Clinical value of procalcitonin for suspected nosocomial bloodstream infection

• Published in: The Korean journal of internal medicine 2018, 33(1), , pp.176-184
• Main Authors: Cha, Joo Kyoung, Kwon, Ki Hwan, Byun, Seung Joo, Ryoo, Soo Ryeong, Lee, Jeong Hyeon, Chung, Jae-Woo, Huh, Hee Jin, Chae, Seok Lae, Park, Seong Yeon
• Format: Article
• Language: English
• Subjects: Adult; Area Under Curve; Bacteremia - blood; Bacteremia - diagnosis; Biomarkers - blood; C-Reactive Protein - analysis; Cross Infection - blood; Cross Infection - diagnosis; Diagnosis, Differential; Humans; Male; Original; Procalcitonin - blood; Republic of Korea; Retrospective Studies; Sensitivity and Specificity; 내과학
• ISSN: 1226-3303; 2005-6648
• DOI: 10.3904/kjim.2016.119

Procalcitonin (PCT) may prove to be a useful marker to exclude or predict bloodstream infection (BSI). However, the ability of PCT levels to differentiate BSI from non-BSI episodes has not been evaluated in nosocomial BSI. We retrospectively reviewed the medical records of patients ≥ 18 years of age with suspected BSI that developed more than 48 hours after admission. Of the 785 included patients, 105 (13.4%) had BSI episodes and 680 (86.6%) had non-BSI episodes. The median serum PCT level was elevated in patients with BSI as compared with those without BSI (0.65 ng/mL vs. 0.22 ng/mL, = 0.001). The optimal PCT cut-off value of BSI was 0.27 ng/mL, with a corresponding sensitivity of 74.6% (95% confidence interval [CI], 66.4% to 81.7%) and a specificity of 56.5% (95% CI, 52.7% to 60.2%). The area under curve of PCT (0.692) was significantly larger than that of C-reactive protein (CRP; 0.526) or white blood cell (WBC) count (0.518). However, at the optimal cut-off value, PCT failed to predict BSI in 28 of 105 cases (26.7%). The PCT level was significantly higher in patients with an eGFR < 60 mL/min/1.73 m than in those with an eGFR ≥ 60 mL/min/1.73 m (0.68 vs. 0.17, = 0.01). PCT was more useful for predicting nosocomial BSI than CRP or WBC count. However, the diagnostic accuracy of predicting BSI remains inadequate. Thus, PCT is not recommended as a single diagnostic tool to avoid taking blood cultures in the nosocomial setting.