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Abstract: TH-PO210

Factors Influencing Hourly Hemodynamic Changes During Hemodialysis

Session Information

Category: Dialysis

  • 701 Dialysis: Hemodialysis and Frequent Dialysis


  • Ashrafi, Sadia anjum, University of Illinois at Urbana Champaign, Urbana, Illinois, United States
  • Perez, Luis M., University of Illinois at Urbana Champaign, Urbana, Illinois, United States
  • Wilund, Kenneth Robert, University of Illinois at Urbana Champaign, Urbana, Illinois, United States

The cardiovascular system adapts to maintain blood pressure during hemodialysis primarily by altering cardiac output and systemic vascular resistance. However, many dialysis patients develop intradialytic hypotension (IDH) or hypertension, both having serious consequences. While blood pressure is consistently monitored during dialysis, other hemodynamic variables are not. The purpose of our study is to examine changes in total peripheral resistance index (TPRI) and cardiac power index (CPI) during each hour of dialysis to determine the primary factors causing IDH and intradialytic hypertension throughout a dialysis session.


Intradialytic systolic blood pressure (SBP), mean arterial blood pressure (MAP), CPI and TPRI were evaluated hourly using peripheral bioimpedance (NiCaS, Inc) in 27 HD patients. Measurements were taken at baseline and after each hour of dialysis for a total of 198 hourly measurements. IDH was defined as a drop of hourly SBP ≥ 20 mmHg or drop of hourly MAP ≥ 10mmHg. Intradialytic hypertension was defined as a rise in hourly BP ≥ 15 mmHg. Measurements of blood pressure not meeting the definitions were defined as non-IDH or non-intradialytic hypertension time periods. Hourly changes in CPI and TPRI were compared.


During the 1st hour of dialysis, neither SBP, CPI nor TPRI changed significantly. During the 2nd hour of dialysis, the average hourly TPRI changes in IDH and non-IDH groups were -211.5 ± 480.6 and 145.6 ± 572.1 (p=0.03). During the 3rd hour, the hourly CPI change was 0.12 ± 0.1 in the intradialytic hypertensive and -0.04 ± 0.1 in non-hypertensive groups (p= 0.02) whereas the average TPRI change was -476.6 ± 701.7 in IDH and 168.4 ± 812.5 in non-IDH groups (p=0.008). During the 4th hour, the hourly CPI change was -0.06 ± 0.07 in the intradialytic hypertensive group and 0.04 ± 0.1 in intradialytic non-hypertensive group (p=0.03).


The predominant change responsible for IDH in the 2nd and 3rd hour of dialysis appears to be reduction in TPRI. By contrast, intradialytic hypertension in the 3rd hour appears to be primarily mediated by increases in CPI. In the 4th hour, there was a paradoxical reduction in CPI in the intradialytic hypertensive group. More closely monitoring hemodynamic changes during dialysis may provide information that could be used to intervene medically to prevent these dialysis-associated complications.


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