Dialysis membranes question


Hello Judith

Is additional pressure needed to pass blood through dialysis membrane?
Do dialysis membranes get clogged and how long they last?

I am talking about the membrane that keeps proteins and cells inside blood and allows smaller molecules to pass.

Can you point me to their technical specifications?




The answers to your questions are fairly technical, and I am not sure how much depth you want. I will, however, try to give you some basic information. The peritoneal membrane serves as a dialyzing membrane. It allows solutes (urea, creatinine, etc) to move from the capillary blood compartment to the peritoneal cavity (which is filled with dialysate fluid.) There are 3 parts, the mesothelial layer, interstitial layer and capillary endothelium, with a large blood supply. Solutes and water move through the membrane by diffusion (small solutes) and convection (ultrafiltration or water). Solutes such as urea and creatinine are small and move rather easily over time while large molecules like protein do not. The peritoneal membrane does not get “clogged” but can be damaged, that is scarred, particularly by infections such as peritonitis. Thus it is very important for PD patients to lower their risk of peritonitis by following very carefully the techniques they have been taught when connecting solutions. Avoiding infections at the exit site by using Staph aureus prophylaxis on the area around the exit site also protects from developing peritonitis as bacteria can travel down the tunnel from the exit site to the peritoneum.
Hope this information helps. Judy Bernardini