title: Clinical characteristics of patients with acute pulmonary embolism: data from PIOPED II.
abstract: BACKGROUND
  Selection of patients for diagnostic tests for acute pulmonary embolism requires recognition of the possibility of pulmonary embolism on the basis of the clinical characteristics. Patients in the Prospective Investigation of Pulmonary Embolism Diagnosis II had a broad spectrum of severity, which permits an evaluation of the subtle characteristics of mild pulmonary embolism and the characteristics of severe pulmonary embolism.
  
  
  METHODS
  Data are from the national collaborative study, Prospective Investigation of Pulmonary Embolism Diagnosis II.
  
  
  RESULTS
  There may be dyspnea only on exertion. The onset of dyspnea is usually, but not always, rapid. Orthopnea may occur. In patients with pulmonary embolism in the main or lobar pulmonary arteries, dyspnea or tachypnea occurred in 92%, but the largest pulmonary embolism was in the segmental pulmonary arteries in only 65%. In general, signs and symptoms were similar in elderly and younger patients, but dyspnea or tachypnea was less frequent in elderly patients with no previous cardiopulmonary disease. Dyspnea may be absent even in patients with circulatory collapse. Patients with a low-probability objective clinical assessment sometimes had pulmonary embolism, even in proximal vessels.
  
  
  CONCLUSIONS
  Symptoms may be mild, and generally recognized symptoms may be absent, particularly in patients with pulmonary embolism only in the segmental pulmonary branches, but they may be absent even with severe pulmonary embolism. A high or intermediate-probability objective clinical assessment suggests the need for diagnostic studies, but a low-probability objective clinical assessment does not exclude the diagnosis. Maintenance of a high level of suspicion is critical.
authors: Department of Research, St. Joseph Mercy Oakland Hospital, Pontiac, Mich 48341-5023, USA. steinp@trinity-health.org
authors: Paul D
authors: PD
authors: Stein
authors: Afzal
authors: A
authors: Beemath
authors: Fadi
authors: F
authors: Matta
authors: John G
authors: JG
authors: Weg
authors: Roger D
authors: RD
authors: Yusen
authors: Charles A
authors: CA
authors: Hales
authors: Russell D
authors: RD
authors: Hull
authors: Kenneth V
authors: KV
authors: Leeper
authors: H Dirk
authors: HD
authors: Sostman
authors: Victor F
authors: VF
authors: Tapson
authors: John D
authors: JD
authors: Buckley
authors: Alexander
authors: A
authors: Gottschalk
authors: Lawrence R
authors: LR
authors: Goodman
authors: Thomas W
authors: TW
authors: Wakefied
authors: Pamela K
authors: PK
authors: Woodard
mesh_terms: D000208:Acute Disease; D017677:Age Distribution; D015897:Comorbidity; D003371:Cough / Q000453:epidemiology; D004417:Dyspnea / Q000453:epidemiology; D005260:Female; D006469:Hemoptysis / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D010146:Pain / Q000453:epidemiology; D010313:Partial Pressure; D015995:Prevalence; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology*; D012307:Risk Factors; D012769:Shock / Q000453:epidemiology; D013610:Tachycardia / Q000453:epidemiology; D014481:United States / Q000453:epidemiology
chemical_list: D010100:Oxygen