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Diffuse Alveolar Hemorrhage (DAH) is a life-threatening pulmonary syndrome characterized by intra-alveolar bleeding, resulting in hemoptysis, anemia, diffuse lung infiltrates, and hypoxemic respiratory failure. It reflects bleeding into the alveolar spaces, not due to trauma or coagulopathy alone.
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Defining alveolar hemorrhage (DAH) syndromes. An alveolar hemorrhage syndrome is present when bronchoscopy produces progressively bloody lavage fluid. Early after hematopoietic cell transplantation, providers often consider prescribing empiric antibiotics, systemic corticosteroids, blood transfusions, procoagulant therapies, and diuretics. To guide communication and tailor treatments, we subcategorize the factors that underlie alveolar hemorrhage as infection-associated, bland, and noninfectious inflammation. A National Institutes of Health workgroup established “diffuse alveolar hemorrhage” after hematopoietic cell transplantation as a subtype of idiopathic pneumonia syndrome. It can be difficult to determine which factor is driving an individual's alveolar hemorrhage and co-existing factors, such as infection and noninfectious inflammation, may benefit from multicomponent intervention. As an example, whenever possible we give early empiric antibiotics and platelet transfusions while awaiting microbiology studies and initiate systemic corticosteroids and withdraw antibiotics when infection is not detected. There is no definitive test to differentiate DAH from drug pneumonitis and it is reasonable to initially treat both with similar corticosteroid-based strategies; drug pneumonitis may have more rapid response and better tolerate taper.
Lynch Y, Vande Vusse LK. Diffuse Alveolar Hemorrhage in Hematopoietic Cell Transplantation. Journal of Intensive Care Medicine. 2023;39(11):1055-1070. doi:10.1177/08850666231207331
Etiologic classification:
| Pathologic Category | Examples |
|---|---|
| Pulmonary capillaritis | |
| (most common) | – ANCA-associated vasculitis (GPA, MPA) |
| – SLE, Goodpasture syndrome | |
| – Drug-induced (PTU, hydralazine) | |
| Bland pulmonary hemorrhage | – Coagulopathy (e.g., DIC) |
| – Anticoagulant overdose | |
| – High-altitude pulmonary edema | |
| Diffuse alveolar damagea (DAD) | – AIP, ARDS |
| – Inhalational injury, sepsis | |
| Other causes | Bone marrow transplant, hematologic malignancy, idiopathic pulmonary hemosiderosis |
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DAH triad: Lung opacities, hemoptysis & anemia
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| Symptom | Frequency |
|---|---|
| Hemoptysis | Occurs in ~50–70%; may be absent initially |
| Anemia | Rapid drop in hemoglobin due to alveolar bleeding |
| Dyspnea and hypoxia | Common, may rapidly progress to respiratory failure |
| Crackles | Bibasilar, may be diffuse |
| Systemic symptoms | Fever, malaise (if vasculitis or autoimmune cause) |
Diagnosis and Management of Diffuse Alveolar Hemorrhage (DAH) Prof. Jacques Cadranel @CadranelJ via via Dr. Benjamin Terrier @TerrierBen
| Investigation | Typical Finding in DAH |
|---|---|
| Hemoglobin | Acute drop in hemoglobin without external bleeding |
| Bronchoalveolar lavage (BAL) | Increasing blood in sequential aliquots (diagnostic hallmark) |
| Hemosiderin-laden macrophages on Prussian blue stain (appear after ~48–72 hours) | |
| Autoimmune serologies | May reveal positive ANCA, anti-GBM antibodies, or ANA depending on etiology |
| Coagulation profile | May be abnormal in bland hemorrhage (e.g., INR ↑, thrombocytopenia) |
| Urinalysis | Microscopic hematuria or proteinuria (suggests pulmonary-renal syndrome) |
Bronchoscopy + bronchoalveolar lavage (BAL):
![The chest CT showed diffuse ground-glass opacities in both lung field (A). Bronchoscopic finding showed productive yellow sputum from trachea and bronchi (B). Bronchoalveolar lavage (BAL) revealed a progressively more bloody return, typical of diffuse alveolar hemorrhage (C).
Suzuki Y, Shiro Imokawa, Fumiya Nihashi, Uto T, Sato J, Suda T. Diffuse alveolar hemorrhage caused by exposure to organic dust. Respiratory Medicine Case Reports. 2015;15:59-61. doi:https://doi.org/10.1016/j.rmcr.2015.05.005