Increase in Extracellular Hydration Status After Initiating Peritoneal Dialysis Electively

Area of Science:

• Nephrology
• Internal Medicine
• Physiology

Background:

• Renal replacement therapy aims to manage uremic symptoms and fluid overload.
• Peritoneal dialysis (PD) is a common renal replacement therapy.
• Initial hypotheses suggested PD should reduce patient overhydration.

Purpose of the Study:

• To investigate changes in body composition and hydration status after initiating PD.
• To determine if PD reduces extracellular water (ECW) overhydration.
• To identify factors associated with changes in hydration status post-PD initiation.

Main Methods:

• 100 patients planned for PD were studied using bioimpedance before training and at first membrane function assessment.
• Body composition, including extracellular water (ECW) and fat mass, was measured.
• Statistical analysis identified factors associated with changes in the ECW/total body water (TBW) ratio.

Main Results:

• ECW overhydration significantly increased post-PD initiation (from -0.06 L to 0.96 L).
• Fat mass also increased significantly (from 22.7 kg to 23.7 kg).
• Increased ECW/TBW was linked to older age, higher comorbidity, faster protein transport, lower serum albumin, and reduced residual renal function.

Conclusions:

• Contrary to hypothesis, PD initiation led to increased ECW overhydration.
• Older, more comorbid patients with inflammation and lower residual renal function experienced greater overhydration.
• These patient characteristics should inform initial PD prescription strategies to mitigate ECW overhydration.