title: Diagnostic value of an initial C-reactive protein level in acute surgical patients.
abstract: BACKGROUND
  In surgical patients, C-reactive protein (CRP) levels are often measured as a marker of inflammation and infection. However, the diagnostic and prognostic value of a single initial CRP measurement in the acute presentation has not been well established. This study was performed to investigate the usefulness of measuring CRP in such a setting.
  
  
  METHODS
  CRP levels were measured retrospectively in 473 surgical patients who presented to the Royal Adelaide Hospital emergency department. This was correlated with patient outcomes, defined by the need for imaging tests and/or surgical interventions, the length of hospital stay and 30-day mortality. Spearman's rank correlation and one-way analysis of variance were used for statistical analysis.
  
  
  RESULTS
  Of 473 patients, 42% had a CRP test in the emergency department within 24 h of admission. Approximately 80% of patients required imaging for diagnosis and 40% required surgery, regardless of the initial CRP level. No correlation was evident between initial CRP level and length of hospital stay (r= 0.06). One-way analysis of variance revealed no variation in levels between patients who required imaging or had surgery compared to those who did not, with P-values of 0.76 and 0.85, respectively. Two patients died within 30 days of presentation.
  
  
  CONCLUSIONS
  CRP has poor diagnostic and prognostic capabilities as a single initial measurement in acute surgical patients. The statistical analyses imply that CRP levels are unable to accurately predict outcomes of such patients. Therefore, we suggest that CRP should not be used as a routine screening tool.
authors.affiliation: University of Adelaide, South Australia, Australia. keithywong@gmail.com
authors.forename: Keith
authors.initials: K
authors.lastname: Wong
authors.forename: Yasin
authors.initials: Y
authors.lastname: Shahab
authors.forename: P Grantley
authors.initials: PG
authors.lastname: Gill
mesh_terms: D000208:Acute Disease / Q000401:mortality / Q000628:therapy; D015415:Biomarkers / Q000378:metabolism; D002097:C-Reactive Protein / Q000378:metabolism*; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data; D010865:Pilot Projects; D011300:Preoperative Care / Q000379:methods*; D011379:Prognosis; D012189:Retrospective Studies; D013514:Surgical Procedures, Operative / Q000401:mortality
chemical_list: D015415:Biomarkers; D002097:C-Reactive Protein