评价膈肌功能指导慢性阻塞性肺疾病患者撤机的可行性研究

Objective To evaluate the predictive performance of neuro-mechanical coupling (NMC) and neuro-ventilatory coupling (NVC) in the weaning outcome in patients with chronic obstructive pulmonary disease (COPD). Methods Sixteen patients were enrolled when the criteria for their first spontaneous breathing trial (SBT) was met. A 30-minute SBT was attempted, with the measurement of electrical activity of the diaphragm (Edi) , NMC, NVC, NVC ×NMC, index of rapid shallow breathing (f/Vt) , airway occlusion pressure (P0.1) and f/Vt ×P0.1 at 0, 5 and 30 min. The receiver operating characteristic (ROC) curve was calculated to evaluate the predictive performance of each index. Results Successful weaning(S group) was observed in 6 patients while weaning failure(F group) in 10 patients. (1)The predictive capacity of Edi: at 30 min of SBT, Edi showed higher values in the F group (P ＜ 0. 05), the area under the ROC curves(AUC) was 0. 817(P ＜0. 05). (2) The predictive capacity of NVC and NMC:at 5, 30 min of SBT, NVC and NMC showed higher values in the S group (P ＜0. 05); at 30 min of SBT NVC presented the largest AUC than any other time of SBT (0. 822, P ＜ 0. 05), while the AUC of NMC was 0. 800 (P ＞ 0. 05). (3) The predictive capacity of NVC × NMC: at 30 min of SBT, the AUC of NVC × NMC was larger than NVC (0. 864, P ＜ 0. 05) , showing greater sensitivity (100. 0%) and specificity (83. 3%) .(4) The predictive capacity of f/Vt and P0.1: f/Vt and f/Vt × P0.1 presented poor predictive performance in the failed patients. Conclusions Edi, NVC and NVC × NMC were good predictor for the weaning outcome in patients with COPD.     

评价膈肌功能指导慢性阻塞性肺疾病患者撤机的可行性研究

Objective To evaluate the predictive performance of neuro-mechanical coupling (NMC) and neuro-ventilatory coupling (NVC) in the weaning outcome in patients with chronic obstructive pulmonary disease (COPD). Methods Sixteen patients were enrolled when the criteria for their first spontaneous breathing trial (SBT) was met. A 30-minute SBT was attempted, with the measurement of electrical activity of the diaphragm (Edi) , NMC, NVC, NVC ×NMC, index of rapid shallow breathing (f/Vt) , airway occlusion pressure (P0.1) and f/Vt ×P0.1 at 0, 5 and 30 min. The receiver operating characteristic (ROC) curve was calculated to evaluate the predictive performance of each index. Results Successful weaning(S group) was observed in 6 patients while weaning failure(F group) in 10 patients. (1)The predictive capacity of Edi: at 30 min of SBT, Edi showed higher values in the F group (P ＜ 0. 05), the area under the ROC curves(AUC) was 0. 817(P ＜0. 05). (2) The predictive capacity of NVC and NMC:at 5, 30 min of SBT, NVC and NMC showed higher values in the S group (P ＜0. 05); at 30 min of SBT NVC presented the largest AUC than any other time of SBT (0. 822, P ＜ 0. 05), while the AUC of NMC was 0. 800 (P ＞ 0. 05). (3) The predictive capacity of NVC × NMC: at 30 min of SBT, the AUC of NVC × NMC was larger than NVC (0. 864, P ＜ 0. 05) , showing greater sensitivity (100. 0%) and specificity (83. 3%) .(4) The predictive capacity of f/Vt and P0.1: f/Vt and f/Vt × P0.1 presented poor predictive performance in the failed patients. Conclusions Edi, NVC and NVC × NMC were good predictor for the weaning outcome in patients with COPD.     

