Effect of peritonitis on peritoneal transport characteristics: Glucose solution versus polyglucose solution

Background. Peritonitis is a common clinical problem and contributes to the high rate of technique failure in continuous ambulatory peritoneal dialysi s treatment. The present study investigated the effect of peritonitis on pe ritoneal fluid and solute transport characteristics using glucose and polyg lucose (icodextrin) solutions. Methods. A four-hour dwell was performed in 32 Sprague-Dawley rats (8 rats in each group), with I-131 albumin as an intraperitoneal volume marker. Per itonitis was induced by an intraperitoneal injection of 2 mL lipopolysaccha ride (100 mu g/mL phosphate-buffered saline) four hours before the dwell. E ach rat was intraperitoneally infused with 25 mL of 3.86% glucose [glucose solution control group (Gcon) and glucose solution peritonitis group (Gpts) ] or 7.5% icodextrin solution [icodextrin solution control group (Pgcon) an d icodextrin peritonitis group (PGpts)]. Results. Net ultrafiltration was significantly lower (by 44%) in the Gpts a s compared with the Gcon group, but was significantly higher (by 138%) in t he PGpts as compared with the PGcon group. The peritoneal fluid absorption rate, including the direct lymphatic absorption rate, was significantly inc reased (by 78%) in the Gpts group as compared with the Gcon group. However, the total fluid absorption did not differ between the PGpts and the PGcon groups. The dialysate osmolality decreased much faster in the Gpts group as compared with the Gcon group, resulting in significantly lower (by 9%) tra nscapillary ultrafiltration in the Gpts group. In contrast, the dialysate o smolality increased faster in the PGpts group as compared with the PGcon gr oup, resulting in higher (by 40%) transcapillary ultrafiltration in the PGp ts group. The in vitro increase in dialysate osmolality was also higher in the PGpts group as compared with the PGcon group. The solute diffusive tran sport rates were, in general, increased in the two peritonitis groups as co mpared with their respective control groups. Conclusions. Our results suggest the following: (1) Peritonitis results in decreased net ultrafiltration using glucose solution caused by (a) decrease d transcapillary ultrafiltration and (b) increased peritoneal fluid absorpt ion. (2) Ultrafiltration induced by the icodextrin solution appears to be r elated to the increase in dialysate osmolality (mainly because of the dc gr adation of icodextrin). (3) Peritonitis results in increased degradation of icodextrin and a faster increase in dialysate osmolality and therefore bet ter ultrafiltration, whereas thc fluid absorption rate does not change. (4) Peritonitis results in increased peritoneal diffusive permeability.