Creatinine Poor Predictor of Acute Kidney Injury in Pediatric ICU

By Gene Emery

November 27, 2016

NEW YORK (Reuters Health) - Acute kidney injury develops in more than one quarter of children and young adults admitted to intensive care units. And in severe cases, it increases the odds of death by 77%, according to a new international observational study conducted in 32 hospitals.

The analysis, reported Friday at the annual meeting of the American Society of Nephrology in Chicago and online by the New England Journal of Medicine, also found that plasma creatinine, by itself, was not an effective method for diagnosing the problem. It failed in 67.2% of patients with low urine output.

"We're missing a really important component to the acute kidney injury picture," said coauthor Dr. Stuart Goldstein, director of the Center for Acute Care Nephrology at Cincinnati Children's Hospital. "Our study demonstrates we have to pay attention to urine output" even if it means keeping patients catheterized longer.

The results "will change practice in the way we need to identify (acute kidney injury) earlier and employ some options we have now, including paying attention to fluid administration, paying attention to medications that can be toxic to the kidney, and being more systematic about when to start dialysis to improve outcomes," he told Reuters Health in a telephone interview.

Although the study has limitations, it "reinforces the concept that it is important to monitor critically ill children for the development of acute kidney injury," Dr. Julie Ingelfinger said in a Journal editorial.

To get a better sense of the scope of the problem, Dr. Goldstein and his colleagues followed the cases of 4,683 ICU admissions to look for the rate of acute kidney injury during the first seven days. The patients were ages three months to 25 years, making it the largest prospective kidney study of critically ill children.

Acute kidney injury developed in 26.9% of the patients and severe acute kidney injury surfaced in 11.6%.

The 77% greater risk of death in the latter group occurred during the first 28 days.

The death rate was 11.0% for children and young adults with severe acute kidney injury versus 2.5% without.

Mortality among patients with stage 3 injury was higher if they had low urine output than if they had a high creatinine level.

In 67% of the patients "who met the urine-output criteria for acute kidney injury, the diagnosis of acute kidney injury would have been missed if only the plasma creatinine criteria had been used," the researchers said.

The mortality rate among the patients with low urine output was 7.8%, versus 2.9% for the children and young adults with normal output.

One reason creatinine may not be a good stand-alone test is that low urine output may be increasing the fluid content of the blood, diluting the creatinine and depressing its apparent level.

Hospitals in Asia, Australia, Europe and North America participated in the study, known as AWARE. "All previous studies in pediatrics were either retrospective, single-center or focused on children who received acute dialysis," Goldstein said.


N Engl J Med 2016.