Rosens 86: Pulmonary Embolism And Deep Venous Thrombosis

Front 1

What is fibrin?

Back 1

- The primary structural framework of embolized clot

Front 2

What is the basic process of fibrin deposition?

Back 2

- Vascular injury and exposure of tissue factor
- Fibrin formation from fibrinogen
- Inflammation, increased fibrinogen formation and further fibrin deposition

Front 3

What is Virchow’s triad?

Back 3

1. Vascular injury, 2. Venous stasis, 3. Hypercoagulability

Front 4

List the veins that make up the deep and superficial venous systems.

Back 4

Superficial

Greater saphenous veins
Short saphenous vein

Deep

Calf veins
- Anterior tibial
- Posterior tibia
- Peroneal
Popliteal
Femoral (superficial femoral)
Deep femoral vein
Common femoral vein
External ileac vein

Differentiate proximal and distal DVT.
- Proximal DVT – Popliteal vein or higher
- Distal DVT – Calf vein thrombosis

Front 5

List a differential diagnosis for DVT. (think outside inward)

Back 5

Muscle strain/hematoma
Popliteal (Baker's) cyst
Lymphedema
Cellulitis
Vasculitis
Fracture

Superficial thrombophlebitis
Chronic venous insufficiency
Proximal venous compression (e.g., tumor, gravid uterus)
Congestive heart failure (swelling usually bilateral)
Hypoalbuminemia (swelling usually bilateral)

Front 6

What is the first step in diagnosising DVT?

Back 6

- Estimating the pretest probability

Front 7

Provide the Well’s score for DVT.

Back 7

Active cancer (treated within the previous 6 mo or currently receiving palliative treatment)1

Paralysis, paresis, or recent plaster immobilization of the lower extremities1

Recently bedridden for ≥3 days or major surgery within 3 months requiring general or regional anesthesia1

Localized tenderness along the distribution of the deep venous system1

Entire leg swollen1

Calf swelling at least 3 cm larger than on the asymptomatic side (measured 10 cm below the tibial tuberosity)1

Pitting edema confined to the symptomatic leg1

Collateral superficial veins (nonvaricose)1

Previously documented deep vein thrombosis1

Alternative diagnosis at least as likely as deep vein thrombosis-2

Front 8

high probability(>1) and negative ultrasound, what do you do?

Back 8

repeat in 1 week

Front 9

What test(s) or combinations rule out a DVT?

Back 9

- Negative D-dime in a low pretest probability patient
- Single negative US in a low pretest probability patients
- Single negative US and a negative D-dimer in a non low pretest probability patient
- Two negative US in a non low pretest probability with positive D-dimer

Front 10

What is D-dimer?

Back 10

- Protein derived from enzymatic breakdown of cross linked fibrin

Front 11

What does an elevated D-dimer mean?

Back 11

- Indicates the presence of clot within the body in the last 72 hours

Front 12

List a differential diagnosis of an elevated D-dimer.

Back 12

Fibrin depositiom
- Malignancy
- Pregnancy
- Advanced age prolonged bed rest
- Recent surgery

- Infection
- Inflammation
- New indwelling catheters
- Stroke
- Myocardial infarction

Front 13

What is the dose of unfractionated heparin?

What is the dose of enoxaparin?

Back 13

- Bolus 80U/kg
- Infusion 18U/kg


- Enoxaparin 1mg/kg Q12H

Front 14

Bates. NEJM.2004.
List LMWH alternatives to UFH and doses.

List alternatives to UFH and LMWH in a patient with HIT.

Back 14

- Dalteparin 100U/kg SC q12h or 200U/kg (max 18 000U/day) SC q24h
- Tinzaparin 175U/kg q12 (max 18000U/day)
- Nadroparin 86U/kg SC q12h or 171U/kg q24h (max 17 100U/day)

- Danaparoid
- Leperudin
- Agratroban

Front 15

What is an evidence based first dose of warfarin?

Back 15

- 10 mg – Achieves therapeutic effect faster and without increased complication

Front 16

Bates. NEJM.2004
How long must heparn and warfarin be overlapped because of delayed antithrombotic effect of warfarin?

Back 16

- At least 5 days and until INR has been therapeutic for 2 consecutive days

Front 17

What is preferred to warfarin in patients with cancer?

Back 17

- Long term LMWH

Front 18

List absolute and relative contraindications to anticoagulation.

