To outline a practical approach for the prevention of venous thromboembolism (VTE) in patients undergoing non-orthopedic surgery.VTE is a common and yet generally preventable cause of post-operative morbidity and mortality. The use of graduated compression stockings (GCS), intermittent pneumatic compression (IPC), low-dose unfractionated heparin (UFH), and low molecular weight heparin (LMWH), combined with early ambulation, have all been shown to reduce post-operative VTE to varying degrees in patients undergoing surgery.# GENERAL PRINCIPLES OF PROPHYLAXIS:
- Thromboprophylaxis decisions rely on a consideration of the balance in the risks of VTE and bleeding, both of which are affected by procedure-specific and patient-specific factors.
- Patients not at low VTE risk without a high bleeding risk should receive pharmacological (anticoagulant) thromboprophylaxis:
- Suggest using LMWH (preferred option in most patients) or UFH (see anticoagulant dosing on page 4) - The use of direct oral anticoagulants (e.g. apixaban, dabigatran, edoxaban, rivaroxaban) has not been well evaluated for thromboprophylaxis in the non-orthopedic surgical setting for thromboprophylaxis 5. For most elective non-orthopedic surgery patients in whom pharmacological thromboprophylaxis is recommended, thromboprophylaxis should be initiated when hemostasis is achieved (for patients without a high risk of bleeding consider starting within 12 hours of surgery). In patients in whom mechanical thromboprophylaxis is recommended, start at the beginning of the procedure. For patients admitted to hospital before surgery, assess for pre-operative pharmacological thromboprophylaxis (see Clinical Guide Thromboprophylaxis: Hospitalized Medical Patients).
- Although the optimal duration of thromboprophylaxis is not well defined, patients with a moderate or high risk for VTE should receive thromboprophylaxis at least until discharge from hospital. Extended duration thromboprophylaxis (up to 30 days) may be considered in select populations.

# THROMBOPROPHYLAXIS APPROACHES IN NON-ORTHOPEDIC SURGERY:
There are three general approaches to thromboprophylaxis in patients undergoing non-orthopedic surgery.
A. Group-based: This approach provides standard thromboprophylaxis to all patients who "belong to" a large group (e.g. abdominal-pelvic surgery, spine surgery, etc.) unless there is a specific patient contraindication. This approach has been adopted by many hospitals in developing their own prophylaxis guidelines.

# B. Individualized:
This strategy is based on individual patient risk assessment using a formal risk assessment model like the Caprini score (/). This score has been validated for general, urologic, and gynecologic surgeries). In general, the estimated VTE risk and thromboprophylaxis recommendations using this approach are similar to the group-based approach.
C. The American Society of Hematology (ASH) 2019 guidelines for management of VTE use a blended approach that incorporates both group-based and individualized recommendations, as summarized in Table 1 below.
Risk of bleeding assessments have not been validated in a formal model for surgical patients.
It is suggested that every institution have a written policy for thromboprophylaxis and, where possible, that thromboprophylaxis protocols be embedded into routinely used electronic or paper order sets.
Evidence is lacking as to whether thromboprophylaxis is needed in neonates and children who have non-orthopedic surgery. However, there may be high-risk cohorts in whom thromboprophylaxis may be considered. Consultation with a pediatrician or hematologist with expertise in pediatric thrombosis is recommended. 

# Date of Version: 31January2022
Please note that the information contained herein is not to be interpreted as an alternative to medical advice from your doctor or other professional healthcare provider. If you have any specific questions about any medical matter, you should consult your doctor or other professional healthcare providers, and as such you should never delay seeking medical advice, disregard medical advice or discontinue medical treatment because of the information contained herein.