Eutectic mixture of local anesthetic cream--topical anesthesia for extracorporeal shock wave lithotripsy.

A 44-year-old man presented with a history of sudden onset left flank pain, accompanied by nausea and microhematuria. The diagnosis of ureteropelvic junction calculus was made and the patient was scheduled for extracorporeal shock wave lithotripsy (ESWL). ESWL uses an electrical spark to generate a shock wave that is focused on a stone in the ureter or kidney. The shock waves mechanically stress and crush the stone, eliminating the need for manipulation or open procedure. The pain of ESWL is caused by skin sensation. Eutectic mixture of local anesthetics (EMLA) cream (2.5% lidocaine and 2.5% prilocaine) has been used as a topical anesthetic on intact skin for various minor procedures. Studies have shown that it is effective in dramatically decreasing or eliminating the pain of ESWL. The use of topical EMLA as an anesthetic management technique for a patient undergoing ESWL is described.