Acute Kidney Injury

What are the symptoms of an acute kidney injury?

Symptoms of an acute kidney injury come on suddenly, over the course of hours or days. They depend on the underlying cause, but some of the most common symptoms include:

• hemorrhage (heavy bleeding)
• fever
• rash
• bloody diarrhea
• severe vomiting
• abdominal pain
• no urine output or high urine output
• pale skin
• edema (swelling of the tissues)
• swelling around the eye
• detectable abdominal mass

If your child has these symptoms, they may be especially at risk of AKI if she has or has had any of the following:

• recent infection
• dehydration
• recent surgery
• trauma
• exposure to heavy metals or toxic solvents

What causes an acute kidney injury?

An acute kidney injury is often caused by a sudden decrease in blood and/or oxygen flow to your child’s kidneys. This could follow:

• an accident
• surgery
• a condition that obstructs blood flow, like cardiac arrest

An acute kidney injury may also occur if your child:

• takes certain medications that may be toxic to the kidneys
• injures her abdomen or back, like a bike-riding accident that results in a fall over the handlebars or a skiing accident
• develops a sudden obstruction or blockage in her urinary tract, such as a kidney stone, that prevents urine from leaving the body
• contracts an infection such as hemolytic uremic syndrome (HUS), usually caused by the E. coli bacteria, resulting in the blockage of the structures and blood vessels in the kidney
• is born with blood vessel abnormalities that cut off blood flow to the kidneys
• has another disease or condition that damages the kidneys, such as glomerulonephritis or lupus

How we diagnose acute kidney injuries in children

The first step in treating your child is forming an accurate and complete diagnosis, and in order to minimize damage to your child’s kidneys, it’s important that AKI be diagnosed early. The doctor may order tests including:

Blood, urine and other tests to determine how well your child’s kidneys are functioning

There are two main ways to measure your child’s kidney functioning: creatinine level and glomerular filtration rate (GFR).

• Creatinine is a waste product that the body makes daily in proportion to a person’s muscle mass. It can leave the body only through the kidneys, and levels can be checked through a simple blood test. If your child has AKI, we will see her creatinine level rise quickly.
• GFR (glomerular filtration rate) is a measurement of how efficiently your kidneys are able to filter your blood. Read more about the GFR test at Children’s Hospital Boston.

Imaging tests to check for blockages in the urinary tract

These tests might include:

• abdominal x-ray: invisible electromagnetic energy beams produce images of internal tissues, bones, and organs onto film
• renal ultrasound (also called sonography): a painless, non-invasive test in which a transducer is passed over your child’s kidneys, producing sound waves that bounce off the kidney and transmit a picture on a video screen. The test can detect a mass, kidney stone, cyst, or other obstruction or abnormality.
• nuclear medicine study: non-invasive, painless tests that can reveal important information about your child's health. Nuclear medicine uses short-lived radiopharmaceuticals and specialized cameras to create images of the human body.

Kidney biopsy

This is a procedure in which tissue samples are removed (with a needle or during surgery) from the kidney for examination under a microscope. Read more about biopsies.

After we complete all necessary tests, our experts meet to review and discuss what they have learned about your child's condition. Then we’ll meet with you and your family to discuss the results and outline the best treatment options.

What are the treatment options for an acute kidney injury?

Treatment for AKI usually involves three components:

Stabilizing your child’s health

To do so your child’s doctors may:

• treat your child with diuretics and/or intravenous (IV) fluids to rebalance the fluids and minerals in her blood
• treat infections with antibiotics
• stabilize the blood pressure

Treating the underlying cause of your child's acute kidney injury

This may include:

• removing an obstruction or blockage
• stopping any medications thought to be causing or contributing to the AKI
• using medication to treat the underlying cause

Supporting your child’s kidneys as they recover

• close monitoring of important electrolytes such as potassium, sodium, and calcium, which may also be replaced through an IV
• medication to control blood pressure or prevent infections
• specific diet requirements to limit the amount of toxins in your child’s bloodstream as the kidneys heal

If your child’s AKI is quite severe, her doctors may recommend dialysis, a procedure that filters and rebalances your child’s blood so that her kidneys can rest and heal.

Typically, your child will be weaned off dialysis as the kidneys repair themselves. In rare cases, after three months on dialysis, the kidneys still might not have regained function. This may indicate that the kidneys are unable to repair themselves enough to work properly, and your child’s doctor may recommend that she continue dialysis or begin to be evaluated for a kidney transplant.

What’s the long-term outlook for a child with an acute kidney injury?

Most children with acute kidney injury get better. After an episode of AKI, your child should consider kidney care to be a permanent part of her health care routine. She should see her doctor and have her blood pressure checked and urine tested every year to make sure that her kidney function has not deteriorated. Her doctor may also recommend that she’s followed by a nephrologist (a doctor who specializes in kidneys).

In some severe episodes of AKI, particularly if your child has another disease or condition, the kidneys may not gain back normal functionality, and your child may be a candidate for long-term dialysis and/or kidney transplant.

How we care for an acute kidney injury

Our Division of Nephrology is the largest pediatric nephrology service in the United States. We care for patients with a wide range of kidney disorders, and we are home to the biggest dialysis and kidney transplant program in New England dedicated to treating and caring for children.

Our seven-bed dialysis unit is the only full-service pediatric dialysis unit in New England. If your child requires dialysis, our dialysis nurses, dietitians, tutors, child life specialists, social workers, psychologists, and pharmacists will do everything they can to make sure your child is comfortable during her treatments.

Our caregivers provide support services for your child and your family throughout all stages of treatment and recovery.

Our areas of innovation for acute kidney injuries

Boston Children’s is home to the world’s most extensive research enterprise at a pediatric hospital. In our End Stage Renal Disease Program — which includes the dialysis unit and our Kidney Transplant Program — our treatment is influenced by our research.

We also have a great number of partnerships with top research, biotech, and health care organizations, and we work together to improve kids’ health. One of these is the Transplant Research Program, which provides a rich environment for collaboration of scientists and physicians in the areas of transplantation and immunology.

If your child has end-stage renal disease, dialysis can filter the blood, but not take over the other roles of the kidney, such as regulating the amounts of some important vitamins and minerals released into the bloodstream and controlling blood pressure. For that, your child needs to take medication and follow a special diet. Our researchers are currently involved in several clinical trials to assess the safety and efficacy of medications, aimed at fulfilling this pharmaceutical component of treating end-stage renal disease. We’re also committed to developing better anti-rejection medication with the goal of more successful transplants and fewer side effects.