Comparative evaluation of ropivacaine and levobupivacaine for postoperative analgesia after ultrasound-guided paravertebral block in patients undergoing percutaneous nephrolithotomy

Background and Aims: Percutaneous nephrolithotomy (PCNL), although a minimally invasive procedure, is associated with substantial postoperative pain that is often underestimated. The present study was undertaken to ascertain the relative analgesic efficacy of levobupivacaine (LB) and ropivacaine (RB) when administered in ultrasound-guided paravertebral block (PVB) in patients scheduled to undergo PCNL. Material and Methods: After obtaining the Institutional Ethics Committee approval and written informed consent, 30 patients aged between 18 and 65 years of either sex, with American Society of Anesthesiologist status I/II and body mass index >18.5 to <25, scheduled to undergo PCNL were enrolled for the study. The patients were randomized to receive single shot of 20 ml of either ropivacaine (0.2%) or levobupivacaine (0.2%) in ultrasound-guided PVB using an in-plane technique. Results: The demographic and the preoperative hemodynamic and respiratory parameters were comparable in both the groups. The postoperative hemodynamic variables, respiratory parameters, and pain scores were also comparable in both the groups. Although the time to first analgesic requirement was more in LB group (1.60 +/- 3.64 h) as compared to RB group (0.33 +/- 1.04 h), it was statistically nonsignificant. No complications attributable to either the procedure or usage of drugs were noted in any group during the entire postoperative period. Conclusions: We conclude that single-shot ultrasound-guided ipsilateral PVB at the end of the surgical procedure provides adequate and effective analgesia in the postoperative period with either of the local anesthetic. Use of ultrasound provides real-time imaging of the anatomical structures and avoids potential complications of the block.