Back 18

Absolute contraindications
- Active bleeding
- Severe bleeding diathesis or platelet count < 20 000
- Neurosurgery, ocular surgery, or intracranial bleeding within the last 10 days

Relative contraindications
- Mild-to-moderate bleeding diathesis of thrombocytopenia
- Brain metastasis
- Major abdominal trauma
- Gatsrointestinal or genitourinary bleeding within 14 days
- Endocarditis
- Severe hypertension (SBP>200 mmHg, DBP >120 mm Hg) at presentation

Front 19

Bates. NEJM.2004
List contraindications to outpatient therapy for DVT.

Back 19

- Massive thrombosis
- Serious coexisting illness
- High risk of hemorrhage (very old, recent surgery, history of bleeding, renal or liver disease)
- Contraindication to LMWH

Front 20

List indications for thrombolytic therapy for DVT.

Back 20

- Limb threatening thrombosis (phlegmasia cerrulea dolens)
- Symptoms < 1 week
- Low risk of bleeding

Front 21

What is the risk of superficial thrombophebitis in the greater saphenous vein that extends above the knee?

Back 21

- Risk for progression to DVT via the saphenous- femoral junction
- Should be considered for anticoagulation

Front 22

When DVT has been excluded, what is the treatment of superficial thrombophebilits?

Back 22

- NSAIDs
- Heat
- Graded compression stockings – 30 – 40mm Hg on the extremity
- Increased ambulation
- Elevation while at rest

Front 23

List the calf veins.

Back 23

- Saphenous
- Tibial
- Peroneal

Front 24

What proportion of isolated calf veins propagate proximally?

Back 24

- 25%

Front 25

Bates. NEJM 2004
What are the sensitivity and specificity of US for proximal DVT?


What are the sensitivity and specificity of US for calf DVT?

Back 25

- Sensitivity: 95%
- Specificity: 95%

- Sensitivity: 70%
- Specificity: 80%

Front 26

What is the approach recommended by Rosen’s for isolated calf DVTs?

Back 26

- ASA
- Repeat US at 3 – 7 days for propagation

Front 27

What is phlegmasia cerulea dolens

Back 27

- Painful blue leg
o Swelling of the entire leg with extensive venous congestion and associated venous ischemia
o Caused by a massive ileofemoral DVT

Front 28

What is phlegmasia alba dolens?

Back 28

- Painful white leg
o Associated arterial vasospasm associated with massive ileofemoral DVT and phlegmasia cerulea dolens due to vasospasm

Front 29

What treatment should be considered for phlagmasia cerulean dolens and phlegmasia cerula alba?

Back 29

- Thrombectomy

Front 30

List complications of DVT.

Back 30

- PE
- Chronic venous insufficiency
o Pain and swelling
o Varicose veins
o Skin changes
o Nonhealing ulcers

Front 31

What is the mortality of PE diagnosed in the ED?

Back 31

- ~ 10%

Front 32

List risk factors for PE.

Back 32

Inherited thrombophilia-Hypercoagulability

Connective tissue disease-Inflammation

Acquired thrombophilia-Hypercoagulability

Carcinoma (all types, allstages)-Hypercoagulability

Limb or generalized immobility-Stasis

Prior PE or DVTMultiple

Trauma within past 4 wk requiring hospitalization-Inflammation, venous injury and stasis

Surgery within past 4 wk requiring general anesthesiaInflammation- venous injury and stasis

Smoking-Inflammation

Estrogen-Hypercoagulability

Pregnancy/postpartum

Front 33

What % of ED patients with PE will have pain?


What % of ED patients with PE will have dyspnea?

Back 33

- ~70%

- ~90%

Front 34

PERC Rule

Back 34

1. AGE < 50
2. HR < 100
3. O2sat ≥ 95%
4. No unilateral leg swelling
5. No hemoptysis
6. No recent trauma or surgery
7. No prior PE or DVT
8. No hormone use
In Addition to “clinical gestalt” that a patient is low risk (pretest probability <15%) reduces the test threshold to < 2% and may be a tool to avoid speculative d-dimer testing for PE

Front 35

What are Hampton’s Hump and Westermark’s sign?

Back 35

Hamptons hump
– Apex-central, pleural based, wedge-shaped area or infiltrate – represents a pulmonary infarction
Westermatrk’s sign
– Unilateral lung oligemia

Front 36

List ECG changes due to PE.

