WEDNESDAY, March 12 A new, easy lab test can identify patients at risk of developing acute kidney injury (AKI) after surgery up to 3 days sooner than the difficulty would otherwise be detected, a pilot study shows.

The finding could lead to before treatment and better patient outcomes, the researchers say.

The test measures a biomarker called neutrophil gelatinase-associated lipocalin (NGAL) in urine.

"Urine NGAL represents a powerful early predictive marker of AKI, preceding the increase in serum creatinine -- the present gold standard -- by several hours to days," study author Dr. Prasad Devarajan, of Cincinnati Children's Hospital Medical Center, said in a prepared statement.

"An early elevation in urine NGAL would trigger an instant shift in clinical management, making caregivers aware of the high potential for development of clinical AKI," Devarajan said. Close monitoring and treatment may help prevent AKI from developing.

In this study, Devarajan and colleagues looked at 196 children who had cardiopulmonary bypass (CPB) surgery to repair congenital heart defects. This surgery is a major risk cause for AKI, a serious difficulty that can cause constant loss of kidney function or death.

AKI happened in 51 percent of the children, who were diagnosed with AKI based on increased levels of creatinine 2 to 3 days after surgery. The researchers found that urine NGAL levels began to increase within a few hours after these children had surgery. NGAL levels were 15 times higher than normal within 2 hours, and 25 times higher than normal within four hours.

Urine NGAL levels were extremely accurate in predicting risk of AKI, said the researchers, who found that NGAL level at 2 hours identified 90 percent of children who later developed AKI. Urine NGAL also predicted the severity of AKI. Children with higher urine NGAL levels were more likely to require dialysis, more likely to die, and took longer to recover kidney function.

The study, which is published in the May issue of the Clinical Journal of the American Society of Nephrology, received funding from Abbott, which is developing the NGAL test.

More research on different groups of patients is required to affirm the value of using NGAL as a biomarker to identify those at high risk for AKI, Devarajan said.

More information

The National Kidney Foundation has more about acute kidney injury.