Definition?
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.
RF?
“THROMBOSIS”:Travel,Hypercoagulable/HRT,Recreational drugs,Old (> 60),Malignancy,Blood disorders,Obesity/Obstetrics,Surgery/Smoking,Immobilization,Sickness (CHF/MI,IBD,nephrotic syndrome,vasculitis)!
ddx?
• 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
Epidemiology?
Age:>60
Sex: Female
Ethnicity:
Aetiology?
• Virchow’s triad
• Stasis,
• hypercoagulability,
endothelial damage,
CP?
• 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
Pathophysiology?
- 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
Investigations first line?
PV exam, Wells Score
Wells score?
active cancer paralysis paresis, immobilisation local tenderness swollen leg->3cm pitting oedema collateral superficial veins PMH Top ddx pf DVT
Second line?
- 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
Investigations-third line?
• Doppler flow
• CT abdo
Thrombophilia
Managment initial proximal?
- Anticoagulation
- Depends on RFS
- First line: DOACs
- Second line: Warfarin, UFH if bleeding, LMWH if cancer
- PA
- Early ambulation
- Gradient stockings
management initial distal?
• Imaging of deep veins and anticoagulation-check if symptoms arise
• PA
Gradient stockings
m-initial preg?
• LMWH or subcut unfractionated heparin
• PA
Gradient stockings
m-bleeding?
• IVC filter
• High risk of complications so removed asap after bleeding
• PA
Gradient stockings
INDIVIDUALISED THERAPY?
include anticoagulation, systemic or selective thrombolysis, open embolectomy, or inferior vena cava filter.
ongoing therapy?
• 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
prognosis?
• Depends on thrombus and RF
High risk of recurrence
complications?
• PE • Bleeding during initial treatment • Heparin-induced thrombocytopenia • Heparin resistance • Post-thrombotic syndrome • Bleeding osteoporosis
warfarin interactions?
· 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
