Hemodynamic and Adrenal Response to Shock Wave Energy *

Abstract

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. There was significant blood pressure elevation during kidney compared with adrenal targeting, accompanied by increases in plasma renin activity and norepinephrine. Aldosterone and cortisol response to ACTH were normal after adrenal treatment, and no histologic changes were found. The results suggest that blood pressure elevation during lithotripsy is mediated by increased renin release and that adrenal function and morphology are not affected by the levels of shock wave energy utilized in clinical treatment.