Prevalence of fluid overload in an urban US hemodialysis population: A cross-sectional study

Area of Science:

• Nephrology
• Cardiovascular Medicine
• Biomedical Engineering

Background:

• Inadequate fluid status is a major cause of cardiovascular complications in chronic hemodialysis (HD) patients.
• Bioimpedance spectroscopy (BIS) is a standard method for fluid overload (FO) quantification in many countries.
• No BIS device is currently approved in the US for kidney patient fluid status assessment, limiting prior data in this population.

Purpose of the Study:

• To conduct the first cross-sectional assessment of fluid status in an urban US hemodialysis population using BIS.
• To quantify fluid overload (FO) and fluid depletion in chronic HD patients in the United States.

Main Methods:

• Whole body BIS (Body Composition Monitor, BCM) was used to determine fluid status in 170 chronic HD patients.
• Pre-dialysis FO was measured directly, and post-dialysis FO was estimated by subtracting intradialytic weight loss from pre-dialysis FO.
• Fluid status was categorized as overloaded, normally hydrated, or fluid depleted based on BCM readings.

Main Results:

• Pre-dialysis, 43% of patients were fluid overloaded (2.2 ± 2.4 L), 53% were normally hydrated, and 4% were fluid depleted.
• Post-dialysis, fluid overload decreased to 12%, while fluid depletion increased to 32% (-0.2 ± 2.7 L).
• Fluid status did not significantly differ between African American and Caucasian patients.

Conclusions:

• Approximately half of the studied US hemodialysis patients had normal fluid status pre-dialysis, but a significant proportion was either fluid overloaded or depleted.
• These findings underscore the critical need for objective tools, like BIS, to accurately quantify fluid status in US chronic HD patients.
• Effective fluid management is essential for reducing cardiovascular morbidity and mortality in this patient group.