DVT Flashcards
What is a DVT? (2 things)
- Formation of thrombus (blood clot) in a deep vein
- Partially / completely blocks blood flow
What percentage of surgical patients do DVT occur in?
25-50%
Who should be assessed for DVT / PE risk and be offered prophylaxis if needed?
ALL HOSPITAL PATIENTS
What are the Risk Factors for DVT? (10 things)
- Age
- Pregnancy
- COCP / Hormone Therapy
- Obesity
- Immobility (Long flights / casts)
- Surgery (esp pelvic / orthopaedic)
- Trauma
- DVT Hx
- Cancer
- Thrombophilia
Make sure u ask ones in bold in OSCE
Why are Venous clots (DVT) easier to form than Arterial clots?
Arterial clots need damage to walls to form clots
Venous clots don’t
What is the Pathophysiology of a DVT? (3 things)
Virchow’s Triad
- Hypercoagulability: Increased Clotting Factor Synth + Increased Platelet adhesion –> Clot
- Endothelial Damage: inflamm / trauma –> Tissue factor exposure –> (Prothombin–>Thrombin) –> (Fibrinogen–>Fibrin) –> Clot
- Stasis: Immobilisation / Venous valve incompetence –> Blood stasis –> Clot
What are the factors that lead to the Hypercoagulability part of Virchow’s Triad? (7 things)
Hereditary causes:
- Antiphospholipid syndrome (causes recurrent miscarriages)
- Factor V Leiden
- Anti-thrombin 3 deficiency
- Protein C/S deficiency
Acquired causes:
- Cancer
- COCP / Hormone Replacement Therapy
- Pregnancy
A FAP COP
So if you see a patient w recurrent miscarriages, she probs has Antiphospholipid syndrome n is @ risk of DVT
What are the factors that lead to the Endothelial Damage part of Virchow’s Triad? (4 things)
- HTN
- Cigarette smoking
- Trauma
- Central Venous Access
What are the factors that lead to the Stasis part of Virchow’s Triad? (4 things)
Immobilisation (long flights / casts)
What are the CF of DVT? (7 things)
- 50% asymptomatic (bc venous collateral channels)
- Unilateral leg pain + swelling
- Calf warmth / tenderness / swelling (entire leg if extensive)
- Red
- Visible superficial veins (bc high venous pressure) (17%)
- Mild fever
- Pitting oedema
What investigations should you do for sus DVT? (3 things)
- Well’s Score
- D-DIMER
- Doppler US
In that order
What does the Well’s Score tell you in sus DVT?
The likeliness of a DVT
2+ score = DVT likely
What does the Well’s Score include? (4 things)
- Recent surgery
- Calf swelling over 3cm (compared to other leg)
- Cancer
- Pitting oedema
1 point each
Ders more but jus remember dese 4
What should you do if the Well’s Score is 2+, aka DVT = likely?
Do a D-DIMER
If your Well’s Score is 2+, but your D-DIMER is NIGGATIVE, what dis mean?
No DVT, go home nigga
If your Well’s Score is 2+, and your D-DIMER is POSITIVE, what dis mean?
Maybe a DVT –> Do a US to confirm
(only “maybe” bc other tings can raise D-DIMER too)
What other tings can cause a raised D-DIMER? (5 things)
- Pneumonia
- Cancer
- HF
- Surgery
- Pregnancy
If your Well’s Score is 2+, D-Dimer is positive, and US is NEGATIVE, what should you do?
Repeat US in 6-8 days
Bc ma mmkin Wells AND D-Dimer both positive n no DVT,wt u playing at
What might you see in a US in DVT? (3 things)
- Increased / Decreased vein diameter*
- Absent colour flow (= completely blocked)
- Increased flow in surrounding superficial veins
*(Increased = Acute DVT / Decreased = Chronic DVT)
What are the FIRST LINE management options for DVT?
DOACs (Apixaban / Rivaroxaban)
What are the SECOND LINE management options for DVT? (2 things)
LMWH (Low Molecular Weight Heparin)
with
Dabigatran / Edoxaban (DOACs) OR Warfarin (Vit K antagonist)
What is the FIRST LINE treatment for DVT but has severe Renal impairment / Antiphospholipid syndrome?
LMWH / Unfractionated Heparin
(DOACs not safe in Renal Impairment bc meant to be cleared by Kidney)
What is the FIRST LINE treatment of DVT in Pregnancy / Breastfeeding?
LMWH
DOACs not safe in pregnancy / breastfeeding
How long should DVT patients take their Anticoagulation meds for?
At least 3 months
After 3 months of anticoagulation meds, what determines if a DVT pt should carry on / stops meds?
If DVT was provoked by an acc event (e.g immobilisation after surgery) (can stop)
or if they jus have acc risk factors (carry on taking for 3 more months)
After 6 month course of anticoagulation meds (bc DVT was unprovoked), what should you do for a DVT pt who will now stop taking meds? (2 things)
Test them for:
- Antiphospholipid syndrome (check for antibodies)
- Hereditary thrombophilias (only if have 1st Degree FHx of DVT / PE)
What are the complications of DVTs? (2 things)
- Pulmonary Embolism
- Post-thrombotic syndrome (50%)
