Test Can Predict Post-Surgery Kidney Damage
A new study led by researchers from Cincinnati Children's shows that a simple urine test can help identify which patients might suffer kidney damage as a result of surgery - in some cases, up to three days before the damage would otherwise be detected.
"In current clinical practice, when kidney failure occurs, the diagnosis is unacceptably delayed,” said Prasad Devarajan, MD, lead author of the study and director of nephrology at Cincinnati Children's. "Ironically, even tragically, effective preventive and therapeutic measures are widely available but rarely administered in a timely manner due to the lack of early biomarkers of kidney failure."
The study, reported in the Clinical Journal of the American Society of Nephrology, found that testing for elevated levels of the biomarker neutrophil gelatinase-associated lipocalin (NGAL) reliably predicts which patients are at risk for developing postoperative acute kidney injury (AKI). This information will help clinicians identify at-risk patients and provide earlier treatment, giving them a chance to prevent or improve outcomes of postoperative AKI.
"Urine NGAL represents a powerful early predictive marker of AKI, preceding the increase in serum creatinine—the current gold standard of prediction—by several hours to days," explains Dr. Devarajan.
The researchers measured NGAL in urine samples from 196 children undergoing cardiopulmonary bypass (CPB), during surgery to repair congenital heart defects. Heart bypass is a major risk factor for AKI.
Fifty-one percent of the children in the study developed AKI. Their diagnosis was based on increased levels of creatinine, which did not occur until two or three days after CPB. In contrast, tests measuring the children's NGAL levels just two hours after surgery identified 90 percent of those who went on to develop kidney problems.
For this group, NGAL increased 15 times higher than normal within two hours after CPB, and 25 times higher by four hours.
The study is the first to show NGAL testing can be reliably used in a clinical setting. According to Dr. Devarajan, the urine test can be easily added to the standard battery of tests administered to patients who undergo bypass surgery. This simple and rapid test will also be useful in several other clinical situations that render a patient at risk for developing acute kidney injury.
