RESUMO
Studies were conducted in 9 dialysis patients with volume-nonresponsive hypotension, 6 dialysis patients with volume-responsive hypotension and in 10 normal subjects in an effort to evaluate the role of dysfunction of the autonomic nervous system (ANS) in the genesis of volume-nonresponsive hypotension. ANS function was evaluated by the Valsalva maneuver, handgrip exercise, and by the response of heart rate and blood pressure to change of posture from a supine to a standing position. Patients with volume-nonresponsive hypotension displayed significant derangements in the function of ANS as compared to normal subjects and to patients with volume-responsive hypotension. Data show that dysfunction of ANS plays an important role in the genesis of volume-nonresponsive hypotension in dialysis patients.