Résumé
Autonomic nervous system dysfunction is common in uremia and in patients under hemodialysis. Changes in serum calcium, serum phosphorus and serum magnesuim always occur during hemodialysis. The relation between these changes and autonomic nervous system activity during hemodialysis has not been fully studied. This study was carried out on 30 patients with chronic renal failure on regular hemo- dialysis with nearly similar age group. We measured serum calcium, serum phosphorus and serum magnesium throughout the session [at predialysis state, middialysis state: after 2 hours of the session and postdialysis: at the end of the hemodialysis Session]. We have also assessed autonomic function [sympathetic by cold pressor test and parasympathetic by Valsalva maneuver test]. Autonomic function tests were assessed at predialysis state, middialysis state and postdialysis state. Calcuim level uncreased throughout the session [P<0.05], phosphorus leuel and Magnesium levels decreased, [P<0.001] and [P<0.05], throghout session . As reguards parasympathetie dysfunetion, there was a significamt relation [P<0.05] with calcuim changes at predialytic and post dialytic states, a highly significant relation [P<0.001] with phosphorus and [P<0.05] with magnesiun, both at predialysis states. Concerging sympathetie dysfunction, there was a significant relation [P<0.05] with calcium levels at end of session. There was a signifcant relation [P<0.05] with predialytic and postdialytic phosphorus levels .There was also significant relation [P<0.05] with predialytic magnesium level