Anticoagulant Acute Injectable Flashcards
What is the virchow’s triad
Vascular wall injury
Venous stasis
Hypercoaguability
What can cause vascular wall injury
Surgery
Trauma
What compromises of venous stasis
Vericose veins
Immobility
Travel (Serena williams)
What can cause hypercoaguability
Thrombophilia
Pregnancy
Cancer
What complications can arise from DVT
Pulmonary embolism
Postphlebitic syndrome
Loss of limb
DVT that occurs above the knee is called
Proximal
DVT that occurs below the knee is called
Distal
What are the complications of pulmonary embolism
Hypertension
Death
Shock
Which form of pulmonary embolism is serious
Saddle embolism
Lobar embolism
What veins are VTE most likely to occur
illiac
Popliteal
Subclavian
Superior and inferior vena cava
Femoral
What are the risk factors for VTE
Age
History of VTE (strongest risk factor)
Venous stasis
Vascular wall injury
Some patient are prone to clotting (thrombophilia) what is the hereditary basis for this pathology
Protein C deficiency
Protein S deficiency
Antithrombin III deficiency
Factor V Leiden: protein C resistance
Prothrombin gene mutation
Some patient are prone to clotting (thrombophilia) what is the acquired basis for this pathology
Antiphospholipid antibody syndrome
- Lupus anticoagulant - Beta 2 glycolprotein antibodies - Anticardiolipin antibody
What are the clinical signs of DVT
Unilateral pain and tenderness
Palpable cord ( thrombus )
Unilateral swelling and discoloration
Positive homan’s sign
Often silent
What is a positive homan’s sign
Pain upon dorsiflexion of the foot
What two imaging tool allow for DVI diagnosis
Venography (gold standard)
Ultrasonography (good sensitivity and specificity for proximal DVT)
Why is the D-dimer lab test done for DVT
To exclude diagnosis of DVT or PE
What are the clinical signs and symptoms PE
Nonspecific
Sudden onset:
Cough
Tachycardia
Dyspnea
Pleuritic chest pain
Tachypnea
What are the more serious signs of PE
Hemoptysis
Cardiovascular collapse
Acute right heart failure
What imaging tool are used for PE diagnosis
Pulmonary angiography (gold standard)
CT pulmonary angiography (high sensitivity and specificity)
V/Q scan (radioactive albumin)
What are the goals of VTE
- reduce recurrence
- prevent post thrombotic syndrome
- reduce thrombus extension
- prevent PE development
- decrease mortality
Which patient population are at risk of developing VTE
Hospitalized
What are the non-pharmacologic intervention
Early ambulation
Graded compression socks
Intermittent pneumatic compression
What are the pharmacology interventions for VTE
Heparin
LMWH
Factor Xa inhibitors
Oral DTI
Warfarin
What are the two LMWH used in prophylaxis of VTE
Enoxaparin
Daltepairin
How is enoxaparin dosed prophylaxis
30 mg SC every 12 hours initiated 12 hours - 24 hours after surgery
-Hip and knee replacement
40 mg SC every 24 hours:
- Acute medical illness - Initiated 12 hours before hip replacement surgery
Or
-Initiated 2 hours before abdominal surgery
What is the post operative dose of dalteparin giving prophiylatically before hip replacement surgery
2500 units SC 4-8 hours after surgery followed by 5000 units SC every 24 hours
How is dalteparin dose prophylactically the evening before a hip replacement surgery
5000 units SC 10-14 hours before
2500 units 4-8hours after followed by 5000 units every 24 hours
How is dalteparin dose prophylactically the day of a hip replacement surgery
2500 units SC 2 hours prior to surgery
2500 units 4-8 hours after surgery followed by 5000 units every 24 hours
How is fondaparinux dosed prophylatically for total hip and knee replacement and hip fracture surgery
2.5mg SQ every 24 hours
How is Apixaban dosed prophylatically for total hip and knee replacement
2.5 mg twice daily
How is dabigatran dosed prophylatically for total hip and knee replacement
110-220mg initially followed by 220mg daily
How is rivaroxaban dosed prophylatically for total hip and knee replacement
10mg daily
How is unfractionated heparin dosed prophylatically for total hip and knee replacement and hip fracture surgery
5000 units SQ every 8 - 12 hours
How is warfarin dosed prophylatically for total hip and knee replacement and hip fracture surgery
Dose adjusted
How is aspirin dosed prophylatically for total hip and knee replacement and hip fracture surgery
Low dose
True or false: anticoagulant therapy is used both inpatient and outpatient
True
When is anticoagulant therapy considered safe for outpatient treatment
