Renal failure

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**Renal failure**
*Classification & external resources*
ICD-10	N 17.-N 19.
ICD-9	584-585
DiseasesDB	26060
MeSH	C12.777.419.780.500

Renal failure or kidney failure is the condition in which the kidneys fail to function properly. Physiologically, renal failure is described as a decrease in the glomerular filtration rate. Clinically, this manifests in an elevated serum creatinine. The serum creatinine is the most widely used blood-chemistry test to assess renal function. Better methods do exist, but they are considerably more costly and may not be as widely applicable. Serum creatinine levels depend not only on kidney function, but on the person's existing muscle mass as well. Muscle mass varies with age, sex, and race. Typically, younger patients, male patients, and African-American patients have higher muscle mass. Certain disease states, such as liver failure, lead to a decrease in muscle mass. In this disease state, known in the medical field as cirrhosis, the serum creatinine may look "normal", but given the state of low muscle mass, may still be abnormal, and thus reflective of abnormal kidney function.

1 Classification
2 Use of the term uremia
3 References
4 External Links

[edit] Classification

Renal failure can broadly be divided into two categories (see flowchart below): acute renal failure and chronic renal failure.

Renal failure classification

Renal Failure

Chronic

Acute

The type of renal failure (acute vs. chronic) is determined by the trend in the serum creatinine. Other factors which may help differentiate acute and chronic renal failure include the presence of anemia and the kidney size on ultrasound. Long-standing, i.e. chronic, renal failure generally leads to anemia and small kidney size.

[edit] Chronic renal failure

Main article: Chronic renal failure

Chronic renal failure (CRF) develops slowly and shows few symptoms initially. It can be the complication of a large number of kidney diseases, such as IgA nephritis, glomerulonephritis, chronic pyelonephritis and urinary retention. End-stage renal failure (ESRF) is the ultimate consequence, in which case dialysis is generally required until a donor for a renal transplant is found. Treatment modalities for ESRF include peritoneal dialysis, hemodialysis, and transplantion from either a living or cadaveric donor. Of these, renal transplantation affords the best quality and quantity of life to the patient, provided they are an appropriate candidate.

[edit] Acute renal failure

Main article: Acute renal failure

Acute renal failure (ARF) is, as the name implies, a rapidly progressive loss of renal function, generally characterised by oliguria (decreased urine production, quantified as less than 400 mL per day in adults,^[1] less than 0.5 mL/kg/h in children or less than 1 mL/kg/h in infants); body water and body fluids disturbances; and electrolyte derangement. An underlying cause must be identified to arrest the progress, and dialysis may be necessary to bridge the time gap required for treating these fundamental causes.

[edit] Acute on chronic renal failure

Acute renal failure can be present on top of chronic renal failure. This is called acute-on-chronic renal failure (AoCRF). The acute part of AoCRF may be reversible and the aim of treatment, as with ARF, is to return the patient to his baseline renal function, which is typically measured by serum creatinine. AoCRF, like ARF, can be difficult to distinguish from chronic renal failure, if the patient has not been monitored by a physician and no baseline (i.e., past) blood work is available for comparison.

[edit] Use of the term uremia

Before the advancement of modern medicine, renal failure was often referred to as uremic poisoning. Uremia was the term used to describe the contamination of the blood with urine. Starting around 1847, this term was used to describe reduced urine output, now known as oliguria, that was thought to be caused by the urine mixing with the blood instead of being voided through the urethra.