RESUMO
Objective To evaluate clinical value of MGFA classification and QMG score on pre-dicting late extubation after thymectomy for myasthenia gravis(MG).Methods Total of 61 patients with MG received extended thymectomy from January 2007 to February 2012 were enrolled.Patients were divided into two groups:normal extubation group contained the other 47 patients without pro-longed postoperative mechanical ventilation and delayed extubation group included 14 patients with prolonged postoperative mechanical ventilation.The following factors were evaluated:gender,age, weight,MGFA classification,QMG score,history of steroid hormones or anticholinesterase drugs be-fore operation,the function of liver and kidney before operation,preoperative electrolyte,preoperative hemoglobin content,etc.Receiver operator characteristic curve (ROC)was plotted,and the predictive value, sensitivity and specificity of preoperative MGFA clinical classification and QMG score predicting postoperative ventilation in MG were calculated.Results Fourteen patients(22.95%)de-veloped breathing support after the anaesthetic or endotracheal intubation again in 48 hours.the area under ROC curve(AUC)for preoperative MGFA clinical classification predicting postoperative ventila-tion was 0.723 in MG,it had the sensitivity of 78.5% and specificity of 63.8%.The AUC for QMG score predicting postoperative ventilation was 0.866,the QMG score threshold value of 8.5 had the sensitivity of 78.6% and specificity of 87.2%.Conclusion MGFA classification and QMG score can predict late extubation after thymectomy in patients with myasthenia gravis.