Acute kidney failure occurs when your kidneys suddenly become unable to filter waste products from your blood. When your kidneys lose their filtering ability, dangerous levels of wastes may accumulate, and your blood’s chemical makeup may get out of balance.
Acute kidney failure — also called acute renal failure or acute kidney injury — develops rapidly over a few hours or a few days. Acute kidney failure is most common in people who are already hospitalized, particularly in critically ill people who need intensive care.
Acute kidney failure can be fatal and requires intensive treatment. However, acute kidney failure may be reversible. If you’re otherwise in good health, you may recover normal or nearly normal kidney function.
Symptoms of Acute kidney failure
Signs and symptoms of acute kidney failure may include:
Decreased urine output, although occasionally urine output remains normal
Fluid retention, causing swelling in your legs, ankles or feet
Shortness of breath
Seizures or coma in severe cases
Chest pain or pressure
Sometimes acute kidney failure causes no signs or symptoms and is detected through lab tests done for another reason.
Causes of Acute kidney failure
Acute kidney failure can occur when:
You have a condition that slows blood flow to your kidneys
You experience direct damage to your kidneys
Your kidneys’ urine drainage tubes (ureters) become blocked and wastes can’t leave your body through your urine
Impaired blood flow to the kidneys
Diseases and conditions that may slow blood flow to the kidneys and lead to kidney failure include:
Blood or fluid loss
Blood pressure medications
Heart attack and Heart disease
Use of aspirin, ibuprofen (Advil, Motrin IB, others), naproxen (Aleve, others) or related drugs
Severe allergic reaction (anaphylaxis)
Damage to the kidneys
These diseases, conditions and agents may damage the kidneys and lead to acute kidney failure:
Blood clots in the veins and arteries in and around the kidneys
Cholesterol deposits that block blood flow in the kidneys
Glomerulonephritis inflammation of the tiny filters in the kidneys (glomeruli)
Hemolytic uremic syndrome, a condition that results from premature destruction of red blood cells
Lupus, an immune system disorder causing glomerulonephritis
Medications, such as certain chemotherapy drugs, antibiotics, dyes used during imaging tests and zoledronic acid (Reclast, Zometa), used to treat osteoporosis and high blood calcium levels (hypercalcemia)
Multiple myeloma, a cancer of the plasma cells
Scleroderma, a group of rare diseases affecting the skin and connective tissues
Thrombotic thrombocytopenic purpura, a rare blood disorder
Toxins, such as alcohol, heavy metals and cocaine
Vasculitis, an inflammation of blood vessels
Urine blockage in the kidneys
Diseases and conditions that block the passage of urine out of the body (urinary obstructions) and can lead to acute kidney failure include:
Blood clots in the urinary tract
Nerve damage involving the nerves that control the bladder
Risk Factors of Acute kidney failure
Acute kidney failure almost always occurs in connection with another medical condition or event. Conditions that can increase your risk of acute kidney failure include:
Being hospitalized, especially for a serious condition that requires intensive care
Blockages in the blood vessels in your arms or legs (peripheral artery disease)
High blood pressure
Tests and Diagnosis
If your signs and symptoms suggest that you have acute kidney failure, your doctor may recommend certain tests and procedures to verify your diagnosis. These may include:
Urine output measurements. The amount of urine you excrete in a day may help your doctor determine the cause of your kidney failure.
Urine tests. Analyzing a sample of your urine, a procedure called urinalysis, may reveal abnormalities that suggest kidney failure.
Blood tests. A sample of your blood may reveal rapidly rising levels of urea and creatinine — two substances used to measure kidney function.
Imaging tests. Imaging tests such as ultrasound and computerized tomography may be used to help your doctor see your kidneys.
Removing a sample of kidney tissue for testing. In some situations, your doctor may recommend a kidney biopsy to remove a small sample of kidney tissue for lab testing. Your doctor inserts a needle through your skin and into your kidney to remove the sample.
Treatment and Drugs
Treatment for acute kidney failure typically requires a hospital stay. Most people with acute kidney failure are already hospitalized. How long you’ll stay in the hospital depends on the reason for your acute kidney failure and how quickly your kidneys recover.
Your doctor will also work to prevent complications and allow your kidneys time to heal. Treatments that help prevent complications include:
Treatments to balance the amount of fluids in your blood. If your acute kidney failure is caused by a lack of fluids in your blood, your doctor may recommend intravenous (IV) fluids. In other cases, acute kidney failure may cause you to have too much fluid, leading to swelling in your arms and legs. In these cases, your doctor may recommend medications (diuretics) to cause your body to expel extra fluids.
Medications to control blood potassium. If your kidneys aren’t properly filtering potassium from your blood, your doctor may prescribe calcium, glucose or sodium polystyrene sulfonate (Kayexalate, Kionex) to prevent the accumulation of high levels of potassium in your blood. Too much potassium in the blood can cause dangerous irregular heartbeats (arrhythmias) and muscle weakness.
Medications to restore blood calcium levels. If the levels of calcium in your blood drop too low, your doctor may recommend an infusion of calcium.
Dialysis to remove toxins from your blood. If toxins build up in your blood, you may need temporary hemodialysis — often referred to simply as dialysis — to help remove toxins and excess fluids from your body while your kidneys heal. Dialysis may also help remove excess potassium from your body. During dialysis, a machine pumps blood out of your body through an artificial kidney (dialyzer) that filters out waste. The blood is then returned to your body.