Acute kidney failure

Alternative Names

Kidney failure; Renal failure; Renal failure - acute; ARF; Kidney injury - acute

Definition

Acute kidney failure is the rapid  loss your kidneys' ability to remove waste and help balance fluids and  electrolytes in your body. In this case, rapid means less than 2 days.

Causes

There are many possible causes of kidney damage. They include:

• Acute tubular necrosis (ATN)
• Autoimmune kidney disease
• Blood clot from cholesterol (cholesterol emboli)
• Decreased blood flow due to very low blood pressure, which can result from:
  • Burns
  • Dehydration
  • Hemorrhage
  • Injury
  • Septic shock
  • Serious illness
  • Surgery
• Disorders that cause clotting within the kidney's blood vessels
• Infections that directly injure the kidney, such as:
  • Acute pyelonephritis
  • Septicemia
• Pregnancy complications, including:
  • Placenta abruptio
  • Placenta previa
• Urinary tract blockage

Symptoms

• Bloody stools
• Breath odor and metallic taste in mouth
• Bruising easily
• Changes in mental status or mood
• Decreased appetite
• Decreased sensation, especially in the hands or feet
• Fatigue
• Flank pain (between the ribs and hips)
• Hand tremor
• High blood pressure
• Metallic taste in mouth
• Nausea or vomiting, may last for days
• Nosebleeds
• Persistent hiccups
• Prolonged bleeding
• Seizures
• Shortness of breath
• Slow, sluggish movements
• Swelling due to the body keeping in fluid
• Swelling, usually in the ankles, feet, and legs
• Urination changes:
  • Little or no urine
  • Excessive urination at night
  • Urination stops completely

Exams and Tests

The doctor or nurse will examine you. Many patients with kidney disease have body swelling caused by fluid retention. The doctor may hear a heart murmur, crackles in the lungs, or other abnormal sounds when listening to the heart and lungs with a stethoscope.

The results of laboratory tests may change suddenly (within a few days to 2 weeks). Such tests may include:

• BUN
• Creatinine clearance
• Serum creatinine
• Serum potassium
• Urinalysis

A kidney or abdominal ultrasound is the preferred test for diagnosing a blockage in the urinary tract. X-ray, CT scan, or MRI of the abdomen can also tell if there is a blockage.

Blood tests may help reveal the underlying cause of kidney failure. Arterial blood gas and blood chemistries may show metabolic acidosis.

Treatment

Once the cause is found, the goal of treatment is to help your kidneys work again and prevent fluid and waste from building up in the body while they heal. Usually, you have to stay overnight in the hospital for treatment.

The amount of liquid you eat (such as soup) or drink will be limited to the amount of urine you can produce. You will be told what you may and may not eat to reduce the buildup of toxins that the kidneys would normally remove. Your diet may need to be high in carbohydrates and low in protein, salt, and potassium.

You may need antibiotics to treat or prevent infection. Diuretics ("water pills") may be used to help remove fluid from your body.

Medicines will be given through a vein to help control your blood potassium level.

Dialysis may be needed for some patients, and can make you feel better. It can save your life if your potassium levels are dangerously high. Dialysis will also be used if:

• Your mental status changes, if you stop urinating
• You develop pericarditis
• You retain too much fluid
• You cannot eliminate nitrogen waste products from your body

Dialysis will most often be short term. Rarely, the kidney damage is so great that dialysis may be permanently needed.

Support Groups

The stress of having an illness can often be helped by joining a support group where members share common experiences and problems.

See: Kidney disease - support group

When to Contact a Medical Professional

Call your health care provider if your urine output slows or stops or you have other symptoms of acute kidney failure.

Prevention

Treating disorders such as high blood pressure can help prevent acute kidney failure.

References

Molitoris BA. Acute kidney injury. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 122.

Sharfuddin AA, Weisbord SD, Palevsky PM, Molitoris BA. Acute kidney injury. In: Taal MW, Chertow GM, et al, eds. Brenner & Rector's The Kidney. 9th ed. Philadelphia, PA: SaundersElsevier; 2011:chap 30.