评价膈肌功能指导慢性阻塞性肺疾病患者撤机的可行性研究

Objective To evaluate the predictive performance of neuro-mechanical coupling (NMC) and neuro-ventilatory coupling (NVC) in the weaning outcome in patients with chronic obstructive pulmonary disease (COPD). Methods Sixteen patients were enrolled when the criteria for their first spontaneous breathing trial (SBT) was met. A 30-minute SBT was attempted, with the measurement of electrical activity of the diaphragm (Edi) , NMC, NVC, NVC ×NMC, index of rapid shallow breathing (f/Vt) , airway occlusion pressure (P0.1) and f/Vt ×P0.1 at 0, 5 and 30 min. The receiver operating characteristic (ROC) curve was calculated to evaluate the predictive performance of each index. Results Successful weaning(S group) was observed in 6 patients while weaning failure(F group) in 10 patients. (1)The predictive capacity of Edi: at 30 min of SBT, Edi showed higher values in the F group (P ＜ 0. 05), the area under the ROC curves(AUC) was 0. 817(P ＜0. 05). (2) The predictive capacity of NVC and NMC:at 5, 30 min of SBT, NVC and NMC showed higher values in the S group (P ＜0. 05); at 30 min of SBT NVC presented the largest AUC than any other time of SBT (0. 822, P ＜ 0. 05), while the AUC of NMC was 0. 800 (P ＞ 0. 05). (3) The predictive capacity of NVC × NMC: at 30 min of SBT, the AUC of NVC × NMC was larger than NVC (0. 864, P ＜ 0. 05) , showing greater sensitivity (100. 0%) and specificity (83. 3%) .(4) The predictive capacity of f/Vt and P0.1: f/Vt and f/Vt × P0.1 presented poor predictive performance in the failed patients. Conclusions Edi, NVC and NVC × NMC were good predictor for the weaning outcome in patients with COPD.     

膈肌功能对慢性阻塞肺疾病加重期插管患者撤机的指导价值分析

目的探讨膈肌功能对慢性阻塞性肺病加重期(AECOPD)插管患者撤机的指导价值。方法选取行机械通气并考虑撤机的AECOPD插管患者为研究对象,根据患者撤机成功与否分为撤机成功组与撤机失败组。具备撤机条件后行自主呼吸试验(SBT)30 min,监测SBT 0、5、30 min时膈肌电活动(Edi)、呼吸浅快指数(f/Vt)及口腔闭合压(P0.1)。结果 37例患者纳入本研究,其中撤机成功组25例,撤机失败组12例。撤机失败组患者血Pa CO2高于另一组患者(P0.05)。撤机成功与失败组患者的年龄、Pa O2、MAP等各方面均无显著差异(P0.05)。SBT 30 min时两组患者Edi均显著高于SBT 0 min;在SBT 30 min撤机成功组Edi低于撤机失败组,以Edi12V为临界值,撤机失败预测的灵敏度为100.0%和特异度为66.7%。在SBT 5、30min时撤机成功组患者f/Vt较撤机失败组低,两组患者P0.1无明显差别(P0.05)。结论 Edi对AECOPD患者撤机具有良好的预测价值。     

机械通气时间对机械通气撤机患者膈肌功能的影响分析

目的 探讨机械通气时间对机械通气患者膈肌功能的影响.方法 以2008年12月至2009年12月入住东南大学附属中大医院ICU行机械通气超过24 h,且准备撤机的患者为研究对象,根据机械通气时间分为机械通气≤3d组(A组)及机械通气＞3d组(B组).行自主呼吸实验(SBT)30 min,监测SBT 0、5及30 min时膈肌电位(Edi)、神经肌肉强度指数(NMS)、神经机械耦连指数(NMC)及神经通气耦连指数(NVC)等膈肌功能指标.结果 44例患者纳入研究,A组患者25例(56.8％),B组患者19例(43.2％).①SBT 0 min时A、B两组患者间Edi、NMS、NMC及NVC差异均无统计学意义.②SBT 5 min时B组患者Edi和NMS显著高于A组.③SBT 30 min时B组患者Edi显著高于A组[(23±11)μV比(15±8)μV,P＜0.05];与A组患者NMS相比,B组患者NMS显著增高[(598±309)μV· cpm比(363±224)μV·cpm](P＜0.05),而B组患者NVC则明显低于A组.结论 SBT 30 min时机械通气＞3 d的患者膈肌收缩能力、耐力均下降;提示机械通气时间增加可能是导致膈肌功能下降的重要原因.     

