[Effects of intravenous and intramuscular atropine on bradycardia during spinal anesthesia].

The effects of intravenous and intramuscular atropine on pulse rate have been studied in 40 patients undergoing gynecological surgery. Intramuscular atropine 0.5 mg was administered 30 min before induction of spinal anesthesia in 20 patients (i.m. group). Intravenous atropine 0.5 mg was administered immediately after induction of spinal anesthesia in 20 patients (i.v. group). Decrease in heart rate after spinal block was significantly less in i.v. group than in i.m. group. Although no one in i.v. group was given an additional atropine, 10% of the patients in i.m. group was given an additional atropine for bradycardia. Authors conclude that intravenous atropine has more significant effect on prevention of bradycardia during spinal anesthesia compared with intramuscular atropine.