Delta neutrophil index as a prognostic marker of early mortality in gram negative bacteremia

Background: Sepsis is a syndrome that results in high morbidity and mortality. We investigated the delta neutrophil index (DN) as a predictive marker of early mortality in patients with gram-negative bacteremia.

Materials and methods: We conducted a retrospective study at a tertiary referral hospital in South Korea from November 2010 to March 2011. The DN was measured at onset of bacteremia and 24 hours and 72 hours later. The DN was calculated using an automatic hematology analyzer. Factors associated with 10-day mortality were assessed using logistic regression.

Results: A total of 172 patients with gram-negative bacteremia were included in the analysis; of these, 17 patients died within 10 days of bacteremia onset. In multivariate analysis, Sequental organ failure assessment scores (odds ratio [OR]: 2.24, 95% confidence interval [CI]: 1.31 to 3.84; P = 0.003), DN-day 1 ≥ 7.6% (OR: 305.18, 95% CI: 1.73 to 53983.52; P = 0.030) and DN-day 3 ≥ DN-day 1 (OR: 77.77, 95% CI: 1.90 to 3188.05; P = 0.022) were independent factors associated with early mortality in gram-negative bacteremia. Of four multivariate models developed and tested using various factors, the model using both DN-day 1 ≥ 7.6% and DN-day 3 ≥ DN-day 1 was most predictive early mortality.

Conclusions: DN may be a useful marker of early mortality in patients with gram-negative bacteremia. We found both DN-day 1 and DN trend to be significantly associated with early mortality.