title: Primary bacteraemia is associated with a higher mortality risk compared with pulmonary and intra-abdominal infections in patients with sepsis: a prospective observational cohort study.
abstract: OBJECTIVE
  To investigate whether common infection foci (pulmonary, intra-abdominal and primary bacteraemia) are associated with variations in mortality risk in patients with sepsis.
  
  
  METHODS
  Prospective, observational cohort study.
  
  
  METHODS
  Three surgical intensive care units (ICUs) at a university medical centre.
  
  
  METHODS
  A total of 327 adult Caucasian patients with sepsis originating from pulmonary, intra-abdominal and primary bacteraemia participated in this study.
  
  
  METHODS
  The patients were followed for 90 days and mortality risk was recorded as the primary outcome variable. To monitor organ failure, sepsis-related organ failure assessment (Sequential Organ Failure Assessment, SOFA) scores were evaluated at the onset of sepsis and throughout the observational period as secondary outcome variables.
  
  
  RESULTS
  A total of 327 critically ill patients with sepsis were enrolled in this study. Kaplan-Meier survival analysis showed that the 90-day mortality risk was significantly higher among patients with primary bacteraemia than among those with pulmonary and intra-abdominal foci (58%, 35% and 32%, respectively; p=0.0208). To exclude the effects of several baseline variables, we performed multivariate Cox regression analysis. Primary bacteraemia remained a significant covariate for mortality in the multivariate analysis (HR 2.10; 95% CI 1.14 to 3.86; p=0.0166). During their stay in the ICU, the patients with primary bacteraemia presented significantly higher SOFA scores than those of the patients with pulmonary and intra-abdominal infection foci (8.5±4.7, 7.3±3.4 and 5.8±3.5, respectively). Patients with primary bacteraemia presented higher SOFA-renal score compared with the patients with other infection foci (1.6±1.4, 0.8±1.1 and 0.7±1.0, respectively); the patients with primary bacteraemia required significantly more renal replacement therapy than the patients in the other groups (29%, 11% and 12%, respectively).
  
  
  CONCLUSIONS
  These results indicate that patients with sepsis with primary bacteraemia present a higher mortality risk compared with patients with sepsis of pulmonary or intra-abdominal origins. These results should be assessed in patients with sepsis in larger, independent cohorts.
authors.affiliation: Department of Anesthesiology, University Medical Center, Georg August University, Goettingen, Niedersachsen, Germany.
authors.forename: Ashham
authors.initials: A
authors.lastname: Mansur
authors.affiliation: Department of Anesthesiology, University Medical Center, Georg August University, Goettingen, Niedersachsen, Germany.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Klee
authors.affiliation: Department of Cardiothoracic Transplantation & Mechanical Support, Royal Brompton and Harefield Hospital, Harefield, London, UK.
authors.forename: Aron Frederik
authors.initials: AF
authors.lastname: Popov
authors.affiliation: Department of Anesthesiology, University Medical Center, Georg August University, Goettingen, Niedersachsen, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Erlenwein
authors.affiliation: Department of General and Visceral Surgery, University Medical Center, Georg August University, Goettingen, Niedersachsen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Ghadimi
authors.affiliation: Department of Medical Statistics, University Medical Center, Georg August University, Goettingen, Niedersachsen, Germany.
authors.forename: Tim
authors.initials: T
authors.lastname: Beissbarth
authors.affiliation: Department of Anesthesiology, University Medical Center, Georg August University, Goettingen, Niedersachsen, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Bauer
authors.affiliation: Department of Anesthesiology, University Medical Center, Georg August University, Goettingen, Niedersachsen, Germany.
authors.forename: José
authors.initials: J
authors.lastname: Hinz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016470:Bacteremia / Q000401:mortality*; D015331:Cohort Studies; D016638:Critical Illness; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D059413:Intraabdominal Infections / Q000401:mortality*; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009102:Multiple Organ Failure; D011446:Prospective Studies; D012141:Respiratory Tract Infections / Q000401:mortality*; D012306:Risk; D018805:Sepsis / Q000401:mortality; D055815:Young Adult