The clinical effect of small oral clonidine doses on perioperative outcomes in patients undergoing abdominal hysterectomy.

Abstract

We assessed the effect of small clonidine doses on anxiolysis, analgesia, and hemodynamic stability in patients undergoing abdominal hysterectomy. A total of 61 patients, ASA status I-II, were randomly assigned to receive either oral clonidine 100 microg (n = 29) or placebo (n = 32) before surgery and 24 h after surgery. The use of clonidine resulted in anxiolysis and analgesia throughout the 72 h after surgery, although the subjects who received clonidine were sleepier than the control group for the first 6 h after surgery. The number needed to treat was 3 (95% confidence interval [CI], 1.72-9.42) to prevent intense anxiety in patients with moderate to intense postoperative pain, compared with 40 (95% CI, 18.79-99.68) in the absence of pain or with mild pain. In the treated patients, 68% had an average heart rate less than 70 bpm during surgery, compared with 21.40% in the placebo group (number needed to treat, 2; 95% CI, 1.29-2.80). The clonidine patients required small ropivacaine doses during the surgery but not less morphine by patient-controlled analgesia. A clinically relevant anxiolytic effect was found in patients who received oral clonidine in the perioperative period, and this suggests that clonidine might be a useful therapeutic alternative to other preoperative sedatives.