Vascular Thromboembolic Disease Flashcards Preview

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Flashcards in Vascular Thromboembolic Disease Deck (47)
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1
Q
Hemostasis
A
the physiologic process by which bleeding stops
2
Q
Thrombosis
A
add definition
3
Q
Thrombus
A
add definition
4
Q
Embolization
A
add definition
5
Q
Emboli
A
add definition
6
Q
Key Pathologic Consequence of clot
A
REDUCTION IN or CESSATION OF BLOOD FLOW
7
Q
Underlying Inciting Event in several Clinical Diseases
A
TIA/CVA, MI, DVT, PE, etc.
8
Q
Substances that can embolize
A
Air
Amniotic Fluid
Foreign Bodies
Parasitic Eggs
Septic Emboli
Tumor Cell
MOST COMMON: Thrombus
9
Q
Location of Thromboembolism
A
can occur anywhere in Cardiovascular System
10
Q
Purpose of Hemostatic System
A
Prevent blood loss due to vascular Injury
11
Q
Thrombus: A leading cause of morbidity and mortality
(Epidemiology)
A
US: cause of death in ~1 million individuals per year

Annual Incidence: ~1 case/1000 individuals
12
Q
Components of hemostatic system
A
Formed Elements: Cells (Platelets, Monocytes, RBCs) &
Plasma Proteins (Clotting Factors, Fibrinolytic Factors, Inhibitors)
Vessel Wall: Epithelium, vonWillibrand Factor (vWF), Collagen, Tissue Factor
13
Q
Hemostasis- Vascular Injury
A
will expose VW factor, collagen matrix, etc. and when this is exposed that’s when coagulation occurs
14
Q
Primary Hemostasis
A
formation of platelet plug
15
Q
Secondary Hemostasis
A
Clotting Cascade: Activate Fibrin (form meshwork that binds everything together)
16
Q
Hemostasis- Fibrinolysis and Regulation
A
once clot is formed, further clot formation is prevented and clot starts to breakdown
17
Q
Arteries
A
Higher Pressure
More smooth muscle
Atherosclerosis
18
Q
Veins
A
More Distensible
Capacitance Vessels
Valves
Virchow’s Triad
19
Q
Arterial Thromboembolism may cause
A
Arterial Occlusive Disease
Myocardial Infarction
Ischemic Cerebrovascular Accident
Mesenteric Ischemia
Vasculitides
20
Q
Venous Thromboembolism (VTE) may cause
A
PE
DVT
Superior Vena Cava Obstruction
Chronic ThromboEmbolic Pulmonary HTN (CTEPH)
Dural Sinus Thrombosis
Portal Vein Thrombosis
Vasculitis-Bechet’s, Granulomatosis with polyangiitis
Mesenteric Vein Occlusion
21
Q
Pulmonary venous thromboembolism (AKA PE)
A
3rd leading cause of death among hospital pts
Often not recognized ante mortem
22
Q
Thrombus description
A
-Most common etiology of emboli
-Most Common Site of Origin is Deep Veins of the Lower extremities
-Found in 50-70% of pts with symptomatic PE
-Can Form AnywhereThrombus
23
Q
Diagnosis of VTE (venous thrombolytic embolism)
A
-NOTORIOUSLY DIFICULT DIAGNOSIS
-Findings depend of size of embolus and preexisting cardiopulmonary disease
-Common signs and symptoms are not specific
24
Q
Signs & Symptoms of VTE
A
*Dyspnea
*Pain on inspiration
*Tachypnea
Cough
Hemoptysis
Leg Pain
Tachycardia
Palpitations
Crackles
Homan’s Sign- Dorsiflex foot and have calf tenderness (may be indication of DVT)
25
Q
DIFFERENTIAL DIAGNOSIS for VTE
A
Pneumonia
Lung Cancer
MI
COPD
Asthma
Traumatic Injury
Muscle Strain
Costochondritis
Inhalation Injury
Aortic Aneurysm
Congestive Heart Failure
26
Q
Virchow’s Triad- 3 things that promote coagulability
A
Stasis, Hypercoagulability, Endothelial injury
27
Q
Description of Stasis (part of Virchow's triad)
A
Stasis
Prolonged immobility
post orthopedic surgery,
Low Cardiac Output
Pregnancy
Post CVA
Travel (Air, Car)
28
Q
Description of Hypercoagulability (part of Virchow's triad)
A
Hypercoagulability
Medications: Oral Contraception, Hormone Replacement
Malignancy
Genetic: Factor V Leiden, Protein C/S/antithrombin III deficiency/dysfunction, prothrombin gene mutation, hyperhomcysteinemia, antiphospolipid antibodies
29
Q
Description of Endothelial Injury (part of Virchow's triad)
A
Traumatic Injury
Recent Surgery
Previous Thrombosis
30
Q
EKG findings of VTE
A
-Abnormal in about 70% of pts with PE
-Most Common Finding: Sinus Tachycardia & Nonspecific SR and T wave changes
-Right Heart Strain: RBBB, Right Axis Deviation, S1Q3T3
-Prominent S wave (lead 1), Prominent Q wave (lead 3) and Inverted T wave (lead 3) -->this may also indicate PE
31
Q
Arterial Blood Gas findings of VTE
A
-Usually Respiratory Alkalosis
-Abnormal pO2 and Alveolar-arterial O2 gradient
-NOT DIAGNOSTIC
-->*Profound Hypoxia with Normal Chest X-ray THINK PE*
32
Q
D-dimer
A
**Indicative of general clot formation (not specific)**
-Fibrin Degradation product
-Can be elevated in trauma, always elevated with inflammation
-Positive D-dimer DOES NOT INDICATE a PE
-Sensitivity 95-97%, Specificity 45%
-NO diagnostic threshold established for positive result
-BEST INFORMATION WHEN NEGATIVE (indicates NO clot has formed)
-Negative
33
Q
Other Lab findings of VTE
A
-Serum Troponins, BNP typically elevated in PE
-Indicative of R heart strain/R heart failure
-Not Useful in diagnosis, correlate with adverse outcomes
34
Q
Findings of Chest Xray with VTE
A
-Useful to rule out other etiologies
-Most Frequent findings: Atelectasis, Parenchymal Infiltrates, Pleural Effusion
35
Q
Uncommon Findings of Chest Xray with VTE
A
Westermark Sign: prominent central pulmonary artery with local oligemia; Absence of vascular markings distal to engorged central pulmonary vein

