[The prediction of the need for postoperative mechanical ventilation in patients with myasthenia gravis undergoing transsternal thymectomy]

Abstract

During a sixteen-year period, 51 patients with myasthenia gravis underwent trans-sternal thymectomy including extended resection of the adipose tissue around thymus. Using the criteria of risk factors described by Leventhal and Kimura, a predictive score was assessed for our 51 patients. Leventhal's scoring system achieved an accuracy of 54.3%, a sensitivity of 20.0% and a specificity of 63.9%. And, Kimura's scoring system achieved an accuracy of 75.0%, a sensitivity of 81.8% and a specificity of 73.0%. From this study it was concluded that Kimura's scoring system is statistically more adaptive for Japanese than Leventhal's scoring system, and the Leventhal's accuracy may have increased by adding "bulbar symptoms" and "preoperative crisis" as other risk factors and by decreasing "points" for "duration of myasthenia" and "pyridoxamine dosage", and the "Kimura's " accuracy may have increased by decreasing "7 points" for preoperative crisis. Consequently, patients who received postoperative ventilation were compared with the group who did not, with respect to the 19 factors. Evidence is that Osserman's type, bulbar symptoms, preoperative crisis and preoperative % VC were influenced to require the postoperative ventilation, but sex, age, thymic histology, duration of myasthenia and pyridoxamine dosage were not any influenced to require the postoperative ventilation.