In vivo Use of Activated Charcoal as a Sorbent in Continuous Ambulatory Peritoneal Dialysis

Abstract

In vitro studies simulating clinical peritoneal dialysis previously showed that small particles of charcoal suspended in peritoneal dialysis solution enhance creatinine clearances. The present studies were undertaken to evaluate the effects of collodion coated and uncoated charcoal particles on peritoneal creatinine clearances in rats. Dialysis solutions containing coated or uncoated charcoal were prepared. The binding properties of the charcoal solutions were initially assessed in vitro. Two groups of 6 rats each underwent peritoneal dialysis exchanges with plain or coated charcoal solutions. For each type of charcoal, two experimental charcoal-containing exchanges (15 ml, 1 h) were bracketed with pairs of exchanges containing standard peritoneal dialysis solution. Total creatinine clearance was increased for both charcoal solutions. Ultrafiltration decreased significantly after all charcoal dialysate solutions; glucose uptake and protein loss also increased. Morphological changes by light and scanning electron microscopy suggest adherence of charcoal to mesothelium, denudation, and widened intercellular gaps. Results are consistent with increased permeability related to mesothelial injury. Although charcoal binds creatinine, adherence to the peritoneum with alterations in integrity of the membrane may limit its usefulness even with a protective coating. However, the finding that mesothelial damage markedly affects the transport properties of dialysis suggests an important role of mesothelium in the peritoneal dialysis barrier.