The Efficacy of Tramadol Used With Ketamine or Morphine in Pain Control after Coronary Artery Bypass Graft Surgery

Background Sufficient analgesia after coronary artery bypass graft surgery (CABG) is important to prevent postoperative complications. One of these analgesic techniques is patientcontrolled analgesia (PCA), in which the patient has self–controlled administration of anesthetics. The purpose of this study was to evaluate the analgesic effect and side effects of tramadol used with ketamine or morphine for post-CABG surgery analgesia. Methods In this prospective, controlled randomized study, we selected 150 patients who were candidates for CABG. The inclusion criteria were adult patients aged 30-60 with coronary artery disease, candidates for CABG, elective surgery, surgery using cardiopulmonary bypass, and ASA II and III. The patients with uncontrolled and significant underlying diseases (diabetes, liver and kidney disease and clotting disorders), excessive obesity and weight over 115 kg, and non-consenting patients were excluded. The patients were divided into three groups of 50 each. At the end of surgery, all the patients were transferred to the post-surgical intensive care unit, where they were extubated. PCA was commenced when the patients were able to communicate. The first group was provided with 100mg of tramadol with normal saline, the second group 50mg of tramadol plus 20mg of morphine, and the third group 50mg of tramadol plus 50mg of ketamine. During the use of the PCA pump, the patients were observed for respiratory depression (respiratory rate and SPO2, PaCO2 every two hours during the first 8 hours and then every 4 hours). The severity of pain was evaluated with the visual analog scale (VAS) method, where zero was no pain and ten was severe pain. The VAS results were recorded 1, 3, 6, 12, 18, 24, 36, and 48 hours after awareness and extubation and recording the base VAS of the patients. Results The average respiratory rate was 14 in all the three groups and respiratory depression was not seen in any of them. At the third hour, the VAS was similar in all the groups (p value<0.05). The decrease in VAS at 6, 12, and 18 hours was significant and the minimum VAS was seen in the second group (tramadol + morphine). Conclusions PCA is a safe and appropriate method for analgesia after CABG. It seems that the combination of tramadol plus morphine can be an effective solution for analgesia after CABG with fewer respiratory complications than other combinations.