Weaning from mechanical ventilation during myasthenic crisis, a monocentric retrospective study

Mechanical ventilation in myasthenic crisis is not standardized and is at high risk of failure. We investigated liberation from mechanical ventilation during myasthenic crisis using a prolonged spontaneous breathing trials (SBT) and sequential pulmonary function tests (PFT). In this retrospective monocenter study, we included patients admitted for a first episode of myasthenic crisis between January 2001 and January 2018. The primary outcome was the incidence of weaning failure upon first extubation in our cohort of patients with MC. Secondary objectives were to determine risk factors and outcome associated with weaning failure upon first extubation in MC. We also compared the characteristics of patients with prolonged weaning. 126 episodes of MC were analyzed. Patient's age was 64 [42-76] years with 72/126 (56.5%) being women. The median delay between weaning initiation and first extubation was 6 [3-10] days and the median total length of MV was 14 [10-23] days. 118/126 (93.7%) patients underwent prolonged SBT of 8 h or more prior to first extubation. The overall weaning failure rate was 18/126 (14.3%). Extubation was more often successful when the factor precipitating the myasthenic crisis was identified (86/108 (79.6%) vs. 8/18 (44.4%); p = 0.004), whereas PFT was similar in failure or successes. Most weaning failures upon first extubation attempt (11/18; 61%) were attributed to an insufficient stabilization of myasthenia gravis. Duration of mechanical ventilation, an infectious trigger and maximal inspiratory pressure upon intubation were independent risk factors for prolonged weaning. In myasthenic crisis, a standardized protocol including prolonged SBT and respiratory function tests might improve the success of first extubation without prolonging mechanical ventilation. The results of this single center study warrant further evaluation in interventional trials.