膈肌电活动对慢性阻塞性肺疾病急性加重期插管患者成功撤机的预测价值

目的 探究膈肌电活动对慢性阻塞性肺疾病急性加重期(AECOPD)插管患者撤机的预测价值.方法 选择2013年5月至2015年5月在哈尔滨医科大学附属第一医院行机械通气治疗并考虑撤机的AECOPD插管患者55例作为研究对象,根据患者是否撤机成功将55例AECOPD患者分为撤机成功组与撤机失败组2组.符合撤机条件后,分别对2组患者行自主呼吸试验(SBT) 30 min,分别监测、记录并比较行SBT后0、10及30 min时2组患者膈肌电活动(Edi)、口腔闭合压(P0.1)及呼吸浅快指数(f/Vt),并监测比较2组患者PaCO2、PaO2、MAP及HR等一般情况.结果 55例患者中,撤机成功者35例,占63.6％,撤机失败者20例,占36.4％,2组患者的年龄、PaO2、MAP等一般情况差异均无统计学意义(t=0.078、1.669、1.150,P＞0.05);与撤机失败组相比,撤机成功组患者的PaCO2均明显偏低,差异有统计学意义(t=2.454,P=0.017);行SBT后10 min及30 min时2组患者Edi均显著高于SBT后0 min时相应组别患者的Edi,差异有统计学意义(P＜0.05);行SBT 30 min时,与撤机失败组相比,撤机成功组患者Edi明显偏低,差异有统计学意义(t=3.505,P=0.001);行SBT后10 min及30 min时撤机失败组患者f/Vt较撤机成功组患者高,差异有统计学意义(t=2.624、2.170,P值均＜0.05);与撤机失败组相比,撤机成功组患者P0.1无明显差异,且差异无统计学意义(P＞0.05).结论 Edi对AECOPD插管患者撤机具有较好的预测价值.     

气道闭合压（P0.1）、用力呼吸指数(CORE)、综合脱机指数(IWI)对ICU患者脱机能力的预测价值

目的 探讨气道闭合压（P0.1）、用力呼吸指数(CORE)、综合脱机指数(IWI)对重症监护病房（ICU）患者脱机能力的预测价值。方法 选取2014年9月—2017年9月我院入住ICU接受机械通气治疗的患者96例作为研究对象,采取撤机筛查实验,对符合条件者采取30 min自主呼吸实验（SBT）,观察患者撤机成功率,对比撤机成功与失败患者年龄、性别、机械通气时间等一般情况与SBT前的P0.1、CORE、IWI水平,以Logistic回归分析探究ICU机械通气患者撤机成功率的影响因素,Spearman相关性分析探讨P0.1、CORE、IWI与ICU患者撤机成功率的相关性,并以受试者操作特征曲线（ROC）分析P0.1、CORE、IWI对ICU患者撤机成功率的预测价值。结果 本组96例ICU患者中撤机成功73例,撤机成功率为76.04%（73/96）;撤机失败23例,撤机失败率为23.96%（23/96）;撤机成功组与撤机失败组年龄、性别、机械通气时间对比,差异无统计学意义（P＞0.05）,撤机成功组SBT前的CORE、IWI高于撤机失败组,P0.1低于撤机失败组,差异有统计学意义（P＜0.05）;Logistic回归分析显示,P0.1、CORE、IWI均为ICU机械通气患者撤机成功率的重要影响因素（P＜0.05）;Spearman相关性分析显示,CORE、IWI与ICU机械通气患者撤机成功率有明显正相关关系（r1=0.789、P1=0.003,r2=0.837、P2=0.001）,P0.1与ICU机械通气患者撤机成功率有明显负相关关系（r=﹣0.757、P=0.004）;ROC曲线分析显示,联合应用P0.1、CORE、IWI对ICU机械通气患者撤机成功率预测的敏感性及准确性高于单一参数（P＜0.05）。结论 P0.1、CORE、IWI与ICU机械通气患者撤机成功率具有密切关系,可将其用于患者撤机评估中,且联合应用三种参数可提高对患者撤机成功率的预测准确性,减少误判情况,有效指导临床治疗,改善患者预后。     

