Delta neutrophil index as a prognostic marker in emergent abdominal surgery

BACKGROUND: Delta neutrophil index (DNI) is the fraction of circulating immature granulocytes provided by a routine, complete blood cell analyzer. It is known to be a useful prognostic marker of sepsis. The aim of this study was to evaluate the role of DNI in the diagnosis and prognosis of patients who had undergone emergent surgery for an acute abdomen. METHODS: A total of 694 patients who had visited the emergency room for acute abdominal pain and undergone emergent abdominal surgery from May 2015 to September 2016 were retrospectively reviewed. Clinical characteristics, laboratory findings on the day of hospital visit, hospital stay, postoperative complications, and 30‐day mortality were investigated. RESULTS: In the analysis of patients who had undergone an operation for acute peritonitis, the DNI was a good predictor for predicting 30‐day mortality rate (area under the curve [AUC]: 0.826). It was not inferior to other laboratory values, including activated partial thromboplastin time (AUC: 0.729), C‐reactive protein (AUC: 0.727), albumin (AUC: 0.834), prothrombin time (AUC: 0.816), and creatinine (AUC: 0.837) known to be associated with sepsis. Patients with high DNI displayed higher incidence of bacteremia and sepsis, longer hospital stay, higher postoperative complication rate, and higher 30‐day mortality rate than patients with low DNI. Among patients diagnosed with acute appendicitis, the DNI was a useful marker for differentiating appendiceal perforation. CONCLUSION: The DNI was a practical and useful marker for predicting the prognosis of patients who needed emergent abdominal surgery.