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oa Pulmonary vasculitis and pulmonary hemorrhage
- Source: Qatar Medical Journal, Volume 2017, Issue 1 - Extracorporeal Life Support Organisation of the South and West Asia Chapter 2017 Conference Proceedings, Feb 2017, 44
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- 14 February 2017
Abstract
Pulmonary vasculitis is a rare disease that typically shows inflammation in pulmonary vessel walls and necrosis.1 The disease is usually immune mediated, common in young patients, triggered by many factors, and with wide clinical and radiologic presentations. Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAVs) is the main focus in most literature and includes granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), Churg–Strauss syndrome (CSS), idiopathic pauci immune pulmonary capillaritis (IPIPC), secondary to systemic lupus erythematosus, and other types like anti-glomerular basement membrane disease, drug-induced vasculitis after cannabis and glue inhalation.2 Diagnosis is usually established after careful history taking clinical, radiologic, and laboratory evidence; bilateral lung infiltrates with or without pulmonary hemorrhages and peripheral distribution, positive ANCA-P component, proteinase-3 ELISA test, anti-glomerular basement membrane antibody, and other antibodies associated with immunologic disease like systemic lupus erythematosus. Sometimes, lung biopsy may be needed but because of the low yield of bronchoscopic biopsies and the need for open lung biopsy, this tool is rarely used specially in critically ill patients. Treatment is by the use of steroids and cytotoxic medications like cyclophosphamide and mycophenolate mofetil. In refractory cases, plasmapheresis or the monoclonal antibody rituximab may be used. Pulmonary hemorrhage is a common manifestation in vasculitic lung syndromes; however, many other disease and toxins can trigger pulmonary hemorrhage, which can be life threatening.3 The diagnosis of pulmonary hemorrhage is generally considered based on clinical and radiological findings and is characterized by acute bilateral patchy lung infiltrates more centrally located but may be diffuse. Sequential aliquots of bronchoalveolar lavage yield progressively bloodier return and help in diagnosis.4 Treatment depends largely on the cause. Extracorporeal membrane oxygenation (ECMO) is a life support modality that can be used in severe cases of pulmonary vasculitis and hemorrhage with great caution and careful assessment of risk of bleeding with anticoagulation and benefit of use as life-saving support. With newer ECMO circuits used (either heparin- or bioline-coated circuits), several days of heparin-free ECMO runs may be successful. In some reported cases, citrate was used as an anticoagulant.5 The ECMO modality shall be carefully chosen especially in the presence of pulmonary hypertension, which may affect the veno-venous (VV) ECMO flow, and hence, echocardiographic assessment before initiation is mandatory to avoid low-efficiency runs. In cases with severe pulmonary hypertension, veno-arterial (VA) ECMO would be more suitable. Institution of treatment using steroids and cytotoxic drugs in addition to plasmapheresis is warranted upon suspected diagnosis. The rapid initiation of treatment may be the key point of survival in such cases. There are some case reports where plasmapheresis and immunosuppressive therapies were used based on clinical and radiographic data alone5 with successful outcome. There is paucity of data regarding drug doses of immunosuppressive drugs used during the ECMO run, and the duration of treatment was variable. Most of the cases reported started with 1 g of methylprednisolone for 3 days followed by either plasmapheresis and cyclophosphamide or cyclophosphamide and rituximab.6 The plasmapheresis circuit installation needs to be addressed whether to be incorporated into the ECMO circuit7 or not.