Back 36

- Tachycardia
- Symmetric T-wave inversion in anterior leads V1-V4
- McGinn-White S1Q3T3 pattern
- Incomplete or complete RBBB

Front 37

Wells PE

Back 37

Symptoms and signs of deep-vein thrombosis 3
Heart rate > 100 1.5
Recent immobilization or surgery < 4 weeks 1.5
Previous DVT or PE 1.5
Hemoptysis 1
Cancer1
Pulmonary embolism more likely than alternative diagnosis3.0

Front 38

What is the test threshold for PE?

Back 38

- ~2% -- pretest probability < 2% are more likely to be harmed by testing
- (Used by Wells and PERC)

Front 39

What is the current best use of D-dimer for PE.

Back 39

- Using an Elisa D-dime < 500 FEU/ml in non high risk patients (PTP < 40%) to reach the test (non test) threshold

Front 40

What is the current sensitivity and specificity of CT scanners?

Back 40

- Sensitivity: 90%
- Specificity: 90%

Front 41

evidence for v/q or ct +/- leg us

Back 41

Anderson JAMA 2007 ct and vq equiv

Meta analysis moores 2004 ctpa miss 1.5%

prospective perrier NEJM 2005 - ok to omit leg us

christopher study 2006 ct good enough

CT only study neg rate -1-1.5%

exluding leg u/s no

Front 42

alternative diagnosis found on CT?

Back 42

Pneumonia (6%)

Unsuspected pericardial effusion (1%)

Mass suggesting new carcinoma (1%)

Aortic dissection (0.5%)

Pneumothorax (0.5%)

Front 43

If the CT scan (or VQ) is to be delayed when should anticoagulation be initiated empiraically?

Back 43

- Implicit or explicit PPT > 40%

Front 44

What is a treatment option for DVT/PE in the patient with contraindications to anticoagulation?

Back 44

- Vena caval filter

Front 45

List indicators available to the emergency physician that a PE is higher risk?

ie other than wells

Back 45

- Hemodynamics
o Persistent tachycardia
o Hypotension SBP < 90
- Oxygenation
o SaO2 < 95%
- Serum marker of cardiac dysfunction
o Elevated troponin
o Elevated BNP
- Echocardiaograohic evidence of right heart dysfunction
o Hypokinesis
o Dilatation

Front 46

List FDA approved fibrinolytic regimens for acute treatment of PE.

Back 46

Streptokinase1 million U infused over 24 hr

Urokinase1 million U bolus followed by 24-hr infusion at 300,000 U/hr

Alteplase15-mg bolus followed by 2-hr infusion of 85 mg. Discontinue heparin during infusion

Front 47

What is the treatment of massive PE?

Back 47

· Anticoagulation + Supportive Care
· Be careful of intubation as this can reduce preload
· Gentle fluid resuscitation (CVP ~ 15mmHg)
· Bad lung down

· Inotropes and Vasopressors
o Norepinephrine then dobutamine

· Thrombolysis
· Catheter Thrombolysis
· Embolectomy

Front 48

What are the indications for thrombolysis in massive PE?

Back 48

· Absolute indications
o Persistent hypotension
o Cardiogenic shock
o Circulatory collapse (syncope and / or the need for CPR)

· Consider in:
o RV strain on echo
o Persistent severe hypoxemia
o Extensive embolic burden
o Free floating thrombus in RA or RV (risk of going to the lung)

Front 49

What are the contraindications to thrombolysis in PE?

Back 49

· Absolute
o History of hemorrhagic stroke
o Intracranial neoplasm
o Head trauma or neuroSx in last 2 months
o Active or recent internal bleed in last 6 months

· Relative
o Bleeding diathesis
o Severe uncontrolled hypertension
o Non-hemorrhagic stroke in last 2 months
o Surgery in last 10 days
o Platelets <100,000

Front 50

What are the thrombolytics that I would use (supported by evidence)?

Back 50

· Infusion
o rt-PA 100 mg over 2hrs
§ 10mg bolus 1-2mins, 90 mg over 2hrs
o Resume heparin
o aPTT < 2X upper limit of normal
· Bolus Dosing
o Cardiac arrest
o 0.6 mg/kg rt-PA over 2 mins
o Heparin

Front 51

how to risk stratify who can be treated as outpatients?

Back 51

PESI (PE Severity Index),class 1,2 ok for outpatient