Patient-controlled analgesia during SWL treatments.

PURPOSE: To identify the factors that influence analgesic consumption during SWL on the Dornier Lithotripter U/50. PATIENTS AND METHODS: In Group 1 (N = 152), analgesia was induced with propofol 0.8 mg/kg and alfentanil 8 microg/kg. In Groups 2 (N = 78) and 3 (N = 250), the induction dose was reduced by 20%. For all patients, the maintenance dose was propofol 0.25 mg/kg and alfentanil 5 mg/kg administered with a patient-controlled analgesia (PCA) device. Groups 1 and 2 had SWL with the EMSE 220 shockwave emitter, whereas Group 3 was treated with the EMSE F150. Data were collected on treatment, total drug doses, and side effects. RESULTS: There was no significant difference in PCA dose among the groups, but analgesic consumption was lower in patients treated with the EMSE F150. Except in Group 2, analgesic consumption tended to decrease with age until age <70. The 20% reduction in the induction dose did not cause an increase in PCA usage. Analgesic consumption was higher for kidney than for ureteral stones and was highest for stones in renal pelvis. Consumption was lower for larger stones than for smaller stones and higher for patients receiving more shockwaves. Almost one quarter of patients in Group 1 exhibited transient O2 desaturation during induction, an effect that was less common in the other groups. Ventricular premature beats were detected only during treatment of stones above the ureteropelvic junction. CONCLUSIONS: Intravenous administration of a combination of alfentanil and propofol via a PCA device is an elegant, reliable, and safe method of analgesosedation for SWL. Patient satisfaction is high, and side effects are uncommon. Faster turnover of patients is possible.

Consecutive experience with four Dornier lithotripters: HM4, MPL 9000, compact, and U/50.

PATIENTS AND METHODS: Since 1987, we have consecutively used four Dornier lithotripters in our Urology Department: an HM4 (N = 319 cases), MPL 9000X (N = 752), Compact (N = 546), and U/50 (N = 427). Both the HM4 and the MPL 9000X are electrohydraulic machines, whereas the Compact and the U/50 are electromagnetic lithotripters. RESULTS: Treatment strategies prove to be influenced largely by the available imaging modalities: only fluoroscopy on the HM4, ultrasound and fluoroscopy with a movable C-arm on the MPL 9000X and Compact, and simultaneous integrated fluoroscopy and ultrasound on the U/50. We noted a slight increase in stone free rates with time: 85% with the HM4, 88.8% in the two Compact series, and 88.7% with the U/50. The auxiliary procedure rate (before and after SWL) showed a steady decline, from 27.6% with the HM4 to only 10.8% with the U/50. There also was a slight improvement in the retreatment rates. There was an overall improvement of the Effectiveness Quotient which could be attributed to several factors: machine related (improved imaging with better targeting, smaller focus), patient related (decrease in average stone size), and operator related (better treatment strategies, experience). CONCLUSION: Although lithotripters may not have become more powerful, SWL treatments have become more effective.

The Dornier Lithotripter U/15/50: a multifunctional and multidisciplinary workstation.

Since February 1, 1996, we have been using the Dornier Lithotripter U/50 in our Stone Center, first and foremost for SWL treatment of urinary lithiasis. In a limited series of 136 patients treated from February 1, 1996, through April 30, 1996, we obtained encouraging results: the average retreatment rate for stones of all sizes was 13.2%, and the stone-free rate at 3 months was 90.4%. We performed auxiliary endourologic procedures in only 5.9% of patients (2.2% before and 3.7% after SWL). Thus, we obtained an Effectiveness Quotient of 77. These results are compared with those in the literature. Apart from SWL treatments in urology, the system was also used for shockwave treatments in orthopedics, for endourologic procedures, and for diagnostic imaging. Because of the encouraging results in SWL and its excellent performance in multifunctional and multidisciplinary use, we consider the Dornier U/50 to be the best lithotripter we have worked with to date.

Experience with the Dornier HM4 and MPL 9000 lithotriptors in urinary stone treatment.

From November 17, 1987 until August 20, 1988 we operated a fluoroscopy guided Dornier HM4 kidney lithotriptor. This lithotriptor subsequently was replaced by the ultrasound guided Dornier MPL 9000 lithotriptor, a multipurpose machine for urinary and biliary stone treatment. With the Dornier HM4 device we performed 447 treatment sessions in 319 patients (483 stones). The mean number of shock waves was 1,848 per patient. The re-treatment rate was 1.17 per patient. After 3 months 85% of the patients were free of stone. Auxiliary procedures were performed in 27.6% of the sessions. From September 20, 1988 until August 30, 1989 we used the Dornier MPL 9000 lithotriptor on 246 patients with 407 stones in 354 treatment sessions. The mean number of shock waves per session was 1,654 per patient, 1.11 treatments were performed per patient and the rate free of stones after 3 months was 85%. Auxiliary measures before and after lithotripsy were performed in 33.6% of the sessions. The experience with both of these machines is discussed in regard to performance, as well as the specific advantages and disadvantages of the different imaging systems.