[Extracorporeal shockwave lithotripsy--what type of anesthesia?].

Since lithotripsy of renal calculi by shock waves is painful, it requires anesthesia. General or regional anesthesia technics may be used. Of more than 1000 treatments at the University Hospital of Zurich, over 90% were done under epidural anesthesia. It is necessary to extend the anesthesia up to the level of Th 4/5 to block all painful sensations. 1-2% carbonated lidocaine was found to be the most suitable anesthetic, providing fast onset and reasonable duration of anesthesia and thus allowing early mobilisation of the patient after treatment. Approximately 3% of the patients were primarily scheduled for general anesthesia for several reasons. These patients were intubated and ventilated by a conventional anesthesia machine at 40-60 breaths per minute. With the small tidal volumes of 200-300 ml there was only minimal displacement of the concretions by respiratory movements. Monitoring of the endtidal CO2 turned out to be problematic in some cases. Epidural anesthesia with carbonated lidocaine is a highly suitable method for anesthesia in over 90% of lithotripsy treatments.