title: Procalcitonin and procalcitonin kinetics for diagnosis and prognosis of intravascular catheter-related bloodstream infections in selected critically ill patients: a prospective observational study.
abstract: BACKGROUND
  Procalcitonin (PCT) has emerged as a valuable marker of sepsis. The potential role of PCT in diagnosis and therapy monitoring of intravascular catheter-related bloodstream infections (CRBSI) in intensive care unit (ICU) is still unclear and was evaluated.
  
  
  METHODS
  Forty-six patients were included in the study, provided they were free of infection upon admission and presented the first episode of suspected CRBSI during their ICU stay. Patients who had developed any other infection were excluded. PCT was measured daily during the ICU hospitalization. Primary endpoint was proven CRBSI. Therapy monitoring as according to infection control was also evaluated.
  
  
  RESULTS
  Among the 46 patients, 26 were diagnosed with CRBSI. Median PCT on the day of infection suspicion (D0) was 7.70 and 0.10 ng/ml for patients with and without proven CRBSI, respectively (p < 0.001). The area under the curve (AUC) for PCT was 0.990 (95% CI; 0.972 - 1.000), whereas a cut-off value of 0.70 ng/ml provided sensitivity and specificity of 92.3 and 100% respectively. In contrast, the AUC for white blood cells (WBC) was 0.539 (95% CI; 0.369 - 0.709), and for C-reactive protein (CRP), 0.603 (95% CI; 0.438 - 0.768). PCT was the best predictor of proven infection. Moreover, an increase >0.20 ng/ml of PCT between the D0 and any of the 4 preceding days was associated with a positive predictive value exceeding 96%. PCT concentrations from the D2 to D6 after suspected infection tended to decrease in controlled patients, whereas remained stable in non-controlled subjects. A PCT concentration exceeding 1.5 ng/ml during D3 was associated with lack of responsiveness to therapy (p = 0.028).
  
  
  CONCLUSIONS
  We suggest that PCT could be a helpful diagnostic and prognostic marker of CRBSI in critically ill patients. Both absolute values and variations should be considered.
authors.affiliation: Department of Intensive Care Unit, University Hospital of Alexandroupolis, Dragana 68100, Alexandroupolis, Greece. vassiliki.theodorou@gmail.com
authors.forename: Vasiliki P
authors.initials: VP
authors.lastname: Theodorou
authors.forename: Vasilios E
authors.initials: VE
authors.lastname: Papaioannou
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Tripsianis
authors.forename: Maria K
authors.initials: MK
authors.lastname: Panopoulou
authors.forename: Elias K
authors.initials: EK
authors.lastname: Christophoridis
authors.forename: Georgios A
authors.initials: GA
authors.lastname: Kouliatsis
authors.forename: Theodora M
authors.initials: TM
authors.lastname: Gioka
authors.forename: Efstratios S
authors.initials: ES
authors.lastname: Maltezos
authors.forename: Sophia I
authors.initials: SI
authors.lastname: Ktenidou-Kartali
authors.forename: Ioannis A
authors.initials: IA
authors.lastname: Pneumatikos
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D055499:Catheter-Related Infections / Q000175:diagnosis*; D015331:Cohort Studies; D016638:Critical Illness; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D011498:Protein Precursors / Q000097:blood*; D012680:Sensitivity and Specificity; D018805:Sepsis / Q000175:diagnosis*
chemical_list: C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D015740:Calcitonin Gene-Related Peptide