Comparison of erector spinae plane block and local anaesthetic infiltration of the incision site for postoperative analgesia in percutaneous nephrolithotomy – A randomised parallel-group study

BACKGROUND AND AIMS: Erector spinae plane block (ESPB) has been found effective in providing postoperative analgesia following a myriad of surgeries. This study was designed to evaluate the effectiveness of ultrasonography (USG) guided erector spinae plane block to provide postoperative analgesia following percutaneous nephrolithotomy (PCNL). METHODS: This was a prospective, double-blinded, randomised parallel-group study conducted in patients undergoing PCNL. Patients in Group C (n = 33) received subcutaneous infiltration of 20 mL of 0.25% bupivacaine at the incision site and Group B (n = 33) received USG guided ESPB with 20 mL of 0.25% bupivacaine postoperatively. Numeric rating scale (NRS) scores were assessed at intervals of 30 min, 60 min, then hourly for six h, followed by four-hourly up to 24 h. The primary objective of the study was to compare postoperative pain relief using the NRS score between the two groups. Secondary objectives were to compare the analgesic requirement and to assess the incidence of complications. Normally distributed data were expressed as mean and standard deviation and analysed using Student's t-test. Data following non-normal distribution were expressed as median and interquartile range and analysed using Mann- Whitney U-test. For categorical data, the Chi-square test was used. RESULTS: NRS scores were lower in Group B than Group C. There was significant prolongation in time for first analgesia in Group B (12 h) compared to Group C (30 min). There was a significant reduction in total tramadol consumption at 24 h postoperatively in the ESPB group. CONCLUSION: Ultrasound-guided ESPB is an efficacious analgesic technique with an opioid-sparing effect following PCNL.