title: The value of serum procalcitonin level for differentiation of infectious from noninfectious causes of fever after orthopaedic surgery.
abstract: BACKGROUND
  Early diagnosis of postoperative orthopaedic infections is important in order to rapidly initiate adequate antimicrobial therapy. There are currently no reliable diagnostic markers to differentiate infectious from noninfectious causes of postoperative fever. We investigated the value of the serum procalcitonin level in febrile patients after orthopaedic surgery.
  
  
  METHODS
  We prospectively evaluated 103 consecutive patients with new onset of fever within ten days after orthopaedic surgery. Fever episodes were classified by two independent investigators who were blinded to procalcitonin results as infectious or noninfectious origin. White blood-cell count, C-reactive protein level, and procalcitonin level were assessed on days 0, 1, and 3 of the postoperative fever.
  
  
  RESULTS
  Infection was diagnosed in forty-five (44%) of 103 patients and involved the respiratory tract (eighteen patients), urinary tract (eighteen), joints (four), surgical site (two), bloodstream (two), and soft tissues (one). Unlike C-reactive protein levels and white blood-cell counts, procalcitonin values were significantly higher in patients with infection compared with patients without infection on the day of fever onset (p = 0.04), day 1 (p = 0.07), and day 3 (p = 0.003). Receiver-operating characteristics demonstrated that procalcitonin had the highest diagnostic accuracy, with a value of 0.62, 0.62, and 0.71 on days 0, 1, and 3, respectively. In a multivariate logistic regression analysis, procalcitonin was a significant predictor for postoperative infection on days 0, 1, and 3 of fever with an odds ratio of 2.3 (95% confidence interval, 1.1 to 4.4), 2.3 (95% confidence interval, 1.1 to 5.2), and 3.3 (95% confidence interval, 1.2 to 9.0), respectively.
  
  
  CONCLUSIONS
  Serum procalcitonin is a helpful diagnostic marker supporting clinical and microbiological findings for more reliable differentiation of infectious from noninfectious causes of fever after orthopaedic surgery.
authors.affiliation: Department of Internal Medicine, University Hospital Basel, Petersgraben 4, CH-4031 Basel, Switzerland.
authors.forename: Sabina
authors.initials: S
authors.lastname: Hunziker
authors.forename: Thomas
authors.initials: T
authors.lastname: Hügle
authors.forename: Katrin
authors.initials: K
authors.lastname: Schuchardt
authors.forename: Isabelle
authors.initials: I
authors.lastname: Groeschl
authors.forename: Philipp
authors.initials: P
authors.lastname: Schuetz
authors.forename: Beat
authors.initials: B
authors.lastname: Mueller
authors.forename: Walter
authors.initials: W
authors.lastname: Dick
authors.forename: Urs
authors.initials: U
authors.lastname: Eriksson
authors.forename: Andrej
authors.initials: A
authors.lastname: Trampuz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D005260:Female; D005334:Fever / Q000097:blood* / Q000209:etiology; D006801:Humans; D007239:Infections / Q000097:blood* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000009:adverse effects*; D011237:Predictive Value of Tests; D011498:Protein Precursors / Q000097:blood*; D055815:Young Adult
chemical_list: D015415:Biomarkers; C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D015740:Calcitonin Gene-Related Peptide