Artificial peritoneal dialysis

As an artificial dialyzer is not used in peritoneal dialysis, use of the term artificial kidney might not be appropriate in this case. In peritoneal dialysis,the dialysate solution is infused into the peritoneal cavity of the patient and later discharged. Uremic toxins in the blood are removed as the blood flows through the capillaries in the peritoneum to the dialysate by diffusion. Water is removed by adding glucose to the dialysate, thereby making the osmolarity of dialysate higher than that of the blood. 

As mentioned already, the artificial kidney is a classic example of chemical engineering prowess. The proper design of such devices requires a description of both water and solute transport to and from blood, across membranes, and to and from an adjacent fluid known as the dialysate. Variations on this theme include hemodilution, hemoconcentration, and hemofiltration. Applications of these same principles have been used to examine continuous ambulatory peritoneal dialysis. Oxygenation of blood,... 

For some patients, dialysis is needed to remove the excess fluid. Dialysis, the filtering of blood through an artificial kidney (or the peritoneal lining) to remove excess fluid and waste products, can be performed directly through hemodialysis with rapid filtration or through peritoneal dialysis with slower filtration across the... 

The decreased clearance of waste materials results in a buildup of waste in the blood. Blood urea nitrogen (BUN) and creatinine are two end products of protein and muscle metabolism. In addition to waste buildup, electrolyte and acid buildup and bicarbonate loss may be noted, leading to imbalances. Supplemental cleansing of the Wood through dialysis— use of an artificial kidney (hemodialysis) or the peritoneal membrane (peritoneal dialysis) to filter blood—may be performed until renal function is restored. 

In other advances, we see polymers and natural tissue in competition. For example, in small diameter blood vessel repair, the saphenous vein is still the best. However, we are now approaching the first human implantation of small diameter synthetic polymer vascular prostheses to help those patients who have no useable saphenous vein. The ball and disc type of heart valve prostheses are still not as good as the processed natural tissue porcine valve. Yet even here we use a polymeric or metal stint to support the porcine tissue. The artificial kidney has been miniaturized, but in terms of patient well-being it has improved very little since the 1940 s. Also, the A/V shunts have given way to A/V fistulas since we do not have good polymers for long-term access. Peritoneal dialysis is becoming a better dialysis procedure for the patient, primarily because of the improvement of a polymeric access to the peritoneal cavity. 

Extracorporeal artificial organs provide mass-transfer operations to support failing or impaired organ systems [126]. Common examples include kidney substitute, hemodialysis, cardiopulmonary bypass (CPB), apheresis therapy, peritoneal dialysis, lung substitute and assist, and plasma separation. A critical component involved in the extracorporeal artificial organ is the membrane, which serves to separate the undesired substance from the blood or plasma. Ideally, materials used as the membrane in these particular applications should have appropriate cellular and molecular permeability, as well as blood compatibility (i.e., hemocompatibility). Over the years, both natural and synthetic polymers have been used as membrane materials. 

Ronco C, Fecondini L. 2007. Vicenza wearable artificial kidney for peritoneal dialysis. Blood Purif.-, 25 383-388. 

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