Case history
A 65-year-old man presents to the emergency department with acute onset of shortness of breath of 30 minutes' duration. Initially, he felt faint but did not lose consciousness. He is complaining of left-sided chest pain that worsens on deep inspiration. He has no history of cardiopulmonary disease. A week ago he underwent a total left hip replacement and, following discharge, was on bed rest for 3 days due to poorly controlled pain. He subsequently noticed swelling in his left calf, which is tender on examination. His current vital signs reveal a fever of 38.0°C (100.4°F), heart rate 112 bpm, BP 95/65 mmHg, and an O₂ saturation on room air of 91%.
Other presentations
Symptoms that are predictive of PE include chest pain, dyspnoea, and a sense of apprehension. Syncope may also occur and is strongly associated with increased clot burden. Important signs include tachypnoea with a respiratory rate ≥20 breaths per minute, fever >37.8°C (>100.0°F), and heart rate >100 bpm.[3]Bell WR, Simon TL, DeMets DL. The clinical features of submassive and massive pulmonary emboli. Am J Med. 1977 Mar;62(3):355-60.
http://www.ncbi.nlm.nih.gov/pubmed/842555?tool=bestpractice.com
[4]Pollack CV, Schreiber D, Goldhaber SZ, et al. Clinical characteristics, management, and outcomes of patients diagnosed with acute pulmonary embolism in the emergency department: initial report of EMPEROR (Multicenter Emergency Medicine Pulmonary Embolism in the Real World Registry). J Am Coll Cardiol. 2011 Feb 8;57(6):700-6.
http://www.onlinejacc.org/content/57/6/700
http://www.ncbi.nlm.nih.gov/pubmed/21292129?tool=bestpractice.com
PE has been reported in patients undergoing chest computed tomography (CT) for reasons other than the research of suspected PE.[5]Dentali F, Ageno W, Becattini C, et al. Prevalence and clinical history of incidental, asymptomatic pulmonary embolism: a meta-analysis. Thromb Res. 2010 Jun;125(6):518-22.
http://www.ncbi.nlm.nih.gov/pubmed/20451960?tool=bestpractice.com
[6]Donadini MP, Dentali F, Squizzato A, et al. Unsuspected pulmonary embolism in cancer patients: a narrative review with pooled data. Intern Emerg Med. 2014 Jun;9(4):375-84.
https://www.doi.org/10.1007/s11739-014-1066-7
http://www.ncbi.nlm.nih.gov/pubmed/24664519?tool=bestpractice.com
In one study, the diagnosis of PE was unsuspected in 70% of those who ultimately died from the condition.[7]Stein PD, Henry JW. Prevalence of acute pulmonary embolism among patients in a general hospital and at autopsy. Chest. 1995 Oct;108(4):978-81.
http://www.ncbi.nlm.nih.gov/pubmed/7555172?tool=bestpractice.com
Early recognition is crucial because, among those who died of an unsuspected PE, death occurred within 1 hour in nearly 79% of patients and within 2.5 hours in 93% of patients.[7]Stein PD, Henry JW. Prevalence of acute pulmonary embolism among patients in a general hospital and at autopsy. Chest. 1995 Oct;108(4):978-81.
http://www.ncbi.nlm.nih.gov/pubmed/7555172?tool=bestpractice.com