Monitoring diaphragm function in a patient with myasthenia gravis: electrical activity of the diaphragm vs. maximal inspiratory pressure

Abstract

Abstract Background Maximal inspiratory pressure (MIP) is used to assess respiratory muscle strength of patients with myasthenia gravis (MG) requiring ventilatory support. Electrical activity of the diaphragm (E-di) has been used to guide weaning. Case presentation The MIP and tidal volume/ΔE-di (the patient-to-ventilator breath contribution) were monitored in a 12-year-old girl with MG requiring ventilator support. The same ventilatory settings were maintained until extubation. During weaning, MIP increased slightly, but varied unpredictably. Tidal volume/ΔE-di decreased at a constant rate as muscle strength recovered. Conclusion In this patient with muscle weakness, E-di was a reliable tool to monitor weaning from mechanical ventilation.

Keywords

• Myasthenia gravis
• Electrical activity
• Diaphragmatic weakness
• Mechanical ventilation
• Weaning