Term
| Where are distal and proximal DVTs? Which is most prominant? |
|
Definition
Distal - calf/tibial veins. Most prominent, least symptoms
Proximal - Femoral, saphenous, popliteal |
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Term
| What is a pulmonary embolism? |
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Definition
| A fibrin clot becomes trapped in the capillaries, causing ischemia and infarction |
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Term
| What are the three sides of Virchow's Triangle? |
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Definition
- Stasis - immobitily, valvular dysfunction
- Vessel wall dmg - trauma, surgery
- Hypercoagulability - cancer, genetic, protein C/S deficient |
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Term
| What are other risk factors for VTE? |
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Definition
Age
Previous VTE
Drug therapy - oral contraceptives, estrogen, SERMs, heparin |
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Term
| What are hypercoagulable states? |
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Definition
- Factor V Leiden
- Prothrombin 20210A gene
- Protein C/S deficiency
- Pregnancy
- Cancer |
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Term
| What area has the highest incidence but the least amount of symptoms of a VTE? |
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Definition
| The distal calf veins are most common but have less symptoms |
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Term
| What is the clinical presentation of a DVT? |
|
Definition
- Swelling, pain, warmth
- Palpable cord
- Unilateral swelling
- Pitting edema |
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Term
|
Definition
-Dopplar - common and noninvasive
- Venography - invasive but more conclusive
- D-dimer - used w/ inconclusive ultrasound, but does not show source |
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Term
| What are complications of a DVT? |
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Definition
- Pulmonary embolism can cause death
- Recurrence of a DVT
- post thrombotic syndrome - insufficient valves, calf pain and swelling |
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Term
| How is a pulmonary embolism diagnosed? |
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Definition
- V/Q scan - block in blood flow but not ventilation results in V/Q mismatch
- Pulmonary angiography - injects dye into pulmonary artery, invasive. |
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Term
| How do you decide risk for a VTE? |
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Definition
| More risk factors, higher age, and more major the surgery = higher the risk |
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Term
| What are the guidelines for VTE PREVENTION? |
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Definition
| - Prophylaxis for 10-14 days with a 12 hour window, up to 35 days for a THR. |
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Term
| What are the guidelines for TREATMENT of VTE with anticoagulation and warfarin? |
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Definition
| Starting on the FIRST treatment day, treat for at least 5 days with overlapping warfarin and anticoagulant until INR is > 2.0 for 24h |
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Term
| After having a VTE, how long should someone be on warfarin? |
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Definition
- Idiopathic or reversible risk factor (stasis, surgery) - 3 months of warfarin
- Active cancer, genetic hypercoagulation states, 2+ episodes of DVT - INDEFINITE warfarin therapy |
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Term
| How is a VTE treated if anticoagulation is contraindicated? |
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Definition
| an inferior vena cava filter |
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Term
| What is the dose for heparin for VTE prevention? |
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Definition
| 5,000 units SQ BID or TID. |
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Term
| What is the dose for heparin treatment of a DVT? |
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Definition
80 units/kg bolus then 18 units/kg/hr IV, remeasure aPTT in 6 hours or after any dose change
- aPTT therapeutic based on hospital parameters. Follow chart instructions. |
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Term
| What are signs of heparin toxicity and how can it be reversed? |
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Definition
- Soft tissue bleeding, blood in the stool or urine, abdominal pain
- Hemoglobin, hematocrit, BP
- Protamine 1mg per 100 units to a max of 50 mg given over 10 minutes neutralizes heparin. |
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Term
| What is the difference between HAT and HIT? |
|
Definition
- HAT - heparin-associated thrombocytopenia - within first few days, platelts don't usually drop below 100k, and then recover
- HIT - heparin-induced thrombocytopenia - after day 5, platelets less that 100,000 or a 50% decrease. IgG mediated |
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Term
|
Definition
Discontinue all heparin sources (including LMWH). No UFH for 3-6 months. IF on warfarin, counteract w/ vit K, may restart when platelets rebound
- alternative anticoagulants: Lepirudin or Argatroban |
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Term
| What advantages does LMWH have over UFH? |
|
Definition
- does not require monitoring
- longer half life
- lower incidence of HIT
- no monitoring needs
- Dose independent clearance |
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Term
| What are the indications for use of Dalteparin/Fragmin? |
|
Definition
| Prophylaxis for replacements, DVT tx ONLY in cancer patients. |
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Term
| What is proper technique to apply Lovenox? |
|
Definition
| - Inject SQ in the abdomen at 90 degrees, do not rub injection site or remove bubble. Alternate sites |
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Term
| How do you calculate CrCl? |
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Definition
| (140-age * IBW / (72*SCr) *0.85 if female |
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Term
| How do you calculate IBW? |
|
Definition
Men = 50 + 2.3(height>60 inches)
Women = 45.5 + 2.3(height>60 inches) |
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Term
| How do you calculate AdjBW? |
|
Definition
For a pt whose body weight>120%
- AdjBW = IBW + 0.4(actual body weight - IBW) |
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Term
| What is the dosing for VTE treatment of Lovenox? |
|
Definition
1 mg/kg q12h or 1.5 mg/kg q24h inpatient
1mg/kg q12h outpatient |
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Term
| What is the LMWH does for VTE prevention for Enoxeparin and Dalteparin? |
|
Definition
Lovenox:
- 40 mg SQ q24 for illness
- 30 mg SQ q12 for trauma starting 12 hrs after surgery. Q24hs if CrCl<30
Fragmin: 5,000 units SQ q24h |
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|
Term
|
Definition
- Monitor CBC q5-10 days for first 2 weeks then 2-4 weeks after
- Monitor anti-factor Xa only if:
- CrCl under 30
- 50- Therapy > 14 days or pregnant
- Measure 4 hours after dose - target 0.5-1 unit/ml |
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Term
| What side effects are seen in LMWH and can they be reversed? |
|
Definition
- Less bleeding than UFH, small risk of spinal paralysis
- 1 mg of protamine per 1 mg Lovenox or 100 units Fragmin inactivates 65%.
