自主呼吸浅快指数趋势分析对拔管成功预测准确性的影响

Trend analysis of rapid shallow breathing indices during spontaneous breathing trial may improvepredictive accuracy of extubation success

目的寻找机械通气自动管道补偿模式（ATC）下自主呼吸试验（SBT）过程中准确预测拔管成功的呼吸参数。方法前瞻性地选择符合撤机准人标准的机械通气患者共105例进行60minATC模式下的SBT。SBT中持续监测心率（HR）、平均动脉压（MAP），1、30、60min时记录分钟通气量（VE），呼吸频率（RR），自主呼吸潮气量（VT），计算呼吸浅快指数（RSBI）及各时点间的变化量和变化率（如ARSBl60_1和ARSBl60_1／RSBll）。比较拔管成功组和拔管失败组的临床资料和SBT过程中各呼吸参数，ROC曲线下面积（AUC）评估各呼吸参数对成功拔管预测的准确性。结果拔管失败组的机械通气时间（10．8±2．7）d较拔管成功组长（7．5±5．1）d（P=0．035），拔管失败率为17．1％。在拔管成功组，SBT开始后随时间延长RSBI呈先增大后减少的趋势，而在拔管失败组，RSBI则持续增加，ARSBl60_1和ARSBl60_1／RSBll在拔管成功组和失败组差异有统计学意义（-11．5±16，6：12．1±38．9，P=0．001；-17±26：13±39，P=0，028）。RSBl60，ARSBl60_1和ARSBl60_1／RSBll的AUC分别为0．75，0．73和0．72。ARSBl60_1／RSBll≤0的敏感性、特异性和诊断准确性分别为81．0％、66．7％、78．5％。结论在ATC模式下动态观察SBT过程中各项呼吸参数很重要，ARSBl60_1和ARSBl60_1／RSBll对拔管成功有预测价值，RSBl60趋于稳定或逐渐降低，拔管成功率越高。

Objective To determine the respiratory indices capable of improving predictive accuracy of extubation success through serial measurements of during spontaneous breathing trial （SBT） in automatic tube compensation （ATC） pattern of mechanical ventilation. Methods For this prospective observational study, patients ventilated over 48 hours were enrolled according to the weaning criterion and underwent a 60 minutes spontaneous breathing trial （SBT） in ATC pattern （ ATC = 100%, FiO2 = 0.4, PEEP =0 cm H20, PS =0 cm H20）. During SBT,heart rate （HR） and mean artery pressure （MAP） were monitored continuously and minute volume （ VE）, respiratory rate （ RR）, tidal volume of spontaneous breath （VT）, rapid shallow breathing index （RSBI）, change and rate of change （ARSB160_ 1 and ARSB160_1/RSBI1, etc. ） were recorded or calculated at the first, 30th and 60th minute of SBT. Patients tolerating the trial were extubated immediately. Clinical data and respiratory indices during SBT were compared between patients in extubation success group and those in extubation failure group. Predictive accuracy of extubation success was assessed by area under the receiver operating characteristic （ROC） curve （AUC） for each index. Results The duration of mechanical ventilation was longer in patients of extubation failure group than that of extubation success group （ 10. 75 ±2. 73 ： 7.47 ± 5. 11, P = 0. 035） and extubation failure rate was 17.14%. During SBT, RSBI increased initially and then decreased in patients of extubation success group, but increased continuously in patients of extubation failure group. There were significant difference of ARSB160_1 and △RSB160_1/RSBI1 in patients between extubation success and failure groups（ - 11.5 ± 16. 6： 12. 1 ± 38.9, P = 0. 001 and - 17 ± 26：13 ± 39, P = 0. 028）. AUCs of RSB160, ARSB160_1 and ARSB160_1/RSBI1 were 0. 75, 0. 73 and 0. 72 and the sensitivity, specificity and diagnostic accuracy 81.0%, 66.7% and 78. 5% respectively. Conclusion It is important to observe change of various respiratory indices dynamically during SBT in patients ventilated in ATC pattern. △RSB160_1 and ARSB160_1/RSBI1 have greater predictive value for extubation success. Stable or decreased RSB160 means higher extubation success rate.