Analgesia in Anesthesia-Free Extracorporeal Shock Wave Lithotripsy: A Standardized Protocol

Abstract

We treated 101 patients at our stone facility with the Dornier HM3 lithotriptor modified with the anesthesia-free design upgrade. A protocol designed by our anesthesiologists consisting of intravenous and intramuscular injections for sedation was used without any general or regional anesthesia required. Pre-medication with intramuscular meperidine and promethazine, and oral diazepam was sufficient sedation in 43 patients, while 37 required additional intravenous meperidine and/or midazolam during the procedure, 16 were treated with intraprocedural medication alone and 5 required no medication at all. Care before, during and after the procedure was rendered by the urology staff for patients in American Society of Anesthesiologists risk category I or II. Treatment was successfully completed in all patients without complications. We compared this group to the 99 patients treated consecutively before the modification. Voltage used, number of shocks and stone burden were comparable in the 2 groups but average treatment time was prolonged with the upgraded equipment (39.2 versus 27.1 minutes) to a significant degree (p less than 0.001).

Drugs for Pain Management in Shock Wave Lithotripsy

“…Several physical variables influencing treatment-related pain have been identified: an important role is played by the type of the shockwave source, size, and site of stone burden (e.g., upper-pole stone near the ribs), peak pressure of the shockwaves, diameter of the focal zone, and size of the aperture of the shockwave source reflecting the area of shockwave entry at the skin [12–14]. …”

Efficacy of Local Subcutaneous Anesthesia Versus Intramuscular Opioid Sedation in Extracorporeal Shockwave Lithotripsy: A Randomized Study

“…Because less energy levels are currently used, the patient experiences less pain. 2 Analgesic requirements during the procedure have decreased but nevertheless continue.…”

“…Patientrelated factors and several physical variables, including the type of lithotripter, size and site of stone burden, cavitation effects, shockwave peak pressure, size of focal zone, and size of the aperture of the shockwave source reflecting the area of shockwave entry at the skin, are additionally responsible for pain. [2][3][4] Improvements in technology and modifications of devices have simplified the procedure and reduced the pain associated with lithotripsy. 4,5 In spite of maximum refinements of shockwave devices, 28% of patients experienced severe pain during SWL with the described-as-painless piezoelectric lithotripters.…”