- Lower risk of HIT or osteoporosis |
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Term
What is Arixtra/Fondaparinux used for?
How is it dosed? |
|
Definition
- Treatment of DVT/PE
- Prevention from hip fracture/replacement, knee replacement & abdominal surgery
- Prevention dose 2.5mg SQ daily 6 hrs after surgery x5-9 days
- Tx dose 5 mg sq if < 50 kg, 7.5 if between 50 and 100, and 10 if over 100 kg
- No monitoring, but reduced dose w/ reduced CrCl, cannot use in CrCl < 30 |
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Term
| What is Rivaroxaban/Xarelto used for? |
|
Definition
- ONLY for VTE prevention after hip/knee replacement
- 10 mg po daily or 12 (knee) or 35 (hip) days, do not use if CrCl < 30 |
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Term
| What drugs are direct thrombin inhibitors, and what are they used for? |
|
Definition
Used for the treatment of HIT via IV
Lepirudin, Desirudin, Bivalrudin, Argatroban |
|
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Term
| What are contraindications to anticoagulation therapy? |
|
Definition
- active bleeding or hemorrhagic conditions
- Severe thrombocytopenia (<20,000) or history of HIT
- malignant HTN
- can't monitor
- Liver disease |
|
|
Term
| What are the different chiralities of warfarin metabolized by? |
|
Definition
S - 5x more potent - 2C9
R - 3A4 |
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Term
| What is warfarin indicated for? |
|
Definition
- Prevention and Tx of DVT and PE, complications for Afib and heart valve replacement, and reduce the risk of thromboembolitic events such as stroke
- Pregnancy Catagory X |
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|
Term
What is a normal INR?
What is the goal range for a DVT patient? |
|
Definition
Normal - 1.0
Goal - 2.0-3.0 |
|
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Term
| How long does it take for warfarin to reach it's full effect and why? |
|
Definition
Factor 2 is depleted last, takes 8-15 days
Initial draw in 3 days |
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|
Term
| When should warfarin therapy be started? |
|
Definition
| The same day that LMWH or Heparin is started, with overlapping therapy for at least 5 days |
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Term
| How are warfarin doses adjusted? |
|
Definition
- Add up weekly dose
- increase/decrease by 5-20% (usually 15-20%). Multiply weekly dose by 20%
- For every dose held, INR drops by 1 |
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Term
| When is warfarin INR monitored? |
|
Definition
- Every 3 days for the first week
- Every 7-14 days until stable
- Every 4 weeks, if very stable every 12 weeks. |
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Term
| How is warfarin therapy handled for a surgery patient? |
|
Definition
- Stop warfarin therapy 5 days before surgery
- Start 12-24 hrs after surgery
- Bridge w/ Lovenox during interruption for high risk patients |
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Term
| What lifestyle factors affect INR? |
|
Definition
- Diet - leafy greens, liver, mayonnaise
- Tobacco - decreases INR (higher risk of DVT)
- Alcohol - Incr INR (bleed risk)
- OTCs, physical activity, travel |
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Term
| What medical conditions increase INR or bleed risk? |
|
Definition
- Impaired liver function
- Heart failure
- Hyperthyroidism
- GI illness |
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Term
| What are signs of bleeding patients should look for with warfarin? |
|
Definition
Blood in the soft tissues such as gums, nose, stool, and urine
Easy bruising
lab monitoring |
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Term
| How is an elevated INR managed? |
|
Definition
INR 3.5-4.5 - hold one or two doses
INR 4.5 - 10 - hold 2-4 doses, phytonadione 2.5-5 mg po once
INR > 10 - phytonadione 5 mg po once |
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Term
| What are two rare toxicities warfarin causes? |
|
Definition
- Skin necrosis - in areas of high SQ fat, on days 3-8. Stop warfarin and counteract.
- Purple Toe syndrome - week 3-8 |
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|
Term
| What drug decreases warfarin absorption |
|
Definition
| Bile acid sequestrants - decrease INR |
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Term
| What drugs will decrease warfarin metabolism through inhibition of warfarin metabolism? |
|
Definition
2C9 and 3a4 inhibitors:
FAB4: Fluconazole, Amiodarone, Bactrim, Flagyl
St John's Wort, Cimetidine, SSRIs
- Increase in INR due to more circulating warfarin |
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|
Term
| What drugs will increase warfarin metabolism due to induction? |
|
Definition
Carbamazepine, phenytoin, phenobarbital, Rifampin
- Decrease INR due to less warfarin |
|
|
Term
| What drugs displace warfarin from proteins, and what is that effect? |
|
Definition
- More circulating warfarin - increased INR
- ASA, gemfibrozil, phenytoin |
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Term
What conditions decrease production of vitamin K by decreasing gut flora?
What conditions increase catabolism of clotting factors? |
|
Definition
Both increase INR
- Oral antibiotics, Diarrhea
- Fever, hyperthyroid |
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|
Term
What decreases platelet aggregation, and therefore increases bleeding risk?
What increases risk for GI bleed? |
|
Definition
- OTCs that start with G: Ginseng, Ginkgo, Garlic, Ginger, also Vit E
- all NSAIDs, plavix, high dose tylenol |
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