Objective: We evaluated the effects of continuous instillation of a local anesthetic at the nephrostomy site on postoperative pain following percutaneous nephrolithotomy (PCNL).

Patients and methods: Sixty patients who underwent PCNL between August 2013 and March 2015 were enrolled in this randomized prospective study. The following three groups comprising 20 patients each were analyzed: Group A, continuous infiltration of local anesthetic at the nephrostomy site; Group B, local anesthetic injected only once; and Group C, 0.9% saline injected as a control at the end of the procedure. Postoperative patients reported pain scores, and amount of analgesic use was recorded at 2, 6, 12, 24, and 48 hours after the surgery.

Results: The mean pain scores of patients in Group A and B were significantly lower compared with Group C patients as much as 12 hours postoperatively (p = 0.001). However, at 24 hours postoperatively, the mean pain scores of Group B and C patients became comparable, while those of Group A patients remained significantly lower until 48 hours after the surgery (p < 0.001). Patients in Group A and C demanded the least and greatest amounts of analgesics, respectively, at all-time intervals (all p < 0.05).

Conclusions: Continuous infiltration of a local anesthetic is effective for both managing pain immediately after surgery and in dealing with pain that occurs late in the recovery period.