Risk of extubation failure in patients with myasthenic crisis

Weaning patients with myasthenic crisis (MC) from mechanical ventilation is often difficult, and the ideal time for extubation is often uncertain. However, little is known about the risk of extubation failure and the factors that may affect its occurrence. The goals of this study were to assess the risk of extubation failure in patients with MC and to determine which clinical variables may predict unsuccessful extubation.

Retrospective review of consecutive patients admitted for MC. Weaning method was categorized as T-piece or continuous positive airway pressure (i.e., T-piece trials not performed). Extubation failure was defined as need for reintubation or tracheostomy due to persistent neuromuscular insufficiency. Functional outcome was assessed using the modified Rankin score.

We identified 26 episodes of MC in 20 patients. Median age was 42.1 years (range 14-83 years). Most patients were treated with immunomodulatory therapy (73%). There were seven episodes of extubation failure (prevalence rate 27%). Median time to reintubation was 36 hours. Older age (p = 0.05), atelectasis (p < 0.01), and pneumonia (p =0.02) were significantly associated with extubation failure. Patients with failed extubation had considerably prolonged intensive care unit stays (median 28 versus 7 days; p < 0.01) and hospital stays (median 40 versus 12 days; p < 0.01).

Extubation failure may often complicate MC. Older age and development of pulmonary complications during mechanical ventilation increase the risk of extubation failure.