title: Abnormal vital signs are associated with an increased risk for critical events in US veteran inpatients.
abstract: OBJECTIVE
  Establish the frequency of abnormal vital signs in medical and surgical ward patients; study their association with "critical events," which for the purposes of this study, were mortality, cardiac arrests and unplanned ICU transfers.
  
  
  METHODS
  Four-month prospective, observational cohort study; University-affiliated US Veteran's hospital. Vital signs from all regular ward medical and surgical inpatients were recorded over the study period and compared with records of cardiac arrests, mortality and ICU admissions.
  
  
  RESULTS
  Using the Hospital's Medical Emergency Team criteria to define normal/abnormal thresholds for vital signs, abnormal vital signs (VS(MET)) were found in 16% of patients; of these; 35% experienced a critical event vs. 2.5% in the patients with normal vital signs (OR 21, 95% CI 12-35, p<0.001). The sensitivity of VS(MET) to predict a critical event was 0.72 and the positive predictive value was 0.35; sensitivity decreased to 0.28 and positive predictive value increased to 0.78 for patients that had two different VS(MET). Survival was significantly lower in both medical and surgical patients with VS(MET) at both 30 days and at 1 year following discharge (p<0.02). Both medical and surgical patients with VS(MET) had twice the length of stay of patients with normal vitals (3 vs. 7 days; p<0.001).
  
  
  CONCLUSIONS
  Even single recordings of VS(MET) signaled increased risk for critical events in hospital ward patients. Use of vital signs as criteria for additional patient assessment and possible ICU admission appears justified. Development of abnormal vitals during hospitalization may signify impaired physiologic reserve that places a patient at higher risk for mortality after discharge.
authors.affiliation: Department of Anesthesia, Stanford University School of Medicine, Stanford, CA 94305, USA. geoffL@stanford.edu
authors.forename: Geoffrey K
authors.initials: GK
authors.lastname: Lighthall
authors.forename: Sharmin
authors.initials: S
authors.lastname: Markar
authors.forename: Robert
authors.initials: R
authors.lastname: Hsiung
mesh_terms: D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006323:Heart Arrest / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology*; D017052:Hospital Mortality; D006787:Hospitals, Veterans; D006801:Humans; D007297:Inpatients; D007362:Intensive Care Units; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012680:Sensitivity and Specificity; D014481:United States / Q000453:epidemiology; D014728:Veterans; D055986:Vital Signs