title: Microbial diagnostics in patients with presumed severe infection in the emergency department.
abstract: BACKGROUND
  Sepsis in the early stage is a common disease in emergency medicine, and rapid diagnosis is essential. Our aim was to compare pathogen diagnosis using blood cultures (BC) and the multiplex polymerase chain reaction (PCR) test.Methods. At total of 211 patients admitted to the multidisciplinary emergency department of our university hospital between 2006 and 2009 with suspected severe infection from any origin were studied. Blood samples for BC (aerobic and anaerobic) and multiplex PCR were taken for identification of infectious microorganisms immediately after hospital admission. Results of the BC and PCR correlated with procalcitonin concentration (PCT) and clinical diagnosis of sepsis (≥2 positive SIRS criteria) as well as with severity of disease at admission and with clinical outcome measures.
  
  
  RESULTS
  Results of the BC were available in 200 patients (94.8%) and PCR were available in 119 patients (56.3%), respectively. In total, 87 BC (43.5%) were positive and identified 94 pathogens. In 45 positive PCRs, 47 pathogens (37.8%) were found. Identical results were obtained in 81.4%. In addition, BC identified 9 Gram-positive and 3 Gram-negative bacteria, while PCR added 5 Gram-negative pathogens. Coagulase-negative staphylococci were detected in blood cultures only (n=20, 21.3%), whereas PCR identified significantly more Gram-negative bacteria than BC. In patients with positive PCR results, the PCT level was significantly higher than in patients with negative PCR (15.0±23.3 vs. 8.8±32.8 ng/ml, p<0.001). This difference was not observed for BC (10.6±25.7 vs. 11.6±44.9 ng/ml, p=0.075). The APACHE II score correlated with PCR (19.2±9.1 vs. 15.8±8.9, p<0.05) and was also higher in positive BC (18.7±8.7 vs. 14.4±8.0, p<0.01). Positive PCR and BC were correlated with negative clinical outcomes (e.g., transfer to ICU, mechanical ventilation, renal replacement therapy, death).
  
  
  CONCLUSIONS
  In patients admitted with suspected severe infection, a high percentage of positive BC and PCR were observed. Positive findings in the PCR correlate with elevated levels of PCT and high APACHE II scores.
authors.affiliation: Department of Medicine III (Cardiology, Angiology and Medical Intensive Care Medicine), University Clinics Halle Ernst-Grube-Str. 40, 06097 Halle (Saale). stefan.hettwer@medizin.uni-halle.de
authors.forename: S
authors.initials: S
authors.lastname: Hettwer
authors.forename: J
authors.initials: J
authors.lastname: Wilhelm
authors.forename: M
authors.initials: M
authors.lastname: Schürmann
authors.forename: H
authors.initials: H
authors.lastname: Ebelt
authors.forename: D
authors.initials: D
authors.lastname: Hammer
authors.forename: M
authors.initials: M
authors.lastname: Amoury
authors.forename: F
authors.initials: F
authors.lastname: Hofmann
authors.forename: A
authors.initials: A
authors.lastname: Oehme
authors.forename: D
authors.initials: D
authors.lastname: Wilhelms
authors.forename: A S
authors.initials: AS
authors.lastname: Kekulé
authors.forename: T
authors.initials: T
authors.lastname: Klöss
authors.forename: K
authors.initials: K
authors.lastname: Werdan
mesh_terms: D000328:Adult; D000368:Aged; D001424:Bacterial Infections / Q000175:diagnosis* / Q000382:microbiology; D001431:Bacteriological Techniques; D001769:Blood / Q000382:microbiology; D002116:Calcitonin / Q000097:blood; D015740:Calcitonin Gene-Related Peptide; D003299:Cooperative Behavior; D003470:Culture Media; D042241:Early Diagnosis; D004636:Emergency Service, Hospital; D005260:Female; D016905:Gram-Negative Bacterial Infections / Q000175:diagnosis / Q000382:microbiology; D016908:Gram-Positive Bacterial Infections / Q000175:diagnosis / Q000382:microbiology; D006801:Humans; D033183:Interdisciplinary Communication; D008297:Male; D008875:Middle Aged; D060885:Multiplex Polymerase Chain Reaction; D009181:Mycoses / Q000175:diagnosis / Q000382:microbiology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011498:Protein Precursors / Q000097:blood; D018805:Sepsis / Q000175:diagnosis* / Q000382:microbiology; D012895:Sleep, REM; D013203:Staphylococcal Infections / Q000175:diagnosis / Q000382:microbiology
chemical_list: C000606589:CALCA protein, human; D003470:Culture Media; D011498:Protein Precursors; D002116:Calcitonin; D015740:Calcitonin Gene-Related Peptide