The Influence of Hemodiafiltration on Blood Pressure Regulation

Plasma Catecholamine Response to Postural Stimulation in Normotensive and Dialysis Hypotension-Prone Uremic Patients

“…During the interdialysis period, postural stimulation, whatever the propensity for the intradialysis hypotension in our patients, resulted in a normal hemo dynamic response, i.e., maintenance of BP and an increase in HR which was directly related to the increase in plasma NE. These findings are consistent with some previous re ports [7.8], but disagree with those works claiming the existence of sympathetic dysautonomy in chronic uremia, chiefly with those that relate the sympathetic dysfunction to the dialysis-dependent hypotension [4][5][6], It must be said, however, that in these latter studies a precise state ment about the exclusion of patients with diabetes or arterial hypertension was not made. Therefore, since some defects of the autonomic sympathetic function have been reported in both diabetes and arterial hypertension [19][20][21], the possibility exists that these diseases, unless recognized, might engender misinterpretations when evaluating the prevalence of autonomic dysfunction due to the chronic uremia per se.…”

“…Therefore, since some defects of the autonomic sympathetic function have been reported in both diabetes and arterial hypertension [19][20][21], the possibility exists that these diseases, unless recognized, might engender misinterpretations when evaluating the prevalence of autonomic dysfunction due to the chronic uremia per se. Moreover, in the earlier works, autonomic function was assessed usually by studying the responsive ness of some cardiovascular parameters during a series of standard maneuvers, including the Valsalva maneuver, the cold pressor test, and others [4][5][6] rather than by direct assessment of the neurosympathetic reflex arc from plasma catecholamine measurements. In some studies [4,5] serum dopamine-(3-hydroxylase was also determined, but the conclusions drawn on this basis are questionable, since the usefulness of serum dopamine-J3-hydroxylase as a measure of acute alterations in neuroadrenergic function in man is not generally agreed upon [22], When our patients of both groups were stimulated by postural changes just before dialysis, both the plasma NE response and the BP be havior were found to be similar to those recorded during the interdialysis period.…”

“…Patients with chronic renal failure are said to have a widespread dysfunction of the autonomic nervous system [1], including the baroreceptors [2,3] and the afferent limb of the sympathetic reflex arc [4] which have been proposed to be the cause of dialysis-induced hypotension [4][5][6],…”