Hampton’s Hump: pleural based areas of increased opacity representing intraparenchymal hemorrhage (may represent pulmonary infarct as well)

LOOK UP PICTURES
36
Q
Gold standard for diagnosing VTE
A
**CT angiography** (WITH CONTRAST)

Very sensitive for large central pulmonary arteries and veins; may see saddle embolus indicated by lack of contrast (filling defect)
37
Q
With VTE, primary and secondary findings of CT angiography are
A
-Requires IV contrast dye
*Primary finding suggestive of PE: Intravascular filling defect, Very sensitive for central vascular filling defects
-~80% sensitive, 96% specific
-15-20% false negative rate (high)

*Secondary Findings suggestive of PE: Abrupt arterial cutoff, asymmetrical blood flow, prolonged or slowed filling
38
Q
Normal CT chest requires
A
initiation of empiric therapy (high pretest probability) or further testing (V/Q scan, etc.)
39
Q
Ventilation Perfusion (V/Q) scan
A
-Perfusion assessed by injection of radiolabeled albumin injected into venous circulation
-Ventilation assessed by records distribution of inhaled radiolabeled gas
-The two mages are compared, looking for defects
40
Q
Ventilation Perfusion (V/Q) scan and probability of VTE
A
-Criteria for assessment are complex, confusing and not standardized
-Reported in terms of probability: low, intermediate, and high
-PIOPED1; If low, 14% probability of PE. Combined with low pretest probability , lowers risk to 4%
-If indeterminate, low or intermediate probability, further testing required (if pretest is low, further testing is required)

-Lower extremity doppler may be used to see if there is a blood clot
41
Q
Venous Ultrasonography: positive and negative tests are indicated by ________
A
-Positive Test: Incompressibility of common femoral or popliteal veins
-In a patient with appropriate symptoms (unilateral swelling, erythema of one limb vs. another) --> Positive predictive value 97% (more likely, probably present)

-Negative Test: Full compressiblity at both vessels
-Negative Predictive value 98% (less likely, probably no there)
-Less accurate in distal thrombi, recurrent thrombi, and asymptomatic patients
42
Q
Integrated Approach to PE Diagnosis: Wells Criteria
A
Wells Criteria: scoring systems to assess PE Risk

1. Clinical Signs and symptoms of DVT: Unilateral edema, and pain with palpation *3 pts*
2. Alternative Diagnosis Less likely than PE (if you’re not suspecting another diagnosis like muscle cramping, traumatic injury, etc) *3 pts*
3. Pulse >100bpm *1.5 pts*
4. Immobilization >3days in past 4 wks *1 pt*
5. Previous DVT/PE *1 pt*
6. Hemoptysis *1 pt*
7. Cancer (With Tx w/in past 6 mo. or Palliation) *1 pt*

Total >4pts: Imaging warranted
Total
43
Q
People who are HIGH RISK for PE/DVT

(DVT/PE ARE preventable)
A
Surgical patients, Major orthopedic procedure/arthroplasty, Abdominal/pelvic cancer undergoing surgery, recent spinal cord injury or major trauma w/in previous 90days,
>3 intermediate criteria
44
Q
People who are INTERMEDIATE RISK for PE/DVT

(DVT/PE ARE preventable)
A
Ambulation 30, OCP/HRT use, Immobilization >72hrs, Hypercoagulable state, nephrotic syndrome, burns, cellulitis, varicose veins, paresis, Systolic Heart Failure, COPD exacerbation
45
Q
People who are LOW RISK for PE/DVT

(DVT/PE ARE preventable)
A
Minor procedures, age
46
Q
Interventions for DVT/PE
A
Sequential Compression Devices
Medication: Heparin, Lovenox
47
Q
Treatment for Pulmonary VTE
A
Heparin or Catheter directed tPA