (3 to 6 years) vomited more often than older ones (7 to 12 years). The incidence of the OCR was higher in patients with more than two eye muscles repaired than in others. Recovery scores were slightly lower in patients with droperidol after completion of surgery; postoperative recovery times did not differ significantly between the study groups. CONCLUSIONS. The timing of the administration of droperidol (75 micrograms/kg) had no influence on postoperative vomiting. The application of atropine (10 micrograms/kg) prior to surgery did not influence vomiting after strabismus surgery. Atropine (10 micrograms/kg) reduced the incidence of the OCR significantly. There was no statistical relationship between the occurrence of the OCR and postoperative vomiting.