DefinitionAcute tubular necrosis is a kidney disorder involving damage to the tubule cells of the kidneys, which can lead to acute kidney failure.
Alternative NamesNecrosis - renal tubular; ATN; Necrosis - acute tubular
Causes, incidence, and risk factorsAcute tubular necrosis (ATN) is usually caused by a lack of oxygen to the kidney tissues (ischemia of the kidneys). It may also occur if the kidney cells are damaged by a poison or harmful substance.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 reactionInjury or trauma that damages the musclesLow blood pressure (hypotension) that lasts longer than 30 minutesRecent major surgerySeptic shock due to severe infectionLiver disease and kidney damage caused by diabetes (diabetic nephropathy) may make a person more susceptible to the condition.ATN can also be caused by:Dye (contrast) used for x-ray (radiology) studiesMedications that are toxic to the kidneys (such as aminoglycoside antibiotics or amphotericin)
SymptomsDecreased consciousnessComaDelirium or confusionDrowsy, lethargic, hard to arouseDecreased urine output or no urine outputGeneral swelling, fluid retentionNausea, vomitingNote: Other symptoms of acute kidney failure may also be present.
Signs and testsThe doctor will perform a physical exam. Your doctor may hear abnormal sounds when listening to the heart and lungs with a stethoscope (auscultation). This is due to too much fluid in the body.Other tests that may be done include:BUN and serum creatinineFractional excretion of sodiumKidney biopsyUrinalysisUrine sodiumUrine specific gravity and osmolarity urine
TreatmentIn most people, ATN is reversible. The goal of treatment is to prevent life-threatening complications of acute kidney failure.Treatment focuses on preventing the excess buildup of fluids and wastes, while allowing the kidneys to heal. Patients should be watched closely for deterioration of kidney function.Treatment can include:Identifying and treating the underlying cause of the problemRestricting fluid intake to a volume equal to the volume of urine producedRestricting substances normally removed by the kidneys (such as protein, sodium, potassium) to minimize their buildup in the bodyTaking medications to help control potassium levels in the bloodstreamMedicines taken by mouth or through an IV to help remove fluid from the bodyTemporary dialysis can remove excess waste and fluids. This can make you feel better, and may make the kidney failure easier to control. Dialysis may not be necessary for all people, but is often lifesaving, especially if serum potassium is dangerously high.Dialysis may be needed in the following cases:Decreased mental statusFluid overloadIncreased potassium levelsPericarditisTo remove toxins that are dangerous to the kidneysTotal lack of urine productionUncontrolled buildup of nitrogen waste products
Expectations (prognosis)How long symptoms last can vary. You may make less urine for a few days to 6 weeks or more. This may be followed by a period of high urine output. This occurs because the healed and newly functioning kidneys try to clear the body of fluid and waste.One or two days after your urine amount rises, symptoms reduce and test results begin to return to normal.
ComplicationsBleeding from the gastrointestinal tractChronic kidney disease and permanent kidney damageHigh blood pressureIncreased risk of infection
Calling your health care providerCall your health care provider if your urine output decreases or stops, or if you develop other symptoms of acute tubular necrosis.
PreventionPromptly treating conditions that can lead to decreased blood flow as well as decreased oxygen to the kidneys can reduce the risk of acute tubular necrosis.Blood transfusions are crossmatched to reduce the risk of incompatibility reactions.Control conditions such as diabetes, liver disorders, and cardiac disorders to reduce the risk of acute tubular necrosis.Carefully monitor exposure to medications that can be toxic to the kidney. Have your blood levels of these medications checked regularly. Drink a lot of fluids after having any radiocontrast dyes to allow them to be removed from the body and reduce the risk of kidney damage.
ReferencesClarkson MR, Friedewald JJ, Eustace JA, Rabb H. Acute kidney injury. In: Brenner BM, ed. Brenner and Rector's The Kidney. 8th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 29.Molitoris BA. Acute kidney injury. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 121.