Acute kidney injury (AKI) is when the kidneys suddenly stop working. Normally, the kidneys filter and “clean” the blood, by removing waste, excess salt and water.

AKI can have many different causes. Nephrologists usually divide them into three groups:

• Less blood flows to the kidneys. This usually happens for children in the emergency room or hospital. In an outpatient setting, the most common cause is dehydration from vomiting or diarrhea, with or without high fever.
• Kidneys get damaged because of inflammation caused by infection or autoimmune disease. There are many medications that can cause AKI. Most common over the counter medications are called NSAIDs which including Motrin, Aleve or Ibuprofen. Aspirin also belongs to NSAIDs but is not commonly used in children.
• Urine could not get out of the kidney because blockage happens downstream. This can be caused by a kidney stone or certain congenital abnormalities of the urinary tract system.

Symptoms

Once children develop AKI, things that should be watched closely are electrolytes, urine output and blood pressure. Not all children with AKI have decreased urine output. As a matter of fact, some might void more urine than their usual amount.

Diagnosis

Children with AKI usually require only minimal blood and urine tests and do not need extensive workup as most of the causes can be identified just based on the history. Some children may need imaging studies like an ultrasound on kidneys and bladder.

Treatment

The nephrologist may ask your child to modify his or her diet and fluid intake temporally. For example, he may request a low potassium or low phosphorus diet. Some children with severe AKI may need hospital stay and require dialysis (a machine that helps clean the blood). However, this typically has to be done as inpatient. Most children with AKI do not need specific therapy after the underlying causes are corrected, or the offending medications are discontinued. Children with AKI related to some kidney diseases, such as certain glomerulonephritis, however, could progress to advanced chronic kidney disease that requires long term follow up with a nephrologist.