Autonomic Insufficiency in Uremia as a Cause of Hemodialysis-Induced Hypotension

Eight patients with chronic uremia who had suffered hypotensive episodes during hemodialysis were studied hemodynamically. To evaluate autonomic function we used the Valsalva maneuver and the heart-rate increment after amyl-nitrite-induced fall in arterial pressure. Two uremic patients had normal autonomic function, normal peroneal-nerve conduction, and the normal compensatory response to hypotension of hemodialysis: a rise in systemic resistance and in heart rate. The six others had evidence of autonomic dysfunction, depressed peroneal-nerve conduction and, during hemodialysis-induced hypotension, a fall in total systemic resistance and fixed heart rate. The hypotension did not improve in the second group of patients after volume expansion but did respond to administration of norepinephrine. Thus, autonomic insufficiency appears to occur in chronic uremia, is probably due to the generalized neuropathy seen in this state, and may contribute to the pathogenesis of hemodialysis-induced hypotension. (N Engl J Med 290:650–653, 1974)