Risk Factors
In addition to a clear description of the presenting symptoms it is also necessary to ascertain if any risk factors for PE are present.
The British Thoracic Society 20037 splits these into major and minor risk factors. The presence of a major risk factor conveys a 5-20 times increased risk of a PE to the patient whilst a minor factor conveys a 2-3 times increased risk (Table 1).
Similarly, NICE guidelines suggest that risk factors for VTE include a prior history of DVT, age over 60 years, surgery, obesity, prolonged travel, acute medical illness, cancer, immobility, thrombophilia (an abnormal tendency for the blood to clot) and pregnancy.
| Major risk factors (relative risk 5-20) | |
| Surgery | Major abdominal/pelvic surgery Hip or knee replacement Post operative intensive care |
| Obstetrics | Late pregnancy Caesarian section Puerperium |
| Lower limb problems | Fracture Varicose veins |
| Malignancy | Abdominal/pelvic Advanced/metastatic |
| Reduced mobility | Hospitalisation Institutional care |
| Previous proven venous thromboembolism | |
| Minor risk factors (relative risk 2-4) | |
| Cardiovascular | Congenital heart disease Congestive cardiac failure Hypertension Superficial venous thrombosis Indwelling central vein catheter |
| Oestrogens | Oral contraceptive Hormone replacement therapy |
| Miscellaneous | COPD Neurological disability Occult malignancy Thrombotic disorders Long distance sedentary travel Obesity |
A full list of risk factors can be viewed here.