In Reply.
—I agree completely that few prior studies have been able to demonstrate that autonomic insufficiency is of major clinical importance as a cause of dialysis hypotension. Perhaps the best study in this regard is by Lilley et al.1 Recently, my colleagues and I prospectively studied 12 dialysis patients, comparing acetate and bicarbonate dialysate from a hemodynamic viewpoint. We tested the patients with Valsalva's maneuver, hand grip, and amyl nitrite tests before entry, and found that seven patients had detectable autonomic dysfunction and five patients had normal autonomic dysfunction. In the studies that followed2 we were only able to show a difference in the two groups when acetate dialysate and a dialysate sodium concentration of 130 mEq/L were used. This difference was manifested only in the area of orthostatic BP response after dialysis. Thus, our study suggests autonomic dysfunction may play a contributing role to dialysis hypotension,