Acute tubular necrosis Health Article

Definition

Acute tubular necrosis is a kidney disorder involving damage to the tubule cells of the kidneys, resulting in acute kidney failure.

Alternative Names

Necrosis - renal tubular; ATN; Necrosis - acute tubular

Causes, incidence, and risk factors

Acute tubular necrosis (ATN) is caused by lack of oxygen to the kidney tissues (ischemia of the kidneys), or by exposure to materials that are poisonous to the kidney (nephrotoxic agents).

The internal structures of the kidney, particularly the tissues of the kidney tubule, become damaged or destroyed. ATN is one of the most common structural changes that can lead to acute renal failure.

ATN is one of the most common causes of kidney failure in hospitalized patients. Risks for acute tubular necrosis include:

• Blood transfusion reaction
• Injury or trauma that damages the muscles
• Recent major surgery
• Septic shock or other forms of shock
• Severe low blood pressure (hypotension) that lasts longer than 30 minutes

Any condition that reduces the amount of blood being pumped by the heart can cause ATN. Liver disease and damage caused by diabetes (diabetic nephropathy) may make a person more susceptible to the condition.

ATN can be caused by:

• Exposure to substances that are toxic to the kidneys (such as aminoglycoside antibiotics)
• Antifungal agents (such as amphotericin)
• Dye used for x-ray (radiographic) studies

Symptoms

• Decreased consciousness
  • Coma
  • Delirium or confusion
  • Drowsy, lethargic, hard to arouse
• Decreased urine output or no urine output
• General swelling, fluid retention
• Nausea, vomiting

Note: Other symptoms of acute kidney failure may also be present.

Signs and tests

Examination usually indicates acute kidney failure. There may be signs of fluid overload, including abnormal sounds on listening to the heart and lungs with a stethoscope (auscultation).

Other signs include:

• BUN and serum creatinine levels may increase
• Fractional excretion of sodium and of urea may be relatively high
• Kidney biopsy may show acute tubular necrosis (but a biopsy is rarely done)
• Urinalysis may show casts, kidney tubular cells, and red blood cells
• Urine sodium may be high
• Urine specific gravity and osmolarity urine indicate dilute urine