Dialysis

:This article is about renal dialysis; for the laboratory technique, see dialysis (biochemistry); for the treatment for liver failure, see liver dialysis

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In medicine, renal dialysis is a method for removing waste such as urea from the blood when the kidneys are incapable of this (i.e. in renal failure).

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In acute renal failure, (renal) dialysis is generally initiated when the renal function has deteriorated to an extent that it is threatening the body's physiology. Volume overload (i.e. hypervolemia) that is unresponsive to strong diuretics, such as furosemide, and severe hyperkalemia are two common indications for dialysis.

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In chronic renal failure the problem is usually longstanding, and the decision is based on the level of kidney function (GFR or creatinine clearance), possibility of a renal transplant and complications of the malfunctioning kidney (e.g. hyperkalemia, uremia). Chronic renal failure that does not have an acute (i.e. reversible) component and requires dialysis is called end-stage renal disease (ESRD). There is no general agreement among nephrologists on when to start dialysis. In Canada some nephrologists advocate that patients with CRF should start dialysis when the GFR is below 15 mL/min and below 20 mL/min for patients with diabetes mellitus. Canadian guidelines suggest considering dialysis when the GFR is less than 12 mL/min. In the United States, dialyisis is initated at a GFR of 15 mL/min in diabetics and 10mL/min in non-diabetics, in conjuction with uremic sypmtoms. Most guidelines agree that dialysis should be started before the GFR drops below 6 mL/min. The rationale for starting dialysis early is that it prevents illness associated with severe uremia and may minimize long-term complications associated with kidney failure. Studies have shown that starting dialysis with a lower GFR is associated with a poor nutritional status which is associated with a higher mortality in the first two years of treatment.

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Acute renal failure can present on top of (i.e. in addition to) chronic renal failure. This is called acute-on-chronic renal failure (AoCRF) and may require dialysis temporarily (until the acute component of the renal failure resolves).

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Dialysis (biochemistry): In biochemistry, dialysis is the process of separating crystalloids and colloids in solution by the difference in their rates of diffusion through a semipermeable membrane....

Liver dialysis: Liver dialysis or artificial extracorporeal liver support is a detoxification treatment for liver failure and has shown promise for patients with hepatorenal syndrome. It is similar to hemodialysis and based on the same principles....

Medicine: Medicine is a branch of health science concerned with maintaining human health and restoring it by treating disease and injury; it is both an area of knowledge, a science of body systems and diseases and their treatment, and the applied practice of that knowledge....