Adult Urology Comparing Two Local Anesthesia Techniques for Extracorporeal Shock Wave Lithotripsy Erkan Demir, Mete Kilciler, Selahattin Bedir, Koray Erten, and Yasar Ozgok OBJECTIVES To evaluate the efficacy of a eutectic mixture of local anesthetics (EMLA) cream compared with dimethyl sulfoxide (DMSO) with lidocaine during extracorporeal shock wave lithotripsy (ESWL) in a prospective randomized study. METHODS Of 167 patients, 85 received 10 g of EMLA cream (EMLA group) and 82 received 10 g of 40% DMSO (DMSO group) with an amount of lidocaine equal to that in the lidocaine gel, applied to the skin of the flank at the area of entry of the shock wave marked by the urologist. A second-generation lithotriptor Siemens Lithostar was used. The degree of pain was rated by the patients using a 10-point visual analog scale. RESULTS In 80 patients in the EMLA group (94%), the entire procedure was performed with no, minor, or tolerable pain after the application of EMLA cream (pain score 5.2  1.3). In 5 EMLA patients (6%), EWSL was interrupted because of intolerable pain. Of the 82 DMSO patients, 80 (98%) underwent the entire procedure with no, minor, or tolerable pain after the application of DMSO with lidocaine (pain score 3.7  1.1). In 2 DMSO patients (2%), EWSL was interrupted because of intolerable pain. The pain scores were significantly lower for the DMSO group than for the EMLA group (P = 0.011). CONCLUSIONS Our findings have indicated that the pain scores were significantly lower for the DMSO group than for the EMLA group. In addition to the local anesthetic effect of DMSO, diuretic, anti-inflammatory, muscle relaxant, and hydroxyl radical scavenger effects can be important for patients undergoing ESWL. These effects should be evaluated with new studies of patients undergoing ESWL. UROLOGY 69: 625– 628, 2007. © 2007 Elsevier Inc. S hock wave lithotripsy has become a routine proce- dure for the treatment of urinary stones. With the additional development of shock wave lithotripsy technology, analgesic requirements during the procedure have decreased, but nevertheless continue. Since 1986, several studies have investigated the effect of different local anesthetic substances on therapy-dependent pain with varying results. 1–5 The effectiveness of local anes- thesia for extracorporeal shock wave lithotripsy (ESWL) is reported to be good, and general anesthesia is necessary for only 5% to 10% of patients. 1 Most centers today use general anesthesia only for children. A eutectic mixture of local anesthetics (EMLA cream) is a topical anesthetic drug designed for use on intact skin. DMSO is quickly absorbed through the skin and relieves musculoskeletal pain when applied topically to painful areas. The aim of the present prospective ran- domized study was to evaluate the efficacy of EMLA cream compared with DMSO with lidocaine in patients undergoing ESWL. MATERIAL AND METHODS After informed consent was obtained, 167 patients with kidney stones were randomized to receive EMLA cream (EMLA group, 85 patients) or DMSO with lidocaine (DMSO group, 82 pa- tients). The EMLA group received 10 g of EMLA (AstraZeneca LP, Wilmington, Del; 1 g contains 25 mg lidocaine and 25 mg prilocaine), and the DMSO group received 10 g 40% DMSO (prepared in our pharmacology section) with an amount of lidocaine equal to that in the lidocaine gel applied to the skin of the flank at the area of entry of the shock wave marked by the urologist. The cream covered approximately 200 cm 2 . The EMLA cream was applied for at least 60 minutes (range 60 to 110). The DMSO with lidocaine was applied 10 minutes before starting the treatment. No patient was given intravenous anes- thesia. A second-generation lithotriptor, Siemens Lithostar, was used. The urinary stones were treated at a power setting of 13 to 19 kV, and 800 to 3500 shock waves were applied. At 10 minutes after beginning ESWL, the degree of pain was rated by the patients using a 10-point visual analog scale. After the From the Department of Urology, Gulhane Military Medical Academy School of Medicine, Ankara, Turkey Reprint requests: Erkan Demir, M.D., Department of Urology, Gulhane Military Medical Academy School of Medicine, GATA U ¨ roloji AD. Etlik, Ankara 06018, Turkey. E-mail: demir74@superonline.com Submitted: July 23, 2006; accepted (with revisions): January 3, 2007 © 2007 Elsevier Inc. 0090-4295/07/$32.00 625 All Rights Reserved doi:10.1016/j.urology.2007.01.003