title: Severe hypoxaemia can predict unfavourable clinical outcomes in individuals with pulmonary embolism aged over 40 years.
abstract: BACKGROUND
  Acute pulmonary embolism (APE) is an urgent clinical condition that can progress in a wide variety of ways. Therefore, we sought to develop an easy-to-apply algorithm, to be based on readily available clinical indicators, effective in predicting unfavourable outcomes.
  
  
  METHODS
  This was a retrospective cohort study based on systematically collected data in a database. The study included 102 patients with APE who were admitted to a tertiary care hospital. The following outcomes were defined as unfavourable: shock, the need for mechanical ventilation, the use of thrombolytics, and death. Logistic regression analysis was used to explore variables significantly associated with outcome and to calculate post-test probabilities.
  
  
  RESULTS
  The prevalence of unfavourable outcomes was 25.5% (26 of the 102 patients with APE). The risk of an unfavourable outcome was reduced to 7.0% for patients with APE who were aged ≤ 40 years. In patients with APE who were aged > 40 years, the presence of hypoxaemia (i.e. peripheral oxygen saturation < 90%) alone increased the risk of an unfavourable outcome to 57.0%. A recent history of trauma and the presence of pre-existing lung or heart disease were significantly associated with unfavourable outcomes. The inclusion of those variables in the logistic regression model increased the post-test risk of an unfavourable outcome to 65.0%-86.0%.
  
  
  CONCLUSIONS
  Advanced age (i.e. > 40 years), the presence of hypoxaemia, a recent history of trauma and the presence of pre-existing lung or heart disease are risk factors for unfavourable outcome in patients with APE.
authors.forename: Caio Simoes
authors.initials: CS
authors.lastname: Souza
authors.forename: Fernanda Simoes Seabra
authors.initials: FS
authors.lastname: Resende
authors.affiliation: SQSW 306, B, 603, Brasília 70673-432, DF, Brazil. pmarcelo27@gmail.com.
authors.forename: Marcelo Palmeira
authors.initials: MP
authors.lastname: Rodrigues
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001938:Brazil; D003625:Data Collection; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000175:diagnosis / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011655:Pulmonary Embolism / Q000175:diagnosis / Q000628:therapy*; D012044:Regression Analysis; D012189:Retrospective Studies; D012306:Risk; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D055815:Young Adult