Extracellular Volume Overload and Increased Vasoconstriction in Patients With Recurrent Intradialytic Hypertension
Background/Aims: Intradialytic hypertension (IH) occurs frequently in some hemodialysis patients and increases mortality risk. We simultaneously compared pre dialysis, post dialysis and changes in extracellular volume and hemodynamics in recurrent IH patients and controls. Methods: We performed a case control study among prevalent hemodialysis patients with recurrent IH and hypertensive hemodialysis controls. We used bioimpedance spectroscopy and impedance cardiography to compare pre dialysis, post dialysis, and intradialytic change in total body water (TBW) and extracellular water (ECW) as well as cardiac index (CI) and total peripheral resistance index (TPRI) Results: The ECW/TBW was 0.453 (0.05) pre dialysis and 0.427 (0.04) post dialysis in controls vs. 0.478 (0.03) and 0.461 (0.03) in IH patients (p=0.01 post dialysis) The ECW/TBW change was 0.027 (0.03) in controls and 0.013 (0.02) in IH patients (p=0.1) In controls, pre and post dialysis TPRI were 3254 (994) and 2469 (529) dynes/sec/cm2/m2 vs. 2983 (747) and 3408 (980) dynes/sec/cm2/m2 in IH patients (p=0.002 post dialysis) There were between group differences in TPRI change (0=0.0001) but not CI (p=0.09) Conclusions: Recurrent intradialytic hypertension is associated with higher post dialysis extracellular volume and TPRI. Intradialytic TPRI surges account for the vasoconstrictive state post dialysis, but intradialytic fluid shifts may contribute to post hemodialysis volume expansion.
Kidney and Blood Pressure Research