脉搏灌注指数和脉搏灌注变异指数在机械通气患者撤机中的应用

目的 观察脉搏灌注指数（PI）和脉搏灌注变异指数（PVI）在机械通气患者撤机中的应用效果。方法 选取116例准备撤机的机械通气患者,通过撤机筛查后采用T-管模式进行自主呼吸试验（SBT）,以患者拔管后自主呼吸时间超过48 h为撤机成功,根据撤机结果将患者分为撤机成功组（90例）和撤机失败组（26例）,使用脉搏血氧仪Radical-7监测SBT前和SBT结束时患者PI、PVI,计算SBT前后PI和PVI的变化（ΔPI、ΔPVI）,利用ROC评估SBT前PI、PVI及ΔPI、ΔPVI对机械通气患者撤机结果的预测价值。结果 与撤机失败组比较,撤机成功组SBT前PVI、SBT后PI、SBT后PVI、ΔPI、ΔPVI增加（P均<0.05）。当SBT前PVI>14.0%时,其预测机械通气患者撤机成功的灵敏度为86.1%,特异度为79.2%,AUC为0.860,95%CI为0.766～0.953;当ΔPVI>10.5%时,其预测机械通气患者撤机成功的灵敏度为91.7%,特异度为83.3%,AUC为0.905,95%CI为0.831～0.978;当ΔPI>12.5%时,其预测机...     

序贯健肌操联合床旁B超监测膈肌预测老年慢性阻塞性肺疾病急性加重期患者机械通气撤机的临床观察

目的 探讨序贯健肌操联合床旁B超监测膈肌预测老年慢性阻塞性肺疾病(慢阻肺)急性加重期患者机械通气撤机情况的效果.方法 60例老年慢阻肺急性加重期患者,所有患者接受序贯健肌操联合床旁B超监测膈肌,观察分析其机械通气撤机成功率及撤机指标〔膈肌电活动(Edi)、口腔闭合压(P0.1)及呼吸浅快指数(f/Vt)〕情况.结果 6...     

PCT及CRP在肺部感染患者机械通气撤机中的预测价值

目的探讨血浆降钙素原(procalcitonin,PCT)及C反应蛋白(CRP)水平与肺部感染患者机械通气撤机结局间的关系。方法回顾性分析入住广安门医院重症监护病房的重症肺部感染患者30例,在患者入院第二天及达到撤机标准行自主呼吸试验(spontaneous breathing trials,SBT)前检测PCT及CRP水平,如通过SBT则予撤机拔管。根据48 h内的撤机结局,将患者分为成功组及失败组。比较两组间性别、年龄、APACHEⅡ评分、机械通气时间、PCT及CRP水平,绘制受试者工作特征曲线(receiver operating characteristic curve,ROC曲线),计算曲线下面积(area under curve,AUC),评价PCT及CRP水平对撤机结局的预测价值。结果 30例患者中,撤机成功组24例,失败组6例,两组男女比例、年龄及APACHEⅡ评分、机械通气时间、入院第二天PCT及CRP水平差异无统计学意义(P0.05)。撤机成功组撤机前PCT及CRP水平均较失败组低(P0.05)。PCT的ROC曲线下面积(AUC)为(0.885±0.061),最佳截点值为0.71 ng/ml,此时的敏感度为83.3%,特异性为20.8%;CRP的ROC曲线下面积(AUC)为(0.382±0.138)(P0.05)。结论 PCT在预测肺部感染患者撤机结局中有一定价值,可作为撤机参考指标之一。     

气道闭合压及其衍生参数在撤离机械通气中的应用研究进展

气道闭合压(P0.1)是一项能够较好的反映呼吸中枢驱动的指标.这一指标及其衍生参数如P0.1与最大吸气压比值(P0.1/MIP)和P0.1与浅快呼吸指数(f/Vt)的乘积(P0.1*f/Vt)可以和其他传统的指标一样用于判断撤离机械通气的预后,并且P01/MIP增加了P0.1单独判断急性呼吸衰竭患者对机械通气需求程度的...     

