Deep Vein Thrombosis and Pulmonary Embolus

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Deep Vein Thrombosis and Pulmonary Embolus

• Wendy Duperouzel
• Acting Staff Development Educator
• NPDU

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• Describe the risk factors for PE and DVT
• Discuss the clinical manifestations of DVT and
  PE, and discuss the collaborative management
• Describe the preventative measures, including
  current research on the efficacy of different
  types of prophylaxis
• Describe the collaborative management of a
  patient receiving anti-coagulant therapy

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Definition

• DVT - formation of a blood clot in a deep vein of
  the lower extremity
• A clot that travels to the pulmonary circulation
  is termed a pulmonary embolus

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Virchows Triad

• Damage to the venous endotherlium
• Venous stasis
• Altered clotting (procoagulant state)

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Thrombogenic Factors

• Damage to the vessel wall
• Platelet aggregation
• Blood coagulation
• Stasis

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Protective Mechanisms

• Intact endothelium
• Adequate blood flow
• Inactivation of clotting factors by the liver
• A functioning fibrinolytic system

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Risk Factors for DVT

• Inherited
• Hypercoagulable states (Antithrombin III
  deficiency, Protein C deficiency, Protein S
  deficiency)
• Dysfibrinogenemia
• Disorders of plasminogen and plasminogen
  activation

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Risk Factors for DVT

• Acquired
• Lupus anticoagulant
• Nephrotic syndrome
• General Anaesthesia
• Cancer
• Stasis (CCF, MI, cardiomyopathy, constrictive
  pericarditis)

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• Advancing age (over 45!)
• Oestrogen therapy
• Sepsis
• Immobilization
• Stroke
• Inflammatory bowel disease
• Obesity
• Prior Thromboembolism

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• Varicose veins
• Pregnancy
• Extended period in theatre

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Pulmonary Embolus

• Most PEs occur as a result of DVT

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Pathophysiology of DVT

• An injury to the vessel triggers the haemostatic
  process
• Platelets adhere to the damaged endothelium
• If blood flow is diminished platelets aggregate
• Protective factors that inhibit this may be
  unable to reach thrombus due to venous stasis

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• Once a thrombus is formed it may undergo partial
  or complete lysis or persist as unorganised
  fibrin
• May become dislodged to circulation

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Assessment

• Non specific and often inaccurate
• Many individuals may be asymptomatic
• Other conditions of muscle, subcutaneous tissues,
  joints and other structures need to be ruled out

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DVT

• Inflammation and obstruction are key causes of
  DVT symptoms
• Pain and tenderness (at or below site)
• Swelling at or below site
• Redness
• Homans sign

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PE

• Tachypnoea
• Dyspnoea
• Chest pain
• Hypotension
• Sense of impending doom
• Haemoptysis
• Syncope
• Circulatory Failure

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Diagnostic Evaluation

• DVT
• Venography
• Doppler Ultrasonography
• PE
• Pulmonary Angiography
• V/Q Scan
• ABGs
• Chest x ray
• ECG

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Collaborative management

• Prevention and early detection are the primary
  goals for both DVT and PE

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Pharmacological Agents

• Warfarin
• Heparin
• LMW Heparin
• Aspirin

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Adverse Effects of Heparin

• Haemorrhage
• Anaphylaxis
• Osteoporosis
• Thrombocytopenia

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Drugs that affect anticoagulant therapy

• Allopurinol
• amiodarone
• antibiotics
• cimetidine
• phenytoin
• sulfonamides
• thyroid preparations
• flu vaccine
• Nsaids

• Antacids
• barbituates
• phenytoin
• rifampicin

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Mechanical measures

• Early ambulation
• Elevation of the foot of the bed
• Ankle exercises
• Graded elastic stockings
• Intermittent pneumatic compression

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Surgery

• Inferior Vena Cava filter
• Pulmonary Embolectomy

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Patient education for Warfarin

• Limit foods high in Vitamin K (Spinach, broccoli,
  lettuce, cabbage, cauli, asparagus, turnips
• Avoid green tea, and limit coffee and alcohol
• Avoid aspirin
• Reduce or stop smoking
• Avoid shaving with razor

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Report following

• Other medications
• bleeding
• blood in urine
• stools
• vomiting blood
• gum bleeding
• easy bruising
• nose bleeds

• Heavy menstral flow
• Severe or continuous headaches
• dizziness
• faintness
• chest pain
• pelvic pain
• lumbar pain

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Notify

• Physicians
• Dentists
• health care providers