Research on the clinical significance of serum procalcitonin in predicting bacteremia

Objective To investigate the relationship of serum procalcitonin( PCT) and bacteremia,and to evaluate the diagnosis significance of serum PCT to predict bacteremia determined by blood cultures. Methods A total of 1 690 patients undergoing blood cultures and PCT were concurrently enrolled for detecting bacteremia by retrospective analysis. The patients were classified into blood culture positive group( 129 cases),blood culture negative group( 1 463cases) and contaminated blood culture group( 98 cases). According to the difference of PCT concentration,the blood culture positive group was subclassified into 3 groups,gram-negative bacterium group,gram-positive bacterium group and Candida mycoderma group. The difference of PCT concentration in the blood culture positive group was further analyzed comparatively. Results The concentration of PCT in blood culture positive group was higher than those of blood culture negative group and contaminated blood culture group [medians( quartiles) were 2. 62( 0. 37-12. 80),0. 17( 0.07-0.62) and 0.20( 0.09-0.72) ng/mL,P 0.000 1]. In gram-negative bacterium group,Candida mycoderma group and gram-positive bacterium group,the positive rates of serum PCT were 74. 5%,37. 5% and 66. 7%,respectively,while the PCT concentrations [medians( quartiles) were 6. 24( 0. 43-16. 09),0. 47( 0. 22-3. 18) and 1.09( 0. 24-4. 05) ng /mL. PCT concentration in gram-negative bacterium group was higher than those in gram-positive bacterium group and Candida mycoderma group( P 0. 05). Conclusions In addition to other clinical parameters,PCT is a reliable parameter for ruling out blood culture contamination and non-bacterial conditions. PCT is effective as a parameter for predicting early bacteremia,and is able to improve the accuracy of diagnosis and avoid the unnecessary antimicrobial usage. PCT has great clinical significance for the clinical diagnosis and treatment.