Patient-controlled analgesia during SWL treatments

Abstract

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.