综合脱机指数、用力呼吸指数和气道闭合压与ARDS撤机患者病情及撤机结局的关系

目的探讨综合脱机指数(IWI)、用力呼吸指数(CORE)和气道闭合压(P0.1)与急性呼吸窘迫综合征(ARDS)撤机患者病情及撤机结局的关系。方法选取2012年1月至2015年6月于我院进行气管插管机械通气治疗的ARDS患者86例为研究对象,行撤机筛查实验,符合条件者行30min自主呼吸实验(SBT),统计其撤机成功率,比较撤机成功和失败患者SBT前的IWI、CORE和P0.1,采用急性生理与慢性健康评分(APACHE II)评价同期病情,采用Pearson线性相关分析法分析IWI、CORE和P0.1与ARDS撤机患者APACHE II评分的关系,并采用Spearman无条件相关分析法分析IWI、CORE和P0.1与ARDS撤机患者撤机成功率的关系。结果 86例ARDS患者撤机成功率为72.09%,与撤机成功患者比较,撤机失败患者的IWI和CORE降低,P0.1和APACHE II评分则升高(P0.05)。Pearson线性相关分析结果显示,IWI、CORE与ARDS撤机患者APACHE II评分均呈负相关(r=-0.993,-0.985,P0.05),P0.1与ARDS撤机患者APACHE II评分则呈正相关(r=0.992,P0.05)。Spearman无条件相关分析结果显示,IWI、CORE与ARDS撤机患者撤机成功率呈正相关(r=0.788,0.795,P0.05),P0.1与ARDS撤机患者撤机成功率则呈负相关(r=-0.812,P0.05)。结论 IWI、CORE和P0.1与ARDS撤机患者病情和撤机结局均密切相关,IWI、CORE和P0.1可能用于ARDS撤机患者撤机和病情评估,指导其治疗从而改善疗效。     

自主呼吸试验在机械通气脱机过程中的应用

目的 自主呼吸试验(SBT)作为程序化拔管步骤在机械通气脱机过程中的应用.方法 程序化拔管患者行前瞻性研究,非程序化拔管患者行回顾性分析,比较两组机械通气时间、呼吸机相关性肺炎(VAP)发生率、48 h复插管率、住ICU天数及ICU病死率.对于程序化拔管组患者,比较SBT成功与SBT失败、拔管成功与拔管失败组SBT前后监测指标的变化.结果 程序化拔管组较非程序化拔管组机械通气小时数(经Ln数据转换后)缩短(4.01±0.71 vs 4.51±0.85,P<0.05).住ICU天数(经Ln数据转换后)缩短(1.86±0.82 vs 2±48±0.92±P<0.05),VAP发生率及48 h复插管率差异无统计学意义.程序化拔管组SBT成功与SBT失败患者SBT前后心率、呼吸频率、浅快呼吸指数(f/Vt)、PaC_2的变化差异有统计学意义;而拔管成功与拔管失败患者SBT前后监测指标的变化差异无统计学意义.5例拔管失败患者中3例由于痰液引流障碍导致48 h内复插管.结论 程序化拔管可缩短机械通气时间.减少住ICU天数,不增加48 h复插管率.SBT前后心率、呼吸频率、f/Vt、PaCO_2变化对于判断SBT是否成功较其他指标更为重要.对于拔管后可能存在痰液引流障碍的患者需谨慎拔除气管插管.     

