Predictors of extubation failure in myasthenic crisis.

BACKGROUND: The ideal timing for extubation of patients with myasthenic crisis (MC) and the factors that influence extubation outcome are not well established.
OBJECTIVES: To assess the risk of extubation failure in MC and to identify predictors of extubation failure.
DESIGN: We reviewed consecutive episodes of MC treated with endotracheal intubation from January 1, 1987, through December 31, 2006.
SETTING: Mayo Clinic. Patients Forty patients with 46 episodes of MC underwent endotracheal intubation and mechanical ventilation. MAIN OUTCOME MEASURES: The main outcome measures were extubation failure and reintubation. Extubation failure was defined as reintubation, tracheostomy, or death while intubated. Reintubation was also analyzed as a separate end point. Univariate logistic regression was used to identify predictors of extubation failure and reintubation.
RESULTS: Of the 46 episodes of MC, extubation failure occurred in 20 (44%), including 9 of 35 episodes (26%) of reintubation. Male sex, history of previous crisis, atelectasis, and intubation for more than 10 days were associated with extubation failure. Lower pH and lower forced vital capacity on the time of extubation, atelectasis, and bilevel intermittent positive airway pressure use after extubation predicted the need for reintubation. Atelectasis showed the strongest association with both end points. Extubation failure and reintubation were associated with significant prolongation in intensive care unit and hospital length of stay.
CONCLUSIONS: Extubation failure is relatively common in patients with MC. Atelectasis is the strongest predictor of this complication.