Abstract
Diffuse alveolar hemorrhage (DAH) secondary to anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis is rare in clinical practice and may present as severe acute respiratory distress syndrome (ARDS) with high mortality. Extracorporeal membrane oxygenation (ECMO) has been reported to be a salvage treatment providing the time necessary for immunosuppressive treatment in cases accompanied by severe ARDS. Prone positioning (PP) has been proven to reduce the mortality in patients with severe ARDS. However, there is no consensus about choosing PP or ECMO in severe ARDS due to DAH secondary to ANCA-associated vasculitis. We reported a case of microscopic polyangiitis (MPA)-related DAH and severe ARDS treated with PP successfully providing the time necessary for early glucocorticoids and plasma exchange to control the underlying disease. Since anticoagulation therapy is not necessary in PP, it does not increase the risk of bleeding tendency unlike ECMO. PP has a life-saving role in the management of patients with severe ARDS due to ANCA-associated pulmonary vasculitis.