Extracorporeal membrane oxygenation for pulmonary hemorrhage in microscopic polyangiitis
Year: 2008
Type: article
Study design: Case Report
Abstract: Microscopic polyangiitis (MPA) is characterized by an inflammatory process of the vessel walls and is classified according to the smallest vessels involved. Diagnosis is based on clinical manifestations, anti-neutrophil cytoplasmic autoantibody (ANCA) testing, and histology. In this disease, pulmonary hemorrhage is seen in 30% of patients and is associated with an eight-fold increase in mortality. Classically, MPA involves the kidneys and upper and lower respiratory tracts. Due to the perceived risk of increased bleeding secondary to the use of systemic anticoagulation, extra corporeal membrane oxygenation (ECMO) is often not used to treat patients with hemorrhage suffered from MPA. Here we report a case of a 50-year-old woman with MPA that was successfully supported with ECMO. CASE REPORT On August 20, 2007, a 50-year-old Chinese woman presented to the Department of Pulmonology at our hospital with a 14-day history of cough, hemoptysis and dyspnea. The patient had been repeatedly evaluated by an outside pulmonologist, and was being treated empirically for community acquired pneumonia (CAP) at the time of admission. Her medical history was remarkable for hepatitis B virus. Physical examination revealed a temperature of 37.9°C, a pulse of 90 beats per minute, a respiratory rate of 28, and blood pressure of 130/80 mmHg. She had pale conjunctiva, bilateral crackles on auscultation, normal heart sounds and no skin rash or joint swelling. Her chest radiograph and CT scan revealed bilateral alveolar opacities (Figure A). Laboratory data were significant for hematuria (508 red blood cells per high-power field), a creatinine level of 119 μmol/L (normal range: 44-115 μmol/L), a blood urea nitrogen (BUN) of 14.1 mmol/L (normal range: 2.9-8.2 mmol/L), proteinuria (4.2 g/24 hours), a WBC count of 16.2×109 cells/L, a hemoglobin count of 93 g/L, hematocrit of 27.4%, and a platelet count of 178×109 cells/L. An arterial blood gas analysis revealed a pH of 7.28, a PCO2 of 51.1 mmHg and a PaO2 of 41.4 mmHg. Mechanical ventilation was begun on continuous mechanical ventilation (CMV) mode with a respiratory rate of 28, a tidal volume 6 ml/kg, a positive end expiratory pressure (PEEP) of 15 cmH2O, FiO2 at 100%, with high peak inspiratory pressure (PIP) of 48 cmH2O. Over the next 2 days, the patient remained severely and progressively hypoxemic with a PaO2 of 50 mmHg on an FiO2 of 100% and increasing levels of PEEP (15 to 35 cmH2O).Figure.: Chest radiograph of the patient. A: Bilateral alveolar opacities on hospital admission. B: Gradual improvement noted after 12 days of ECMO (taken by bedside).Despite these ventilator settings, she became progressively hypoxemic and produced hemoptysis. She continued to have blood stained secretion in the endotracheal tube, and bronchoscopy revealed blood-stained fluid coming from both lungs. The patient's oxygen saturation and PaO2/FiO2 ratio continued to worsen. She had to be manually bagged to sustain oxygenation, and the decision was made to emergently place her on veno-venous ECMO for respiratory support. The patient was then taken to the ICU for placement of a 17F cannula in her right internal jugular vein and a 21F cannula in her right femoral vein. The initial ECMO settings were a flow of 3.5 L/min, which caused a rapid improvement in the patient's oxygenation. Subsequent arterial blood gas revealed a pH of 7.5, a PCO2 of 28.6 mmHg, a PaO2 of 61 mmHg, and an oxygen saturation of 96%. Ventilator settings were gradually reduced to a tidal volume of 6 ml/kg, PEEP 8 cmH2O, FiO2 21%, and a respiratory rate of 15/min. The ECMO circuit was anti-coagulated with heparin infusion titrated to maintain an activated clotting time (ACT) between 120 and 200 seconds. There was no further bleeding from the lungs. The following day, perinuclear anti-neutrophil cytoplasmic antibodies (P-ANCA) and anti-myeloperoxidase antibodies (anti-MPO) were reported positive. Because of her poor status, biopsy of the kidney could not be performed. Based on her clinical presentation and immunology results, a diagnosis of MPA was made. She was aggressively treated with high-dose cyclophosphamide (200 mg iv daily × 3 days) and methylprednisolone (500 mg iv daily × 3 days). Then, we used cyclophosphamide 200 mg intravenously once every other day for 30 days, and intravenous methylprednisolone 80 mg continously for 14 days. While on ECMO support, plasmapheresis was instituted for 5 days with daily 1.0 volume plasma exchange with fresh frozen plasma. Hemodialysis was begun and continued for 5 days. Intravenous immunoglobulin was also given (20 g for 5 days). Because the use of ECMO and aggressive immunosuppression interfered with our ability to monitor for signs and symptoms of infection, the patient received empiric therapy with broad-spectrum antibiotics, and daily surveillance cultures were collected. On the 15th hospital day (12th day of ECMO), the patient was able to remain without ECMO for our goal of 4 hours with an oxygen saturation in the mid-95% range. An arterial blood gas analysis revealed a pH of 7.35, a PCO2 of 37.6 mmHg and a PaO2 of 97.8. Chest radiograph showed gradual improvement (Figure B). The patient was decannulated at the bedside. Mechanical ventilation was continued using a pressure support ventilation/synchronized intermittent mandatory ventilation (PSV/SIMV) mode. Ventilator parameters were set as follows for subsequent days: PEEP 10 cmH2O, FiO2 60%, and respiratory rate of 20 with low PIP (40 cmH2O). On the 80th hospital day, the patient was extubated to face-mask oxygen, chest radiograph findings gradually improved, and the patient had normal renal function. The patient was placed on oral prednisone 30 mg daily and cyclophosphamide 200 mg intravenously once every two weeks to prevent remission and transferred to a rehabilitation hospital. DISCUSSION MPA is one of the most serious complications of ANCA-associated vasculitis. The clinical features of these vasculitis syndromes are very similar, and the differential diagnosis is somewhat difficult. Diagnosis is based on clinical manifestations, ANCA testing, and histology.1 ANCA is an antibody to neutrophil cytoplasmic antigen, and may constitutively activate primed neutrophils, promote binding of the primed neutrophil to the vascular endothelium, subsequent degranulation, and the release of neutrophil chemoattractants, thereby creating an auto-amplifying loop. ANCA is determined by the state of neutrophil activation. cANCA (cytoplasmic ANCA) has been reported to be positive in approximately 10% (5/51) of MPA, while pANCA (perinuclear ANCA) has been reported to be positive in 50% to 80% of MPA. In the present case with MPA, pANCA was positive.2-4 In MPA, besides the manifestation of glomerulonephritis, diffuse alveolar hemorrhage (DAH) due to alveolar capillaritis is the most frequent manifestation of respiratory involvement, and is accompanied clinically by hemoptysis, respiratory distress and anemia. Our patient had the typical clinical manifestations: rapidly progressive alveolar hemorrhage and hypoxia. While awaiting the suppression of autoimmune process by plasmapheresis and immunosuppressive drugs and resolution of pulmonary hemorrhage in MPA, ECMO was a suitable therapeutic option in this patient. We believe that this is the first case in China that used ECMO in treating a patient with MPA. ECMO was developed as a supportive therapy for severe respiratory failure, and has been shown to be life-saving in respiratory failure.5 ECMO can support oxygenation and ventilation, thus enabling the ventilator settings to be markedly reduced. This can help to prevent the lung from iatrogenic injury caused by high airway pressures and oxygen toxicity, while allowing more time for aggressive treatment of the underlying pathology.6 Although ECMO is a highly invasive technique with a high risk of bleeding complications, it may still be appropriate if the patient suffers from potentially reversible pathology like MPA and has no underlying chronic lung disease. As the initial treatment of MPA, prednisolone and cyclophosphamide are generally used. As a result, symptoms such as hemoptysis could markedly improve with medical treatment. Plasmapheresis and hemodialysis also play important roles in the treatment of MPA.
Source: Chinese Medical Journal
Authors: Hua ZHONG, Ji-hua CHEN, Sai-qi LI, Li-yan JIANG, Xin LI, Bao-hui HAN
Institution: Shanghai Chest Hospital
Language: English
Subfield: Pulmonary and Respiratory Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $2,000
OpenAlex ID: W2258324280