Effective peritoneal capillary blood flow and peritoneal transfer parameters

In uremic patients peritoneal transfer was evaluated at 0-45-minute dwells in exchanges 3-5,9-11, and 15 -17 of single intermittent peritoneal dialysis (IPD) and compared to effective peritoneal blood flow (EPBF) simultaneously estimated as KBD for CO2 gas using the two-sample model of Garred et al. for a 2.5-minute dwell. During single IPD, a decrease in peritoneal transfer of HCO3-,tCO2,K+, and urea was observed (lower values of transfer in exchanges 15-17 than in exchanges 3-5). With a dialysis solution with pH 7.25, there were higher values of peritoneal clearances (Cp) for CO2 gas during the entire 45-minute dwell compared to respective values obtained with a pH 6.22 solution. Transfer parameters of urea and uric acid were also higher with a dialysis solution with pH 7.25, but there were significant differences only during the first 5-20 minutes of the dwell. All mentioned differences were not dependent on EPBF. Significant correlations between EPBF and peritoneal transfer parameters were shown only for CO2 gas, HCO3-, and tCO2. We consider these findings to be the correlation between the transfer of CO2 gas (not EPBF) and the transfer of other forms of CO2. Our data provide evidence that peritoneal transfer is not limited by changes in EPBF occurring during IPD in clinically stable uremic patients.