Intercostal Blocks with Local Infiltration Anesthesia for Extracorporeal Shock Wave Lithotripsy

Abstract

Extracorporeal shock wave lithotripsy (ESVVL) is being used more frequently for disintegration of upper urinary tract stones. The procedure requires patients to be strapped in a semireclining position into an hydraulically operated chair-like support system and then submerged in water, from the clavicles down, in a large immersion tub. High-pressure shock waves are generated under water by an electrode to which 18–24 kV of energy is applied. The shock waves, transmitted through water, enter the body through the flank and are focused on the target stone using biplanar fluoroscopy. The impact of the shock waves at the entry site in the flank, the most painful stimulus in the procedure, necessitates anesthesia. To date, continuous epidural anesthesia (1) and general anesthesia with conventional mechanical ventilation or high-frequency jet ventilation have been recommended (2). Physiologic changes due to immersion, remote monitoring, and positioning present additional problems to the anesthesiologist (1,3). In the first 800 patients treated with ESWL at the New York Hospital-Cornell Medical Center, we employed epidural, spinal, and general anesthesia with controlled ventilation. Recently, we introduced a regional anesthetic technique using intercostal nerve block combined with local infiltration, which offers a simple, safe, and acceptable method of administering anesthesia for ESWL. The following is a report of our experience with 72 patients undergoing ESWL who had intercostal nerve blocks combined with local infiltration.