Noninvasive Ventilation in Myasthenia Gravis

Myasthenic crisis (MC) is mainly managed by invasive ventilation (IV) which is associated with prolonged intubation and ventilation and respiratory complication.

To report the characteristics of patients who can be managed by noninvasive ventilation (NIV) and also predictors of NIV in myasthenia gravis (MG).

In a retrospective study at tertiary care hospital in India during 2013-2015, patients with MG were evaluated. MG was diagnosed by clinical, repetitive nerve stimulation, and acetylcholine receptor antibodies. Patients were intubated based on arterial blood gas criteria. Demographic variables, Myasthenia Gravis Foundation of America (MGFA) score, and clinical examination were done. NIV success was defined if patient did not need mechanical ventilation (MV) in the management or for 72 h after extubation and was considered unsuccessful if patients required MV during this period.

Twenty three out of 68 MG patients had MC, 16 patients were given NIV, and 16 IV. Median intensive care unit stay was 18 (4-94) days. Predictors of crisis were infection, bulbar weakness, MGFA > 2b, and history of crisis. NIV was the only respiratory support in 7 patients and reintubation was prevented in 3 patients. NIV failed in 9 patients. Comparison of NIV success and failure did not reveal any difference.

With NIV, intubation was prevented in 7 and reintubation in 3 patients. NIV has lower incidence of complications. NIV should be tried in patients with impending MC.