Postoperative Analgesia with Epidural Infusion of Buprenorphine Versus Transdermal Buprenorphine in Total Abdominal Hysterectomy: A Prospective Observational Cohort Study

Introduction: Transdermal Buprenorphine (TDB) patches have recently gained popularity owing to its non-invasive dosing, minimal side-effects and longer duration. Epidural opioids provide excellent analgesia thus permitting early ambulation. Aim: To compare the efficacy of epidural buprenorphine infusion and TDB to relieve postoperative pain following total abdominal hysterectomy. Materials and Methods: In this prospective observational cohort study, 116 patients undergoing total abdominal hysterectomy in a tertiary care institution, were divided into two equal groups. All patients were given subarachnoid anaesthesia using 3.4 ml 0.5% bupivacaine heavy with 60 μg buprenorphine. Group T patients had TDB (10 μg/h) patch applied 12 hours prior to procedure; while Group E patients received epidural buprenorphine infusion (10 μg/h) postoperatively. Postoperative analgesia was assessed using Numerical Rating Scale (NRS) at 2 hours, 4 hours, 24 hours, 36 hours, 48 hours, 60 hours, 72 hours after surgery. Inj. diclofenac 75 mg IV or Inj. paracetamol 1gm Intravenous (IV) infusion were given as rescue analgesic. The requirement of rescue analgesics was also recorded every 24 hours. Occurrence of adverse effects like sedation, respiratory depression, hypotension, bradycardia, nausea, vomiting, pruritus, headache, dizziness etc., were observed and compared between the two groups. Chi-square and Independent t-test were used for categorical and continuous variables, respectively. Results: Better postoperative analgesia with lower NRS scores were seen in Group E when compared to Group T at all the measured intervals (p-value<0.001). The median rescue analgesic requirement was significantly higher in Group T {Diclofenac 75 (0,150) mg, Paracetamol 2 (1,2) g} than Group E {Diclofenac 0 (0, 75) mg, Paracetamol 1 (0, 1) g}. Sedation was more for epidural buprenorphine at 2 hour, 24 hours, 36 hours and 48 hours. The occurrence of nausea and vomiting was more with TDB (p-value<0.001). There were no other significant adverse effects in both the study groups. Conclusion: Epidural infusion of buprenorphine is safe and more effective than an equal dose of TDB in postoperative analgesia for abdominal hysterectomy.