Kidney Failure

Definition

The kidney is an important organ of the body which helps excrete the waste products of the body in the form of urine. Kidney failure is simply the inability of the kidneys to function as normal. It can be acute or chronic. Acute kidney failure develops over a span of a few hours or days and is treatable with normal function of the kidney returning with time. Chronic renal failure on the other hand is gradual onset and usually starts with minimal symptoms which may progress even up to end-stage renal disease.

Symptoms

  • Urine output is usually decreased.
  • Swelling of legs and arms due to fluid retention.
  • Shortness of breath.
  • High blood pressure.
  • Chest pain.
  • Fatigue.
  • Muscle ache.
  • Confusion.
  • Nausea and vomiting.
  • Drowsiness.
  • Itching.
  • Difficulty sleeping.

In severe cases, seizures may occur and a patient may even slip into a coma.

Causes

The causes of acute kidney failure can be classified into three main categories – pre-renal, renal and post-renal.

Pre-renal is where the blood flow to the kidney is diminished.

  • Volume depletion due to diarrhea, vomiting, salt wasting disorders or massive hemorrhage (bleeding).
  • Decrease in cardiac output with a heart attack or other heart diseases.
  • Redistribution of extracellular fluid as a result of peritonitis, burns, peripheral vasodilation and low albumin states such as in nephrotic syndrome.

Renal causes are due to structural kidney problems. This includes :

  • Glomerulonephritis.
  • Acute interstitial nephritis.
  • Vasculitis which is a feature of most collagen vascular diseases.
  • Acute tubular necrosis secondary to impaired blood loss or exposure to toxic substances.
  • Acute cortical necrosis where all structural elements of kidney are involved.

Post-renal causes is mainly due to obstruction of the urinary tract in pelvis, ureter, bladder or urethra.

  • Urinary calculi in kidney, bladder, ureter or urethra.
  • Cancers of bladder or prostate.
  • Strictures of ureter or urethra.
  • Congenital deformities such as urethral valve.

Certain diseases and conditions such as diabetes, hypertension, polycystic kidney disease, glomerulonephritis, vesicoureteral refluxes and pyelonephritis can impair kidney function which can then lead to chronic renal failure.

Risk factors for developing acute renal failure are:

  • Diabetes mellitus.
  • Hypertension (high blood pressure).
  • Acute cases are seen during hospitalizations in ICUs.
  • Heart, liver and kidney diseases.
  • Obesity, smoking and high cholesterol.

Treatment

Hospitalization is necessary in the treatment of acute renal failure. The cause of renal failure must first be diagnosed and treated. Measures are taken to prevent complications which include monitoring of fluid intake, control of excessive potassium in the blood with medication and maintaining calcium levels.

  • Increased potassium levels can be life-threatening causing cardiac issues and heart attacks so maintaining a normal potassium levels is very important.
  • Blood pH (acid-base balance of the blood) is maintained.
  • Medications that may cause renal toxicity are avoided.
  • Dialysis may be performed to remove the wastes from the blood if necessary. Dialysis is also indicated where there is irreversible damage to kidneys.
  • Proper diet is maintained to reduce work of kidneys including reduced or no protein in diet and avoiding potassium containing foods and salt.
  • A kidney transplant is required for end-stage renal disease.

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