Home noninvasive ventilation in Myasthenia Gravis: features and predictors.

Abstract

Noninvasive ventilation (NIV) has an important role during myasthenic crisis avoiding endotracheal intubation, however, there is few documented information concerning long-term home NIV in stable outpatients with myasthenia gravis (MG). The aim of the study was to describe the characteristics of a cohort with MG outpatients and to analyze contributing factors that could predict the need of NIV. We performed a cross-sectional study that included patients with diagnosis of MG managed in the Respiratory Care Unit in the previous year. Subjects underwent a clinical analysis that included demographics, functional respiratory evaluation (FRE), arterial blood gas analysis (ABG). 37 were included (54,1% female). Blood test analysis showed 28 (75,7%) positive for AchRS antibodies. 29,7% patients were treated with home NIV. 70,3% had a diagnosis of generalized MG. Bulbar symptoms were developed in 13 (35,1%). Levels of PaCO2 and HCO3 in patients with MG improved after the initiation of NIV (Table 2). The only variable which predicted the need for long-term NIV in outpatients was predicted forced vital capacity (%FVC) (OR=0.94 95%CI 0.895–0.994, p=0.028). FVC is the only parameter that could predict the need of NIV.