Application of the combined determination of serum procalcitonin and C reactive protein in patients with bacterial infection

Objective To evaluate the clinical significance of the combined determination of serum procalcitonin(PCT) and C reactive protein(CRP)in the curative effect and prognosis of bacterial infection.Methods Serum PCT and CRP levels and their dynamic change of 60 patients with bacterial infection in intensive care unit(ICU)were measured,and the results were analyzed and compared with those of virus infection.The patients with bacterial infection were classified into serious infection group and local infection group.Results The medians of PCT and CRP concentrations in serious infection group were 15.0 μg/L and 90.0 mg/L.The medians of PCT and CRP concentrations in local infection group were 1.8 μg/L and 55.3 mg/L.The levels of PCT and CRP in bacterial infection group increased significantly,and there were statistical significance between bacterial infection and virus infection(P0.001).There was statistical significance of the levels of PCT and CRP in bacterial infection group between before and after the antibiotic treatment(P0.05).There were statistical significances between serious infection group and local infection group(P0.001,0.05).For the assessment of bacterial infection at cut-off value of PCT0.5 μg/L,the sensitivity was 96.7%(58/60) and the specificity was 85.3%(29/34).For the assessment of bacterial infection at cut-off value of CRP8 mg/L,the sensitivity was 96.7%(58/60) and the specificity was 73.5%(25/34).Conclusions The combined determination of serum PCT and CRP assists the early diagnosis,estimation and prognosis of bacterial infection.Monitoring dynamically PCT level will help to evaluate the curative effect.