Diffuse Alveolar Hemorrhage

Overview

Diffuse alveolar hemorrhage (DAH) is bleeding into the lungs. There are not a lot of known causes of DAH. People with DAH are very sick and usually in the ICU at a hospital.


Bleeding into the alveolar spaces of the lungs characterizes the syndrome of diffuse alveolar hemorrhage (DAH) and is due to disruption of the alveolar-capillary basement membrane. This disruption is caused by injury or inflammation of the arterioles, venules, or alveolar septal (alveolar wall or interstitial) capillaries. Hemoptysis is the usual presenting symptom; however, it is not always present, even when hemorrhage .[1]

Etiology

  • One of three different histopathologic patterns may be seen:
    • pulmonary capillaritis
    • bland pulmonary hemorrhage
    • diffuse alveolar damage (DAD)
Bland hemorrhage
Anti-GBM
SLE
Anticoagulant therapy
Platelet glycoprotein IIaIIIb therapy
Thrombocytopenia
Idiopathic pulmonary hemosiderosis
Leptospirosis
Mitral stenosis
Promyelocytic leukemia

Capillaritis

Microscopic polyarteritis

Behcet's
Cryo
Granulomatosis with polyangiitis
HSP
IgA nephropathy
Paucimmune GN


Diffuse alveolar damage

Infection causing ARDS
Opportunistic infection
Polymyositis
SLE
Amiodarone
Amphetamine
Crack cocaine
Cytotoxic drugs
isocyonate
nitrofurantoin
Penicillamine


Clinical

  • Coughing up blood (hemoptysis)
  • Shortness of breath

Imaging

  • Chest x-ray and CT chest show diffuse infiltrate. Nothing about it is specific for blood as blood and inflammation density looks similar on imaging. 

Lab

  • Anemia usally severe and sudden
  • Evaluate for underlying disease
    • ANCA, ANA, GBM ab

Treatment

High dose steroids 

Actemra

References

[1] S Danoff, R Hallowell. The diffuse alveolar hemorrhage syndromes. Uptodate.