Risk factors for venous thromboembolism:
(1) adenocarcinoma
(2) distant metastases
(3) pneumonectomy, lobectomy or other surgery
(4) chemotherapy
(5) therapy with antiangiogenic drugs (thalidomide, other)
(6) anti-VEGF (vascular endothelial growth factor) targeted drugs
(7) an elevated pretreatment platelet count
(8) erythropoietin therapy
where:
• If erythropoietin therapy is a risk factor for thromboembolism, then polycythemia secondary to COPD may also be a risk factor.
• The authors also list increased circulating tissue thromboplastin as a risk factor, but since this is not routinely measured it is not included in the implementation.
• Brain metastases would be expected to generate tissue thromboplastin.
• The PT and PTT do not correlate with the risk of thrombosis.
• A patient may develop thrombosis after surgery despite prophylactic therapy.
• A person with multiple risk factors should take precautions on long airplane flights.
Additional risk factors not listed in the paper:
(1) pre-existing hypercoagulable disorder
(2) prolonged immobility
