Haematology

• Complications of venous thromboembolism (VTE)

  • Complications of Deep Vein Thrombosis (DVT)
  • Complications of Pulmonary Embolism (PE)
  • General Complications of VTE
• Post-thrombotic Syndrome (PTS)


  Chronic pain, swelling, and discoloration in the affected limb due to long-term venous insufficiency
• Symptoms of Post-thrombotic Syndrome (PTS)

  • Pain
  • Heaviness
  • Itching
  • Swelling
  • Ulcers in severe cases
• Recurrent DVT


  A new DVT occurring in the same or different vein after initial treatment
• Venous Insufficiency


  Inadequate blood flow return through the veins, leading to chronic swelling and discomfort
• Pulmonary Hypertension


  Increased blood pressure in the pulmonary arteries due to chronic obstruction from blood clots
• Symptoms of Pulmonary Hypertension


  • Shortness of breath
  • Fatigue
  • Chest pain
  • Palpitations
• Right-Sided Heart Failure (Cor Pulmonale)


  Strain on the right side of the heart due to increased resistance in the pulmonary arteries
• Symptoms of Right-Sided Heart Failure

  • Swelling in the legs
  • Ascites
  • Jugular venous distention
  • Fatigue
• Recurrent PE


  Subsequent episodes of PE after the initial event
• Bleeding Complications from Anticoagulation Therapy

  • Gastrointestinal tract
  • Brain (intracranial hemorrhage)
  • Other vital organs
• Chronic Thromboembolic Pulmonary Hypertension (CTEPH)

  A rare but serious condition where blood clots do not dissolve completely and block pulmonary arteries
• Symptoms of Chronic Thromboembolic Pulmonary Hypertension

  • Persistent shortness of breath
  • Fatigue
  • Exercise intolerance
• Paradoxical Embolism


  A rare event where a blood clot travels from the venous system to the arterial system through a heart defect, such as a patent foramen ovale
• Risk factors for VTE

  • Stagnation of blood flow (venous stasis)
  • Enhanced coagulation (hypercoagulability)
  • Vascular damage
  • Endothelial injury
• Causes of venous stasis

  • Immobility (intentional or unintentional)
  • Venous obstruction (e.g. varicose veins, damage after previous DVT)
  • Heart failure
• Frequency of INR monitoring

  • Check INR daily or every other day during initiation
  • Once stabilized, monitor INR every 1-4 weeks
• Therapeutic Range for INR


  The target INR for VTE treatment is usually between 2.0 and 3.0
• Managing INR values


  • Subtherapeutic INR (<2.0): Increase the warfarin dose
  • Supratherapeutic INR (>3.0): Decrease the warfarin dose, consider holding doses and using vitamin K for reversal in severe cases
• Patient education on warfarin

  • Importance of regular INR monitoring
  • Signs of bleeding and thrombosis
  • Potential dietary interactions, particularly with vitamin K-rich foods
• Non-Vitamin K Antagonist Oral Anticoagulants (NOACs)


  A class of medications used to prevent and treat blood clots, also known as direct oral anticoagulants (DOACs)
• Types of NOACs


  • Direct Thrombin Inhibitors (e.g. dabigatran)
  • Direct Factor Xa Inhibitors (e.g. rivaroxaban, apixaban, edoxaban)
• Indications for NOACs


  • Prevention of stroke and systemic embolism in patients with non-valvular atrial fibrillation
  • Treatment and prevention of recurrence of deep vein thrombosis (DVT) and pulmonary embolism (PE)
  • Thromboprophylaxis after certain surgeries, such as hip or knee replacement
• Advantages of NOACs


  • Predictable Pharmacokinetics
  • Rapid Onset and Offset
  • Fewer Dietary Restrictions
  • Fewer Drug Interactions
• Disadvantages of NOACs


  • Cost
  • Renal Function
  • Limited Reversal Agents
• Patient Considerations for NOACs

  • Renal Function
  • Adherence
  • Bleeding Risk
• Differences between heparin and enoxaparin

  • Heparin: Fast-acting, administered IV or SC, requires monitoring of aPTT, can be reversed with protamine sulfate
  • Enoxaparin: Subcutaneous administration, more selective inhibition of Factor Xa, less monitoring required, partial reversal with protamine sulfate
• Comparison of warfarin and NOACs

  • Warfarin: Inhibits vitamin K-dependent clotting factors, requires regular INR monitoring and dose adjustments, numerous drug and food interactions, slow onset and offset
  • NOACs: Direct thrombin or Factor Xa inhibitors, fixed dosing, rapid onset and offset, fewer interactions and dietary restrictions, more convenient but typically more expensive, reversal agents available
• Patient education points for anticoagulants

  • Dosage and Administration
  • Monitoring and Follow-up
  • Diet and Lifestyle
  • Side Effects and Complications
  • Drug and Food Interactions
  • Special Precautions
  • Emergency Situations