Pulmonary Embolism Risk Factors

Introduction to Risk Factors

The American Thoracic Society suggests that the most significant risk factors for pulmonary embolism (PE) beyond travel include surgery, immobility, malignancy, pregnancy/postpartum state, older age, thrombophilia, and hormone therapy 1, 2

Major orthopedic lower limb surgery and postoperative intensive care are associated with a high risk of PE, according to the British Thoracic Society 2, 3
Immobility due to stroke, neurological diseases, and prolonged hospitalization significantly increases PE risk, as stated by the European Respiratory Society 3, 4
Cardiorespiratory disorders, particularly myocardial infarction, congenital heart disease, congestive heart failure, and irreversible airways disease are major risk factors, as reported by the American College of Chest Physicians 3, 5
Cancer, especially of the uterus, pancreas, breast, and stomach, as well as advanced and metastatic disease, significantly increases PE risk, according to the National Comprehensive Cancer Network 3, 4
The association between PE and occult malignancy is significant, with many patients diagnosed with PE later found to have previously undetected cancer, as noted by the American Society of Clinical Oncology 4, 6

Age is a significant risk factor, with PE risk increasing exponentially with age, particularly over 40 years, as stated by the American Geriatrics Society 1, 3
Obesity has been confirmed as an independent risk factor for PE, according to the Obesity Society 3, 4

Estrogen therapy increases PE risk, especially with "third generation" agents, as reported by the American College of Obstetricians and Gynecologists 1, 7
Pregnancy and postpartum state carry increased risk, particularly with pre-eclampsia, cesarean section, and multiple births, as stated by the Society for Maternal-Fetal Medicine 1, 7
While oral contraceptives increase risk 2-4 times compared to controls, the absolute risk remains low with current low-dose formulations, according to the American College of Obstetricians and Gynecologists 4, 6

Inherited or acquired thrombophilia is found in 25-50% of patients with PE, as reported by the International Society on Thrombosis and Haemostasis 1, 7
Factor V Leiden mutation increases PE risk 3-5 fold, but in combination with estrogen therapy, this risk rises to 35-fold, as stated by the American Heart Association 1, 7

Central venous catheterization can lead to PE, though these are rarely fatal, as noted by the Society of Interventional Radiology 4, 6
Upper limb spontaneous clots are less common and rarely lead to PE compared to lower limb thrombosis, according to the American College of Phlebology 4, 6

All patients with possible PE should have clinical probability assessed and documented, as recommended by the American College of Chest Physicians 7, 9
The presence of risk factors significantly influences the pre-test probability of PE and should guide diagnostic strategies, as stated by the European Respiratory Society 7, 10
Not recognizing that PE risk increases exponentially with age is a common pitfall, as noted by the American Geriatrics Society 1, 3
Failing to consider thrombophilia in patients with unexplained thrombotic episodes is a common oversight, according to the International Society on Thrombosis and Haemostasis 8
Overlooking the synergistic effect of multiple risk factors is a common mistake, as reported by the American Heart Association 1, 7
Underestimating the significance of immobility as a risk factor is a common error, as stated by the European Respiratory Society 3, 5