Platelet indices in critically ill septic patients as a predictor of mortality

Abstract

ABSTRACT Background Platelet (PLT) indices are used to quantify the total number of PLTs, their morphology, and their proliferation kinetics. The aim of this work was to explore whether platelet indices (PLT count, platelet distribution width (PDW), mean platelet volume (MPV) and platelet crit (PCT) can be used to predict mortality in critically ill septic patients. Methods This prospective cross-sectional study was carried out on 54 critically ill septic patients according to sequential organ failure assessment (SOFA) scores from May 2020 to May 2021. Patients were grouped into: (1) survivors’ group and (2) non-survivors’ group. Complete blood count, C-reactive protein (CRP) and procalcitonin serum levels were measured. Results A rise in MPV, PDW, procalcitonin and CRP and a fall in PLT and PCT was associated with non-survivors’ group. For prediction of mortality, PLT, MPV and PDW at cut-off value ≤183 *103/dl, >10.9 fl and >14% had (57.89%, 84.21% and 78.95%) sensitivity, (71.43%, 80% and 74.29%) specificity, (52.4%, 69.6% and 62.5%) positive predictive value (PPV), negative predictive value (NPV) (75.8%, 90.3% and 86.7%), (0.672, 0.868 and 0.856) area under the curve (AUC) and (0.038, <0.001 and <0.001) P value respectively. For prediction of mortality, procalcitonin at cut-off value 5.6 ng/dl had 94.74% sensitivity, 85.7% specificity, 78.3% PPV, NPV 96.8, 0.919 AUC and <0.001 P value. In multivariate regression analysis, most affecting factors for mortality were procalcitonin, MPV and PDW (P value<0.05). Conclusions Platelet indices are low-cost, readily accessible metrics that have the potential to be valuable prognostic markers in sepsis.