The Role of Non-Invasive Ventilation and Factors Predicting Extubation Outcome in Myasthenic Crisis

INTRODUCTION: Myasthenic crisis is a great threat to patients with myasthenia gravis. Usage of non-invasive ventilation (NIV) to prevent intubation and timing of extubating of patients in myasthenic crisis are important issues though not well documented. METHODS: To explore the factors predicting NIV success and extubation outcome in myasthenic crisis , we reviewed the records of 41 episodes of myasthenia crisis. RESULTS: NIV was applied to 14 episodes of myasthenic crisis and eight (57.1%) of them were successfully prevented from intubation. An Acute Physiology and Chronic Health Evaluation (APACHE) II score of or = 40 cmH(2)O was a good predictor of extubation success. Extubation failure led to poorer outcomes. CONCLUSIONS : NIV may be applied to those patients with a low APACHE II score and a lesser degree of metabolic compensation for respiratory acidosis. For patients undergoing invasive mechanical ventilation, extubation failure is associated with significant in- hospital morbidity in myasthenic crisis. Adequate levels of Pemax and cough strength correlate significantly with extubation success