see also:

• DVT prophylaxis
• see also DVT / VTE risk assessment scores and tools

• surgery for THR, TKR, or hip fracture
• abdominal or pelvic surgery for cancer
• multiple major trauma injuries
• acute spinal cord injury with paresis

• not in high or low risk categories

• ambulatory patient without VTE risk factors (see below)
• ambulatory patient with VTE risk factors but expected hospital LOS < 2 days
• minor surgery (operating time < 30 minutes) in patient with VTE risk factors

• Prior venous thromboembolic disease
• Presence of hypercoagulable state
  • see inherited thrombophilias
  • Oestrogen use
  • Pregnancy (mainly 2nd/3rd trimesters)
  • Puerperium
  • Malignancy
  • Sepsis
  • COVID-19 coronavirus (2019-nCoV / SARS-CoV-2)
  • JAK2 V617F mutation with or without essential thrombocytosis or overt myeloproliferative neoplasm mainly associated with splanchnic vein or cerebral vein thromboses
  • other medications
    • JAK inhibitors
• Impaired venous return or leg oedema
  • Varicose veins
  • Congestive cardiac failure
  • Myocardial infarction
  • Respiratory failure / smoker
  • Obesity (BMI>28.5)
  • large abdominal masses including advanced pregnancy
  • Nephrotic syndrome in particular with hypoalbuminuria
  • Prolonged immobility or paralysis
    • stroke
    • trauma, spinal cord injury and burns
    • major surgery, in particular operations involving the abdomen, pelvis and lower extremities, or lasting > 45 minutes
    • fractures of the pelvis, hip or leg
    • long-haul travel
    • substance use
• Active inflammatory bowel disease
• Indwelling large vein catheter includes peripheral/central lines, Hickmann’s, etc.
• Age
  • relevant in the presence of other risk factors (clinically becomes important by 40 years and increases with further aging)