Thrombophilia, as the name implies is a blood disorder that increases the risk of clotting and therefore increases the risk of venous thromboembolism. It can be acquired through conditions such as heart failure, irritable bowel syndrome and nephritic syndrome. Or it may be inherited. Up to half of those treated for VTE are thought to have hereditary thrombophilia. This is known because patients who have had VTE are routines screened to see if there was an inherited factor in their episode. If a family member has had a previous VTE, genetic screening can be offered to identify and deal with the risk in others. Tests are carried out a month after anticoagulant treatment has finished as these interact with the antithrombin, protein S and protein C that are screened for deficiencies.
The risk of developing VTE in patients with thrombophilia is increased with dehydration and immobility/inactivity, surgery (particularly major general surgery and orthopaedic surgery to the legs) leg fractures, hip fractures, spinal cord inury, varicose veins or congestive heart or respiratory failure. Some forms of contraception can also increase the risk of VTE, therefore they are not normally recommended for patients with hereditary thrombophilia. The progestogen only pill (POP) is generally used instead of combined oral contraceptives. Pregnancy is also a risk factor, particularly if the mother is obese or more mature. This is the biggest cause of maternal mortality, especially after Caesarean section. Cancer patients are at increased risk too, but there’s also a secondary risk with chemotherapy.
In the acute setting, patients will generally be prescribed five days of anti-coagulation treatment with low molecular weight heparin (LMWH) or unfractionated heparin (if in renal failure). This is then followed by six months of oral anticoagulants. Because of the increased risk of haemorrhage, anticoagulants are not normally continued in such cases after six months.