Neutrophil cell population data: useful indicators for postsurgical bacterial infection

Abstract

The Coulter LH750 analyzer can determine white blood cell count (WBC) with differentials and determine their intrinsic biophysical properties, known as cell population data (CPD). Previous studies demonstrated that neutrophil CPD, mean neutrophil volume (MNV), and neutrophil volume distribution width (NDW) were significantly increased during bacterial infection. This study investigated the clinical usefulness of MNV/NDW to differentiate postoperative infection. Cell population data from 212 controls, 135 patients without postsurgical infection, and 62 with infection were studied. All patients had normal WBC and percent neutrophils prior to surgery. No significant differences in MNV and NDW were observed before surgery between infected and noninfected patients when compared with controls. The MNV and NDW in infected patients were significantly increased after surgery when compared with noninfected patients. Although WBC and percent neutrophils were also increased after surgery, no statistical differences were seen between noninfected and infected patients. A MNV cutoff of ≥152.4 and NDW cutoff of ≥24.26 produced 90.3% and 88.3% sensitivity and 88.4% and 76.3% specificity, respectively. Neutrophil CPD, MNV, and NDW are better indicators for postoperative bacterial infection. The potential clinical usefulness of these parameters merits further exploration in a larger prospective study.