title: Emergency department hypotension predicts sudden unexpected in-hospital mortality: a prospective cohort study.
abstract: OBJECTIVE
  The prevalence and prognostic significance of nontraumatic hypotension measured in the emergency department (ED) have not been studied. We hypothesized that ED hypotension confers risk of in-hospital mortality.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Large urban ED with 115,000 visits per year.
  
  
  METHODS
  Nontrauma ED patients aged > 17 years admitted to the hospital were prospectively identified on a random sample of 24-h blocks during 2004 to 2005. "Exposures" had any systolic BP (SBP) < 100 mm Hg in the ED; "nonexposures" all had SBP >/= 100 mm Hg in the ED. Deaths were classified as sudden and unexpected by independent observers using explicit criteria.
  
  
  METHODS
  Mortality rates were compared with confidence intervals (CIs), Kaplan-Meier survival curves, and multivariate logistic regression.
  
  
  RESULTS
  A total of 4,790 patients were enrolled during the study period, with 887 patients (19%) in the exposure group. Exposures were more likely to die in the hospital compared with nonexposures (8% vs 3%; 95% CI for difference of 5%, 4 to 8%). Exposures were more likely to have sudden and unexpected death compared with nonexposures (2% vs 0.2%, 95% CI for difference of 1.8%, 1 to 3%). Kaplan-Meier estimates showed increased mortality in the exposure group at all time points (log-rank test, p < 0.001). Multivariate logistic regression revealed exposure to hypotension as an independent predictor of in-hospital mortality (odds ratio, 2.0; 95% CI, 1.3 to 2.8).
  
  
  CONCLUSIONS
  Nontraumatic hypotension was documented in 19% of a random sample of ED patients admitted to the hospital. Patients exposed to hypotension had a significantly increased risk of death during hospitalization.
authors.affiliation: Department of Emergency Medicine, 1000 Blythe Blvd, MEB 304D, Carolinas Medical Center, Charlotte, NC 28203, USA.
authors.forename: Alan E
authors.initials: AE
authors.lastname: Jones
authors.forename: Vasilios
authors.initials: V
authors.lastname: Yiannibas
authors.forename: Charles
authors.initials: C
authors.lastname: Johnson
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Kline
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure / Q000502:physiology; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003645:Death, Sudden / Q000453:epidemiology* / Q000209:etiology; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D017052:Hospital Mortality; D006786:Hospitals, Urban / Q000706:statistics & numerical data; D006801:Humans; D007022:Hypotension / Q000209:etiology / Q000401:mortality* / Q000503:physiopathology; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009657:North Carolina; D016017:Odds Ratio; D011446:Prospective Studies; D012306:Risk; D016019:Survival Analysis; D013599:Systole / Q000502:physiology