CORRELATES OF CHANGE IN EXTRACELLULAR VOLUME MEASURED BY WHOLE BODY BIOIMPEDANCE SPECTROSCOPY (WBIS) IN HEMODIALYSIS (HD) PATIENTS

Abstract

Interdialytic weight gain (IDWG) expressed as % dry weight (IDWG%DW) of >5.7 % correlates with excess mortality (Kidney Int.; 64:254–62,2003). WBIS can estimate the gain of extracellular volume (gECVWBIS) representing IDWG between two dialysis treatments (Kidney Int.;60:2337–42,2001). The present study was aimed to test for correlation of ECV gain (gECV), between two dialysis sessions, measured by WBIS, and, parameters of fluid overload and nutrition. We studied 11 HD patients with IDWG%DW <5.0%. ECV was measured by WBIS (Xitron 4200) between the 2nd and 3rd weekly dialysis session. Protein catabolic rate (PCR) was determined using urea kinetic modeling and the pre- dialysis sodium gradient was calculated as the difference between dialysate and pre-HD serum Na+ levels. There was a correlation between gECVWBIS and IDWG (r= 0.8; p=0.001), dry weight (r=0.7; p=0.01), PCR (r=0.6; p=0.044) and age (r= -0.6; p=0.07). gECVWBIS and pre HD serum Na+gradient was not correlated (r= -0.45; p=0.16). gECVWBIS correlates well with IDWG and PCR in our population. gECVWBIS could represent interdialytic protein intake and nutritional status in addition to salt and fluid intake in those with IDWG%DW < 5%.Table 1: Patient Characteristics (n=11)