VTE Flashcards by alyssa smith

Venous thrombi

Composed of RBC, fibrin, and some platelets
Mostly RBCs

How well did you know this?

Not at all

Perfectly

VTE symptoms present when

Flow is obstructed
Vasc tissue is inflammed

How well did you know this?

Not at all

Perfectly

DVTs and PEs

All PEs come from DVTs
Not all DVTs lead to PEs

How well did you know this?

Not at all

Perfectly

Virchow’s triad

Conditions that increase clotting risk
Hypercoagulable state
Endothelial injury
Circulatory state

How well did you know this?

Not at all

Perfectly

Hypercoagulable state

Abnormal clotting components
Ex. pregnancy, cancer

How well did you know this?

Not at all

Perfectly

Endothelial injury

Abnormal surfaces in contact with blood flow
Ex. post-op, traumatic injury

How well did you know this?

Not at all

Perfectly

Circulatory stasis

Abnormal blood flow
Ex. long period of immobility, hospitalization

How well did you know this?

Not at all

Perfectly

Coagulation cascade overview

Cascade initiates -> increases production of thrombin -> results in clot formation

How well did you know this?

Not at all

Perfectly

Factor II

Prothrombin

How well did you know this?

Not at all

Perfectly

Factor IIa

Thrombin

How well did you know this?

Not at all

Perfectly

Postthrombotic syndrome

Long-term complication of DVT
Caused by damaged venous valves
Pigmentation and skin hardening

How well did you know this?

Not at all

Perfectly

DVT risk factors

Age > 40 years
HF, MI
Obesity
Pregnancy
Immobilization > 10 days

How well did you know this?

Not at all

Perfectly

DVT non-pcol treatment

Bed rest w anticoag prn
Elevate feet
Pain management
Compression stockings

How well did you know this?

Not at all

Perfectly

PE non-pcol treatment

Oxygen
Mechanical ventilation
Compression stockings

How well did you know this?

Not at all

Perfectly

Ideal anticoagulant

Oral
Once daily dosing
Quick onset
Limited monitoring and drug interactions
Available and effective antidote
Wide therapeutic index
Low cost

How well did you know this?

Not at all

Perfectly

UFH

Rapid parenteral anticoag
Variable response -> incr aPTT monitoring

How well did you know this?

Not at all

Perfectly

Heparin associated thrombocytopenia (HAT)

Non-immune mediated
Mild platelet decrease
48-72 hours post-admin
Don’t need to d/c heparin

How well did you know this?

Not at all

Perfectly

Heparin induced thrombocytopenia (HIT)

Immune mediated
7-14 days post-admin
Platelet decrease > 50% or to < 100,000 mm3

How well did you know this?

Not at all

Perfectly

HIT management

Stop all heparin products
Give alt anticoag
Don’t give platelet infusions
Don’t give warfarin until platelet > 150,000

LMWH vs UFH

LMWH usually preferred
Better bioavailablility
Predictable dose response
Longer half life -> less freq dosing
Less risk HIT

Injectable FXa inhibitors and DTIs

Fondaparinux : prophylaxis and tx
- Don’t use if renal dysfunction
- Can be used in HIT
Lepirudin: HIT tx
Bivalirudin: HIT tx, alt to UFH during PCI
Argatroban: HIT tx

Warfarin available forms

Coumadin, Jantoven, warfarin
1, 2, 2.5, 3, 4, 5, 6, 7.5, 10mg tablets

Warfarin MOA

Inhibit vitamin K formation and dependent clotting factors (FII, VII, IX, X, Protein C and S)

Test before warfarin if

Warfarin naïve AND
Results available before sixth dose AND
Pt at high risk of bleeding w high INR

Drugs that incr INR w warfarin

Erythromycin Anabolic steroids Metronidazole Bactrim Ciprofloxacin Acute alcohol use

Drugs that decr INR w warfarin

Rifampin Carbamazepine Chronic alcohol ingestion Extreme Vit K ingestion

Antiplatelets in VTE

Limited role ASA if CHA2DS-VASc score = 1 Dipyridamole w warfarin if prosthetic heart valves Adjunct w anticoags and incr bleeding risk

Bleeding management

Discontinue meds Manual compression Maintain BP Surgical or radiological intervention BP products ± PCC ± targeted antidote

Bleeding targeted reversal

UFH, LMWH: protamine sulfate Dabigatran: idarucizumab FXa inhibitors: andexanet alfa

Bleeding w warfarin

INR 4.5-10 + no bleeding -> avoid vit K INR > 10 + no bleeding -> PO vit K Major bleeding -> PCC pref to FFP

VTE prophylaxis

UFH, LMWH, FXa inhibitors, Vit K antagonists

VTE: low risk

< 10% No specific pcol tx recommended

VTE: moderate risk

10-40% Most non-orthopedic surgeries - UFH, LMWH, fondaparinux Acute illness - UFH, LMWH, fondaparinux, rivaroxaban, betrixaban

VTE: high risk

40-80% Orthopedic surgery - LMWH, fondaprinux, rivaroxaban, apixaban, dabigatran (hip), UFH, vit K antagonist Major trauma or spinal cord injury

CHA2DS2-VASc measures

Risk factors for stroke or systemic VTE ONLY w afib pts

HAS-BLED measures

Risk factors for bleeding

CHA2DS2-VASc factors

CHF: 1 HTN: 1 Age ≥ 75 years: 2 Diabetes: 1 Stroke: 2 Vascular disease: 1 Age 65-74 years: 1 Female: 1

HAS-BLED factors

HTN: 1 Abnormal renal/liver funct: 1 or 2 Stroke: 1 Bleeding risk: 1 Labile INR: 1 Age > 65 years: 1 Drugs or EtOH: 1 or 2

Dabigatran approved indications

Hip prophylaxis Non-valvular afib DVT/PE tx

Rivaroxaban approved indications

Post-op prophylaxis Non-valvular afib DVT/PE tx - 1st line Secondary prevention of repeat DVT/PE VTE prophylaxis - usually in-pt use

Apixaban approved indications

Post-op prophylaxis Non-valvular afib DVT/PE tx - 1st line Secondary prevention of repeat DVT/PE

Edoxaban approved indications

Non-valvular afib (adjust w renal impair) DVT/PE tx

Warfarin dosing

Initial dose: 5mg po q1d Healthy outpt dose: 10mg po q1d x2d Bridge w UFH/LMWH/Xa for ≥ 5 days AND until INR is therapeutic (~2-3)

Recommended INR goals

2.5-3.5 - Mechanical heart valve (mitral, caged ball, high risk) 2-3 - VTE prophylaxis - VTE/PE tx - Systemic embolism prophylaxis - Mechanical heart valve (aortic) 1.5-2 - Mechanical On-X

Five D's when interviewing pt

Drugs Diseases Doses Diet Drinking

Bridging procedure w warfarin

Done w invasive procedures Stop warfarin 5 days before surgery Give LMWH or UFH until surgery - Stop LMWH 24 hrs before - Stop UFH 4-6 hrs before Resume warfarin 12-24 hrs post-op