Deep Vein thrombosis and Pulmonary embolism

1. DVT and PE
Evans Omondi
Munyaga Byanjo

2. CONTENT
Definition
Epidemiology
Aetiology
Risk factors
Pathophysiology
Clinical Presentation
Investigations
Treatment
Complications
Prevention

3. Defn:
Deep vein thrombosis(DVT)
• Is the formation of blood clots in the deep
veins.
Most commonly involves calf, femoral or iliac veins.
Is less common in the upper limbs but the axillary
vein may be involved as a complication of trauma,
long venous infusion catheters, neoplasm or
radiotherapy.

4. Epidemiology
• Common in older women >40 years
• Incidence is at 0.2% in ante-natal period and
0.6% in postpartum. The incidence rises to 1-
2% post caesarian section.
• Left leg>80%
• Ileofemoral more common than calf vein (72%
versus 9%)
• Unfortunately only 5-10% are symptomatic.

5. Aetiology
This is based on the Virchow’s triad:
• Stasis
• Endothelial injury
• Hypercoagulability state
Venous stasis-immobility (prolonged bed rest,
limb paralysis) low cardiac output(heart failure)
varicose veins.

6. • Venous injury- Trauma, i.v cannulation.
• Increase coagulability-malignant diseases,
drugs(oestrgen,oral
contraceptives)dehydration,polycythaemia
• Inherited coagullation effect- Antithrombin III,
protein C, protein S.

7. Risk factors
• Abdominal or pelvic surgery
• Old age
• Prolonged surgery and general anaesthesia
• Obesity
• Malignancy
• Prior DVT
• Increase coagulation diseases-protein C or S

8. • Oestrogen
• Oral contraceptive pills
• Smocking
• Prolonged bed rest
• Pregnancy

9. Pathophysiology
• The thrombus occur in the deep veins of the
leg. Usually originate around the valves. The
calf vein is the usual site.
• It may also originate in the iliac or femoral
vein.
• There is progressive obstruction following
thrombosis in the deep veins.

11. Clinical presentation
Symptoms:
»Asymptomatic
»Pain
» Swelling
» Increase in temperature
» Engorgement of superficial veins
» Erythema

12. Signs:
» Fever, calf warmth, tenderness, pitting
oedema, cyanotic limb.
» Homan’s sign (increased resistance/ pain on
forced foot dorsiflexion)- may dislodge the
thrombus.

13. Well’s Score
Each of following scores a point
» Active cancer(Rx within last 6mths or palliative)
» Paralysis, paresis or recent plaster immobilisation
» Major surgery in last 4wks or recently bedridden > 3days.
» Local tenderness along distribution of deep venous system
» Entire leg swollen
» Calf swelling > 3cm compared to asymptomatic leg
measured 10cm below the tibial tuberosity
» Pitting oedema> in the symptomatic leg
» Collateral superficial vein

14. » Alternative diagnosis is more likely than DVT
minus 2 pts.
» Score ≥ 3pts, DVT is likely
» Score 1-2, treat as suspected DVT and perform
compression US
» Score ≤ 0 perform D- dimer test.

15. Investigations
• Ascending venograpthy; invasive but more
sensitive than duplex
• Doppler U/S
• Blood
• CBC
• INR
• Duplex U/S
• Venography

16. Treatment
• Aim of Rx is to prevent further thrombosis and
pulmonary embolisation,
• Bed rest, elevate the limb, good hydration.
• Calf vein thrombosis may be treated by
compression stockings.
• LMWH e.g. Enoxaparin preferred to
unfractionated heparin because:
» It has a higher bioavailability.
» Less risk of bleeding

17. Oral anticoagulants:
» Warfarin- it inhibits synthesis of vitamin k
dependent clotting factors (II, VII, IX, X), proteins
C and S.
» LMWH is given first for 3-5 days then Warfarin
» The duration for Warfarin is still debatable
However if the risk is reversible its given for 6wks-
6months
» Before starting and during treatment, the
patient’s INR is monitored.

18. DDx
• Ruptured Baker’s cyst
• Cellulitis
• Calf hematoma
• Lymphoedema

19. Complication
• PE-most feared
• Venous Gangrene
• Recurrent DVT
• Varicose veins
• Chronic venous insufficiency
• Post phlebitic syndrome (pain, oedema,
ulceration)

20. Prevention
• Avoid the risk factors-obesity,smoking
• Prevent blood stasis in susceptible patients
through ambulation, use of elastic stockings,
exercise or elevation of legs
• Prophylaxis of susceptible patients with low
dose Aspirin

21. Thank you