title: Blood cultures and bacteraemia in an Australian emergency department: Evaluating a predictive rule to guide collection and their clinical impact.
abstract: OBJECTIVE
  The objective of the present study is to determine whether a predictive rule could safely reduce the number of negative blood cultures collected in an Australian ED and to assess the clinical impact of positive results from blood cultures taken in the ED.
  
  
  METHODS
  All positive blood cultures taken in the ED at a single facility were retrospectively identified for the calendar year 2012. Clinically significant bacteraemia episodes were assessed against a predictive rule using major and minor clinical and laboratory criteria gathered from medical records and pathology databases, and compared with a randomly generated sample of ED patient episode with negative blood cultures. The ED and final diagnoses and blood culture impact on clinical management were also collected.
  
  
  RESULTS
  The predictive rule has a high sensitivity (98.8%) and modest specificity (48.7%), and if applied stringently would have prevented almost half of all blood cultures in our ED but missed two positives. Blood cultures altered the clinical management of 94.3% bacteraemic patients, representing 3.4% of all ED patients with blood cultures performed. High discordance (54%) between ED diagnosis and discharge diagnosis of bacteraemic patients was noted.
  
  
  CONCLUSIONS
  Bacteraemia detected in the ED alters subsequent patient management. The predictive rule can be safely applied in the ED to determine need for blood culture collection. Blood cultures should not be omitted in the ED based entirely on preliminary diagnosis given the high discordance seen between ED and discharge diagnosis.
authors.affiliation: Institute for Clinical Pathology and Medical Research, Centre for Infectious Diseases and Microbiology, Westmead Hospital, Sydney, New South Wales, Australia.|Department of Infectious Diseases, Blacktown Mount Druitt Hospital, Sydney, New South Wales, Australia.
authors.forename: Jeremy D
authors.initials: JD
authors.lastname: Brown
authors.affiliation: Department of Infectious Diseases, Blacktown Mount Druitt Hospital, Sydney, New South Wales, Australia.|Department of Medicine, Western Sydney University, Sydney, New South Wales, Australia.
authors.forename: Scott
authors.initials: S
authors.lastname: Chapman
authors.affiliation: Department of Infectious Diseases, Blacktown Mount Druitt Hospital, Sydney, New South Wales, Australia.|Marie Bashir Institute, Emerging Infections and Biosecurity, The University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Patricia E
authors.initials: PE
authors.lastname: Ferguson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use; D016470:Bacteremia / Q000175:diagnosis*; D000071997:Blood Culture / Q000379:methods / Q000592:standards*; D003661:Decision Support Techniques; D004636:Emergency Service, Hospital / Q000458:organization & administration / Q000706:statistics & numerical data; D005260:Female; D017408:Guidelines as Topic / Q000592:standards*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009517:New South Wales; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D000900:Anti-Bacterial Agents
keywords: bacteraemia; blood culture; emergency department; prediction