Comparing the Effectiveness of Patient Control Analgesia Pump and Bolus Morphine in Controlling Pain After Cardiopulmonary Bypass Graft Surgery

Postoperative pain is a complex process commonly caused by surgical trauma. It is one of the major concerns of patients undergoing heart surgery. Despite new techniques and modern analgesic treatments, postoperative pain is still one of the most important controversial issues.
68 patients scheduled for elective CABG with CPB were included in a prospective, double-blind clinical trial. They were randomly divided into two groups. One group received PCA pump including morphine (group P) with underlying infusion of 0.02 mg/kg/Qh, bolus dose of 1 mg, lockout time of 15 minutes, and a maximum of 4 bolus of 0.02 mg/kg for one hour and the other group received morphine bolus (group B). Three patients were excluded from the study, and 33 and 32 patients participated in the groups P and B, respectively. Variables including age, gender, pump time, aortic clamp time, duration of surgery, complications (nausea and vomiting, GI Bleeding, and hypoxia), level of pain based on VAS, opioid consumption, hemodynamic, and sedation status were measured in both groups.
There was no significant difference between the groups regarding age, gender, pump time, clamp time, duration of surgery, complication, sedation score, and hemodynamic status in most of the assessment periods. By assessing the pain severity in the groups at different periods, results showed a significant difference between the groups except at enrollment, and a lower severity of pain was noted in the group P compared to the group B. The consumed opioid was significantly higher in the group P than in the group B. However, higher doses of diclofenac and paracetamol were administered in the group B compared to the group P.
Results showed that higher morphine would be used in patients with PCA pump after extubation following heart surgery, and this increased dose of opioid was associated with better pain control and lack of complication. Therefore, PCA pump with underlying infusion could be effectively used in patients undergoing CABG that are directly assessed in intensive care unite.