principles
Last reviewed 01/2018
Dialysate is introduced into the abdominal cavity through a catheter. Solutes diffuse through the peritoneal membrane between capillary blood and dialysate membrane according to their concentration gradients. Ultrafiltration is effected by using dialysate that is hypertonic to plasma. Glucose or another osmotically active substance is used, for example, the glucose polymer icodextrin. The higher the osmolarity of the dialysate, the higher the rate of ultrafiltration.
About 2 litres of dialysate fluid are instilled per session. Equilibration usually occurs over 6-10 hours. The instilled fluid is then drained back through the catheter into a bag and discarded. The contents of a new bag are introduced and a new cycle commenced.