Abstract: Objective To investigate the safety and feasibility of anesthesia for patients with myasthenia gravis using target controlled infusion without muscle relaxant. Methods 31 patients with myasthenia gravis were involved into study. A target controlled infusion was started with targeting effect-site concentration of propofol 3μg/ml and remifentanil 4ng/ml. Intubation was performed when patients were unconsciousness and target concentrations of both drugs were reached. No muscle relaxant was used during anesthesia. Blood pressure,heart rate, performance of intubation and respiratory recovery including extubation and wake time were observed. Result All patients were intubated successfully in one attempt. 38.7% patients were present mild cough when the endotracheal tube past through the vocal cord during intubation. Blood pressure and heart rate at post-intubation increased significantly compared with pre-intubation (P<0.01). After cease of drugs, time of spontaneous breathing recovery was 6.5±2.9min. Extubation and wakeup time were 9.8±3.6 and 7.4±3.1min respectively. No adverse event was noted. Conclusion Target controlled infusion without muscle relaxant was safe and effective anesthesia for myasthenia gravis patients undergoing thymectomy.

Key words: Anesthesia, muscle relaxant, target controlled infusion, myasthenia gravis