6.8 Venous Thrombosis & Hypercoagulability

Question 1

What are the most common risk factors for developing DVT/hypercoagulable state?

What past history puts you at higher risk?

Answer 1

• Risk factors
  
  • Immobility
  • Trauma
  • Recent hospitalization
  • Pregnancy
• Past Hx
  
  • Hx of DVT
  • Prothrombotic disorder: SLE, IBD, Nephrotic syndrome, myeloproliferative disorders
  • Drugs: oral contraceptives, hormone replacement, hydralazine, procainamide, phenothiazines
  • Indwelling central lines and catheters

Question 2

What are the two main categories of thrombophilia, and what are common causes of each?

Answer 2

• Inherited thrombophilia: genetic tendency toward VTE (20-40% of DVT patients)
  
  • Promoting clots:
    
    • Factor V leiden mutation
    • Prothrombin gene mutation
  • Impeding anticoagulation:
    
    • Protein C/S deficiency
    • Antithrombin deficiency
  • 2 or more defects common, and increase risk dramatically
• Acquired thrombophilia
  
  • Malignancy and cancer tx
  • Myeloproliferative dz
    
    • Polycthemia vera
    • Essential thrombocythemia
  • Surgery - orthopedic
  • Trauma
  • Antiphospholipid syndrome
  • HF - sluggish forward flow
  • Cenvtral venous catheter
  • Pregnancy
  • OCP use, hormone therapy
  • Immobility
  • Severe liver dz
  • IBD
  • Nephrotic syndrome
  • Paroxysmal noctural hemoglobinuria
    *

Question 3

Describe Well’s Criteria for DVT and for PE

Answer 3

• DVT
  
  • Score > 2, likely DVT
  • Score < 2, unlikely DVT
  • Active cancer
  • Surgery in past 12 weeks or immobile > 3 days
  • Calf swelling > 3cm
  • Collateral superficial veins
  • Entire leg swollen
  • Localized tenderness along venous system
  • Pitting edema in symptomatic leg only
  • Paralysis, paresis, or immobilization of symptomatic leg
  • Hx of DVT
  • No alternative diagnosis more likely
• PE
  
  • >4, Likely PE
  • <4, Unlikely PE
  • HR > 100
  • Surgery in pasr 4 wks or immobile past 3 days
  • Hx DVT/PE
  • Hemoptysis
  • Malignancy with tx
  • Signs of DVT
  • No alternative dx more likely

Question 4

Describe your DVT workup

Answer 4

• Wells score
• Doppler studies of BLEs
• Doppler BUEs if upper extremity DVT suspected (assymetric swelling, indwelling cath, thrombophebitis)
• Evaluate for provoked vs unprovoked etiologies
• CBC, PT/INR, PTT
• Consider angiogram
  
  • Evaluate blood flow in extremity
  • May reveal vascular injury or anomaly or anatomical variation causing external compression on vessel
  • Thoeracic outlet obstruction, aneurysm, mass

Question 5

Describe your PE workup

Answer 5

• Wells criteria
• CTA chest gold standard
• If cannot undergo CTA, consider VQ but less specific

Question 6

How will you treat your patient with DVT/PE?

What if they’re in shock?

What if they cannot be anticoagulated?

Answer 6

• Systemic AC with heparin IV or therapeutic weight-based enoxaparin
• Transition to PO agent for 3 month course of AC
  
  • Wafarin vs DOAC
    
    • Apix, dabig, rivarox
• If in severe shock/cardiac arrest
  
  • IV TPA
• If unable to anticoagulate systemically
  
  • Consider IVC filter