The use of delta neutrophil index and myeloperoxidase index as diagnostic predictors of strangulated mechanical bowel obstruction in the emergency department

Early detection of bowel strangulation is difficult in patients with mechanical bowel obstruction (MBO). There have been no previous reports of predicting strangulation in MBO cases using the delta neutrophil index (DNI), which is a measure of the proportion of circulating immature granulocytes, or the myeloperoxidase index (MPXI), which is a measure of serum myeloperoxidase level. Therefore, we evaluated differences in initial DNI and MPXI upon presentation at the emergency department (ED) according to strangulation presence in MBO patients. This is a retrospective observational study of consecutive patients older than 18 years who were diagnosed with MBO over a 31-month period. MBO was ultimately confirmed by computed tomography (CT) findings by a radiology specialist. Patients were categorized by a strangulation group (SG) and nonstrangulation group (NSG). The SG was defined by surgical and pathologic findings after the surgical operation. Initial serum counts of white blood cells and neutrophils, C-reactive protein levels, and DNI and MPXI scores were investigated in the ED. Fifteen of 160 patients were allocated to the SG (9.4%), and among the inflammatory markers, median initial DNI value was the only one that was significantly higher in the SG (0% vs 3.2%, P = 0.003). Although the areas under the receiver operation characteristic (ROC) curves for initial DNI and CT for differentiating strangulated from nonstrangulated bowel obstruction were 0.713 (95% confidence interval [CI]: 0.636–0.782) and 0.883 (95% CI: 0.823–0.928), respectively; there was no significant difference between DNI and CT (P = 0.147). The area under the curve (AUC) for predicting strangulated bowel disease from a combination of initial DNI score and CT findings (0.983, 95% CI: 0.948–0.997) was higher than the AUC for CT alone, although the difference was not significant (P = 0.052). In conclusion, initial DNI, which was performed in the ED, was found to be significantly higher in the SG than in the NSG. Initial DNI might be a useful additional parameter for improving the prediction accuracy of CT.