Common causes are low blood flow to the kidneys (such as caused by low blood pressure), medications that damage the kidneys, and severe bodywide infections.
People have no symptoms unless kidney injury is severe.
Diagnosis is based mainly on the results of laboratory tests.
Treatment is directed at the cause, for example, stopping medications that are damaging the kidneys, giving intravenous fluids to raise blood pressure, and giving antibiotics to treat infection.
Injury to the kidney tubule cells harms the ability of the kidneys to filter the blood. Thus, waste products such as urea and creatinine build up in the bloodstream.
(See also Overview of Kidney Filtering Disorders Overview of Kidney Filtering Disorders Each kidney contains about 1 million filtering units (glomeruli). The glomeruli are made up of many microscopic clusters of tiny blood vessels (capillaries) with small pores. These blood vessels... read more .)
Causes of Acute Tubular Necrosis
Acute tubular necrosis usually develops only in people who are seriously ill and in the hospital. The most common causes are
An episode of low blood pressure Low Blood Pressure Low blood pressure is blood pressure low enough to cause symptoms such as dizziness and fainting. Very low blood pressure can cause damage to organs, a process called shock. Various drugs and... read more , leading to insufficient blood flowing through the kidneys
Medications that damage the kidneys
The most common causes of low blood pressure leading to acute tubular necrosis are significant blood loss (due to injury or major surgery), serious burns Burns Burns are injuries to tissue that result from heat, electricity, radiation, or chemicals. Burns cause varying degrees of pain, blisters, swelling, and skin loss. Small, shallow burns may need... read more , serious bodywide infection (sepsis Sepsis and Septic Shock Sepsis is a serious bodywide response to bacteremia or another infection plus malfunction or failure of an essential system in the body. Septic shock is life-threatening low blood pressure ... read more ), and pancreatitis Overview of Pancreatitis Pancreatitis is inflammation of the pancreas. The pancreas is a leaf-shaped organ about 5 inches (about 13 centimeters) long. It is surrounded by the lower edge of the stomach and the first... read more .
Sepsis also can directly damage kidney cells, which worsens the effects of the low blood pressure caused by sepsis.
Medications that commonly damage the kidneys include aminoglycoside antibiotics (such as gentamicin and tobramycin), amphotericin B (a medication used to treat severe, bodywide fungal infections), colistimethate (an antibiotic used to treat infections that develop in people hospitalized for another disorder), vancomycin (an antibiotic used to treat infections that are resistant to other antibiotics), and nonsteroidal anti-inflammatory drugs (NSAIDs). Aminoglycosides are more likely to be a cause among people who are older, have had major surgery, or have severe disorders of the liver, gallbladder, or bile ducts. Rarely, exposure to a contrast agent during an imaging procedure can cause kidney damage (contrast nephropathy Radiopaque Contrast Agents Radiographic contrast agents are substances used to distinguish between internal structures in medical imaging, such as various types of x-rays and magnetic resonance imaging (MRI). During imaging... read more ).
Acute tubular necrosis is more likely to develop in people who are older, are critically ill, or have underlying kidney disorders, diabetes, or both.
Symptoms of Acute Tubular Necrosis
People with acute tubular necrosis usually have no symptoms. However, if the condition is severe, kidney failure Overview of Kidney Failure Kidney failure is the inability of the kidneys to adequately filter metabolic waste products from the blood. Kidney failure has many possible causes. Some lead to a rapid decline in kidney function... read more (loss of most kidney function) develops and people's urine output drops below normal. If kidney failure becomes severe, people may have nausea and vomiting, become weak, develop involuntary muscle spasms, and become confused.
Diagnosis of Acute Tubular Necrosis
Blood and urine tests
Doctors usually first suspect the disorder when blood tests show signs of kidney injury in people who have been exposed to a possible trigger, such as major surgery, an episode of low blood pressure, or a medication that can damage the kidneys. Similar findings can occur in people who are dehydrated, so doctors use other blood tests and urine tests to diagnose acute tubular necrosis.
Treatment of Acute Tubular Necrosis
Medications that are damaging to the kidneys are stopped. Doctors also give intravenous fluids as needed to maintain a normal blood flow to the kidneys. Infections and other underlying disorders are treated. Dialysis Dialysis Dialysis is an artificial process for removing waste products and excess fluids from the body, a process that is needed when the kidneys are not functioning properly. There are a number of reasons... read more may be required for people who do not respond to supportive care.
Prognosis for Acute Tubular Necrosis
Outcome depends on correction of the disorder that caused acute tubular necrosis. If that disorder responds rapidly to treatment, kidney function usually returns to normal in 1 to 3 weeks. Prognosis is usually better if people's urine volume exceeds 400 mL (about 13.5 ounces) every 24 hours. People who are more seriously ill, especially those who require care in an intensive care unit, have a higher risk of death.
Prevention of Acute Tubular Necrosis
When a person is very ill, doctors give intravenous fluids and sometimes medications to maintain blood pressure to try to maintain normal blood flow to the kidneys. Medications that are damaging to the kidneys are avoided whenever possible. If such medications are necessary, kidney function is closely monitored. In people with diabetes, blood sugar levels are controlled.