Term
deep vein thrombosis
pulmonary embolism |
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Definition
| examples of venous thromboembolism (VTE) |
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Term
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Definition
| What is the goal INR of a patient with venous thromboembolism on warfarin? |
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Term
1st occurrence: > or equal to 3 months
2nd occurrence: lifelong
if the cause if reversible, 3 months may be ok, if it is not reversible the patient may need to stay on warfarin for 6 months or more. |
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Definition
| How long should a patient with venous thromboembolism (VTE) stay on warfarin after a 1st occurrence and a 2nd occurrence? |
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Term
CHADS-2
C: congestive heart failure = 1
H: hypertension (or treated hypertension) = 1
A: age > 75 years = 1
D: diabetes = 1
S: prior stroke or transient ischaemic attack = 2
a higher score means a higher risk for stroke
patients with a score >/= 2 should be on warfarin lifelong
patients with a score of 1 should be on either warfarin or aspirin lifelong
patients <75 and no risk factors should be on aspirin and warfarin is not indicated
if score is 1 and the patient is at high risk of bleeding, warfarin is not indicated |
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Definition
| risk factor test for patients with A.fib to determine if they should be put on warfarin |
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Term
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Definition
| What is the goal INR for a patient with A.fib on warfarin? |
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Term
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Definition
| How long should a patient with A.fib stay on warfarin? |
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Term
INR: 2.5-3.5, lifelong
EXCEPTIONS:
bioprosthetic valve ex) bovine/porcine/equine valve, goal INR is 2-3 for a duration of >/= 3 months
bileaflet or tiltingdisk valve in the aortic position with normal sinus rhythm and no left artial enlargement goal INR is 2-3 lifelong |
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Definition
| What is the goal INR for a patient with a mechanical valve on warfarin? |
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Term
cholestyramine
sucralfate
If the patient is taking one of these medications with warfarin, there will be lower concentrations of warfarin and INR will be lower. |
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Definition
| pharmacokinetic interactions of warfarin that effect the absorption |
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Term
phenytoin - will displace warfarin from the protein, increase levels of warfarin, increase INR
aspirin
sulfamethoxazole
warfarin is very protein bound. Medications that have high protein binding will increase INR. |
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Definition
| pharmacokinetic interactions of warfarin that effect distribution |
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Term
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Definition
| warfarin is metabolized by these 3 enzymes |
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Term
inhibitors of CYP2C9/2C19:
metronidazole
TMP/SMX
Fluconazole
Isoniazid
Cimetidine
Amiodarone
Omeprazole
Lovastatin
Inhibitors of CYP3A4:
Ciprofloxacin
Clarithromycin
Erythromycin
Cimetidine
Azole antifungals
Omeprazole
Sertraline
Diltiazem
Isoniazid
Simvastatin
Grapefruit juice
inhibition of the metabolism of warfarin leads to higher warfarin levels |
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Definition
| pharmacokinetic interactions of warfarin that inhibit the metabolism of warfarin. |
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Term
Inducer of CYP1A2:
smoking
Inducer of CYP3A4:
phenobarbital
carbamazepine
rifampin
decrease warfarin levels |
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Definition
| pharmacokinetic interactions of warfarin that induce the metabolism of warfarin |
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Term
diet: dark green veggies
liver
green tea
missed dose of warfarin
lead to decreased INR |
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Definition
| pharmacodynamic interactions of warfarin that increase availability of vitamin K |
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Term
diarrhea/vomiting
extra dose of warfarin
causes an increase in INR |
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Definition
| pharmacodynamic interactions of warfarin that decrease the availability of vitamin K |
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Term
levothyroxine: too much, hyperthyroidism, high TSH, increase INR
cancer: new onset of cancer, INR goes up
hepatic dysfunction: INR goes up
acetaminophen: at 2-4g/day causes INR to go up |
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Definition
| pharmacodynamic interactions of warfarin that change clotting factor metabolism |
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Term
aspirin
clopidogrel
NSAIDs
Fluoxetine/Sertraline (SSRIs) |
