Makindo Medical Notes

A retrospective review of 34 cases of DAH revealed that nearly one-third of the cases were caused by granulomatosis with polyangiitis (previously known as Wegener granulomatosis).

About

• Diffuse Alveolar Haemorrhage (DAH): A condition where blood acutely fills multiple alveolar spaces throughout the lungs.

Aetiology

• Disruption of the alveolar-capillary basement membrane.
• Bleeding originates from the pulmonary (not bronchial) vasculature.
• Blood escapes through the capillary walls into the alveoli.
• Triggers include injury, inflammation, and hypertension.
• Bleeding may occur from arterioles, venules, or alveolar septal capillaries.

Associations

• Pulmonary vasculitis, including ANCA-associated vasculitides:
• Microscopic polyangiitis
• Granulomatosis with polyangiitis
• Churg-Strauss vasculitis
• Goodpasture syndrome
• Henoch-Schönlein purpura
• Systemic Lupus Erythematosus (SLE)
• Mixed connective tissue disease
• Coagulopathy
• Cryoglobulinaemia (associated with HCV/HIV)
• HIV (may be associated with Kaposi sarcoma)
• Inhaled toxins
• Mitral valve disease and heart failure
• Pulmonary veno-occlusive disease
• Hemorrhage associated with infection, alveolar damage, or malignancy
• Antiphospholipid syndrome
• Allogeneic haematopoietic stem cell transplantation (allo-HSCT)

Triad

• Lung Opacities: Associated with dyspnoea, haemoptysis, and anaemia.
• Chest CT: Typically shows diffuse ground-glass opacities and alveolar infiltrates without pleural effusion, and a normal heart.
• Bronchoscopy with BAL: Progressive bloody return on sequential lavage aliquots.

Clinical Features

• Acute onset of hypoxaemia and dyspnoea, often accompanied by haemoptysis.
• In severe cases, patients may present with shock and renal failure.

Investigations

• FBC: Falling haemoglobin (Hb) and haematocrit levels.
• LDH: Often increased.
• Serologic tests: ANA, dsDNA, ANCA, anti-GBM, and antiphospholipid (APL) antibodies.
• Clotting Screen: Evaluate for coagulopathy.
• CXR: Diffuse alveolar infiltrates.
• ABG: Evidence of respiratory failure.
• Echocardiography: Performed to exclude underlying cardiac disease.
• Bronchoscopy: Progressive bloody bronchoalveolar lavage (BAL) is characteristic.
• Chest CT: Shows ground-glass changes and may reveal progressive fibrosis.

Complications

• Respiratory failure
• Disseminated Intravascular Coagulation (DIC)
• Organizing pneumonia

Management

• Initial Stabilization: Follow ABC protocols, provide oxygen, and initiate supportive care. Mechanical ventilation may be necessary in cases of respiratory failure. If infection is suspected, administer appropriate antibiotics.
• Withdrawal of Offending Agents: Discontinue any drugs that may be contributing to the alveolar haemorrhage and correct any coagulopathy.
• Immunosuppressive Therapy: Use high-dose corticosteroids along with immunosuppressant drugs. Plasmapheresis may be indicated, particularly in conditions such as Goodpasture syndrome.
• Targeted Treatments:
  • For systemic vasculitis (e.g., granulomatosis with polyangiitis, microscopic polyangiitis, Churg-Strauss vasculitis): Cyclophosphamide or Rituximab.
  • For anti-GBM disease: Cyclophosphamide combined with plasmapheresis (PLEX).
  • For antiphospholipid syndrome: Rituximab may be considered.

References

• Diffuse Alveolar Haemorrhage – Pulmonology Advisor