title: A composite score combining procalcitonin, C-reactive protein and temperature has a high positive predictive value for the diagnosis of intensive care-acquired infections.
abstract: BACKGROUND
  Nosocomial infection diagnosis in the intensive care unit (ICU) remains a challenge. We compared routine measurements of procalcitonin (PCT), C-reactive protein (CRP), white blood cell count (WBC) and temperature in the detection of ICU-acquired infections.
  
  
  METHODS
  Prospective observational cohort study in a University hospital Medicosurgical ICU. All patients admitted to the ICU ≥ 5 days (n = 141) were included into two groups, either infected (documented infection, n = 25) or non-infected (discharged from the ICU without diagnosis of infection, n = 88).
  
  
  RESULTS
  PCT, CRP, WBC and temperature progression from day -4 (D-4) to day 0 (D0) (day of infection diagnosis or ICU discharge) was analysed. Differences (Δ) were calculated as D0 levels minus the lowest preceding value. D0 PCT and CRP were significantly increased in infected compared to non-infected patients (median, 1st and 3rd quartiles): 3.6 ng/mL (0.92-25) for PCT, 173 mg/L (126-188) for CRP versus 0.02 ng/mL (0.1-0.9) and 57 mg/mL (31-105) respectively (p < 0.0001). In multivariate analysis, D0 temperature > 38.6°C, PCT > 1.86 ng/mL, and CRP > 88 mg/L, performed well (AUCs of 0.88, 0.84, and 0.88 respectively). The sensitivity/specificity profiles of each marker (76%/94% for temperature, 68%/91% for PCT, and 92%/70% for CRP) led to a composite score (0.068 × D0 PCT + 0.005 × D0 CRP + 0.7 × temperature) more highly specific than each component (AUC of 0.90 and sensitivity/specificity of 80%/97%).
  
  
  CONCLUSIONS
  Combining CRP, PCT and temperature is an approach which may increase of nosocomial infection detection in the ICU.
authors.forename: Laurent
authors.initials: L
authors.lastname: Robriquet
authors.forename: Caroline
authors.initials: C
authors.lastname: Séjourné
authors.forename: Eric
authors.initials: E
authors.lastname: Kipnis
authors.forename: Michele
authors.initials: M
authors.lastname: D'Herbomez
authors.forename: François
authors.initials: F
authors.lastname: Fourrier
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D001831:Body Temperature; D002097:C-Reactive Protein / Q000378:metabolism*; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D003428:Cross Infection / Q000097:blood / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011498:Protein Precursors / Q000097:blood*; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers; C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D002097:C-Reactive Protein; D015740:Calcitonin Gene-Related Peptide
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