title: Procalcitonin does discriminate between sepsis and systemic inflammatory response syndrome.
abstract: OBJECTIVE
  To evaluate whether procalcitonin (PCT) and C reactive protein (CRP) are able to discriminate between sepsis and systemic inflammatory response syndrome (SIRS) in critically ill children.
  
  
  METHODS
  Prospective, observational study in a paediatric intensive care unit. Kinetics of PCT and CRP were studied in patients undergoing open heart surgery with cardiopulmonary bypass (CPB) (SIRS model; group I1) and patients with confirmed bacterial sepsis (group II).
  
  
  RESULTS
  In group I, PCT median concentration was 0.24 ng/ml (reference value <2.0 ng/ml). There was an increment of PCT concentrations which peaked immediately after CPB (median 0.58 ng/ml), then decreased to 0.47 ng/ml at 24 h; 0.33 ng/ml at 48 h, and 0.22 ng/ml at 72 h. CRP median concentrations remained high on POD1 (36.6 mg/l) and POD2 (13.0 mg/l). In group II, PCT concentrations were high at admission (median 9.15 ng/ml) and subsequently decreased in 11/14 patients who progressed favourably (median 0.31 ng/ml). CRP levels were high in only 11/14 patients at admission. CRP remained high in 13/14 patients at 24 h; in 12/14 at 48 h; and in 10/14 patients at 72 h. Median values were 95.0, 50.9, 86.0, and 20.3 mg/l, respectively. The area under the ROC curve was 0.99 for PCT and 0.54 for CRP. Cut off concentrations to differentiate SIRS from sepsis were >2 ng/ml for PCT and >79 mg/l for CRP.
  
  
  CONCLUSIONS
  PCT is able to differentiate between SIRS and sepsis while CRP is not. Moreover, unlike CRP, PCT concentrations varied with the evolution of sepsis.
authors.affiliation: Laboratory of Medical Investigation-LIM/36-Department of Pediatrics, School of Medicine, University of São Paulo, Brazil.
authors.forename: R
authors.initials: R
authors.lastname: Arkader
authors.forename: E J
authors.initials: EJ
authors.lastname: Troster
authors.forename: M R
authors.initials: MR
authors.lastname: Lopes
authors.forename: R R
authors.initials: RR
authors.lastname: Júnior
authors.forename: J A
authors.initials: JA
authors.lastname: Carcillo
authors.forename: C
authors.initials: C
authors.lastname: Leone
authors.forename: T S
authors.initials: TS
authors.lastname: Okay
mesh_terms: D000293:Adolescent; D001424:Bacterial Infections / Q000175:diagnosis*; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis* / Q000378:metabolism; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D002315:Cardiopulmonary Bypass; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D006330:Heart Defects, Congenital / Q000601:surgery; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011183:Postoperative Complications / Q000175:diagnosis*; D011446:Prospective Studies; D011498:Protein Precursors / Q000097:blood*; D018805:Sepsis / Q000175:diagnosis*; D018746:Systemic Inflammatory Response Syndrome / Q000175:diagnosis*
chemical_list: D015415:Biomarkers; C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D002097:C-Reactive Protein; D015740:Calcitonin Gene-Related Peptide