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Definition
| pharmacodynamic interactions of warfarin that increase the risk of bleeding (antithrombotic effects) |
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Term
CHF: increase PT/INR response
acute intake of alcohol will increase INR
chronic intake of alcohol will decrease INR
steroids will either increase or decrease INR (variable) |
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Definition
How do the following impact INR:
CHF
alcohol
steroids |
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Term
5mg
factors associated with reducing initial dose: elderly (> 60), CHF, malnourished, liver disease, debilitated, recent major surgery, medications that increase warfarin sensitivity |
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Definition
| usual starting dose of warfarin |
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Term
baseline: INR, CBC
daily INR after 2-3 doses (practice = daily)
discontinue bridging therapy after 2 consecutive INRs at goal
stable INR: check INRs 2-3x/week for 1-2 weeks, then weekly, maximum monitoring interval is 4 weeks |
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Definition
| timeline for monitoring INRs |
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Term
assess contributing factors
0-2 extra doses (for acute issue) OR increase weekly dose by 5-20% (for chronic issue)
recheck INR in 1-2 weeks |
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Definition
| what should be done if a patient has a subtherapeutic INR? |
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Term
assess contributing factors
skip 0-2 doses (for acute issue) OR decrease weakly dose by 5-20% (for chronic issue)
recheck INR in consecutive therapeutic INR: 1st - recheck in 1 week, 2nd - recheck INR in 2 weeks, 3rd and 4th - recheck INR in 3 weeks |
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Definition
| what should be done if a patient has a supratherapeutic INR, but is <5 with no bleeding? |
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Term
assess contributing factors
skip 0-2 doses
recheck INR in 1-2 days |
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Definition
| what should be done if a patient has a supratherapeutic INR that is between 5 and 9 with no bleeding? |
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Term
assess contributing factors
stop warfarin
vitamin K po 2.5-5mg
recheck INR in 24 hours |
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Definition
| what should be done if a patient has a supratherapeutic INR of >9 with no bleeding? |
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Term
ER/call 911
vitamin K IV or PO
fresh frozen plasma
prothrombin complex |
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Definition
| what should be done if a patient is bleeding while on warfarin? |
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Term
vascular injury: platelets adhere, become activated, and aggregate. releases tissue factors to begin the extrinsic coagulation cascade. Causes: venipuncture, catheters, fractured bones, surgery, heart valves, Acute MI, Atherosclerosis
venous status: altered or decreased blood flow in deep veins, lack of venous emptying = endothelial damage to venous valves due to hypoxia. Causes: immobility, prolonged bed rest, obesity, HF, varicose veins, shock, MI, Afib, LV dysfunction, paralysis
hypercoaguability: disease states that could predispose you to clots. Causes: activated Protein C resistance, protein C/S deficiency, antithrombin III deficiency, cancers, pregnancy and other coagulation disorders |
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Definition
| 3 factors of Virchow's triad |
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Term
| deep vein thrombosis (DVT) |
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Definition
most involve veins of the lower extremities
develop behind venous valve cusps or intramuscular veins of calves
consequences: post phlebotic syndrome (post thrombotic syndrome) - symptoms similar to acute thrombotic state (leg swelling, pain, tenderness, skin discoloration, ulceration), possible hypoxia, pulmonary embolism |
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Term
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Definition
most are due to DVT
15-20% of DVT will form this if untreated
high mortality rate
classification: submassive (<50% occluded), massive (>50% occluded) |
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Term
signs and symptoms are neither sensitive or specific
local pain/tenderness
unilateral edema +/- pain
possible cyanosis/reddish color
+/- palpable cord
+ Homan's sign - dorsiflexion of foot produces pain
stasis ulcers/infection |
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Definition
| signs and symptoms of DVT |
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Term
signs and symptoms are neither sensitive or specific
sudden onset of unexplained dyspnea/cough
diaphoresis (sweating)/chest pain/tachypnea (rapid breathing)
hemoptysis (vomiting blood)
circulatory collapse/syncope |
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Definition
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Term
doppler ultrasonography: looks at blood flow through the veins
