ALVEOLAR HEMORRHAGE

Alveolar hemorrhage (AH) is a clinical syndrome with diverse etiologie s both immune and nonimmune. The defining pathological feature of AH i s the presence or absence of pulmonary capillaritis. The antineutrophi l cytoplasmic antibody (ANCA) related vasculitis and systemic lupus er ythematosus are the commonest causes of immune AH with pulmonary capil laritis, whereas Goodpasture's syndrome and idiopathic pulmonary hemos iderosis are common causes of immune AH without pulmonary capillaritis . The major nonimmune causes of AH are primarily drug induced, or due to hematological malignancy and disorders of coagulation. Clinical fea tures of AH include: dyspnea, fever, hemotypsis, bilateral crackles an d pallor. Hypoxemia and bilateral diffuse airspace disease on the ches t radiograph with relative sparing of the bases and apices which most often clears within 48 hours after its onset further characterize this syndrome. The major clinical implications of this syndrome are its po tential to cause respiratory failure in severe cases and its sequelae of pulmonary fibrosis with associated morbidity and disability. In add ition, AH may be the initial manifestation of a systemic immune disord er which can be managed optimally if recognized early. The diagnosis o f AH is confirmed by bronchoalveolar lavage by demonstrating a progres sively bloody return on successive aliquots of instilled saline or hem osiderin laden macrophages in the bronchoalveolar lavage fluid. The op en lung biopsy remains the gold standard for the diagnosis of AH but i s reserved for inapparent cases in whom corticosteroids and immunosupp ressive therapy may be life saving. Serologic testing and examination of the urine sediment are useful adjuncts to the diagnosis. The treatm ent of AH is primarily supportive while an attempt is made to determin e its etiology and initiate specific therapy. Glucocorticoids and cycl ophosphamide are the cornerstones of therapy in immune AH with adjunct ive plasmapheresis in life-threatening cases.