Intradialytic Blood Pressure Abnormalities: The Highs, The Lows and All That Lies Between

Abstract

Background: Frequent blood pressure (BP) measurements are necessary to ensure patient safety during hemodialysis treatments. Intradialytic BPs are not optimal tools for hypertension diagnosis and cardiovascular risk stratification, but they do have critical clinical and prognostic significance. We present evidence associating intradialytic BP phenomena including fall, rise and variability with adverse clinical outcomes and review related pathophysiologic mechanisms and potential management strategies. Summary: Observational studies demonstrate associations between intradialytic hypotension, hypertension and BP variability and mortality. Lack of consensus regarding diagnostic criteria has hampered data synthesis, and prospective studies investigating optimal management strategies for BP phenomena are lacking. Mechanistic data suggest that cardiac, gut, kidney and brain ischemia may lie on the causal pathway between intradialytic hypotension and mortality, and endothelial cell dysfunction, among other factors, may be an important mediator of intradialytic hypertension and adverse outcomes. These plausible pathophysiologic links present potential therapeutic targets for future inquiry. The phenomenon of intradialytic BP variability has not been adequately studied, and practical clinical measures and treatment strategies are lacking. Key Messages: Intradialytic BP phenomena have important prognostic bearing. Clinical practice guidelines for both intradialytic hypotension and hypertension exist, but their underlying evidence is weak overall. Further research is needed to develop consensus diagnostic criteria for intradialytic hypotension, hypertension and BP variability and to elucidate optimal treatment and prevention strategies for each BP manifestation.

Intradialytic hypotension, blood pressure changes and mortality risk in incident hemodialysis patients

“…Currently our interventions to IDH are reactive, relying upon rapid nursing assessment and intervention. Typical reactive interventions include: repositioning patient to optimize hemoperfusion of vital organs (supine or Trendelenburg position); cessation of ultrafiltration; fluid resuscitation via isotonic saline, hypertonic saline or glucose; and in some centers albumin and cessation of dialysis [13,21]. Although these interventions are necessary and beneficial, they may not prevent the adverse consequences of IDH events.…”

Novel Insights into the Pathogenesis and Prevention of Intradialytic Hypotension

“…Moreover, higher slopes of RBV decline were associated with an increase in arterial oxygenation, suggesting a beneficial effect on pulmonary oxygen exchange due to fluid removal [10]. Therefore, it might be suggested that higher ultrafiltration rates may be associated with increased mortality because of impaired tissue perfusion, and because of the accompanied patient characteristics, a low decline in blood volume or a rise in SBP may be associated with adverse outcomes because of concomitant fluid overload in these patients [22, 23]. In a recent study, we noticed that the prognostic value of changes in SBP was related to the pre-dialytic blood pressure.…”

“…While prevention of interdialytic weight gain by sodium restriction is a cornerstone of treatment [41], the dilemma between too rapid fluid removal and persistent fluid overload may in some cases be solved only by increasing dialysis time and/or frequency [42]. As preventive methods have been discussed in detail both in older and more recent literature [8, 23], we will focus here on recently published trials. Antlanger et al [43] randomized fluid overloaded patients, defined as an overhydration/extracellular water ratio above 15%, to a reduction in dry weight using conventional strategies, to ultrafiltration-dialysate conductivity controlled feedback modelling and to ultrafiltration-temperature controlled feedback.…”

Intradialytic Hypertension Frequency and Short-Term Clinical Outcomes Among Individuals Receiving Maintenance Hemodialysis

“…2,8,9 Observational data suggest that intradialytic hypertension may represent a modifiable risk factor among individuals receiving maintenance hemodialysis. A predialysis to postdialysis systolic BP rise (vs. decline) has been associated with increased long-term morbidity and mortality.…”