Prognostic value of procalcitonin in blood stream infections in the intensive care unit patients

The aim of this study is to determine the effectiveness of procalcitonin (PCT) in predicting bloodstream infection (BSI), to identify risk factors for the development of BSI and to investigate the causes of mortality. Our study was designed as a retrospective case-control study, which was consisted of 164 patients who were hospitalized in the Anesthesia and Reanimation Intensive Care (ICU) of our hospital over a three-year period. PCT culture day values were higher in the case group than the control group and were found to be effective in detecting BSI, while C-Reactive Protein (CRP) culture day values were not found significant. Similarly, PCT culture day value was found to be effective in predicting pathogen classes, while CRP culture day value did not differ. However, it was observed that the culture day values of PCT and CRP were correlated in detecting culture positivity and defining the pathogen classes. The strongest correlation was seen in multipathogen BSI, and BSI due to Gram-negative and fungal agents were observed, respectively. It was seen that there was no correlation between PCT and CRP in detecting BSI caused by Gram-positive pathogens. The PCT culture day value compared with 0.353 ng/dL threshold value. When evaluated in the ROC analysis to predict Gram-negative bacteremia, the area under the curve is 0.653 (P=0.002), the sensitivity is 80.3%, the specificity is 51.2%, and the positive predictive value is 50.6% and the negative predictive value was 80.8%. In the analysis, no significant threshold value was found related to other pathogens. PCT culture day values had a statistically significant difference in terms of clinical outcome (P=0.002) and predicting 28-day mortality (P=0.049). Backward Stepwise (Wald) logistic regression analysis revealed that the risk factors were only hypoalbuminemia (OR:2,4, P=0.015) in the development of BSI; oncologic (OR:5.3, P=0.016), GIS disease (OR:51.3, P=0.003) diagnosis, intubation (OR:30,4, P<0.001), central venous catheter (OR :5, P=0.001 presence for the clinical outcome status and the presence of intubation (OR:2.4, P=0.015) for the development of 28-day mortality. Key Words: Bloodstream infection, Procalcitonin, Risk factors