title: Procalcitonin used as a marker of infection in the intensive care unit.
abstract: OBJECTIVE
  To determine the value of procalcitonin (ProCT) as a marker of infection in critically ill patients.
  
  
  METHODS
  Prospective, observational study.
  
  
  METHODS
  Medicosurgical department of intensive care (31 beds).
  
  
  METHODS
  One hundred eleven infected and 79 noninfected patients.
  
  
  METHODS
  None.
  
  
  RESULTS
  ProCT and C-reactive protein (CRP) concentrations were monitored daily. The best cutoff values for ProCT and CRP were 0.6 ng/mL and 7.9 mg/dL, respectively. Compared with CRP, ProCT had a lower sensitivity (67.6 vs. 71.8), specificity (61.3 vs. 66.6), and area under the receiver operating characteristic curve (0.66 vs. 0.78, p < .05). The combination of ProCT and CRP increased the specificity for infection to 82.3%. In the infected patients, plasma ProCT, but not CRP, values were higher in nonsurvivors than in survivors. Infected patients with bacteremia had higher ProCT concentrations than those without bacteremia, but similar CRP concentrations. ProCT levels were particularly high in septic shock patients.
  
  
  CONCLUSIONS
  ProCT is not a better marker of infection than CRP in critically ill patients, but it can represent a useful adjunctive parameter to identify infection and is a useful marker of the severity of infection.
authors: Department of Intensive Care, Erasme University Hospital, Free University of Brussels, Belgium.
authors: H
authors: H
authors: Ugarte
authors: E
authors: E
authors: Silva
authors: D
authors: D
authors: Mercan
authors: A
authors: A
authors: De Mendonça
authors: J L
authors: JL
authors: Vincent
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism*; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D002648:Child; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007362:Intensive Care Units; D007902:Length of Stay; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D011498:Protein Precursors / Q000097:blood*; D012680:Sensitivity and Specificity; D018805:Sepsis / Q000097:blood / Q000145:classification / Q000175:diagnosis*; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D002097:C-Reactive Protein; D015740:Calcitonin Gene-Related Peptide