Comparison of prognostic scales of myasthenic crisis after thymectomy in patients with myasthenia gravis

Myasthenia gravis (MG) is an autoimmune disease accompanied by muscle weakness and abnormal muscle fatigue. Thymectomy (TE) is advisable for these patients. Some anesthetic prognostic scales were proposed to assess the likelihood of postoperative myasthenic crisis (POMC). There are no literature data on comparison of prognostic scales for this postoperative complication. Objective. To compare prognostic effectiveness of different scales in prediction of POMC after TE in MG patients. Material and methods. We retrospectively analyzed 37 case histories of seropositive MG patients who underwent TE under general anesthesia. ROC-analysis was performed to compare 5 prognostic sales. Results. The scale by T. Kanai et al. with VC% (0.93 [95% CI 47.8—100.0]) and FVC% (0.90 [95% CI 47.8—100]), as well as QMGS scale (0.94 [95% CI 89.1—100.0]) showed higher results compared to scales by S.R. Leventhal et al. (0.67 [95% CI 14.7—94.7]) and G. Leuzzi et al. (0.80 [95% CI 58.4—99.5]) in predicting POMC. Pairwise comparison with DeLong test found no significant differences. Conclusion. Kanai and QMGS scales are preferable for prediction of postoperative myasthenic crisis after thymectomy in patients with myasthenia gravis.