[Thoracic epidural anesthesia for extracorporeal lithotripsy. Comparison of 4 anesthetic solutions]

Extracorporeal shock-wave lithotripsy (ESWL) is a new non-invasive procedure allowing disintegration of upper urinary tract calculi, usually carried out in epidural anaesthesia (EA). The patient strapped to a stretcher is immersed in a bath. At the bottom of the tube is the shock-wave generator. The release of shock waves (1,000 to 2,000 for each treatment) is triggered by the R-wave of the patient's ECG. Arrhythmias and extrasystoles (ES) may occur. In the investigational trial, the preferred anaesthesia was continuous lumbar EA with a large volume of 2% lidocaine extended to the level of T6. This study was conducted to assess continuous thoracic EA at the T12 interspace with a lesser dose (12 ml) of 2% lidocaine (XT, comparing it with single dose EA with the same volume of three other agents: bupivacaine 0.5% (Ma) and mixtures of 2% lidocaine-0.2+ tetracaine (XT), and 2% lidocaine-fentanyl 50 micrograms (XF), all with 1/200,000th adrenaline. Eighty patients (ASA class I or II) were assigned randomly to receive one of the four types of EA. All were monitored with Holter's method. The demographic distribution was similar for the four groups. Mean duration of the procedure was 32 +/- 15 min. Premedication was given only in 16 patients, very anxious. The results were excellent in 68 patients; 11 had to be supplemented with one or two doses of intravenous agents: diazepam and/or fentanyl: one failure was given an intravenous general anaesthesia. Mild hypotension occurred in four patients. 242 ES occurred in 48 patients (60%).(ABSTRACT TRUNCATED AT 250 WORDS)