Opioid-sparing effects of diclofenac and paracetamol lead to improved outcomes after cardiac surgery

Abstract Objective : This study assessed the analgesic efficacy, side effects, time to extubation, and oxygenation of 3 analgesic regimens after coronary artery bypass surgery using diclofenac, paracetamol, and placebo suppositories. Design : Prospective, randomized, double-blind, placebo-controlled study. Setting : Referral center for cardiothoracic surgery at a university hospital. Participants : Sixty consenting adults scheduled for elective coronary artery bypass grafting (CABG). Interventions : Patients were divided into 3 groups postoperatively: diclofenac/paracetamol: diclofenac, 100 mg rectally, and paracetamol, 1 g rectally. Diclofenac was repeated after 18 hours and paracetamol every 6 hours for 24 hours; diclofenac: diclofenac as in diclofenac/paracetamol, with placebos replacing paracetamol; and placebo: 2 placebo suppositories at same times as diclofenac/paracetamol. All patients received morphine patient-controlled analgesia. Results : Twenty-four hour morphine consumption with diclofenac/paracetamol was 12 ± 6 mg, diclofenac 22 ± 13 mg, and placebo 37 ± 15 mg (diclofenac/paracetamol and diclofenac, p = 0.0003 and p = 0.0159 compared with placebo). Patients in the placebo group had significantly greater pain scores at 12 and 24 hours compared with diclofenac/paracetamol and diclofenac. Extubation time was significantly prolonged in the placebo group compared with the diclofenac/paracetamol and diclofenac groups (mean [SD] minutes diclofenac/paracetamol, diclofenac, and placebo 478 [150], 487 [257], and 710 [326], respectively). Oxygenation following extubation was significantly lower in the placebo group compared with the diclofenac/paracetamol and diclofenac groups (mean [SD] mmHg: diclofenac/paracetamol, diclofenac, and placebo 175 [44], 157 [43], and 117 [22], respectively). Episodes of nausea and vomiting were significantly less in the diclofenac/paracetamol and diclofenac groups than in the placebo group (46% and 51% reduction, respectively). All groups had similar blood loss and change in serum creatinine. Conclusion : Diclofenac alone or with paracetamol has a significant opioid-sparing effect after CABG, producing more rapid extubation and better oxygenation.