The use of intravenous atropine after a saline infusion in the prevention of spinal anesthesia-induced hypotension in elderly patients

We investigated the efficacy of IV atropine for preventing spinal anesthesi a-induced hypotension in elderly patients. Seventy-five patients undergoing transurethral prostate or bladder surgery were randomized to receive eithe r placebo (n = 25), atropine 5 mug/kg (small-dose atropine, n = 25) or atro pine 10 mug/kg (large-dose atropine, n = 25) after the induction of spinal anesthesia. All the patients received an IV infusion of 10 mL/kg 0.9% norma l saline over 10 min before the induction of anesthesia. The systolic blood pressure decreased in all three groups after spinal anesthesia. There was a significant increase in the mean heart rate in both atropine groups as co mpared to the placebo group (placebo group: 78 bpm, 95% confidence interval [CI]: 76.6-78.5; small-dose atropine group: 86 bpm, 95% CI: 83.9-88.8; lar ge-dose atropine group: 97 bpm, 95% CI: 94.5-100.3; P = 0.001). There was a significant decrease in the incidence of hypotension in patients who recei ved atropine (placebo group: 76%, small-dose atropine group: 52%, large-dos e atropine group: 40%, P = 0.03). The mean dose of ephedrine required was s ignificantly decreased in the atropine groups (placebo group: 12.2 mg [SD = 10 5], small-dose atropine group: 7.4 mg [SD = 10.0], large-dose atropine group: 5.4 mg [SD = 8.7 mg], P = 0.048). The total amount of IV fluid and n umber of patients requiring metaraminol in addition to 30 mg of ephedrine w ere not significantly different among the three groups. Significant side ef fects, such as confusion, ST segment changes or angina were not detected in any of the patients. We conclude that IV atropine may be a useful suppleme nt to the existing methods in preventing hypotension induced by spinal anes thesia.