Delta Neutrophil Index as a Prognostic Marker in the Pediatric Intensive Care Unit

Background: The delta neutrophil index (DNI) is a useful marker for diagnosing and predicting the prognosis of sepsis. The purpose of this study was to investigate the usefulness of DNI as a prognostic marker in patients within the pediatric intensive care unit (PICU), as well as its association with other prognostic factors. Methods: A total of 516 children admitted to Severance Children’s Hospital PICU from December 2009 to February 2015 were analyzed. DNI was measured on the day of PICU admission. Mortality was defined as death within 28 days following PICU admission. Results: The median value of DNI was 1.2% (interquartile range [IQR] 0-4.3%) in the survivor group and 9.5% (IQR 2.3-20.8%) in the non-survivor group, and the difference was statistically significant (p < 0.001). DNI was significantly positively correlated with ICU scores such as Pediatric Index of Mortality 3 and Pediatric Risk of Mortality III, as well as with C-reactive protein and lactate levels. The area under the receiver operating characteristic curve of DNI for mortality was 0.748 (95% CI: 0.687-0.808) and the cut-off value was 4.95%. Conclusions: The initial DNI level can be considered a useful indicator for predicting prognosis in PICU patients.