Question | Answer |
VTE | clot in the body within the venous system |
DVT | clot in the extremities |
PE | clot in the lungs |
Virchow's Triad | Alteration in blood, alteration in vessel, alteration in blood flow |
hypercoagulable state | malignancy, gene mutations, hereditary deficiencies, pregnancy |
vascular injury | major orthopedic surgery, trauma, fracture, indwelling venous catheters |
venous stasis | major medical illness, major surgery, paralysis, plycythemia vera (thick blood), obesity, varicose veins |
strongest risk factor for VTE | prior history of DVT and PE |
VTE risk factors | age > 40, obesity, history of VTE, cancer, bed rest > 5 days, major surgery, HF, varicose veins, fracture, estrogen tx, stork, multiple trauma, childbirth, MI |
pathophysiology of VTE: vessel | vascular injury, exposed subendothelium tissue factor, collagen |
pathophysiology of VTE: blood/circulating elements | Hypercoagulable state: platelets, platelet activating factor, clotting factors, prothrombin, fibrinogen, vWF |
pathophysiology of VTE: blood flow | venous stasis: slow rate of flow, turbulent flow |
Hypercoaguable state must have 1-2 of the following: | thrombosis with first incident at age < 40, recurrent thrmobosis, family history of thrombosis, thormbosis in an unusual site |
clnical presentation of VTE | most patients never develop symptoms, may suffer long-term consequences: PTS, recurrent VTE |
DVT signs and sx | dilated superficial veings, palpable cord in affected leg, homan's sign, unilateral leg edema, erythema, tenderness, leg swelling, pain, warmth, skin discoloration |
DVT dx lab tests | D-dimer (elevated), ESR (elevated) WBC (elevated) |
DVT dx diagnostic tests | duplex ultrasonography (most common), venography (gold standard) |
DVT complications | loss of a limb, post-thrombotic syndrome, may progress to a PE, death |
PE signs and sx | tachypnea, tachycardia, diaphoresis, distended neck veins, diminished breath sounds, circulatory shock (worst); cough +/- blood, chest pain, chest tightness, SOB, palpitations, dizziness |
PE dx | if D-dimer is postive, then CT scan (most common), ventilation/perfusion scan, pulmonary angiography (gold standard) |
VTE px goals | identify all patients at risk, determine each patient's level of risk, implement regiments that provide sufficient protection for the level of risk |
VTE risk classifaction | rogers score, caprini score |
VTE px, non-pharmacologic | ambulation, graduated compression stockings, intermittent pneumatic compression, inferior vena cava (IVC) filters |
ambulation | increases venous flow, promotes the flow of natural antithrombotic factors in the lower extermities |
graduated compression stockings | constricts the diameter of veints, increases the rate of blood flow; actually has an additive effect with pharmacologic interventions |
Intermittent pneumatic compressions | constricts the diameter of the veins, increases the rate of blood flow |
inferior vena cava filter | prevents the embolization of a thrombus formed in the lower extremities in the pulmonary circulation. does not prevent formatino of thrmbous; only use if high risk for PE and risk of bleeding is too high for pharmacologic therapy |
VTE px- pharmacologic | UFH or LMWH, fondaparinux, warfarin, DOACs |
Heparin dose for VTE px | 5000 units sq q 8 or 12 h, no monitoring |
Enoxaparin dose for VTE px | 30 mg sq q 12 h or 40 mg sq d; CrCl <30 ml/min: decrease dose to 30 mg qd |
Fondaparinux dose of VTE px | 2.5 mg sq daily; C/I if CrCl< 30 ML/min |
INR target for warfarin and VTE px | 2 to 3 |
rivaroxaban dose for VTE px | 10 mg po qd; CrCl < 30: avoid use, avoid use in hepatic impairment |
apixaban dose for VTE px | 2.5 mg po BID: CrCl < 30: not recommended for prophylaxis |
VTE risk level for minor surgery, fully ambulatory | low |
Recommended VTE px options for low risk | early ambulation +/- intermittent pneumatic compression devices |
VTE risk level for most surgical patients | moderate |
VTE risk level for medically ill with limited mobility or bed rest | moderate |
VTE risk level for major trauma patients | moderate |
Recommended VTE px options for moderate risk | LMWH, low dose UFH, fondaparinux (medically ill only) OR IPC alone |
VTE risk level for surgical patients (non-ortho) or medically ill with additional risk factors | high |
VTE risk level for spinal cord injury patients | high |
Recommended VTE px options for high risk | LMWH, low dose UFH, PLUS IPC |
VTE risk level for ortho surgery patients | very high |
Recommended VTE px options for very high risk patients | depending on surgery type: LMWH, fondaparinux, apixaban, dabigatran, rivaroxabna, low dose UFH, warfarin or aspirin |
VTE px duration for medical/surgical patients | until discharge or fully ambulatory |
