Upload
hidayat-shariff
View
60
Download
0
Tags:
Embed Size (px)
Citation preview
DEEP VEIN DEEP VEIN THROMBOSISTHROMBOSIS
Prepared by : Maria Devi Adlin
Supervisor : Dr Hasmali
OUTLINEOUTLINE Definition Epidemiology Anatomy Pathophysiology Risk factor Approach to DVT Management complication Prevention Take home message
DefinitionDefinitionDeep venous thrombosis (DVT) is
a formation of blood clots or thrombus in the deep vein of legs or pelvic.
Anatomy of deep Anatomy of deep veinsveins
In the lower leg, three pairs of deep veins exist:
anterior tibial vein (ATV), draining the dorsum of the foot;
posterior tibial vein (PTV), draining the medial aspect of the foot;
the peroneal vein, draining the lateral aspect of the foot.
Just below the knee, all the deep veins joint to become the single large popliteal vein.
In the proximal thigh, the FV and the DFV join together to form the common femoral vein (CFV), which passes upward and form the iliac vein.
Superficial Vein :Superficial Vein :The Great Saphenous Vein originates from
the dorsal venous arch of the foot.After passing anterior to the
medial malleolus, it runs up the medial side of the leg.
At the knee, it runs over the posterior border of the medial epicondyle of the femur bone.
The great saphenous vein then courses medially to lie on the anterior surface of the thigh before entering the saphenous opening.
It joins with the femoral vein in the region of the femoral triangle at the saphenofemoral junction.
AetiologyAetiology
Virchow’s triad:
a) Endothelial injuryb) Stasis or turbulence of blood flowc) Hypercoagulability of the blood
ENDOTHELIAL INJURY
Reduced or stagnant blood flow HYPERCOAGULABILITY
THROMBOSIS
Virchow’s triadVirchow’s triad
In extremely sluggish flow ,thrombus formationin the vein valve pockets is. Thrombus formation occurswhen the natural antithrombotic mechanisms are overcome.By production of• prostacyclin, nitric oxide and tissue plasminogen activator• cell-surface glycosaminoglycans (e.g. heparin sulphate)• the physiological inhibitors of clotting (e.g. antithrombin,proteinC, protein S, see below).
Endothelial damage (due to directtrauma and/or damage to endothelial cells by hypoxia causedby stasis) in the presence of activated clotting factors initiatesthrombosis
there are four main anticoagulant mechanismsin the coagulation cascade that maintain blood flow and restrict thrombosis only to site of injury:• antithrombin• protein C and protein S• tissue factor pathway inhibitor• the fibrinolytic system
Risk FactorsRisk FactorsSTASIS/ENDOTHELIAL INJURY
THROMBOPHILIA MEDICAL CONDITION
DRUGS OTHER
Indwelling venous device
Surgery (most common pelvic and orthopedic)
Major trauma, fracture
Prolonged travel
Paralysis (including anaesthesia > 30 min)
Varicose vein
Activated protein C resistance
Prothrombin gene mutation
Factor V Leiden
Dysfibrinogenemia
Dysplasminogenemia
Hyperhomocysteinemia
Anticardiolipin antibodies
Lupus anticoagulant
Elevated factor VIII level
Protein C deficiency
Protein S deficiency
Malignancy (solid tumor & myeloproliferative disorder)
Pregnancy
MI
CHF
Stroke
Obesity
IBD
Nephrotic syndrome
History of DVT
Heparin-induced thrombocytopenia
Paroxysmal nocturnal hemoglobinuria
Oral contraceptive use
Hormone replacement therapy
Chemotherapy (inclding Tamoxifen)
Increasing age
How to Approach DVTHow to Approach DVT• History
• Presenting complaint – pain, swelling• Time of onset• Is it both legs?• Has there been any trauma?• Is there any pain? (65% below knee DVT are
asyptomatic)• Is there any swelling? How recent?• Have there been any skin changes?• Any odema anywhere else?• Is the patient mobile?• Recent surgery or trauma/fractures• Paralysis/paresis• Plaster immobilisation of lower limb• Recently bedridden for >3 days or major surgery
<4 weeks.
• Look for Symptoms of PE– Pleuritic, sharp chest pain– Acute onset of breathlessness– Haemoptysis
• Previous Medical History– DVT or PE. Arthritis. Malignancy (ongoing treatment, within 6 months or
palliative)– Thrombophilia. Recurrent miscarriages. Diabetes. MI. AF. CVA
• Family History– DVT or PE. Cardiac problems. CVA. Clotting disorders
• Risk Factors– Age, smoker, pregnancy, long haul travel, obesity, immobility
• Drug history & Allergies– Immunosuppressant drugs. Contraceptive pill. Warfarin. IV drug user
Clinical featuresClinical featureshalf of all DVT cases do not cause
symptoms depend on the location and size
swellingrednessTendernessmuscle indurationMild pyrexia
Homan’s sign - tenderness during passive dorsiflexion of foot.
Pratt’s sign - Squeezing of posterior calf elicits pain
Phlegmasia alba dolens - pale, pulseless cold limb due to concurrent arterial spasm
Phlegmasia caerulea dolens - cyanosed limb due to obstructed vein
Clinical PresentationClinical Presentation
Phlegmasia alba dolens Phlegmasia caerulea dolens
DiagnosisDiagnosis• InvestigationsInvestigations
»Complete blood count – Hb, PCV, Platlet count and White cell count»Primary coagulation study»Liver enzymes»Renal function and electrolytes»D – Dimer – fibrin degradation product) is increasingly being used as a screening adjunct. It has a sensitivity of >90% and a specificity of 30–40%.»ECG
• ImagingImaging– Chest radiograph– B-mode ultrasound
–is the first-line non-invasive investigation–a non-compressible thrombus in the thigh and popliteal veins can be diagnosed with 97% sensitivity and 94% specificity
– Venography–invasive, uncomfortable and requires injection of contrast.
– Spiral CT and CT pulmonary angiography –investigations to diagnose pulmonary embolism.
Well’s CriteriaWell’s CriteriaClinical feature PointsActive cancer (treatment within 6 months, or palliation)
1
Paralysis, paresis, or immobilization of lower extremity
1
Bedridden for more than 3 days because of surgery (within 4 weeks)
1
Localized tenderness along distribution of deep veins
1
Entire leg swollen 1Unilateral calf swelling of greater than 3 cm (below tibial tuberosity)
1
Unilateral pitting edema 1Collateral superficial veins 1Alternative diagnosis as likely as or more likely than DVT
-2
Total points
Wells Clinical Prediction Rule for Deep Venous Thrombosis (DVT) Risk score interpretation (probability of DVT): •>/=3 points: high risk (75%); •1 to 2 points: moderate risk (17%);•<1 point: low risk (3%).
• not universally used, still debatable
ComplicationsComplications• Pulmonary Embolism
»The clot from lower limb become detached & passes via IVC & right heart to the pulmonary arteries and may totally occlude the perfusion to part or all of one or both lungs
• Post-thrombotic Limb»Valves in the deep venous channels of the
lower leg have been damaged by thrombotic process
» Recanalized deep veins are functionally inadequate because of the damaged valve.
» bidirectional flow & abnormally high ambulatory venous pressure in the deep vein→ transmitted to subcutaneous vein→ edema, pigmentation, edema, pigmentation, fibrosis, and later, dermatitis, cellulitis fibrosis, and later, dermatitis, cellulitis and ulcerationand ulceration
TAKE HOME MESSAGES :TAKE HOME MESSAGES : DVT is one of those things that has a number of predisposing
causes, so it is in fact mostly preventable Clinical predictive rule : Well’s criteria