Diseases & Conditions

Acute Renal Insufficiency - Renal Failure


Overview, Causes, & Risk Factors

Acute renal failure occurs when the filtering function of the kidneys changes suddenly. The kidneys are not able to maintain healthy body function.

What is going on in the body?

The kidneys filter the blood in the body and produce urine. They clear the body of many drugs and toxins. They also produce hormones and control blood pressure. The blood flow to each kidney is supplied by a large artery. Blood flow to the kidneys is crucial both for kidney health and to allow the kidneys to perform their functions of cleaning and maintaining the blood. Anything that leads to a sudden drop in blood flow to the kidneys can cause acute renal failure. When this happens, the regular functions of the kidneys can be altered or destroyed.

What are the causes and risks of the disease?

The following can lead to acute renal failure:

  • a blockage of urine flow out of the kidneys and into the bladder
  • exposure to certain drugs
  • exposure to toxic substances
  • significant loss of blood or sudden drop in blood flow to the kidneys
  • Kidneys that have preexisting disease or damage are at higher risk for acute renal failure.


    Symptoms & Signs

    What are the signs and symptoms of the disease?

    At first, there are no specific signs or symptoms of acute renal failure. But as the disease gets worse, many people have decreased urine output. As a result, fluid builds up in the body tissues and organs. Here are some common symptoms of acute renal failure:

  • irregular heartbeats, called arrhythmias
  • excess fluid in the abdomen, called ascites
  • cognitive impairments, which include an altered mental status
  • coma
  • palpitations, which are unusual sensations of the heart beating rapidly in the chest
  • shortness of breath
  • edema, which means swelling of the extremities

  • Diagnosis & Tests

    How is the disease diagnosed?

    Diagnosis of acute renal failure begins with a medical history and physical exam. The doctor may order blood tests and urine studies. Ultrasound imaging of the kidneys can help pinpoint the cause of the disorder.


    Prevention & Expectations

    What can be done to prevent the disease?

    Acute renal failure can't always be prevented. Drugs that can damage the kidneys should be avoided. Persons with preexisting kidney disease need to be very careful to avoid certain medicines that are known to affect kidney function.

    What are the long-term effects of the disease?

    Most cases of acute renal failure will resolve with supportive therapy. Having had acute renal failure does not mean a person is at risk for long-term kidney damage. However, a person who has underlying kidney disease may not completely recover healthy kidney function. Sometimes, a person can develop progressive kidney damage as a result of acute renal failure and require long-term dialysis therapy.

    What are the risks to others?

    Acute renal failure does not put other people at risk.


    Treatment & Monitoring

    What are the treatments for the disease?

    Diuretic medicines, known as water pills, are sometimes used to help the kidneys get rid of fluid in the body. In other situations, fluids are given to promote increased blood flow to the kidneys.

    If blood loss or shock has occurred, blood transfusions ay be given. Salt imbalances are monitored closely. Medicines can be given to lower elevated electrolytes levels. Dialysis may be used to replace kidney function until the acute renal failure resolves. Dialysis is a procedure where the blood flow from a person is redirected through a special machine. The machine filters the blood and then returns it to the person.

    What are the side effects of the treatments?

    In most cases, there are few side effects to treatment of acute renal failure. The complexity of the disease itself can lead to further difficulties though. When dialysis is needed, a large intravenous tube, called a catheter, is placed into a vein in the upper arm or chest. The catheter is used for withdrawing fluids from the body or adding fluids. This can pose the risk of bleeding or infection.

    What happens after treatment for the disease?

    After normal kidney function has returned, the person will be monitored for overall kidney and electrolyte function.

    How is the disease monitored?

    Any new or worsening symptoms should be reported to the doctor.


    Attribution

    Author:Bill Harrison, MD
    Date Written:
    Editor:Crist, Gayle P., MS, BA
    Edit Date:08/17/02
    Reviewer:Sandy Keefe, RN, MSN
    Date Reviewed:08/22/01