Effect of Rectal Diclofenac in Reducing Postoperative Pain and Rescue Analgesia Requirement after Cardiac Surgery

Abstract

Adequate analgesic medication is mandatory after coronary artery bypass grafting (CABG) surgery. The aim of this study was to assess the analgesic efficacy, side effects, and need for rescue analgesia after CABG surgery comparing diclofenac and placebo rectal suppository. Thirty-seven consenting adults undergoing elective CABG surgery were randomly assigned in a double-blind fashion to receive either rectal diclofenac 100 mg (Group 1, n = 19) or placebo suppository (Group 2, n = 18) postoperatively, just after extubation. Both groups were given intravenous tramadol as a rescue analgesic. Pain scores in the two groups were assessed on a 10-cm visual analog scale at 0, 0.5, 1, 1.5, 2, 6, 12, 18, and 24 hours after suppository administration. Rescue analgesic consumption, sedation, nausea, and vomiting in both the groups were also recorded. Twenty-four-hour tramadol consumption in Group 1 was 92.5 +/- 33.5 mg compared to 157.5 +/- 63.4 mg in Group 2 (P = 0.002). Patients in the placebo group had significantly greater pain scores 1.5 to 12 hours after extubation. Group 1 patients were significantly more awake compared to Group 2 (P < 0.05). The incidence of postoperative nausea was less in Group 1 than in Group 2 (P = 0.001). Though not statistically significant, three patients in Group 2 each had a single episode of vomiting, whereas no patient had vomiting in Group 1. Rectal diclofenac suppository with tramadol provides adequate pain relief after cardiac surgery, and also reduces tramadol consumption and side effects commonly associated with tramadol.