The Reflex Control of Vasopressin in Haemodialysis Patients

Abstract

We studied the reflex arginine vasopressin (AVP) response to hypotensive, isosmotic fluid subtraction (by isolated UF) in 14 uraemic patients on renal dialysis treatment: five with normal autonomic function and nine with autonomic involvement of various degrees. Fluid subtraction caused a comparable mean arterial pressure (MAP) decrease in the two groups. The reduction in right atrial pressure was inversely related with the severity of autonomic neuropathy (rs = -0.72, P = 0.004), being distinctly attenuated in the second group (P = 0.006). Plasma arginine vasopressin increased similarly in patients with normal autonomic function and in those with autonomic involvement. The response of patients with haemodialysis hypotension was similar to that of other patients. Reflex control of arginine vasopressin is preserved even in the presence of afferent/central neuropathy or more advanced, widespread autonomic damage in uraemic man. The data suggest that it is unlikely that altered release of arginine vasopressin is involved in the pathogenesis of haemodialysis hypotension.

Dialysis Hypotension: A Role for Inadequate Increase in Arginine Vasopressin Levels? A Systematic Literature Review and Meta-Analysis

“…Four studies used UF-only. The course of plasma AVP levels in response to the course of blood pressure in these studies appeared to be in line with the physiological expectation: a stable blood pressure was associated with unchanged AVP levels [45,58] while a decrease in blood pressure was accompanied by increases in plasma AVP levels [46,47]. …”

“…Despite considerable variation, the studies in which healthy controls were included [24,25,35,37,45,46,47] uniformly showed that pretreatment plasma AVP levels were more than twice as high in dialysis patients compared with healthy controls (6.4 ± 3.5 vs. 2.5 ± 1.3 pg/ml, p = 0.003) in an indirect comparison (fig. 3a) as well as in a direct comparison (fig.…”

“…Plasma AVP levels in patients varied widely, with some studies reporting pre-HD plasma AVP levels above the concentration regarded as the upper level of normal of 4 pg/ml [2,16,24,25,35,37,38,39,40,41,45,46,47,48,49,50,51,52,53,54], while others found pretreatment plasma AVP levels around or below 4 pg/ml [32,33,34,43,44,55,56,57] (fig. 3a).The variation in pretreatment plasma AVP levels might be due to analytical variation resulting from the use of different assays.…”

“…These studies showed mixed results, but it is important to note that plasma AVP levels were generally measured after intradialytic hypotension instead of during intradialytic hypotension. In addition, in these eight studies a total of five different definitions of intradialytic hypotension were used [21,29,34,47,60], whereas in three studies no definition was provided at all [2,45,48]. In some of these studies it was found that plasma AVP levels were higher after intradialytic hypotension had occurred [45,48,60], whereas others found no difference in plasma AVP levels between patients with and without intradialytic hypotension [47], or only observed higher AVP levels when intradialytic hypotension was accompanied by nausea [29].…”

Plasma Adrenomedullin Levels in Patients on Hemodialysis

“…On the other hand, Washimine et al [8]and Mallamaci et al [11]reported that there was no significant correlation between plasma AM level and MBP in patients on HD. Furthermore, AM could not be removed by dialysis treatment with a cuprophan membrane [8, 11], by which the loss of peptide hormones with a molecular weight exceeding 1 kD was negligible during the performance of sham ultrafiltration [12]. However, there has been no report of AM removal during HD performed by the use of a high-flux dialyzer that can remove a considerable amount of β 2 -microglobulin (11.8 kD).…”