Diagnostic and prognostic values of serum procalcitonin and C-reactive protein in patients of bacterial sepsis

Abstract

To explore the diagnostic and prognostic values of serum procalcitonin (PCT) and C-reactive protein (CRP) in patients of bacterial sepsis. From July 2012 to May 2013, a total of 120 critically ill patients at our intensive care unit (ICU) were recruited. They included septic (sepsis group, n = 63) local infection (local infection group, n = 57) and healthy people (control group, n = 30). The serum levels of PCT and CRP were measured. Septic patients were divided into survival and death groups according to the prognosis. They were also divided into gram-positive and gram-negative bacteria groups according to the results of bacterial cultivation. The serum levels of PCT and CRP, as well as acute physiology and chronic health evaluation II (APACHEII) scores and sepsis related organ failure assessment (SOFA) scores in the sepsis group were significantly higher than those in the local infection and control groups (P < 0.05). And those in the local infection group were higher than those in the control group (P < 0.05). The sensitivity, specificity, positive predictive value and negative predictive value for serum PCT in diagnosing bacterial sepsis were significantly larger than those for serum CRP (P < 0.05). The serum levels of PCT and CRP in survival group were less than those in death group at Day 1, 5, 10 and 15 (P < 0.05). Moreover, there were significant time effects on the serum levels of PCT and CRP in the survival group (P < 0.05), but not in the death group (P > 0.05). When PCT was ≥ 10.0 µg/L, the patients of gram-negative bacteria were more than those of gram-positive bacteria (P < 0.05). The serum levels of PCT and CRP are reliable in the diagnostic and prognostic evaluations of bacterial sepsis. Both also have certain reference value for local infection. Moreover the sensitivity and specificity of serum PCT were better those of serum CRP.