TRANSPERITONEAL TRANSPORT OF SODIUM DURING HYPERTONIC PERITONEAL-DIALYSIS

The mechanisms of transperitoneal sodium transport during hypertonic p eritoneal dialysis were evaluated by kinetic modelling. A total of six nested mathematical models were designed to elucidate the presence or absence of diffusive, non-lymphatic convective and lymphatic convecti ve solute transport. Experimental results were obtained from 26 non-di abetic patients undergoing peritoneal dialysis. The model validation p rocedure demonstrated that only diffusive and non-lymphatic convective transport mechanisms were identifiable in the transperitoneal transpo rt of sodium. Non-lymphatic convective sodium transport was the most i mportant quantitative transport mechanism during the first 90 min of t he dwell. Significant sodium sieving was demonstrated and explains the observation of hypernatremia in dialysis with hypertonic dialysis flu id.