Comparative evaluation of the analgesic efficacy of ultrasound-guided erector spinae plane block versus intrathecal morphine in patients undergoing percutaneous nephrolithotomy surgery: A prospective randomized pilot study

Objectives: Existing research on erector spinae plane block and intrathecal morphine in patients undergoing percutaneous nephrolithotomy surgery is limited. Methods: In this prospective, randomized study, 60 patients aged between 18 and 60 years were randomized into two groups (erector spinae plane block and intrathecal morphine). In the erector spinae plane block group, ultrasound-guided erector spinae plane block was performed, following which a mixture of 20 mL of 0.375% ropivacaine and 0.5 mcg/kg of clonidine was injected. In the intrathecal morphine group, 150 mcg preservative-free morphine with 2 mL of normal saline was administered intrathecally. The primary outcome was to evaluate the perioperative opioid consumption in the first 24 h. The secondary outcomes were to evaluate hemodynamic response to surgical stimulus, visual analogue scale score, time to first analgesic requirement, postoperative nausea and vomiting, postoperative opioid consumption, urethral irritation, and incidence of drug-related adverse effects. Results: Total perioperative opioid consumption in the erector spinae plane block group was 355.0 (265.0, 485.0) μg and 240.0 (145.0, 370.0) μg in the intrathecal morphine group (P = 0.09). However, the patients in the erector spinae plane block group had significantly greater postoperative fentanyl consumption (235.0 [120.0, 345.0] μg) compared with those in the intrathecal morphine group (105.0 [30.0, 225.0] μg). There were no statistically significant differences noted for intraoperative opioid consumption, postoperative visual analogue scale score, time to first analgesic request, postoperative nausea and vomiting, and catheter irritation between the two groups. Conclusions: Although no statistically significant difference in intraoperative opioid consumption was seen between the erector spinae plane block and intrathecal morphine groups, postoperative opioid consumption was significantly higher in the erector spinae plane block group than in the intrathecal morphine group in patients undergoing percutaneous nephrolithotomy surgery.