Management of intradialytic hypertension: current evidence and future perspectives

Abstract

Intradialytic hypertension (IDH), that is, a paradoxical rise in blood pressure (BP) during or immediately after a hemodialysis session, affects approximately 10-15% of the hemodialysis population. It is currently recognized as a phenomenon of major clinical significance as recent studies have shown that BP elevation extends to the whole interdialytic interval and associates with increased cardiovascular and all-cause mortality. The pathophysiology of IDH is complex involving volume and sodium overload, endothelial dysfunction, excess renin-angiotensinaldosterone system and sympathetic nervous system activation, and other mechanisms. For several years, there was a scarcity of studies regarding IDH treatment; recently, however, several attempts to examine the effect of nonpharmacological and pharmacological measures on BP levels in IDH are made. This review attempts to summarize this latest evidence in the field of management of IDH and discuss areas for future research.

Association of Intradialytic Hypertension with Future Cardiovascular Events and Mortality in Hemodialysis Patients: Effects of Ambulatory Blood Pressure

“…Several mechanisms that are pathophysiologically involved in the development of this phenomenon have been proposed to be implicated in the high cardiovascular risk of these individuals [4,5,19]. Among them, volume overload and intradialytic sodium gain, endothelial dysfunction, increased arterial stiffness, overactivity of renin-angiotensin-aldosterone system and sympathetic nervous system are considered significant determinants, but these have not been extensively confirmed in human studies [4,20]. Over the past years, several studies identified the presence of IDHTN as a factor strongly associated with increased risk of cardiovascular and all-cause mortality [7][8][9].…”

Mechanistic Basis for Intradialytic Hypertension with Hemodialysis

“…A randomized crossover trial with dialysate sodium 5 mEq/L lower versus 5 mEq/L higher than serum sodium and at least three subsequent studies with individualized or low versus standard dialysate sodium concentrations showed an effect of these interventions on intradialytic hypertension and/or systolic and diastolic BP before/after hemodialysis. 11…”

“…2 To convince reluctant patients, it is helpful to collect data in favor of fluid overload: bioimpedance; intradialytic blood volume monitoring, a flat or positive curve indicating active intradialytic refilling; and ambulatory BP monitoring, high interdialytic BP reflecting fluid excess. Antihypertensives with proven benefit 11 may not be avoidable, but fluid removal is worth a try. The interesting study by Elsayed et al 1 reminds us that it is time to act.…”

“…Two research groups have, moreover, shown higher ambulatory BP levels among patients with intradialytic hypertension compared with those without, indicating that intradialytic hypertension is an exacerbation of hypertension in general. 11 Mechanistically, there is another important relationship, linking fluid overload and intradialytic hypertension with the endothelium, through vascular refilling. In the study mentioned above, 3 patients in the intradialytic hypertension group had a significant pre- to post-dialysis increase of peripheral resistance, plasma endothelin, and lower post-dialysis nitric oxide over endothelin-1 ratio, compared with the control group.…”