VTE px duration for ortho patients | at least 10-14 days (suggested up to 35 days) |
long distance travel tips to prevent VTE for flights > 8 hours | avoid constrictive clothing around waist or lower extremities, maintain adequate hydration, frequent calf muscle contraction, isle seat preferred (add graded compression stockings for those with mild risk factors for VTE) |
long distance travel tips to prevent VTE for flights > 8 hours for patients WITH risk factors for VTE | same as everyone else + graded compression stockings |
VTE tx goals- short term | aim is to prevent: propagation or local extension of clot, embolization, death |
VTE tx goals- longer term (> 6 months) | prevent complications, such as: post-thrombotic syndrome (PTS), pulmonary hypertension, recurrent VTE |
VTE tx: acute phase (5-14 days) | IV or SC UFH, SC LMWH, SC Fondaparinux, DOACs |
VTE tx: subacute phase (3 to 6 months) | PO warfarin, INR 2-3, SC LMWH in cancer patients or patients with CI's to warfarin, DOACs |
VTE tx: chronic phase (> 6 months) | PO warfarin, INR 2-3, DOACs |
VTE acute tx | want to use fast-acting agents; treatment DOES NOT actively dissolve clots; prevents them from getting bigger |
DVT tx | outpatient treatment is preferred |
PE tx | low-risk PE outpatient tx or early discharge within 5 days is preferred |
Acute tx- UFH | aim for aPTT 60-100 seconds, IV dose 80 units/kg bolus followed by 18 units/kg/hr drip |
Acute tx- LMWH, enoxaparin | dose 1 mg/kg sq BID or 1.5 mg/kg sq qd; adjustment needed if CrCl < 30 |
Acute tx- Fondaparinux | dose adjusted based off of weight; <50 kg = 5 mg sq qd; 50-100 kg = 7.5 mg sq qd; >100kg = 10mg sq qd; CrCl 30-50, use cation; CrCl < 30: C/I |
Acute tx- Rivaroxaban | 15 mg po BID for 3 weeks, then 20 mg po qd; Avoid if CrCl < 30 |
Acute tx- Apixaban | 10 mg po BID for 7 days, then 5 mg po BID; no renal adjustments for DVT/PE |
Acute tx- other options- DTIs | must have parenteral anticoagulant for 5-10 days; ONLY for patinets with HIT or a history of HIT with VTE |
acute tx- other options- antiplatelets | not effective for VTE |
acute tx- fibrinolytics | Alteplase (FDA indicated); Still anitcoagulate with UFH, but at reduced doses |
Catheter-Directed CDT- DVT | recommended over systemic administration |
Catheter-Directed CDT- PE | systemic administration is preferred over CDT |
Acute treatment- thrombectomy | recommended for PE if: hypotension, failed thrombolysis, shock that is likely to cause death before thrombolysis can take effect |
acute tx- length of therapy | acute tx: given for at least 5 days; overlapped with a long-term treatment for those 5 days; acute treatment can be d/c once stable on long-term tx |
long term treatment options | warfarin, LMWH, DOAC, IVC filter |
warfarin bridge therapy | must be overlapped by acute treatment for at least 5 days regardless of INR, must have at least 2 consecutive therapeutic INR values; MOST MEET BOTH OF THESE REQUIREMENTS |
INR monitroing | once INR is stable, you can monitor once every 12 weeks, for stable patients with a single out-of-range INR of < 0.5 above or below therapetuic, we suggest continuing current dose and testing INR within 1-2 weeks |
Warfarin reversal | Vitamin K should only be administered when bleeding is present or when INR > 10 |
Warfarin counseling | indication for warfarin and goal INR, importance of lab monitoring, stress compliance, drug ineractions, dietary interaction, alcohol, signs/sx of clotting and/or bleeding |
long term treatment- LMWH | enoxaparin 1 mg/kg sq q 12 h for at least 3 months |
long-term treatment- dabigatran | 150 mg PO BID |
long-term treatment- rivaroxaban | 15 mg PO BID for 3 weeks, then 20 mg PO d |
long-term teratment- apixaban | 10 mg po BID for 7 days, then 5 mg po bid |
provoked VTE | trauma, surgery, cancer, exogenous androgen, estrogens, etc |
unprovoked VTE | no identifiable cause |
long term tx-duration provoked | 3 months of tx is recomended |
long term tx- duration unprovoked | 3 months of tx then evaluate bleed risk |
long term tx- pregnancy | D/C LMWH or UFH 24 hours before schedules delivery; anticoagulation continued until 6 weeks after delivery and at least 3 months of therapy |
long term tx- cancer patients | LMWH x 3 months, then evaluate risk; Xa inhibitors have limited studies and is not currently recommended |
long term tx- LMWH in obesity recommendations | enoxaparin 1mg/kg BID preferred |
long term tx- renal impairment | UFH is not clinically affected, doses of LMWH should be adjusted for renal impairment; fondaparinux C/I; Oral anti-xa inhibitors C/I with CrCl < 30 ml/min; Apixaban is not adjusted in VTE tx of px; dabigatran adjusted at CrCl 15-30 min |
monitoring for VTE- aPTT | for UFh at treatment doses |
monitoring for VTE- INR | for warfarin only |
monitroing for VTE- Anti-Xa | can be used for LWMH, heparin and fondaparinux |