Delta neutrophil index as a prognostic marker in the pediatric intensive care unit

Abstract

Purpose: The delta neutrophil index (DNI) is known to be 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: The medical records of 149 children admitted to Severance Children’s Hospital PICU in Korea were analyzed retrospectively. DNI was measured from day of admission until day seven of the PICU stay. Results: The DNI was significantly higher in the non-survivor group (mean ± SD, 7.8 ± 9.7) than the survivor group (2.0 ± 3.1) (p < 0.0001). Subjects were categorized into the following three groups based on DNI: low group (<5), intermediate group (5-10) and high group (>10). The percentage of survivors was lowest in the high DNI group (p < 0.0001). DNI had a significant correlation with ICU score, white blood cell count, hemoglobin, platelet count, CRP and aPTT. DNI at PICU admission (OR=1.118; 95% CI, 1.016–1.231; p =0.022) was found to be statistically significant for predicting mortality on multivariate logistic regression analysis. The area under the receiver operating characteristic curve of DNI for mortality was 0.673 and the cut-off value was 3.1%. Survival curves showed significantly higher survival rates in the DNI <3.1 group as compared to the ≥3.1 group (p < 0.0001). The mean values of DNI during the first seven days of the ICU stay were significantly higher in the non-survivor group (p < 0.0001). When analyzed only 109 patients who meet the criteria of sepsis or SIRS, DNI on day 6 only showed a statistically significant difference between sepsis and SIRS group (p =0.006) and DNI on the day of admission was higher in the non-survivor group vs. survivor group (p =0.045). Conclusions: The initial DNI level and trend are considered useful indicators for predicting prognosis in PICU patients.