Role of buprenorphine in prolonging the duration of post-operative analgesia in percutaneous nephrolithotomy: Comparison between bupivacaine versus bupivacaine and buprenorphine combination

INTRODUCTION: Percutaneous nephrolithotomy (PCNL) is the treatment of choice for large renal calculi. Pain around the nephrostomy tube is a clinical problem and we have previously reported alleviation of pain by peritubal block with bupivacaine, which lasted for 14 hours. The present study aimed to investigate the role of buprenorphine and bupivacaine combination in prolonging the duration of analgesia in peritubal block. MATERIALS AND METHODS: A prospective, randomized controlled study was undertaken in 40 American Society of Anesthesiologists (ASA) grade I and II patients who were scheduled for PCNL. Group I patients received 20 mL of 0.25% bupivacaine and group II patients received 20 mL of 0.25% bupivacaine with 100 μg of buprenorphine. Peritubal infiltration was given under fluoroscopic guidance along the nephrostomy tube from the renal capsule to the skin. Post-operative pain was assessed by Visual Analog Score (VAS), dynamic VAS (DVAS), sedation score, duration of analgesia and number of rescue analgesic demands. Rescue analgesia was inj tramadol 1 mg/kg IV if pain score exceeded 3. RESULTS: Demographic data were comparable between the groups. Median duration of analgesia was 16 h in group I and 20 h in group II (P = 0.002). The maximum median VAS was 4 in group I and 2 in group II (P = 0.002). The median area under curve (AUC) for VAS was 7 and 5 in groups I and II, respectively (P = 0.047). The median maximum DVAS in group I was 6 and 4 in group II. The median AUC for DVAS in 24 h was 16 in group I and 15 in group II (P = 0.017). CONCLUSIONS: Peritubal infiltration of 0.25% bupivacaine with 100 μg buprenorphine around a nephrostomy tube increased the duration of analgesia following PCNL without any side-effects.