Cardiovascular effect of oral atropine premedication during halothane anaesthesia in infants

ABSTRACT

A solution containing either atropine sulfate 0.02 mg/kg body weight, or a placebo was randomly administered orally to 30 infants 1-6 months old and 30 infants 7-16 months old, 30-45 minutes before induction of anesthesia. Anesthesia was induced using halothane in rising concentration up to 3% in a mixture of nitrous oxide/oxygen 60/40%; endotracheal intubation was done under deep halothane 3%. Anesthesia was maintained using 1% halothane with nitrous oxide/oxygen 60/40%. The onset of action of atropine was 25 minutes after oral administration as determined by 15% increase in heart rate above the baseline level. Heart rate, systolic blood pressure and mean arterial blood pressure were measured at 3-minute intervals starting just before induction of anesthesia and continued until the onset of surgical stimulation. It was concluded that the depressant effect of halothane on cardiovascular system is age related and that oral atropine premedication [0.02 mg/kg] is effective in attenuating the cardiovascular depression associated with halothane anesthesia in infants