Association of intradialytic blood pressure changes with hospitalization and mortality rates in prevalent ESRD patients

Abstract

The relationship between blood pressure (BP) and clinical outcomes among hemodialysis patients is complex and incompletely understood. This study sought to assess the relationship between blood pressure changes with hemodialysis and clinical outcomes during a 6-month period. This study is a secondary analysis of the Crit-Line Intradialytic Monitoring Benefit Study, a randomized trial of 443 hemodialysis subjects, designed to determine whether blood volume monitoring reduced hospitalization. Logistic regression was used to estimate the association between BP changes with hemodialysis (Deltasystolic blood pressure=postdialysis-predialysis systoic BP (SBP) and the primary outcome of non-access-related hospitalization and death. Subjects whose systolic blood pressure fell with dialysis were younger, took fewer blood pressure medications, had higher serum creatinine, and higher dry weights. After controlling for baseline characteristics, lab variables, and treatment group, subjects whose SBP remained unchanged with hemodialysis (N=150, DeltaSBP -10 to 10 mm Hg) or whose SBP rose with hemodialysis (N=58, DeltaSBP > or =10 mm Hg) had a higher odds of hospitalization or death compared to subjects whose SBP fell with hemodialysis (N=230, DeltaSBP < or =-10 mm Hg) (odds ratio: 1.85, confidence interval: 1.15-2.98; and odds ratio: 2.17, confidence interval: 1.13-4.15). Subjects whose systolic blood pressure fell with hemodialysis had a significantly decreased risk of hospitalization or death at 6 months, suggesting that hemodynamic responses to dialysis are associated with short-term outcomes among a group of prevalent hemodialysis subjects. Further research should attempt to elucidate the mechanisms behind these findings.

Figure 1

Unadjusted annual non-access-related hospitalization rates among prevalent ESRD subjects plotted per 10 mm Hg increment increase in ΔSBP (ΔSBP = postdialysis–predialysis SBP).