血浆BNP对慢性阻塞性肺疾病有创机械通气撤机的指导价值

目的探讨撤机前后血浆BNP水平及其变化对慢性阻塞性肺疾病(简称慢阻肺)患者有创机械通气撤机的指导价值。方法回顾性调查满足条件的70例患者,测定患者开始有创机械通气时,自主呼吸试验(SBT)前、后的血浆BNP水平,分别标为(BNP 0、BNP 1、BNP 2),SBT前、后的血浆BNP水平差值(ΔBNP),并根据患者撤机结局分为撤机成功组与撤机失败组。绘制ROC曲线,分析血浆BNP水平对慢阻肺患者撤机结局的预测价值。结果 70例患者中,成功撤机52例,撤机失败18例。BNP 0、BNP 1、BNP 2预测慢阻肺患者撤机失败的AUC分别为0.6079、0.8568、0.9081,ΔBNP预测撤机失败的AUC为0.9466。结论血浆BNP水平对预测慢阻肺患者撤机结局有指导价值,其中ΔBNP预测慢阻肺患者撤机结局的价值最大。     

浅快呼吸指数指导缺血性脑卒中患者撤机的临床观察

目的探讨浅快呼吸指数(RSBI)指导缺血性脑卒中患者撤机的临床价值。方法前瞻性研究,入选在重症医学科进行有创机械通气24 h 40例缺血性脑卒中患者,根据撤机结果将患者分为成功组26例,失败组14例。应用低水平压力支持通气法进行自主呼吸实验(SBT),40例患者均通过了1 h的自主呼吸实验,记录SBT前和SBT1h、SBT1.5h及SBT2h的RSBI,同时记录年龄、性别、APACHEⅡ评分、撤机前30 min的血气分析。结果成功组和失败组年龄、性别、GCS评分、APACHEⅡ评分无明显差异(P0.05),失败组合并冠心病比例较成功组明显升高(P0.05)。以RSBI≤105 bpm/L为标准预测撤机成功的灵敏度和特异度分别为:SBT前93.8%、10.6%,SBT1 h 100%、40.24%、SBT1.5 h 98.2%、38.7%SBT2 h 96.3%、38.2%。结论SBT1 h的RSBI预测缺血性脑卒中患者撤机成功的准确率高。动态观察RSBI对缺血性脑卒中患者成功撤机有一定的预测价值。     

Predictive parameters for weaning from mechanical ventilation

The use of predictive parameters for weaning from mechanical ventilation is a rather polemic topic, and the results of studies on this topic are divergent. Regardless of the use of these predictive parameters, the spontaneous breathing trial (SBT) is recommended. The objective of the present study was to review the utility of predictive parameters for weaning in adults. To that end, we searched the Medline, LILACS, and PubMed databases in order to review articles published between 1991 and 2009, in English or in Portuguese, using the following search terms: weaning/desmame, extubation/extuba??o, and weaning indexes/indices de desmame. The use of clinical impression is an inexact means of predicting weaning outcomes. The most widely used weaning parameter is the RR/tidal volume (V T) ratio, although this parameter presents heterogeneous results in terms of accuracy. Other relevant parameters are MIP, airway occlusion pressure (P0.1), the P0.1/MIP ratio, RR, V T, minute volume, and the index based on compliance, RR, oxygenation, and MIP. An index created in Brazil, the integrative weaning index, has shown high accuracy. Although recommended, the SBT is inaccurate, approximately 15% of extubation failures going unidentified in SBTs. The main limitations of the weaning indexes are related to their use in specific populations, the cut-off points selected, and variations in the types of measurement. Since the SBT and the clinical impression are not 100% accurate, the weaning parameters can be useful, especially in situations in which the decision as to weaning is difficult.     

