title: Severe sepsis in the emergency department and its association with a complicated clinical course.
abstract: OBJECTIVE
  Infection severity as determined by clinical criteria has been recently classified and studied in hospitalized inpatients. The objective of the study was to use modified criteria to determine the clinical course associated with three levels of infection severity in infected patients admitted from the ED.
  
  
  METHODS
  This was a retrospective cohort study involving all patients 18 years of age and older admitted through the ED of an urban teaching hospital during a four-month period whose primary reason for requiring hospitalization was an infection that was recognized in the ED. ED records were reviewed for criteria used to classify patients by three levels of infection severity: no systemic inflammatory response syndrome, sepsis, and severe sepsis (SS). The relationships between these classifications as well as certain clinical characteristics and any complicated clinical course as measured by death and/or admission to an intensive care unit (ICU), and/or prolonged hospitalization, were analyzed.
  
  
  RESULTS
  Of 408 patients entered into the study, 138 (33.8%) fulfilled the criteria of SS in the ED. Patients with SS in the ED had a mortality of only 4.3%, though with an increased risk of dying compared with that of the other groups combined [relative risk (RR) = 11.64, 95% confidence interval (CI) = 1.43 to 96.53], an increased risk of ICU stay (RR = 7.65, 95% CI = 4.08 to 14.36), and an increased risk of prolonged hospitalization (RR = 1.99, 95% CI = 1.38 to 2.88). Although age over 60 years and several comorbid conditions also were identified by univariate analysis as risk factors, multivariate analysis revealed that only SS and diabetes mellitus (DM) were independent predictors of a complicated course. In the authors' institution, the positive predictive value (PPV) of SS for complicated clinical course was 0.48 and the negative predictive value (NPV) of no SS for no complicated course was 0.77. The PPV of [SS + DM] was 0.83, and the NPV of [SS, DM, or both] was also 0.83.
  
  
  CONCLUSIONS
  Although the strongest correlate of a complicated clinical course identified in the ED is SS as defined by the study criteria, its specificity and PPV are low. The mortality of ED patients with SS is much lower than the mortality rates reported for inpatients with SS. SS as defined by the study criteria is too sensitive and therefore lacks utility in the ED setting.
authors.affiliation: Department of Emergency Medicine, Hennepin County Medical Center, and the University of Minnesota Medical School, Minneapolis 55415, USA. smith253@tc.umn.edu
authors.forename: S W
authors.initials: SW
authors.lastname: Smith
authors.forename: A
authors.initials: A
authors.lastname: Pheley
authors.forename: R
authors.initials: R
authors.lastname: Collier
authors.forename: A
authors.initials: A
authors.lastname: Rahmatullah
authors.forename: L
authors.initials: L
authors.lastname: Johnson
authors.forename: P K
authors.initials: PK
authors.lastname: Peterson
mesh_terms: D000328:Adult; D000368:Aged; D004636:Emergency Service, Hospital; D005260:Female; D006760:Hospitalization; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D009017:Morbidity; D015999:Multivariate Analysis; D012189:Retrospective Studies; D018805:Sepsis / Q000150:complications / Q000401:mortality / Q000503:physiopathology*; D012720:Severity of Illness Index