Analysis of influencing factors of postoperative myasthenic crisis in 564 patients with myasthenia gravis in a single center

Abstract

Objective: To study the influencing factors of myasthenic crisis in patients with myasthenia gravis during perioperative period.

Methods: A total of 564 myasthenia gravis (MG) patients who underwent standard expanded resection of thymoma/thymoma in the Department of Thoracic Surgery of Beijing Hospital from January 2011 to March 2022 were retrospectively included in the study. Clinical indicators such as gender, age, thymoma, American Society of Anesthesiologists (ASA) score, operation time, intraoperative blood loss, and some others were recorded.

Results: Osserman-stages IIB + III + IV (odds ratio [OR] 16.091, 95% confidence interval [CI] 5.170-50.076, p value < 0.001), the dosage of pyridostigmine bromide more than 240 mg (OR 6.462, 95% CI 3.110-13.427, p value < 0.001), ASA score 2 and 3 (OR 3.203, 95% CI 1.461-7.020, p value = 0.004), low diffusion lung capacity for carbon monoxide (DLCO%) (OR 0.981, 95% CI 0.963-1.000 p value = 0.049), and blood loss greater than 1000 ml (OR 16.590, 95% CI 1.911-144.011, p value = 0.011) were independent risk factors for myasthenic crisis.

Conclusions: Patients with poor Osserman stages, higher preoperative dosage of pyridostigmine bromide, higher ASA score, poor pulmonary function (low DLCO%), and more intraoperative bleeding should be highly vigilant for the occurrence of postoperative myasthenic crisis.

Keywords: ASA score; myasthenia gravis; myasthenic crisis; thymectomy; thymoma.