Options for Patients with Renal Failure

Haemodialysis - blood from the patient is pumped through an array of semipermeable membranes which brings blood into close proximity with dialysate (a solution with a different concentration of waste products which allows waste products from the blood to diffuse into the solution).

haemofiltration - removal of plasma water and its dissolved constituents by convective flow across high-flux semipermeable membrane and replacing it with a solution of desired biochemical composition.

peritoneal dialysis - uses peritoneal membrane as semipermeable membrane avoiding need for extracorporeal circulation of blood. a tube is inserted into the peritoneal cavity through anterior abdominal wall. dialysate is run into the peritoneal cavity usually usually under gravity. urea, creatinine, phosphate and other uraemic toxins pass into the dialysate down the concentration gradient. water is attracted into the peritoneal cavity by osmosis depending on osmolarity of dialysate, which is determined by the glucose or polymer content of the dialysate. the fluid is changed regularly to repeat the process.

Reference: Kumar and Clark
Monica