[Anesthesia during extracorporeal shock wave lithotripsy]

Three important anaesthesiological methods are considered to be appropriate in anaesthetizing patients undergoing extracorporal shock wave lithotripsy: general anaesthesia, epidural anaesthesia and recently opioid analgesia. In 161 patients who underwent ESWL in epidural anaesthesia, the dosage of the local anaesthetic (bupivacaine 0.5% without adrenaline) was dependent on the level of insertion of the Tuohy-needle and on the age of the patients. Under a sufficient therapy with crystalloids and colloids, cardiovascular parameters such as blood pressure and heart rate remained remarkably stable. In 10 patients the influence of epidural anaesthesia during ESWL on the glomerular filtration rate (GFR) was investigated. After the injection of radio-labelled 51-Cr-EDTA the GFR was significantly reduced by the epidural block. Under the influence of extracorporal shock waves the GFR increased significantly and in some cases exceeded the original value. Opioid analgesia with alfentanil in awake, spontaneously breathing patients is well accepted by patients with kidney stone disease who have to undergo ESWL. The analgesia is achieved by administering an initial bolus injection (30 micrograms/kg) of alfentanil and applying additional injections--each 15 micrograms/kg--on demand. A study with 360 patients was performed in order to investigate the suitability of opioid analgesia during ESWL with special regard to cardiovascular and respiratory depression and other side-effects. Mean systolic and diastolic blood pressure and heart rate were almost not affected. Under insufflation of oxygen by a nasal tube, the mean PaCO2 always showed normal values. Mean PaCO2 increased to 50 mm Hg. A mild drowsiness could be observed in all patients. Two of them developed a complete respiratory arrest accompanied by a muscular rigidity of the chest wall so that respiratory support by mask ventilation became necessary. The "extracorporal piezoelectric lithotripsy" (EPL) is a new method of non-invasive disintegration of kidney stones and can be performed in the non-anaesthetized patient. The efficacy of this much more profitable procedure is equivalent to the ESWL, so that the EPL seems to have a great future.