BACKGROUND: Propofol increases the risk of bradycardia compared with other anesthetics. This paper reports the heart rate response to intravenous atropine during propofol and enflurane anesthesia.

METHODS: Sixty patients undergoing a transabdominal hysterectomy under general anesthesia were randomly assigned to two groups: the propofol group and the enflurane group. All the patients received midazolam 2 mg intramuscularly and were then anesthetized with propofol or enflurane. The blood pressure and heart rate were taken at 1 min intervals for 10 min after a bolus injection of atropine 5µgram/kg.

RESULTS: In the enflurane group, the systolic blood pressure and heart rate were increased significantly at 1, 2 and 3 min after the atropine injection (P < 0.05). When the two groups were compared, the heart rate in the enflurane group was significantly higher at 1, 2 and 3 min after atropine injection than in the propofol group (P < 0.05).

CONCLUSIONS: The heart rate response to intravenous atropine during propofol anesthesia is attenuated compared with enflurane anesthesia.