Guideline Development Group

Table 4: Reduced mobility as a risk factor for VTE^{18, 24}

Degree of immobility	OR	95% CI	P value
Normal	1.0
Limited	1.73	1.08-2.75	0.02
Wheelchair 30 days	2.43	1.37-4.30	0.002
Bed rest 30 days	2.73	1.20-6.20	0.02
Wheelchair 15-30 days	3.33	1.26-8.84	0.02
Bed rest 15-20 days	3.37	1.00-11.29	0.05
Wheelchair 15 days	4.32	1.50-12.45	0.007
Bed rest < 15 days	5.64	2.04-15.56	0.0008
OR = Odds ratio; CI = confidence interval

Table 5: Education Topics for Patients at High Risk for DVT^69

Risk factors for DVT Possible consequences of DVT Interventions to decrease the risk of DVT Signs/symptoms of DVT and importance of seeking medical help if suspect DVT Importance of follow-up monitoring Importance of compliance Medication issues e.g. regimen, adverse side effects and interactions, dietary restrictions

Table 6: Definition of Immobility in Residents of Long-Term Care Facilities^43

Presence of at least 1 of the following: Lower limb cast Bedridden Bedridden except for bathroom privileges Recent decreased ability to walk at least 10 feet for a least 72 hours Inability to walk at least 10 feet

Table 7: Signs and Symptoms of a LE DVT ^35, 42, 59, 61

Pitting edema Tenderness and pain in leg Erythema Warmth Swelling of the leg Prominent superficial veins

Table 8: Two-Level DVT Wells Score^65
Clinical Feature	Points
Active cancer (treatment ongoing, within 6 months, or palliative)	1
Paralysis, paresis or recent plaster immobilisation of the lower extremities	1
Recently bedridden for 3 days or more or major surgery within 12 weeks requiring general or regional anaesthesia	1
Localised tenderness along the distribution of the deep venous system	1
Entire leg swollen	1
Calf swelling at least 3 cm larger than asymptomatic side	1
Pitting edema confined to the symptomatic leg	1
Collateral superficial veins (non-varicose)	1
Previously documented DVT	1
Alternative diagnosis at least as likely as DVT	−2
Clinical probability simplified score
DVT ‘likely’	2 points or more
DVT ‘unlikely’	Less than 2 points

Table 9: Current Anticoagulation Options In Use^30, 35, 42, 57, 59, 60, 69, 78-84, 86, 87, 89, 136
Classifications and mechanism of action	Medication Names	Dosage and method of delivery	Peak therapeutic levels achieved **
Unfractionated Heparin Mechanism of action: inactivates thrombin and activated factor X (factor Xa) by binding to antithrombin through a high-affinity pentasaccharide.	Heparin	Delivery: IV Dose: Bolus 80 units/kg followed by infusion of 18 units/kg/hr	24-48 hours
Low Molecular Weight Heparins Mechanism of action: binds to antithrombin which is mediated by a unique pentasaccharide sequence which causes a change in antithrombin and inactivates factor Xa	Lovenox (enoxaparin) Fragmin Enoxaparin (ext release) Innnohep (tinzaparin sodium) Others?	Delivery: Subcutaneous injections Prophylactic dose: 30-40 mg q 12-24 hr Therapeutic dose: 1-1.5 mg/kg q 12-24 hr	3-5 hours
Fondaparinux (synthetic drug) Mechanism of action: provides antithrombotic activity via selectively binding to antithrombin III (ATIII) which in turn results in inhibition of Factor Xa	Arixtra	Delivery: subcutaneous injections Prophylactic Dose 2.5 mg/day Therapeutic Dose: 5-10 mg/day (based on weight)	2-3 hours
Vitamin K antagonists Mechanism of action: inhibiting the synthesis of vitamin K-dependent clotting factors, especially the C1 subunit of vitamin K epoxide reductase (VKORC1) enzyme complex	Coumadin (warfarin)	Delivery: oral Dosing: individualized based upon individual’s INR response to drug	Used with LMWH or UFH INR 2-3
Oral direct thrombin inhibitor Mechanism of action: Directly inhibits thrombin	Pradaxa (dabigatran)	Delivery: oral Dosing: 150 mg bid	Peak achieved in 2 hours
Oral direct Xa inhibitors Mechanism of action: exerts anticoagulant effect via direct inhibition of a single Factor within the coagulation cascade: Factor Xa.	Xarelto (rivaroxaban) Eliquis (Apixaban	Delivery: oral Xarelto Dosing: 15 mg bid for first 21 days, 20 mg qd after day 21 Eliquis dosing: 5 mg bid	2-3 hours

