Diffuse Alveolar Hemorrhage in the ICU

Abstract

Alveolar spaces may fill with blood as a result of gross disruption of the delicate structures which form the alveolar-endothelial membrane. Collagen-vascular and immune diseases are the most common causes of diffuse alveolar bleeding, but several other underlying pathological conditions have been identified. Sometimes, the cause is obvious, as in patients with acute respiratory distress syndrome (ARDS) or those who have sustained chest trauma with lung contusion [1]. Occasionally, patients with pulmonary infections and pneumonia may present with severe diffuse alveolar bleeding [2, 3]. Patients with pulmonary metastases from solid tumors [4, 5], hematological malignancies [6, 7], and angio-sarcomas [8–10] may occasionally present with diffuse alveolar hemorrhage, while patients with allogeneic [11] and autologous bone marrow transplants [12] may also develop alveolar bleeding. Occasionally, alveolar spaces may fill with blood due to aspiration from a bleeding focus in the upper airways or from the upper digestive tract; usually, clinical evaluation will rule out this possibility. This chapter will focus primarily on clinical presentation, diagnosis and treatment of collagen-vascular and immune causes of diffuse alveolar bleeding, usually referred to as diffuse alveolar hemorrhage (DAH). Patients with collagen-vascular disorders usually develop signs and symptoms suggesting systemic disease. Although such clinical presentation may mimic endocarditis, sepsis and even malignancy, specific patterns can be suggestive of collagen-vascular diseases. Malaise, arthralgias, eye symptoms like episcleritis and uveitis, and skin changes, e.g., petechiae, palpable purpura, and leukocytoclastic vasculitis in vasculitic syndromes, butterfly-rash, notably in systemic lupus erythematosus, etc., usually lead in the right direction in the diagnostic work-up. Infrequently, however, DAH is the presenting sign of systemic disease. Close co-operation with specialists in the field of collagen-vascular and immune disorders may then help to reach a definitive diagnosis and install appropriate treatment.