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Anatomic proximity of the adrenal gland may result in exposure to high-energy shock waves during extracorporeal shock wave lithotripsy of kidney stones. Observation of increased blood pressure and decreased cardiac output during stone treatment in humans (Anesth Analg 1987; 66:354) suggests increased catecholamine or renin release. We developed a canine model to measure the acute hemodynamic effects of kidney and adrenal exposure to shock waves and the subsequent effect on adrenal function and histology. Four weeks after removal of the left adrenal gland and placement of radiopaque metal clips around the left kidney and right adrenal in five mongrel dogs, these organs were treated sequentially with 2000 shocks at 16 to 18 kV. Blood pressure, heart rate, and cardiac output were measured, and plasma renin activity and catecholamine levels were determined during treatment. Cortical function of the solitary treated adrenal was tested over the next 7 weeks, after which the adrenals were examined histologically...

The painful stimuli produced by a new generation of electrohydraulic/electromagnetic lithotripters are such that continuous infusion analgesia rather than general or regional anesthesia is appropriate. We describe our experience with continuous alfentanil infusion supplemented with intravenous bolus midazolam in caring for patients treated with an unmodified Medstone STS 1050 lithotripter. Ninety consecutive treatments using this technique averaged 63 minutes, compared with 69 minutes for 14 treatments done with general anesthesia and 88 minutes for 58 treatments done with epidural anesthesia. The stone burden, kilovoltage, and number of shocks were similar for the three groups, as was the immediate stone fragmentation rate. Only 2 of 90 patients received inadequate analgesia with the intravenous technique and required the induction of general anesthesia. Continuous-infusion analgesia appears sufficient to blunt the stimulus provided by the unmodified spark-gap lithotripters still in common use.