title: Ventilation and the oculocardiac reflex. Prevention of oculocardiac reflex during surgery for squints: role of controlled ventilation and anticholinergic drugs.
abstract: A randomised prospective study was carried out in children undergoing surgery for squint correction, to determine the value of controlled ventilation as a prophylaxis against the occurrence of the oculocardiac reflex. One hundred patients anaesthetised with nitrous oxide/oxygen and halothane were randomly assigned to either ventilated or spontaneously breathing groups of 50 each. Half the patients in each group received glycopyrronium 7.5 micrograms/kg intravenously at the time of induction of anaesthesia. Heart rate, rhythm, blood pressure and end tidal CO2 concentration were monitored throughout. A positive oculocardiac reflex, defined as a fall in heart rate of 20% or more and/or the occurrence of dysrhythmias, was observed in 72% of spontaneously breathing patients and in 100% of ventilated patients not receiving prophylactic intravenous glycopyrronium. The incidence of a positive reflex in patients receiving glycopyrronium was 10% (4 and 16% respectively in spontaneously breathing and ventilated patients). It is concluded that controlled ventilation is of no value as a preventive measure against the occurrence of the oculocardiac reflex in patients undergoing squint surgery and that prophylaxis is safely achieved with the use of intravenous glycopyrronium.
mesh_terms: D000293:Adolescent; D001145:Arrhythmias, Cardiac / Q000209:etiology; D002648:Child; D002675:Child, Preschool; D006024:Glycopyrrolate / Q000494:pharmacology*; D006339:Heart Rate; D006801:Humans; D007431:Intraoperative Complications; D011446:Prospective Studies; D011759:Pyrrolidines / Q000494:pharmacology*; D012018:Reflex / Q000187:drug effects*; D012024:Reflex, Oculocardiac / Q000187:drug effects*; D012121:Respiration, Artificial; D013285:Strabismus / Q000150:complications / Q000601:surgery*
chemical_list: D011759:Pyrrolidines; D006024:Glycopyrrolate