Acute kidney injury, in which the kidneys suddenly stop working properly, is a potentially severe condition that often follows major surgery and causes serious complications for patients. Now for the first time, researchers show that treatment with ultrasound beforehand can help prevent the problem in mice.

The protection from acute kidney injury (AKI) comes from the anti-inflammatory effects of this simple, drug-free, non-invasive treatment, the scientists believe.

Mark Okusa and Joseph Gigliotti of the University of Virginia and colleagues report their findings in the Journal of the American Society of Nephrology.

Dr. Mark Okusa told the press:

“Our studies using non-invasive ultrasound now provide us with an active treatment that appears to be simple, effective, and nontoxic for the prevention of acute kidney injury.

“To our knowledge this has never been described for the prevention of tissue or organ injury.”

Acute kidney injury is becoming an increasingly common complication in patients who have major surgery. It occurs because sometimes during major surgery the normal blood flow to the kidneys is disrupted. Once AKI sets in, it is very difficult to treat.

Acute kidney injury not only affects quality of life for patients, but also increases healthcare costs, and raises the risk of death following major surgery, note the authors.

A study published in 2008, showed that risk of death persists in heart patients with AKI even after discharge from hospital.

For their study, the researchers exposed anesthetized mice to ultrasound 24 hours before disrupting the blood supply to their kidneys.

They used the same kind of device that clinicians use to take regular ultrasound images.

Once blood flow was restored, they found that the health of the animals’ kidneys had been preserved.

Another group of mice that received a sham treatment did not show preserved kidney health: their kidneys showed significant injury.

On further analysis, the researchers found that the ultrasound seemed to have stimulated the spleen to produce an anti-inflammatory response that protected the kidneys.

The researchers believe that the mechanisms that cause the acute kidney injury may also be responsible for similar damage to lung, heart and liver and that this type of treatment could prevent injury in other organs too.

Experts suggest the study offers numerous and promising possibilities because there are many procedures that carry a high risk of AKI.

In an editorial in the same issue of the journal, Alain Le Moine of Erasme Hospital in Belgium, and colleagues, note that:

In searching for novel approaches to prevent and even cure AKI, we believe that splenic ultrasound stimulation has a bright future ahead.”

Progress is also being made in predicting which post-operative patients are at higher risk for acute kidney injury. Current methods – such as measuring serum creatinine and urine output – may not show changes for several days, allowing time for serious kidney damage to have happened already.

But in an international study published earlier this year, researchers found two biomarkers that spot AKI risk sooner.

Written by Catharine Paddock PhD