Researchers from China developed a new tool to predict the risk of postoperative myasthenic crisis in patients with myasthenia gravis. The tool can identify patients who are at high risk and ensure they receive the necessary treatment before surgery and the attention they need to avoid complications after.

To develop their tool, the team of Yi Zhang from the Department of Thoracic Surgery, Xuanwu Hospital Capital Medical University, in Beijing, China, retrospectively reviewed the medical records of 177 patients with MG who had a thymectomy to treat their disease between January 2018 and September 2022.

Read more about the treatment of myasthenia gravis

The study is published in the journal Interdisciplinary Cardiovascular and Thoracic Surgery.

The researchers divided the patients into 2 groups based on whether or not they developed myasthenic crises following the operation. A total of 42 patients (23.7% of all patients analyzed) developed myasthenic crisis. 

Independent risk factors associated with myasthenic crisis were body mass index, Osserman classification, percentage of predicted forced vital capacity and predicted forced expiratory volume in the first second, and the ratio of albumin to globulin.

These factors were entered into a nomogram to intuitively show the results. The researchers reported that the calibration curve that they used to evaluate the performance of the nomogram showed good concordance between the predicted and the actual probability of the need for prolonged ventilation postoperatively.

“Our model is a valuable tool for predicting [post-operative myasthenic crisis] in myasthenia gravis patients,” the authors concluded.

Myasthenia gravis is a rare autoimmune disease affecting the neuromuscular junction. A thymoma may be indicated for some patients with generalized myasthenia gravis and those who present with a thymoma.

Myasthenic crisis is a complication of myasthenia gravis characterized by the worsening of muscle weakness that can lead to respiratory failure and the need for mechanical ventilation.


Wei B, Lu G, Zhang Y. Predictive factors for postoperative myasthenic crisis in patients with myasthenia gravis. Interdiscip Cardiovasc Thorac Surg. Published online February 21, 2023. doi:10.1093/icvts/ivad040