摘要目的 探讨超声监测膈肌位移预测重症患者机械通气撤机的能力.方法 选2014年6-12月河北医科大学第四医院重症医学科连续收治的拟撤机、机械通气＞48 h的呼吸衰竭患者.根据撤机是否成功分为撤机成功组和撤机失败组.应用T管法行自主呼吸试验(SBT),使用呼吸机测气道闭合压(P0.1)、最大吸气压(MIP),计算P0.1/MIP、浅快呼吸指数(RSBI);SBT开始1h内,由同一位医生采用床旁经胸超声M超测量患者的膈肌位移.AUCROC预测各指标撤机成功的效力.结果 共纳入98例呼吸衰竭患者,其中撤机成功组74例,撤机失败组24例.撤机成功组与撤机失败组撤机参数P0.1[(2.00±2.00) cmH2O(1 cmH2O =0.098 kPa)比(3.00±2.75) cmH2O,P＜0.05]、RSBI(39.14±16.81比52.00±19.18,P＜0.05)、左侧膈肌位移[(1.12 ±0.97) cm比(0.69±1.00) cm,P＜0.001]、右侧膈肌位移[(1.87±0.75) cm比(1.17 ±0.76)cm,P＜0.001]、平均膈肌位移[(1.57 ±0.52)cm比(0.83 ±0.53)cm,P＜0.001]比,差异有统计学意义.撤机失败组患者机械通气时间[4.00(2.00 ～5.00)d]、ICU留治时间[8.50(6.25 ～ 15.25)d]、总住院时间[25.00(20.25 ～37.25)d]均较撤机成功组长[2.00(2.00 ～4.00)d;4.50(3.00 ～7.25)d;20.00(15.00 ～25.25)d],差异均有统计学意义(P值均＜0.05).膈肌位移的ROC最佳界值为1.14 cm,预测撤机成功的敏感性为89.2％,特异性为75.0％,AUCROC为0.849.结论 超声可早期发现膈肌功能障碍,在指导撤机方面膈肌位移可能优于传统参数.

abstractsObjective To evaluate the excursion of the diaphragm and analyze the value in predicting weaning from mechanical ventilation in intensive care unit patients.Methods The patients with mechanical ventilation (＞48 hours) in ICU at Hebei Forth Medical University Hospital from June 2014 to December were classified into a success group or a failure group according to the weaning outcome.T-piece spontaneous breathing (SBT),airway occlusion pressure at 0.1 sec (P0.1) and maximal inspiratory pressure (MIP),rapid shallow breathing index (RSBI) and P0.1/MIP were measured or calculated.During the period of the 1 st hour SBT,the excursion of diaphragm was measured with ultrasonography.The predictive value of each parameter to weaning was evaluated with ROC curve.Results A total of 98 patients were enrolled in this study,including 74 successfully weaning and 24 failed.There were significant differences between two groups (success group and failure group) in P0.1 [(2.00 ± 2.00) cmH2O (1 cmH2O =0.098 kPa) vs (3.00 ±2.75)cmH2O,P ＜0.05],RSBI (39.14 ± 16.81 vs 52.00 ± 19.18,P ＜0.05),left diaphragmatic excursion [(1.12 ± 0.97) cm vs (0.69 ± 1.00) cm,P ＜ 0.001],right diaphragmatic excursion(1.87 ± 0.75) cm vs (1.17 ± 0.76) cm,P ＜ 0.001] and mean value of left and right diaphragmatic excursion [(1.57 ± 0.52) cm vs (0.83 ± 0.53) cm,and P ＜ 0.001].The ventilation time [2.00 (2.00-4.00) d vs 4.00 (2.00-5.00) d],ICU hospital lengths of stay [4.50 (3.00-7.25) d vs 8.50 (6.25-15.25) d] and total hospital lengths of stay [20.00 (15.00-25.25) d vs 25.00 (20.25-37.25)d] were also statistically significant in success group and failure group respectively (all P ＜ 0.05).The cutoff value of diaphragmatic excursion for predicting successful extubation was determined to be 1.14 cm by ROC curve analysis.The sensitivity of diaphragmatic excursion to predict successful weaning was 89.2％ and the specificity was 75.0％,the AUCROC was 0.849.Conclusion As an early predictor of diaphragmatic dysfunction,diaphragmatic excursion is probably superior to the traditional parameters in predicting weaning from ventilator in ICU patients.