Extracellular Volume Overload and Increased Vasoconstriction in Patients With Recurrent Intradialytic Hypertension.
OBJECTIVE
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.
University of Texas Southwestern Medical Center, Department of Internal Medicine, Division of Nephrology, Dallas, TX, USA.
Peter Noel
PN
Van Buren
Yunyun
Y
Zhou
Javier A
JA
Neyra
Guanghua
G
Xiao
Wanpen
W
Vongpatanasin
Jula
J
Inrig
Robert
R
Toto
D000328:Adult; D001834:Body Water / Q000378:metabolism; D016022:Case-Control Studies; D017097:Electric Impedance; D045604:Extracellular Fluid / Q000502:physiology*; D005260:Female; D018495:Fluid Shifts / Q000502:physiology; D006801:Humans; D006973:Hypertension / Q000209:etiology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D006435:Renal Dialysis / Q000009:adverse effects*; D014661:Vasoconstriction