Table 10: Indicators of Heparin Induced Thrombocytopenia (HIT)

Skin lesion reaction at injection site Systemic reaction to a bolus administration of heparin 50% decrease in platelet count from baseline labs while on heparin Delayed onset HIT: thromboembolic complications 1-2 wks after receiving last dose of LMWH or UFH mild to moderate thrombocytopenia

Table 11: Risk of Bleeding^19
Active bleeding Acute stroke Acquired bleeding disorders (such as acute liver failure) Concurrent use of anticoagulants known to increase the risk of bleeding (such as Coumadin with an INR >2) Lumber puncture/epidural/spinal anesthesia expected to be given within next 12 hours Thrombocytopenia (platelets less than 7,500) Uncontrolled systolic hypertension (defined as BP of 230/120 mm Hg or higher) Untreated inherited bleeding disorders such as hemophilia or von Willebrand’s disease
Table 12: Indications and Contraindications to Inferior Vena Cava Filter Placement^137
Absolute Indications	Relative Indications
Contraindication to anticoagulation	Large free-floating proximal DVT
Therapeutic anticoagulation is unable to be achieved or maintained	Therapeutic anticoagulation not achieved
	VTE with decreased cardiopulmonary reserve
	Poor compliance with anticoagulation medication
	High risk of complication from anticoagulation
Absolute Contraindications	Relative Contraindications
Complete, chronic thrombosis of the IVCF	Severe, uncorrectable coagulopathy
Inability to gain central venous access	Bacteremia or sepsis

Table 13: Complications Related to Inferior Vena Cave Filters^137, 138
Insertion Complications	Thrombotic Complications
Hematoma at insertion site	Insertion site thrombosis
Misplacement	IVCF thrombosis
Pneumothorax	New or progression of DVT
IVC damage/wall penetration	New or progression of PE
Filter migration	Post-thrombotic syndrome
Air embolism
Carotid artery puncture
Arteriovenous fistula
Infection

List of Figures

Figure 1. Search strategy by keywords, MeSH terms, and databases

Figure 2: Screening for Risk of Venous Thromboembolism Algorithm

Figure 3: Determining Likelihood of a Lower Extremity Deep Vein Thrombus Algorithm

Figure 4: Mobilizing Patients with Known Lower Extremity Deep Vein Thrombus Alogrithm

Figure 1. Search strategy by keywords, MeSH terms, and databases

Keywords: DVT “Venous Thrombosis” “Deep Vein Thrombosis” VTE “Venous Thromboembolism" “Pulmonary Embolism” Walking Walk Ambulation Ambulate Ambulated Movement Mobility Immobilization Immobilisation "Mobility Limitation" “Motor Activity” “Early Ambulation" "Early Activization" "Early Activisation" "Early Mobilization" "Early Mobilisation" Anticoagulants Anticoagulant Anticoagulation Dabigatran Desirudin Ximelagatran Edoxaban Rivaroxaban Apixaban Betrixaban "YM150" Razaxaban “Factor Xa Inhibitor” “Factor Xa Inhibitor” “Direct Thrombin Inhibitors” “Direct Thrombin Inhibitor” Coumadin Warfarin Fondaparinux Idraparinux “International Normalized Ratio" “INR” “Prothrombin Time” “Vena Cava Filter*” "Intermittent Pneumatic Compression Devices” "Compression Stockings" "Compression Socks" "Compression Hose" "Compression Hosiery"	MeSH Terms: “Venous Thrombosis" "Pulmonary Embolism" “Walking” “Movement” "Immobilization" "Mobility Limitation" "Motor Activity" "Early Ambulation" "Activities of Daily Living" "Anticoagulants" "Coumarins "Fibrin Modulating Agents" "Factor Xa/antagonists and inhibitors" "Thrombosis/prevention and control" "Antithrombins" "Citric Acid" "Heparinoids" "Vitamin K/antagonists and inhibitors" "Antithrombin Proteins" "Fibrinolytic Agents" "International Normalized Ratio" "Prothrombin Time" "Vena Cava Filters" "Intermittent Pneumatic Compression Devices" "Stockings, Compression"	Databases: PubMed CINAHL Web of Science Cochrane Database of Systematic Reviews Database of Abstracts of Reviews of Effects (DARE) Physiotherapy Evidence Database (PEDro)