Measuring both procalcitonin and C-reactive protein for a diagnosis of sepsis in critically ill patients.
BACKGROUND
The usefulness of procalcitonin (PCT) and C-reactive protein (CRP) as individual biomarkers, and in combination, for the identification of infections in a critically ill patient cohort was evaluated retrospectively.


METHODS
Best cut-off values for PCT and CRP for a diagnosis of sepsis in critically ill patients were determined using receiver operator characteristic (ROC) curve analysis. Both combined tests and individual tests were performed for PCT and CRP, with positive and negative results recorded, and accuracy evaluated using odds ratios (OR).


RESULTS
In the 55 critically ill patients studied, the best cut-off value for PCT for a diagnosis of sepsis was 1.1 ng/ml (sensitivity, specificity and negative predictive values [NPV] were 82%, 68% and 71%, respectively). In addition, the best cut-off value for CRP was 50.7 mg/l ( sensitivity, specificity and NPV of 90%, 68% and 83%, respectively). Measuring PCT and CRP in combination provided a sensitivity of 79%, a specificity of 86%, and a positive predictive value (PPV) of 90%. Diagnostic OR for the combination of biomarkers versus CRP alone (19 and 18, respectively) were greater than that for PCT (9).


CONCLUSIONS
For critically ill patients, CRP and CRP in combination with PCT were found to be suitable biomarkers for diagnosing sepsis, based on their NPV and PPV.
Intensive Care Unit, The First Hospital of Jilin University, Changchun, China.
Hong-Xiang
HX
Li
Intensive Care Unit, The First Hospital of Jilin University, Changchun, China.
Zhong-Min
ZM
Liu
Intensive Care Unit, The First Hospital of Jilin University, Changchun, China.
Shu-Jie
SJ
Zhao
Intensive Care Unit, The First Hospital of Jilin University, Changchun, China.
Dong
D
Zhang
Intensive Care Unit, The First Hospital of Jilin University, Changchun, China.
Shi-Ji
SJ
Wang
Intensive Care Unit, The First Hospital of Jilin University, Changchun, China wang_yushan2010@163.com.
Yu-Shan
YS
Wang
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism*; D002116:Calcitonin / Q000097:blood*; D016638:Critical Illness; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D018805:Sepsis / Q000097:blood / Q000175:diagnosis*
D015415:Biomarkers; D002116:Calcitonin; D002097:C-Reactive Protein
Biomarker; C-reactive protein; NPV; PPV; combination; procalcitonin; sensitivity; sepsis; specificity