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Chapter 31. Prevention of Venous Thromboembolism (continued)

Table 31. 1. Mechanical and pharmacologic preventative measures for VTE

Practice Type Description Comment
Graduated Elastic Stockings (ES) Mechanical Fitted hose that extend above the knee Fitted hose are more efficacious than non-fitted
Intermittent pneumatic compression (IPC) Mechanical Devices fitted over lower extremities that sequentially inflate and deflate  
Aspirin Pharmacologic Usually 325 mg/d  
Warfarin Pharmacologic 5-10 mg started the day of or after surgery; adjust to achieve an INR of 2-3 Monitoring of INR needed
Low-dose unfractionated heparin (LDUH) Pharmacologic Generally 5000 U subcutaneous bid or tid, though some studies have adjusted dose to maintain PTT at high end of normal Contraindicated if active bleeding or history of thrombocytopenia; no need to follow coagulation studies (unless adjusted dose is used)
Low Molecular Weight Heparin (LMWH) Pharmacologic Dose depends on type of surgery and VTE risk* No need to monitor coagulation studies

*LMWH dosing: Enoxaparin 20 mg SC daily (moderate risk surgery) or 40 mg SC daily (can go up to 30 mg SC q12h for high risk general surgery, major trauma or acute spinal cord injury); dalteparin 2500-5000 U SC daily; nadroparin 2500 U SC daily; tinzaparin 3500-4500 U SC daily (may be dosed 75U/kg/d for orthopedic surgery).

Table 31. 2. Summary of DVT risk and prophylactic methods providing significant risk reduction*

Surgery/ Condition Risk of all DVT in untreated patients Type of Prophylaxis Risk Reduction with Prophylaxis Number of Studies
General Surgery2 25% ES 44% 3
LDUH 68% 47
LMWH 76% 21
IPC 88% 2
THR2 54% LMWH 70% 30
warfarin 59% 13
TKR2,23 64% LMWH 52% 13
IPC 73% 6
Neuro-surgery27,28 28% LMWH 38% 3
LDUH 72% 1a
Trauma2,30 30-60% LMWH 30% (compared to LDUH) 1
Acute Spinal Cord Injury2 80% Not established    
Ischemic stroke2 55% LDUH 56% 5
LMWH 58% 3
Danaparoid 82% 4
Medical conditions2 16% LMWH 76% 2a
39% 2
LDUH 61% 3a

*DVT indicates deep venous thrombosis; ES, graduated elastic stockings; IPC, intermittent pneumatic compression; LDUH, low-dose unfractionated heparin; LMWH, low molecular weight heparin; THR, total hip replacement; and TKR, total knee replacement.

aDVT diagnosed by fibrinogen uptake test (FUT)

Table 31. 3. Recommended VTE prophylaxis for surgical procedures and medical conditions*

Surgery/Condition Recommended Prophylaxis Comments
General Surgery—low-risk: minor procedures, <40 years old, no additional risks None Early ambulation
General Surgery—moderate risk: minor procedure but with risk factor, nonmajor surgery age 40-60 with no risks, or major surgery <40 years with no risks LDUH, LMWH, ES, or IPC  
General Surgery—high risk: nonmajor surgery over age 60 or over age 40 with risks. LDUH, LMWH  
General Surgery—very high risk: major surgery over age 40 plus prior VTE, cancer or hypercoagulable state LDUH or LMWH combined with ES or IPC May consider postdischarge LMWH or perioperative warfarin
Elective Hip Replacement LMWH or warfarin May combine with ES or IPC; start LMWH 12 hours before surgery, 12-24 hours after surgery, or 4-6 hours after surgery at half the dose for initial dose. Start warfarin preoperatively or immediately after surgery, target INR 2. 0-3. 0.
Elective Knee Replacement LMWH or warfarin  
Hip Fracture Surgery LMWH or warfarin  
Neurosurgery IPC, LDUH or LMWH Start LMWH post-surgery
Trauma LMWH with ES or IPC If high risk of bleeding, may use ES and/or IPC alone.
Acute Spinal Cord Injury LMWH Continue LMWH during rehabilitation or convert to warfarin (target INR 2. 5)
Ischemic Stroke LDUH, LMWH, or danaparoid If contraindication to anticoagulant, use ES or IPC.
Medical Conditions LDUH or LWMH

*Adapted with permission from Geerts WH, Heit JA, Clagett GP, Pineo GF, Colwell CW, Anderson FA, et al. Prevention of venous thromboembolism. Table: Regimens to prevent VTE, pp. 156S-158S. Chest 2001. Sixth ACCP Consensus Conference on Antithrombotic Therapy. 2 ES indicates graduated elastic stockings; INR, international normalized ratio; IPC, intermittent pneumatic compression; LDUH, low-dose unfractionated heparin; LMWH, low molecular weight heparin; and VTE, venous thromboembolism.


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