RESUMO
BACKGROUND: Noninvasive ventilation (NIV) plays an important role in avoiding endotracheal intubation during myasthenic crisis, yet there are few published data concerning long-term home NIV in stable out-patients with myasthenia gravis (MG). The aim of this study was to describe the prevalence of NIV in a cohort of subjects with stable MG and to analyze contributing factors that could predict the need of NIV. METHODS: We performed a cross-sectional study that included subjects diagnosed with MG managed in the respiratory care unit over the previous year. Subjects underwent clinical analysis including demographic, clinical, and functional respiratory data. RESULTS: Of the 50 subjects included, 35 (70%) were positive for nicotinic acetylcholine receptor antibodies, and 68% had a diagnosis of generalized MG. Bulbar symptoms developed in 16 (32%), and 10 (20%) subjects needed long-term home NIV. The only variable predicting the need for long-term NIV was MG severity measured with Myasthenia Gravis Foundation of America (MGFA), mainly grades IIB (odds ratio 0.14 [95% CI 0.02-0.85], P = .03) and IIIB (odds ratio 0.02 [95% CI 0.01-0.34], P = .01). CONCLUSIONS: Home NIV was needed in a substantial percentage of medically stable subjects with MG, mainly in those with generalized type and with oropharyngeal and/or respiratory muscle involvement (MGFA grades IIB and IIIB).
