Venous Thromboembolism

incidence of VTE is associated with _

age

3 common risk factors for VTE

hospitalized, immobilized

pregnant/postpartum

malignancy

virchow’s triad

venous stasis

endothelial injury

hypercoaguability

4 common sources of hypercoagulability

cancer

pregnancy

estrogen exposure

thrombophilia

3 sources of endothelial injury

surgery

trauma

intravascular catheter

lower extremity thrombi commonly begin around _

venous valve pockets

_ increases potential for embolization

propagation into proximal veins

how do emboli get to the pulmonary arterial circulation

via the right heart

physiological effects of PE

perfusion is blocked → dead space created → V/Q mismatch → hypoxemia

increased pulmonary vascular resistance → RV afterload increased → RV dilation → reduced filling → reduced CO

4 persistent risk factors for VTE

active cancer

autoimmune disease

inflammatory bowel disease

chronic immobility

4 major risk factors for VTE

surgery > 30 min

72+ hour hospitalization

C-section

lower limb fracture

inherrited thrombophilias

Factor V Leiden

prothrombin mutation

antithrombin deficiency

protein C deficiency

protein S deficiency

acquired thrombophilia

antiphospholipid syndrome

DVT presentation

UNILATERAL (still possible to be bilateral though)

• swelling

• pain

• tenderness

• warmth

• erythema

upper extremity DVT may cause _

prominent superficial veins

palpable superficial cord suggests _

superficial venous thrombosis

common PE symptoms

dyspnea

pleuritic or non-pleuritic chest pain

severe PE symptoms

abrupt hypotension

shock

cardiac arrest

other presentations of PE

cough, hemoptysis

presyncope/syncope

unexplained exercise tolerance

red flag pulmonary embolism exam findings

hypotension

evidence of poor perfusion

respiratory distress

signs of RV failure

physical exam findings of PE

tachycardia

tachypnea

hypoxia

possible evidence of poor perfusion

confusion

mottled skin

delayed capillary refill

disposition for Wells score of 0

DVT unlikely

D-dimer

• US if D-dimer positive

features of Wells Score

active cancer

paralysis/immobilization

localized tenderness

entire leg swollen

calf swelling > 3 cm

pitting edema in symptomatic leg

collateral superficial veins

history of DVT

function of plasmin

breaks down fibrin

what is D-dimer

a degradation product of fibrin

when is D-dimer generated

as a thrombus is degraded

normal D-dimer threshold

< 500 (or age x10 for patients 50+)

first line imaging for suspected DVT

ultrasonography

key finding of DVT imaging

non-compressibility

initial evaluation for PE

vitals and perfusion - to assess stability

CBC and CMP - baseline before contrast/anti coag

troponin - ischemia

NTproBNP - RV dilation

ABG - significant hypoxia

cardiac biomarkers are more helpful for _ in PE evaluation

risk stratification

first line imaging for PE

CT pulmonary angiography

CXR classic signs for PE

hampton hump

westermark sign

how does CXR appear in PE

usually normal or non-specific

EKG pattern of PE

sinus tachycardia

S1 Q3 T3

RBBB

most common abnormality on ECG for a PE

sinus tachycardia

Wells score features of PE

signs of DVT

PE most likely

HR > 100

immobilization >3 days

surgery within 4 weeks

hemoptysis

cancer

history of DVT or PE

Revised Geneva score

uses objective findings only and includes age

what does PERC algorithm do

identifies low risk patients who don’t need further PE testing

which algorithm tool is helpful in pregnancy

YEARS algorithim

what does YEARS criteria do

D-dimer cutoff changes with the number of positive itemse

_ on CTPA can represent a thrombus

a filling defect

additional finding in CTPA for PE

RV enlargement

alternative imaging to CTPA for PE

ventilation/perfusion scintigraphy

when is pulmonary arteriography used for PE evaluation

during catheter-directed therapy

for management of complications

when can bedside echo or POCUS be useful for PE

high clinical suspicion + patient is too unstable for CT

significant RV overload may support empiric treatment

when is formal echocardiogram useful for PE

for a stable patient with confirmed PE to assess RV

(particularly category C or >)

echocardiogram for PE is helpful for _

risk stratification

5 clinical categories of risk for PE

A: subclinical

B: symptomatic with low severity

C: symptomatic with elevated severity

D- incipient cardiopulm failure

E: cardiopulmonary failure

index for assessing PE mortality

pulmonary embolism severity index (PESI)

