This guideline follows closely the American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition) [R] and the American Society of Regional Anesthesia and Pain Medicine guidelines. Areas of divergence from the American College of Chest Physicians guideline recommendations are the use of aspirin following orthopedic procedures.
The recommendations for venous thromboembolism prophylaxis are presented in the form of a Table with 9 components, accompanied by detailed annotations. Clinical highlights, the Table, "Thromboembolic Prophylaxis for Adult Patients", and selected annotations (numbered to correspond with the Table) follow.
Class of evidence (A-D, M, R, X) and conclusion grade (I-III, Not Assignable) definitions are provided at the end of the "Major Recommendations" field.
1. General Recommendations |
1-1 All patients should have venous thromboembolism risk assessed and addressed upon hospital admission, change in level of care, and discharge.
1-2 All patients should have proper education regarding venous thromboembolism risk, signs and symptoms of venous thromboembolism, and mechanical prophylaxis methods available.
1-3 All patients should be encouraged to ambulate as early as possible, and as frequently as possible.
1-4 All non-ambulatory patients should have, at a minimum, mechanical prophylaxis – unless contraindicated.
1-5 All patients with moderate to high risk of venous thromboembolism should have pharmacologic prophylaxis based on the recommendations in this table – unless contraindicated.
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2. Patient-Related Thromboembolic Risk Factors |
- Prior history of deep vein thrombosis/pulmonary embolism (probably the most important predictor of the development of a new venous thromboembolism)
- Active cancer or myeloproliferative disorder admission to the intensive care unit
- Extended immobility or estimated length of stay of four or more days
- Age greater than 60
- Thrombophilia – congenital or acquired
- Uncompensated congestive heart failure
- Acute respiratory failure
- Acute infection
- Inflammatory bowel disease
- Nephrotic syndrome
- Rheumatoid/collagen vascular disorder
- Obesity (body mass index >30)
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3. Special Situations – General |
High Risk of Bleeding
- Active significant bleeding
- Craniotomy within two weeks
- History of intracerebral hemorrhage within two weeks
- Active intracranial lesions/neoplasms/monitoring devices
- Vascular access/biopsy sites inaccessible to hemostatic control within 24 hours
- Bacterial endocarditis
- Proliferative retinopathy
(See the NGC summary of the Institute for Clinical Systems Improvement [ICSI] Antithrombotic Supplement for a more detailed discussion of risk factors for bleeding)
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Thromboembolic prophylaxis: mechanical prophylaxis |
- History of heparin induced thrombocytopenia
- Platelet count <50,000
- History of coagulopathy (e.g. hemophilia, von Willebrand's)
|
Thromboembolic prophylaxis: mechanical prophylaxis and consult an anticoagulation expert to discuss options for pharmacologic prophylaxis |
4. Special Situations – Dose Adjustment |
|
Dalteparin |
Enoxaparin |
Fondaparinux |
Unfractionated Heparin |
Warfarin |
Aspirin |
Morbidly obese (body mass index >35) |
No dosing recommendation available |
40 mg sq every 12 hr or 50 mg sq daily |
No dosing recommendation available |
5,000 units sq every 8 hr or continuous IV infusion |
-- |
-- |
Small body mass |
-- |
30 mg sq daily if <45 kg |
Contraindicated if <50 kg |
-- |
-- |
-- |
Geriatric |
2,500 units sq daily |
Based on CrCl |
Empiric dose adjustment based on CrCl |
-- |
-- |
-- |
Renal Insufficiency (creatinine clearance [CrCl]<30) |
No dosing recommendation available |
30 mg sq daily |
Contraindicated |
-- |
-- |
-- |
5. Special Situations – Neuraxial Blockade |
|
Dalteparin |
Enoxaparin |
Fondaparinux |
Unfractionated Heparin |
Warfarin |
Aspirin |
|
Insertion: at least 12 hr after the last dose, epidural catheter not recommended with twice daily regimens.