自主呼吸试验在COPD机械通气患者撤机中的作用

目的评估自主呼吸试验（SBT）在COPD机械通气患者撤机过程中的作用。方法选择52例COPD机械通气撤机成功的患者,分为两组：S组24例,采用SBT方式撤机拔管;NS组28例,采用逐渐降低机械通气支持水平的方式撤机拔管。对比两组患者的拔管时间、住重症监护病房（ICU）时间、呼吸机相关性肺炎（VAP）发生率、48 h内再插管率以及住院病死率。结果 S组与NS组的拔出气管插管时间120 min和（300.01±65.23）min）、住ICU时间（9.50±4.20）d和（18.60±10.30）d、VAP发生率12.50%和28.57%,均有统计学差异（P〈0.05）,而48 h内再插管率20.83%和21.43%、ICU病死率16.67%和17.85%,无统计学差异（P〉0.05）。结论应用SBT法撤机比渐减机械通气支持水平的方法具有更早拔出气管插管、住ICU时间短的优点,而且降低了VAP的发生率。     

Minute ventilation recovery time: a predictor of extubation outcome

STUDY OBJECTIVES: To determine if minute ventilation (E) measured as a trend following the final weaning trial prior to extubation may identify patients ready for extubation and be useful as a predictive measure of extubation outcome. DESIGN: Prospective observational study. SETTING: Community hospital medical/surgical ICU. PATIENTS: Sixty-nine patients receiving mechanical ventilation enrolled in an ICU weaning protocol who underwent planned extubation during 6 months of prospective evaluation. The failed extubation group included patients reintubated within 7 days. Patients were excluded if they received ventilation by noninvasive mask, bilevel positive airway pressure, tracheostomy, or were self-extubated. INTERVENTIONS: Patients tolerating a spontaneous breathing trial (SBT) and ready for planned extubation were placed back on their pre-SBT ventilator settings for up to 25 min, during which respiratory parameters were recorded. Respiratory parameters (respiratory rate, tidal volume, E, rapid shallow breathing index [f/VT]) were obtained at three time points: baseline (pre-SBT), posttrial (immediate conclusion of SBT), and recovery (return to baseline). Patients were assumed to recover when E decreased to 110% of the predetermined baseline. MEASUREMENTS AND RESULTS: Fifty-nine patients were successfully extubated, and 10 patients required reintubation after 2.5 +/- 2.6 days (mean +/- SD). Both groups were similar in age, comorbid status, primary diagnosis, APACHE (acute physiology and chronic health evaluation) II score, mode of weaning, and SBT length (p > 0.1). Respiratory parameters measured were similar at all three time points studied (p > 0.1). E recovery time of successful extubations was significantly shorter than failed extubations (3.6 +/- 2.7 min vs 9.6 +/- 5.8 min, p < 0.011). Multiple logistic regression adjusted for age, sex, and severity of illness revealed that E recovery time was an independent predictor of extubation outcome (p < 0.01). The area under the receiver operating characteristic curve for E recovery time (0.85 +/- 0.07) was larger than that for baseline E, posttrial E, posttrial f/VT, or PaCO(2). CONCLUSIONS: E recovery time is an easy-to-measure parameter that may assist in determining respiratory reserve. Preliminary data demonstrates that it may be a useful adjunct in the decision to discontinue mechanical ventilation.     

单导联对宽QRS波鉴别诊断价值的应用

目的 验证应用Ⅱ导联QRS波第1峰时限(RWPT)、aVR导联形态及Vi/Vt比值对宽QRS波的鉴别诊断价值。方法 回顾性分析已明确诊断的261例室性早搏及127例房性早搏伴心室内差异传导患者12导联体表心电图的Ⅱ导联RWPT、aVR导联形态及Vi/Vt比值,比较3种方法鉴别诊断宽QRS波形早搏的敏感度、特异度、阳性预测值、阴性预测值、准确度,并比较aVR导联形态法前3步的鉴别价值。结果 ①Ⅱ导联RWPT、aVR导联形态法鉴别宽QRS波差异无统计学意义(P>0.05),均有较高的准确度、敏感度、特异度、阳性预测值;Vi/Vt比值法与其余两种方法相比准确度、敏感度较低(P<0.05),特异度、阳性预测值较高(P<005)。②应用aVR导联形态法第1步、第3步有较高的特异度,第3步有较高的阳性预测值。结论 鉴别诊断宽QRS波时,Ⅱ导联RWPT、aVR导联形态法较Vi/Vt比值法诊断价值高,且具有简便、快捷、准确的优点。