Significance of serum procalcitonin levels in patients with different bacterial infections

Objective To investigate the changes in serum procalcitonin(PCT) levels in patients with different bacterial infections and to evaluate the significance of PCT levels for differentiating gram-positive and gram-negative bacterial infection.Methods Two hundren and sixty-six intensive care unit(ICU) patients infected with severe bacterial infections were divided into 2 groups(gram-positive bacteria group and gram-negative bacteria group) according to the bacterial culture results,and serum PCT,C-reaction protein(CRP),white blood celKWBC) and neutrophil ratio(Neu%) were detected,and data of two groups were analysed statiscally.Results Serum levels of PCT in patients with severe bacterial infection significantly rose.When defined by the value of PCT≥2 ng/mL as positive, the positive rate of PCT in gram-negative bacteria group(92.36%) was significantly higher than that of gram-positive bacteria group(76.23%)(x~2 = 13.45,P0.001);When the value of PCT≥10 ng/mL,the possibility of gram-negative bacterial infection was great.The routine infection markers,including CRP,WBC and Neu%,were not significantly different between gram-positive bacteria group and gram-negative bacteria group(both P0.05). Conclusion PCT levels can be used as indicator for differentiating gram-positive and gram-negative bacterial infection, and may provide valuable information for sensitive antimicrobial selection.