Removal: at least 12 hr after the last dose
At least 2 hr before the next dose
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Insertion: at least 12 hr after the last dose, epidural catheter not recommended with twice daily regimens.
Removal: at least 12 hr after the last dose
At least 2 hr before the next dose
|
Insertion: not recommended prior to insertion
Removal: at least 36 hr after the last dose
At least 12 hr before the next dose
|
Insertion: at least 4 hr after the last dose
Removal: at least 4 hr after the last dose
At least 1 hr before the next dose
|
Insertion: no consensus regarding highest acceptable international normalized ratio (INR)
Removal: within 48 hr of initiation of warfarin and INR <2.0
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-- |
Pharmacologic Prophylaxis |
6. Hospitalized Non-Surgical Patients Including Burns |
|
Dalteparin |
Enoxaparin |
Fondaparinux |
Unfractionated Heparin |
Warfarin |
Aspirin |
Duration |
No additional risk factors |
Not recommended |
Not recommended |
Not recommended |
Not recommended |
-- |
-- |
-- |
Additional risk factors |
5,000 units sq every 24 hr |
40 mg sq every 24 hr |
2.5 mg sq every 24 hr |
5,000 units sq every 8-12 hr |
If on warfarin for other indications, probably sufficient venous thrombo-embolism (VTE) prophylaxis |
May use aspirin for other indications, but not sufficient alone for VTE prophylaxis |
Until discharge |
7. General Gynecologic and Urologic Surgery |
|
Dalteparin |
Enoxaparin |
Fondaparinux |
Unfractionated Heparin |
Warfarin |
Aspirin |
Duration |
Outpatient or laparoscopic procedure or C-section + no additional risk factors |
Not recommended |
Not recommended |
Not recommended |
Not recommended |
Not recommended |
Not recommended |
-- |
Outpatient or laparoscopic procedure or C-section + additional risk factors or major procedure |
2,500 units sq 1-2 hr preop, then every 24 hr |
40 mg sq 2 hr preop, then every 24 hr |
-- |
5,000 units sq every 12 hr postop |
-- |
-- |
Until discharge |
Previous venous thromboembolism, malignancy or other significant risk factors |
5,000 units sq 1-2 hr preop, then every 24 hr |
40 mg sq 2 hr preop, then every 24 hr |
-- |
5,000 units sq every 8 hr postop |
-- |
-- |
Continue up to 4 weeks after discharge |
8. Bariatric Surgery |
|
Dalteparin |
Enoxaparin |
Fondaparinux |
Unfractionated Heparin |
Warfarin |
Aspirin |
Duration |
All bariatric procedures |
No dosing recommendation available |
40 mg sq every 12 hours
(± mechanical prophylaxis)
|
No dosing recommendation available |
5,000 units sq every 8 hours or continuous infusion (target antiXa level 0.15-2.0)
(± mechanical prophylaxis)
|
-- |
-- |
Until discharge or up to 10 days postop [B] |
9. Orthopedic Surgery |
|
Dalteparin |
Enoxaparin |
Fondaparinux |
Unfractionated Heparin |
Warfarin |
Aspirin |
Duration |
Hip Fracture |
5,000 units sq every 24 hr beginning 12-24 hr postop + mechanical prophylaxis
If surgery is delayed, initiate between admission and surgery
Must stop at least 12 hours prior to neuraxial anesthesia (see table section #5, "Special Situations – Neuraxial Blockade" above)
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30 mg sq every 12 hr beginning 12 hr postop + mechanical prophylaxis
Epidural catheter not recommended with twice daily regimens
If surgery is delayed, initiate between admission and surgery
Must stop at least 12 hours prior to neuraxial anesthesia (see table section #5 above)
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2.5 mg sq every 24 hr beginning 6-8 hr postop + mechanical prophylaxis
Epidural catheter not recommended with twice daily regimens
Note: not recommended preoperative
If surgery is delayed, initiate LMWH between admission and surgery
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Not recommended |
INR 2.5 (2.0-3.0) beginning postop day of surgery + mechanical prophylaxis (spinal anesthetic OK, but if used with an epidural catheter, the catheter should be removed within 48 hours and INR < 2.0) (see table section #5, "Special Situations – Neuraxial Blockade" above)
Note: not recommended preoperative
If surgery is delayed, initiate LMWH between admission and surgery
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See discussion in Annotation #9 of the original guideline.
