[Analyses of the risk factors of delayed extubation after extended thymectomy in patients with myasthenia gravis].

Abstract

Objective: To explore the risk factors of delayed extubation after expanded thymectomy in patients with myasthenia gravis. Methods: Patients with myasthenia gravis who underwent expanded thymectomy from May 2021 to January 2024 and were admitted to Intensive Care Unit (ICU) after surgery were retrospectively analyzed. Patients were divided in to the delayed extubation and successful extubation according to the length of mechanical ventilation whether exceeding than 48 hours. Multivariable logistics regression was used to explore the risk factors for delayed extubation after expanded thymectomy in patients with myasthenia gravis. Results: A total of 95 patients were included.15 (15.8%) of whom were delayed extubation. Compared with the successful extubation patients, the length of mechanical ventilation (94.0 h vs. 15.5 h, P<0.001), ICU station (7.1 days vs. 1.7 days, P<0.001), and hospitalization station (16.0 days vs. 9.1 days, P<0.001) were significantly prolonged in the delayed extubation patients. Adjusted for age,gender, BMI, clinical classification, pathological classification of thymoma, dose of pyridostigmine preoperative, perioperative pneumonia, preoperative pulmonary dysfunction, SBT passing for the first time, neck lift time greater than 20 seconds, the multivariable logistic regression shown, the risk of delayed extubation increased by 29% (OR=1.290, 95%CI 1.090-1.714), 1% (OR=1.009, 95%CI 1.002-1.034), 3.9-fold (OR=4.977, 95%CI 1.486-10.939), and 64% (OR=1.635, 95%CI 1.396-2.682) for every 60 mg/day increase in preoperative dose of pyridostigmine, pathological classification of thymoma, perioperative pneumonia, and preoperative pulmonary dysfunction, respectively. Neck lift time greater than 20 seconds can reduce the risk of delayed extubation 48% (OR=0.524, 95%CI 0.322-0.794). Conclusion: Preoperative administration of a large dose of pyridostigmine, pulmonary dysfunction, pathological classification of thymoma, and perioperative pneumonia were risk factors for delayed extubation after thymectomy in these patients. And neck lift time greater than 20 seconds decreased the risk of delayed extubation. In the clinical practice,for high risk of MG patients with delayed extubation, the neck lifting test may be used to assess muscle strength and reduce the occurance of tracheal reintubation and its advise effects.