Leventhal, et al. Described a preoperative scoring system for myasthenic patients undergoing transsternal thymectomy, which inciudes four key risk factors. There were: 1) duration of myasthenia gravis greater than 6 years(12 points); 2) a history
of
chronic respiratory disease not dur to myasthenia gravis(10 points); 3) dose of pyridostigmine greater than 750 mg per day 48 hours before operation(8 points); 4) a preoperative vital capacity less than 2.9L (4 points).
Thirty-seven patients with myasthenia gravis undergoing transsternal thymectomy under general inhalation anesthesia with or without muscle relaxants were applied to scoring system by Leventhal, et al. Retrospectively. The prodicitive score was
assessed
for each patient and the duration of postoperative mechanical ventilation was also noted for each patient.
In this study, there was correct in 23.37(62.2%) of the cases, with 9 out of 27 being incorrectly predicted to be ready for tracheal extubation(false positive) and 5 out of 10 being incorrectly predicted to need ventilation(false positive).
In conclusion, the scoring system proposed by Leventhal, et al. May be some value in predicting whether or not a particular myasthenic patient was likely to to need mechanical ventilation following transsternal thymectomy.
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