目前大部份的泌尿道結石醫師優先採用體外震波碎石術來治療。於體外震波碎石過程中，約有50%的病人須靜脈注射麻醉劑或鎮靜劑且須積極的生命徵象監視。此乃研究局部麻藥軟膏應用於體外震波碎石之病評估其減輕病患疼痛及減少麻藥使用的程度。從1995年4月至5月，共有40位泌尿道結石病人，分研究、對照兩組進入本研究。研究組20位病患，於震波碎石進入皮膚位置塗抹30克局部麻醉軟膏（2.5% Lidocaine及Prilocaine, Astra Pharmaceuticeutical）至少90分鐘；另20位病患，不使用局部麻醉軟膏者當成對照組。並於震波碎石過程中記錄疼痛分數及是否進一步使用靜脈鎮靜麻醉劑。結果顯示兩組病人對於疼痛減輕侑靜脈鎮靜麻醉劑使用麻藥軟膏應用於體外震波碎石之泌尿道結石病人，不能有效達到疼痛疼制。

Nowadays a majority of patients with urolithiasis are treated primarily with extracorporeal shock wave lithotripsy (ESWL). Almost 50% of the patients need intravenous anesthetics with subsequent extensive vital signs monitoring during the ESWL procedure. A trial was carried out, of local application of a eutectic mixture of local anesthetics (EMLA) in patients with urolithiasis to assess the pain and the consumption of anesthetics during the ESWL procedure. From April to May 1995, a total of 40 patients were enrolled in this study. They were randomly divided into study and control groups. EMLA cream (2.5% lidocaine and prilocaine, 30 gm, Astra Pharmaceutical) was applied to 20 patients at least 90 minutes before the ESWL procedure, and 20 patients without EMLA application served as controls. The verbal pain scoring and systemic analgesic requirement were recorded. The results showed that there was no significant difference between the two groups in terms of pain score and sedative requirements. In conclusion, topical EMLA application alone is not effective for pain control in ESWL treatment of stone patients.