American College of Chest Physicians recommends against the use of aspirin alone for all patient groups.
Recommends mechanical prophylaxis as the sole means for VTE prevention only for those patients with prohibitive bleeding risks.
American Academy of Orthopedic Surgeons: May consider in combination with mechanical prophylaxis in patients with no additional VTE risk factors. Not recommended in patients with additional VTE risk factors.
Not recommended as a sole method of prophylaxis (i.e., without mechanical prophylaxis)
Note: not recommended preoperative
If surgery is delayed, initiate LMWH between admission and surgery
|
10-35 days post-operative |
Hip replacement |
5,000 units sq every 24 hr beginning 12-24 hr postop + mechanical prophylaxis |
30 mg sq every 12 hr beginning 12 hr postop + mechanical prophylaxis
Epidural catheter not recommended with twice daily regimens
|
2.5 mg sq every 24 hr beginning 6-8 hr postop + mechanical prophylaxis
Epidural catheter not recommended
|
Not recommended |
INR 2.5 (2.0-3.0) beginning day of surgery + mechanical prophylaxis (spinal anesthetic OK, but if used with an epidural catheter, the catheter should be removed within 48 hours and INR <2.0) |
See discussion in Annotation #9 of the original guideline.
American College of Chest Physicians: recommends against the use of aspirin alone for all patient groups.
Recommends mechanical prophylaxis as the sole means for VTE prevention only for those patients with prohibitive bleeding risks.
American Academy of Orthopedic Surgeons: May consider in combination with mechanical prophylaxis in patients with no additional VTE risk factors.
Not recommended in patients with additional VTE risk factors.
Not recommended as a sole method of prophylaxis (i.e., without mechanical prophylaxis)
Note: not recommended preoperative
If surgery is delayed, initiate LMWH between admission and surgery
|
10-35 days postoperative |
Knee replacement |
5,000 units sq every 24 hr beginning 12-24 hr postop + mechanical prophylaxis |
30 mg sq every 12 hr beginning 12 hr postop + mechanical prophylaxis
Epidural catheter not recommended with twice daily regimens
|
2.5 mg sq every 24 hr beginning 6-8 hr postop + mechanical prophylaxis
Epidural catheter not recommended
|
Not recommended |
INR 2.5 (2.0-3.0) beginning day of surgery + mechanical prophylaxis (spinal anesthetic OK, but if used with an epidural catheter, the catheter should be removed within 48 hours and INR <2.0) |
See discussion in Annotation #9 of the original guideline.
American College of Chest Physicians recommends against the use of aspirin alone for all patient groups.
Recommends mechanical prophylaxis as the sole means for VTE prevention only for those patients with prohibitive bleeding risks.
American Academy of Orthopedic Surgeons: May consider in combination with mechanical prophylaxis in patients with no additional VTE risk factors. Not recommended in patients with additional VTE risk factors.
Not recommended as a sole method of prophylaxis (i.e., without mechanical prophylaxis)
Note: not recommended preop
If surgery is delayed, initiate LMWH between admission and surgery
|
10-35 days postop |
Knee arthroscopy + no risk factors |
Not recommended |
Not recommended |
Not recommended |
Not recommended |
Not recommended |
Not recommended |
-- |
Knee arthroscopy + risk factors |
5,000 units sq every 24 hr beginning 12-24 hr postop |
40 mg sq every 24 hr beginning 12- 24 hr postop |
Not recommended |
Not recommended |
Not recommended |
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7-14 days |
Out of the Scope of This Guideline |
CABG, Thoracic Surgery, Neurosurgery, Spine Surgery, Multiple Trauma |