The role of plasma volume and fluid overload in the tolerance to ultrafiltration and hypotension in hemodialysis patients

• Published in: Renal failure Vol. 45; no. 1; p. 2151917
• Main Authors: Ramos-Gordillo, Jesús Manolo, Pérez-Campuzano, Carlos, Relles-Andrade, Elizabeth, Peña-Rodríguez, José Carlos
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis 01.12.2023; Taylor & Francis Ltd; Taylor & Francis Group
• Subjects: bio-impedance; Blood pressure; Body water; Body weight; Clinical Study; dry weight; fluid overload; Heart Failure - etiology; Hematocrit; Hemodialysis; Hemoglobin; Humans; Hypotension; Hypotension - etiology; Plasma Volume; plasma volume hypotension; Renal Dialysis - adverse effects; Renal Dialysis - methods; Spectroscopy; Ultrafiltration; Water; water spaces; Ultrafiltration; water spaces; fluid overload; dry weight; bio-impedance; plasma volume hypotension
• ISSN: 0886-022X; 1525-6049
• DOI: 10.1080/0886022X.2022.2151917

Ultrafiltration (UF) in hemodialysis (HD) patients is accompanied by irregular falls in plasma volume (PV) and blood pressure (BP). We obtained in 321 patients (large cohort), body weight (BW), BP, samples of blood to determine hemoglobin (Hb) and hematocrit (Ht), Pre and Post HD. We estimated the % variation of the PV and its effect on the BP. In a small cohort of 38/321 patients, arterial blood was drawn Pre and Post HD and at 2, 48, and 72 h to determined Hb and Ht and % variation of the PV. Bio-impedance spectroscopy (BIS) was performed, in the same times, to estimate: dry weight (DW), total body water (TBW), extracellular water (ECW), Fluid overload (FO) and phase angle (PhA). We divided our large cohort in two groups. The Hypotensive group with a fall equal or more than 20 mmHg (96/321,30%) and Normotensive group with a drop equal or less than 19 mmHg (225/321,70%). The UF was 2.73 ± 0.72 L in the Hypotensive group and 2.53 ± 0.85 L in the Normotensive group (p < 0.0001). The % PV was −11.7 ± 17.8 in the Hypotensive group and −8.53 ± 10.07 in the Normotensive group (p < 0.0001). The systolic blood pressure (SBP) correlated with the % change of the PV (r = -0.232; p < 0.0001). The FO was contrasted with the % of water removed by UF (r = -0.890; p < 0.0001). The SBP drop was secondary to the fall in the PV after UF. The FO was irregular and modulates in part the fall in the SBP.