Pulmonary-renal syndromes.

Although they are complex, the pulmonary-renal syndromes can be readily understood and managed using a clinical approach firmly grounded in the fundamental pathophysiology of these disorders. Several important principles must be borne in mind. First, therapeutic intervention must be preceded by making as firm a diagnosis as possible. In these disorders, histologic confirmation of the diagnosis is almost always mandatory, because the therapy differs substantially from one disorder to the next and several of the therapeutic options carry significant toxicity. Open lung biopsy is frequently required to obtain sufficient tissue to warrant a specific diagnosis, and repeat open biopsy may be necessary at times to differentiate relapse of disease from supervening infection or complications of therapy. The course of the pulmonary-renal disorders may be extraordinarily fulminant, leading to irreversible organ failure and death in a matter of hours to days; this mandates an aggressive approach to therapy, with close attention paid to monitoring of the side effects of therapy. Lastly, as these illnesses are often characterized by a relapsing course, patients must be followed with vigilance.