Intermittent perirenal instillation of bupivacaine after tubeless percutaneous nephrolithotomy under spinal anesthesia: a double-blind, placebo-controlled clinical trial

Pain at the surgery site is a common complaint in patients who experience percutaneous nephrolithotomy (PCNL). The aim of this double-blind, randomized clinical trial is evaluation of the effect of scheduled infusion of bupivacaine on postsurgical pain and narcotic consumption after tubeless PCNL under spinal anesthesia. Forty patients were randomly divided into two groups. A small caliber fenestrated feeding tube was placed into the nephrostomy tract under direct vision in a manner in which its tip lied close to the renal capsule. The study group received infusion of diluted bupivacaine while physiologic saline was injected in the control group. Each patient was given the same dose every 6 hours until 24 hours after the surgical procedure. Mean pethidine injection was significantly lower in the group who underwent bupivacaine instillation (20.5±14.5 vs 3.97±2.4 mg: P=0.009). There was no significant difference between mean visual analogue scale (VAS) score in these two groups after 6 and 12 hours while it was significantly lower after 18 and 24 hours in the patients who had received bupivacaine. Mean time to the first analgesic request was significantly longer in the study group (11.35 vs 6.44 hours: P=0.001). Intermittent perirenal instillation of bupivacaine via the nephrostomy tract after PCNL decreases the need for more systemic narcotics and provides acceptable analgesia in the postoperative period.