DVT

Question 1

Definition?

Answer 1

Blood thrombus formation in a major deep vein of the thigh, abdomen or lower leg that can impaired venous blood flow and so obstruct circulation.

Question 2

RF?

Answer 2

“THROMBOSIS”:Travel,Hypercoagulable/HRT,Recreational drugs,Old (> 60),Malignancy,Blood disorders,Obesity/Obstetrics,Surgery/Smoking,Immobilization,Sickness (CHF/MI,IBD,nephrotic syndrome,vasculitis)!

Question 3

ddx?

Answer 3

• Cellulitis-redness, heat, small swelling, defined margins
• Calf muscle tear-spasm
• Calf muscle haematoma-ecchymosis, no truma
• Baker’s cyst-tenderness in popliteal fossa
Tumour in leg-no pain

Question 4

Epidemiology?

Answer 4

Age:>60
Sex: Female
Ethnicity:

Question 5

Aetiology?

Answer 5

• Virchow’s triad
• Stasis,
• hypercoagulability,
endothelial damage,

Question 6

CP?

Answer 6

• Unilateral
• Left lower extremity
• Tightness or heaviness
• Warmth, erythema and livid discolouring
• Tenderness
• Dull pain
• Homan sign-calf pain on dorsiflexion of foot
• Meyer sign-calf compression causes pain
• Payr sign-pain when pressure applied over medial sole
• Distension of superficial veins
• Normal distal pulses
• Fever
PE signs

Question 7

Pathophysiology?

Answer 7

• Blood back to heart through network of veins propelled by skeletal muscle contraction and valves
• Blood into RA then RV and pulmonary artery
• Endothelial damage causes VC limiting blood flow
• Platelet activation by clotting cascade forming platelet plug-primary haemostasis
• Clotting proteins made cleaved and goes so on
• Fibrin mesh to form a secondary platelet plug
• Controlled by anticoagulation proteins
  
  • AT-9, 10, 11, 12 and 7, thrombin
  • PC-5 and 8
• Clot grows-low blood flow and high pressure
• TE-breaks off
• Clot TE can move and obstruct PE
• Stasis-turbulent-causes slow collections or inactivity of skeletal muscle pump
  
  • Adhere and activate platelets and clotting factors
• Hypercoagulation-genetic or acquired causes more clotting factors or less anticoagulants
• Endothelial cell injury-infections inflammation or toxins expose collagen and tissue factors

Question 8

Investigations first line?

Answer 8

PV exam, Wells Score

Question 9

Wells score?

Answer 9

active cancer
paralysis paresis, immobilisation
local tenderness
swollen leg->3cm
pitting oedema
collateral superficial veins
PMH
Top ddx pf DVT

Question 10

Second line?

Answer 10

• D dimer level-elevated
• Proximal Duplex US-
  
  • abnormal: inability to fully compress lumen of vein using ultrasound transducer, reduced or absent spontaneous flow, lack of respiratory variation, intraluminal echoes, colour flow patency abnormalities; normal: all vein segments fully compressible, non-diagnostic
• Whole-leg ultrasound-same as above
• INR and aPTT-before warfarin or heparin
• Urea and Creatinine-renal impairment
• LFTs-hepatic failure/cancer
• FBC-assessing bleeding risk for anticoagulant use

Question 11

Investigations-third line?

Answer 11

• Doppler flow
• CT abdo
Thrombophilia

Question 12

Managment initial proximal?

Answer 12

• Anticoagulation
  
  • Depends on RFS
  • First line: DOACs
  • Second line: Warfarin, UFH if bleeding, LMWH if cancer
• PA
  
  • Early ambulation
• Gradient stockings

Question 13

management initial distal?

Answer 13

• Imaging of deep veins and anticoagulation-check if symptoms arise
• PA
Gradient stockings

Question 14

m-initial preg?

Answer 14

• LMWH or subcut unfractionated heparin
• PA
Gradient stockings

Question 15

m-bleeding?

Answer 15

• IVC filter
• High risk of complications so removed asap after bleeding
• PA
Gradient stockings

Question 16

INDIVIDUALISED THERAPY?

Answer 16

include anticoagulation, systemic or selective thrombolysis, open embolectomy, or inferior vena cava filter.

Question 17

ongoing therapy?

Answer 17

• Anticoagulation-3 months min
• BF-LMWH or subcut unfractionated heparin-doesn’t cross into breastmilk
• No BF-anticoagulation
• Check INR before
Further investigations of underlying causes

Question 18

prognosis?

Answer 18

• Depends on thrombus and RF

High risk of recurrence

Question 19

complications?

Answer 19

• PE
• Bleeding during initial treatment
• Heparin-induced thrombocytopenia
• Heparin resistance 
• Post-thrombotic syndrome
• Bleeding
osteoporosis

Question 20

warfarin interactions?

Answer 20

· Avoid eating foods high in vit K frequently eg leafy greens, chickpeas or foods inducing ccP450
· CI in heart meds, NSAIDs, cholesterol-lowering meds, Abs, vitK supplements, anti-fungals
· Drink alcohol in normal ranges