Real-time B-mode ultrasonography: 3D image that shows where the clot is present
duplex ultrasonography: combination of blood flow and 3D
D-dimer: blood drawn to see if there has been tissue damage
Venography: gold standard, contrast dye is injected. very invasive, many complications |
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Definition
| tests for diagnosis of DVT |
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Term
chest X ray
EKG
arterial blood gases
ventilation/perfusion lung scan: uses 2 radionuclides, xenon measures ventilation and technetium measures perfusion
pulmonary angiogram: injects contrast dye into pulmonary arteries and detects filling defects. gold standard but invasive complications associated. |
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Definition
| tests for the diagnosis of PE |
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Term
initial dose of 80units/kg bolus and 18units/kg/hr infusion
dosage adjustments may be made later |
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Definition
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Term
thrombus extending above the popliteal vein
calf vein thrombosis
documented PE
prevention of VTE or active VTE |
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Definition
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Term
hypersensitivity to UFH
intracranial hemorrhage
actively bleeding/hemophilia
severe hypertension
thrombocytopenia (HIT or HITT) |
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Definition
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Term
aPPT (intrinsic pathway): measured q6h until steady, then qd. should be between 1.5 and 2.5 times the control value.
platelets: obtain CBC at baseline and q2-3d during therapy. monitor for HIT or HITT
hemoglobin/hematocrit: obtain baseline CBC and q1-2d during therapy
PT/INR: obtain baseline and when starting warfarin therapy and thereafter to monitor warfarin |
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Definition
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Term
osteoporosis: possible if receiving 20,000units/d x6months
hemorrhage: can be related to dose, route, duration, age, past history of PUD, comorbid diseases and medications
thrombocytopenia: platelets<150,000/mm^3
HAT (heparin associated thrombocytopenia): benign, transient within first few days (days 2-4), heparin naive patients
HIT (heparin induced thrombocytopenia): platelets drop below 150,000 or 50%, requires immediate intervention, monitor at least every 2 days, treatment - stop heparin and begin DTI
heparin induced thrombocytopenia with thrombosis (HITT): treatment - DTI and begin warfarin when platelets >150,000 |
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Definition
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Term
routine monitoring is not used
aPTT is not severely affected with LMWH
plasma anti Xa activity: obese, severe renal impairment (SrCr < 30), weight < 50kg, prolonged treatment (pregnancy) - after 2nd-3rd dose, 4-6 hours post injection |
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Definition
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Term
hemorrhage
HIT or HITT
hypersensitivity skin reactions
osteoporosis - less than UFH
possibly increase LFTs |
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Definition
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Term
prophylaxis of DVT for patients undergoing hip replacement, abdominal surgery
with warfarin, treatment of acute DVT +/- PE |
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Definition
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Term
love handles (2 inches from belly button)
cleanse site
pinch skin and inject at a 90 degree angle |
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Definition
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Term
prophylaxis/treatment of VTE - ALWAYS, minimum 5 days + LMWH/heparin/fondaparinux, D/C LMWH/heparin/fondaparinux with 2 consecutive INRs at goal, INR goal = 2-3
prophylaxis/treatment or VTE associated with Afib and/or cardiac valve replacement
reduce risk of death, recurrent MI and stroke or systemic embolism after MI or Afib |
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Definition
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Term
goal INR = 2-3
3-6 months: 1st event with reversible cause or time limited RF
>6 months: idiopathic VTE (1st event)
12 months-life: recurrent event, recurrent idiopathic event, 1st event with cancer, anticardiolipin therapy, antithrombin deficiency |
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Definition
| long term anticoagulation, duration of therapy for DVT/PE |
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Term
stable
normal vitals
hemodynamically stable
low bleeding risks
no other conditions needing hospitalization
PE: submassive |
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Definition
| when can an acute DVT/PE be treated outpatient? |
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Term
surgery
age
clinical risk factors
severity of illness |
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Definition
| when is VTE prophylaxis used? |
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