浅快呼吸指数和气道闭合压作为呼吸机撤离指标的临床研究

Clinical study of rapidshallowbreathing index and airway occlusion pressure as weaning predictors in mechanically ventilated patients

目的 :探讨浅快呼吸指数 (RVR)和气道闭合压对机械通气患者撤机的指导意义。方法 :将准备撤机的 90例患者按呼吸衰竭病因分为慢性阻塞性肺疾病 (COPD)急性恶化组和急性呼吸衰竭 (ARF)组。床旁监测呼吸频率 (RR)、潮气量、每分钟通气量 (MV)、气道阻力 (Raw)、顺应性、气道闭合压、内源性呼气末正压(PEEPi) ;在自主呼吸试验开始 3分钟和 30分钟时分别测定 RR、潮气量 ,比较常规撤机指标 (RR、潮气量、MV)与 RVR、气道闭合压对撤机的预测价值。结果 :撤机成功与失败组 RVR分别为 :COPD急性恶化组 (6 3±2 2 )次· min- 1· L- 1与 (91± 2 0 )次· m in- 1· L- 1 ,P<0 .0 5 ;ARF 组 (6 3± 2 1)次· min- 1· L- 1与 (81±2 1)次· min- 1 · L- 1 ,P<0 .0 5 ;全部患者组 (6 3± 2 1)次· min- 1 · L- 1 与 (88± 2 0 )次· m in- 1 · L- 1 ,P<0 .0 5。撤机成功与失败组的气道闭合压分别为 :COPD急性恶化组 (0 .2 8± 0 .0 8) k Pa与 (0 .47± 0 .0 7) k Pa,P<0 .0 5 ;ARF 组 (0 .2 7± 0 .0 5 ) k Pa与 (0 .40± 0 .0 8) k Pa,P<0 .0 5 ;全部患者组 (0 .2 8± 0 .0 8) k Pa与 (0 .45± 0 .0 8) k Pa,P<0 .0 5。以 RVR≤ 10 5次· m in- 1· L- 1为标准预测撤机成功的诊断正确率、灵敏度和特异度 ,3组?

Objective:To evaluate the significance of rapidshallowbreathing index(RVR),and airway occlusion pressure as weaning predictors in mechanically ventilated patients.Methods:Respiratory rate(RR), tidal volume,minute ventilation(MV),airway resistance(Raw),compliance of the respiratory system ,airway occlusion pressure,intrinsic positive endexpiratory pressure(PEEPi) were measured in 90 cases with mechanical ventilation at the bedside.RR and tidal volume were measured after 3 minutes and 30 minutes of a spontaneous breathing trial.The outcome of weaning from mechanical ventilation was compared with the traditional predictors including RR,tidal volume,MV and RVR,airway occlusion pressure.The patients were divided into 3 groups:①acute exacerbation of COPD; ②ARF; ③all patients(TOTAL).Results:Compared with failure of weaning,the successful weaning patients had lower RVR in different populations〔COPD (63± 22)beats·min -1 ·L -1 vs.(91± 20)beats·min -1 ·L -1 ,ARF(63±21)beats·min -1 ·L -1 vs.(81± 21)beats·min -1 ·L -1 ,TOTAL(63±21)beats·min -1 ·L -1 vs.(88±20)beats·min -1 ·L -1 ( P <0 05)〕 and lower airway occlusion pressure in different populations〔COPD (0 28±0 08)kPa vs.(0 47±0 07)kPa,ARF(0 27±0 05)kPa vs.(0 40±0 08)kPa,TOTAL(0 28±0 08)kPa vs.(0 45±0 08)kPa(all P <0 05).Using an RVR≤105 beats·min -1 ·L -1 as the threshold value for predicting successful weaning,the diagnostic accuracy ,sensitivity,specificity were:COPD 79%,91% ,40%;ARF 79%,96%,17%;TOTAL 79%,93%,33%.Using airway occlusion pressure≤0 44 kPa as the threshold value for predicting successful weaning,the diagnostic accuracy,sensitivity,specificity were:COPD 82%,87%,67%;ARF 83%,96%,50%;TOTAL 83%,90%,62%.To perform Logistic regression analysis with the weaning outcome as the dependent variable, RVR and airway occlusion pressure were the only significant variables in the model.Conclusions:RVR and airway occlusion pressure are superior to traditional predictors in predicting weaning outcomes.