What are the risk factors for pulmonary embolism and how can they be mitigated?

Pulmonary Embolism Risk Factors and Mitigation Strategies

Major risk factors for pulmonary embolism include surgery, immobility, malignancy, pregnancy, older age, thrombophilia, and hormone therapy, which should be systematically assessed and addressed to prevent potentially fatal outcomes. 1

Major Risk Factors

Surgical and Trauma-Related Factors

• Major trauma, surgery (particularly orthopedic procedures involving lower limbs), lower-limb fractures and joint replacements, and spinal cord injury are strong provoking factors for PE 2
• Hip or knee replacement surgery significantly increases the risk of pulmonary embolism 3
• Major orthopedic surgery carries one of the highest risks for PE development 1

Immobility and Hospitalization

• Prolonged immobility due to stroke, neurological diseases, and hospitalization significantly increases PE risk 1
• Hospitalization for heart failure or atrial fibrillation/flutter within the previous 3 months is a strong risk factor 3
• Myocardial infarction within the previous 3 months substantially increases PE risk 3, 4

Cancer-Related Factors

• Cancer is a well-recognized predisposing factor for PE, with risk varying by cancer type 2
• Pancreatic cancer, hematological malignancies, lung cancer, gastric cancer, and brain cancer carry the highest risk 2
• Cancer is a strong risk factor for all-cause mortality following an episode of VTE 2
• Most PE cases in cancer patients occur within the first year of cancer diagnosis, particularly in those with metastatic disease 5

Hormonal and Pregnancy-Related Factors

• Estrogen-containing oral contraceptives increase VTE risk 2-6 fold over baseline 2, 3
• Third-generation combined oral contraceptives (containing desogestrel or gestodene) have higher VTE risk than second-generation products 2
• Pregnancy and the postpartum period carry increased risk, especially with operative delivery 2
• Hormone replacement therapy in post-menopausal women carries variable risk depending on formulation 2

Age and Other Demographic Factors

• PE risk increases exponentially with age, particularly over 40 years 2, 3
• Obesity has been confirmed as an independent risk factor for PE 2

Medical Conditions and Previous History

• Previous venous thromboembolism is a strong risk factor for recurrent PE 3, 4
• Cardiorespiratory disorders, including myocardial infarction, congestive heart failure, and chronic obstructive pulmonary disease increase risk 2
• Infection is a common trigger for VTE 2
• Inherited or acquired thrombophilia significantly increases PE risk 1

Mitigation Strategies

Surgical and Hospital Settings

• Pharmacological prophylaxis with anticoagulants should be implemented for high-risk surgical patients 6
• For orthopedic surgery patients, fondaparinux sodium 2.5 mg SC once daily has been shown to reduce VTE risk compared to enoxaparin 6
• In abdominal surgery patients, prophylaxis with fondaparinux sodium 2.5 mg SC once daily is effective in reducing VTE risk 6

Cancer Patients

• Cancer patients should receive special attention for PE risk, particularly those with metastatic disease or undergoing chemotherapy 5
• Elevated levels of lactic acid, increased platelet count, and low serum levels of carcinoembryonic antigen, albumin, and D-dimer may help identify asymptomatic PE in cancer patients 5

Hormonal Therapy

• For women with personal or strong family history of VTE, hormone-releasing intrauterine devices and progesterone-only pills are safer alternatives to combined oral contraceptives 2
• Women requiring hormone replacement therapy should be prescribed formulations with the lowest VTE risk profile 2

Risk Assessment and Early Detection

• All patients should have clinical probability of PE assessed and documented 1
• Risk stratification tools should be used to identify high-risk patients who may benefit from more aggressive prophylaxis or monitoring 7
• The Geneva Prognostic Score offers a rapid clinical assessment approach to identify high-risk patients 7

Treatment Approaches Based on Risk

• Low-risk patients can be effectively managed with intensive anticoagulation alone 7
• Higher-risk patients may require more aggressive intervention with thrombolysis or embolectomy 7
• For confirmed PE cases, anticoagulation is the standard treatment, with consideration of thrombolysis or embolectomy for high-risk cases 3

Common Pitfalls and Caveats

• Failing to recognize that PE risk increases exponentially with age is a common oversight 1
• Overlooking the synergistic effect of multiple risk factors can lead to underestimation of overall PE risk 1
• Underestimating the significance of immobility as a risk factor is a common error 1
• Not considering thrombophilia in patients with unexplained thrombotic episodes may miss important preventable cases 1
• PE is often undiagnosed in hospitalized patients, requiring a high index of suspicion, especially in those with risk factors 8
• Excessive use of imaging for suspected PE increases radiation exposure risks; clinical decision rules should guide diagnostic approaches 8