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