- patient is hemodynamically stable
- no comorbidity that would cause hospitalization
- no recent trauma or surgery
- no current hemodialysis or active bleeding
When is heparin alternatives to VTE treatment considered
Allergy or HIT
Patient with high mortality risk are not first treated with anticoagulant, when is a patient considered high mortality risk
Hemodynamics instability ( SBP < 90 mmHg or vasopressor use)
sPESI ≥1:
80 yrs, cancer, chronic pulmonary disease, pulse ≥ 110, SBP < 100, oxygen < 90%
Right ventricular dysfunction
Elevated cardiac troponins
What therapy is used in high mortality risk patient or rescue for hemodynamic deterioration despite anticoagulants
Thrombolytic agents:
Alteplase or streptokinase
Or
Thrombectomy(Surgery) (Surgery)
What medications falls under the antithrombotic class indirect thrombin inhibitor
Unfractionated Heparin or LMWH
What medication make up LMWH
Enoxaparin
Dalteparin
Tinzaparin
What medications of antithrombotic agent falls under the class Factor Xa Inhibitor
Fondaparinux
Apixaban
Endoxaban
Rivaroxaban
Betrixaban
What medications of antithrombotic agent falls under the class direct thrombin inhibitor
Argatroban
Bivalirudin
Desirudin
Dabigatran
What medications of antithrombotic agent falls under the class vitamin K antagonist
Warfarin
Which antithrombotic are considered DOACs
Betrixaban
Edoxaban
Apixaban
Rivaroxaban
Dabigatran
In the treatment of VTE with heparin,fondaparinux or LMWH when should a switch be done to dabigatran or Edoxaban
After the first 5 days switch to:
Dabigatran 150 mg PO twice daily through maintenance and prevention
Or
Edoxaban 60 mg PO daily through maintenance and prevention
In the treatment of VTE with heparin,fondaparinux or LMWH when should an overlap with warfarin be done
After 5 days and INR > 2.0 and dose adjust to INR target of 2.5 through maintenance and prevention
In VTE treatment how is Apixaban dosed
First 7 days: 10 mg twice daily
Day8-prevention: 5 mg twice daily
After the first 6 months: 2.5 mg twice daily
In VTE treatment how is rivaroxaban dosed
First 21 days: 15 mg twice daily
Day 22 till prevention: 20 mg daily
After the first 6 months; 10 mg daily
What is the target INR for warfare dosing
2.0-3.0
When patient has transient risk factor (stasis): immobility, surgery or estrogen use, how long should duration of therapy be
3 months
When patient has unprovoked DVT or PE (i.e no underlying cause) how long should duration of therapy be
3 months to long term
For patients with DVT or PE and cancer after the first 3-6 months initial treatment, how long should treatment be extended
Indefinitely or after cancer resolves
For patients with recurrent VTE or continuous risk factor such as thrombophilias, how long should therapy last
Extended
What therapy is preferred when term is considered
DOACs
What is the basis for heparin dosing during the acute phase treatment
Weight
What is heparin loading dose during acute phase treatment
70-100 units/kg
What is heparin maintenance infusion rate during acute phase treatment
15-25 units/kg/hr
How’s heparin dose adjusted
Based on aPTT
How is infusion rate adjusted for heparin
Use Nomogram
For acute phase treatment how is enoxaparin dosed
1 mg /kg SQ every 12 hrs
or
1.5 mg/kg SQ every 24 hrs
For acute phase treatment how is dalteparin dosed
200 IU/kg SQ every 24 hours
What is the basis for LMWH dosing and what if patient is obese
A) weight
B) use actual body weight
When patient has renal insufficiency (CrCl <30 ml/min) what is the preferred treatment
Heparin over LMWH
How is unfractionated heparin and LMWH dosed prophylaxis
UH: lower doses SQ BID or TID
LMWH: lower doses SQ daily or BID
How is heparin monitored
Measure aPTT 6 hours after initiation and after any dose adjustment
How is LMWH monitored
Not routinely done
For pregnant patient what therapy is preferred
LMWH over heparin
How is hemorrhage managed for patient on heparin or LMWH
Use protamine to reverse hemorrhage
How’s protamine dosed
1 mg for every 100 units of heparin
1 mg for 60% LMWH
When is a patient on heparin experiencing HIT
Platelet <100,000 or drop by >30 -50%
If its 5-10 days of heparin therapy
Thrombosis is present
No other explanation for low platelet
How is HIT managed
Discontinue Heparin
Consider switching to DTIs, fondaparinux or DOACs
For direct thrombin inhibitors, which should PTT be monitored
Argatroban
Which have long half life
Factor Xa inhibitors