what is Hestia score used for in PE

to determine whether a patient with confirmed PE should be treated outpatient or hospital

management with _ can worsen RV failure

excessive volume from fluids

stabilization for confirmed PE

assess ABCs

use fluids cautiously to not overwhelm the RV

• may be better to use norepi

provide respiratory support (o2, ECMO)

what does initial anticoagulation do for treating VTE

prevents propagation and recurrent embolization while the natural fibrinolytic system gradually breaks down the clot

preferred IV pharmacotherapy for patients to treat VTE

low molecular weight heparin

circumstances where unfractionated heparin is useful

severe renal dysfunction

situations requiring tightly controlled interruption

preferred long term anticoagulation treatment

DOACs (apixaban, rivaroxaban)

why are DOACs preferred over warfarin

less risk of major bleeding

what pharmacotherapy is preferred in preganancy

low molecular weight heparin

when is reperfusion used

clinical categories D or E

patients with extensive DVT

4 types of reperfusion

systemic thrombolysis

catheter directed thrombolysis

mechanical thrombectomy

surgical embolectomy

drugs used for systemic thrombolysis

alteplase

tenecteplase

what is catheter-directed therapy

thrombolytic infused via catheter into pulmonary arteries

_ removes clot using aspiration or extraction devices

mechanical thrombecotmy

when is mechanical thrombectomy useful

to provide reperfusion when bleeding risk from thrombolytic is unacceptable

when is surgical embolectomy an option

for selected critically ill patients at experienced surgical centers

when should IVC filter be considered

for acute VTE with an absolute contraindication to anticoagulation

IVC filter does not _

treat existing clot or prevent new/propogation of DVT

what does IVC filter do

mechanically intercepts emboli traveling from lower extremity veins

primary treatment length of anticoagulation

3-6 months

when is extended/indefinite anti-coagulation therapy indicated (3)

unprovoked clot

persistent risk factor

recurrent VTE

medication options for extended therapy

reduced dose apixaban/rivaroxaban

acute complications of VTE

RV failure

obstructive shock

cardiac arrest

pulmonary infarction

recurrent VTE

bleeding

phlegmasia cerulea dolens

long term sequelae of VTE

post-thrombotic syndrome

post-PE syndrome

chronic thromboembolic pulmonary disease

when is risk of recurrence highest

after unprovoked VTE

with persistent risk factors

when is risk of recurrence lower

after a RESOLVED major transient provoking factor

drug treatment for cancer associated VTE

DOAC or LMWH while coordinating with oncology

caution with what drug for patients with GI/GU cancers?

DOACs

length of treatment in cancer associated VTE

at least 6 months, typically indefinite

what kind of catheter can often remain in place

one that is necessary, functional, and uninfected

therapy for catheter associated DVT

anticoagulation for at least 3 months or as long as the catheter is in place

preferred treatment for antiphospolipid syndrome

warfarin, long-term or indefinitely

preferred treatment for VTE recurrence during anticoagulation therapy

switch to LMWH

2 risks to balance with managing VTE

immediate danger and bleeding

how to manage VTE + high bleeding risk

identify active bleeding

correct modifiable risks

consider using IVC filter

DON’T use reduced DOAC dose for acute VTE

things to review for high bleeding risk patient

antiplatelets

NSAIDs

drug interactions

organ dysfunction

isolated subsegmental PE management

anticoagulate

or

clinical surveillance + serial US for low risk

acute isolated distal calf DVT management

serial US if there’s no severe sx’s or risk factors

what kind of SVT warrants full dose anticoagulation

location less than 3 cm from deep-vein junction

when is anticoagulation for SVT indicated

presence of risk factors

pharmacotherapy for superficial venous thrombosis

fondaparinux for 45 days (intermediate risk)

standard DVT anticoag for high risk

therapy for VTE in pregnancy

LMWH through pregnancy and at least 6 weeks postpartum
(3 month total MINIMUM)

which drugs are contraindicated in pregnancy

warfarin

DOACs

drug options for VTE during lactation

LMWH and warfarin

drug prophylaxis for hospitalized patients at high risk

LMWH preferred

UFH or fonaparinux as alternatives

_ is an alternative to pharmacological prophylaxis in hospital

mechanical prophylaxis and mobility

two kinds of surgery that prophylactic treatment is warranted for

major orthopedic surgery

major abdominal/pelvic cancer surgery

post op prophylaxis from major orthopedic surgery

LMWH or

DOAC or

aspirin from 2-5 weeks

post op prophylaxis from major abdominal cancer surgery

extended LMWH