Background: Postoperative pain relief is one of the most important concerns for patients undergoing cardiac surgery and is one of the most clinically challenging for anesthesiologist. Traditionally, analgesia following cardiac surgery has been obtained with intravenous opioids. Tramadol is the most commonly used opioid for postoperative pain relief at our institution. Presently, no study has been conducted on the use of intravenous oxycodone in cardiac surgery for postoperative pain relief in our institution. Our objective is to compare the analgesic efficacy and compare the incidence of side effects of intravenous oxycodone versus intravenous tramadol in preventing pain in patients undergoing coronary artery bypass and grafting surgery.
Method: We conducted a randomized, double-blind controlled trial involving elective patients for CABG surgery under cardiopulmonary bypass. We randomized patients to receive either intravenous oxycodone 0.05 mg/kg IV bolus q8h or intravenous tramadol 50 mg IV q8h with the first dose given upon arrival at the Surgical Intensive Care Unit (SICU). Pain was assessed using a Visual Analog Scale (VAS) before and after giving the doses of the test medications. Postoperative nausea and vomiting and all adverse effects were concomitantly registered with pain assessment. Continuous data was presented as a mean ± SD and is compared between groups using an Independent T-test. Chi-Square tests were used for categorical data. Univariate analysis of variance was used in adjusting for the difference in the cardiopulmonary bypass time and aortic cross clamp time between the two groups. VAS score is compared between groups for each parameter depending on time interval.
Results: A total of 60 patients, 30 per group were enrolled in the study. Patients in the oxycodone group showed a superior pain relief compared with tramadol before and after the 8th, 16th and 24th hour postoperatively (p value of 0.003-0.005). There were 2 cases (12.5%) incidence of vomiting in the Tramadol group and none in the Oxycodone group (p value of 0.492). There were no major complications that occurred such as respiratory depression, hypotension or pruritus during the whole study period.
Conclusion: This study demonstrated that Oxycodone is superior than tramadol in preventing post-operative pain in patients undergoing CABG surgery and that there was no significant difference in terms of the incidence of side effects.