呼吸做功量和吸气时间分数在呼吸机撤离中的应用

目的 通过埘使用机械通气患者撤离呼吸机的临床治疗研究,探究呼吸做功量和吸气时间分数对于呼吸机撤离的临床价值.方法采用前瞻性研究86例2007年1月至2008年1月收治于中国医科大学附属第一医院急诊监护室的患者,满足预设的撤机条件且上机时间不少于72 h的患者的临床资料,然后根据临床确定诊断分为慢性阻塞性肺疾病(COPD)组和急性中毒组,然后COPD组与急性中毒组再根据实际成功撤机与否,分别进一步细分为撤机成功组和失败组,对其相关参数进行统计学分析处理,并与现常规应用的撤机参数进行相火件统计学分析比较,来判断呼吸做功量和吸气时间分数对于预测撤机成功与否的参考价值.结果 撤机成功组与失败组的呼吸做功量相比较可以看出与,WOB<0.75 J/L的现认可的撤机参考结果相近,并且撤机成功组与失败组的患者的心率,机械通气时间,呼吸做功量,吸气时间分数和撤机结果差异具有统计学意义(P<0.05).Logistic回归分析显示呼吸做功量和吸气时间分数对于呼吸机撤机的预测具有一定的临床参考价值(OR值均大于1).结论 呼吸做功量和吸气时间分数作为目前撤机方案的一种补充和完善,需要和其他撤机参数联合使用.目前呼吸机撤离的研究,主要强调的是多项参数的综合性和动态性的联合分析比较,并尝试探寻无创通气代替有创通气的可能,同时也需要医生的有效治疗为根本,给撤机成功提供最大的基础保证.     

自主呼吸试验在机械通气撤机过程中的应用

目的；探讨在终止机械通气后，自主呼吸试验（SBT）时间对成功拔管的作用。方法：采用回顾组与前瞻组对比的方法，回顾组将成功拔管患者按SBT时间不同及病种不同分别对SBT结果进行记录及统计不处理；前瞻组除慢慢阻塞性肺疾病（COPD）采用1－2小时SBT外，其余病种患者均采用30分钟SBT。记录并比较2组的成功率、再插管率，并进行统计学处理。结果：回顾组患者按时间分组显示，拔管成功率无显著性差异（P＞0.05）；若按病种分别计算，COPD1－2小时组成功率要高于30分钟组（P＜0.05），心力衰竭（心衰）患者30分钟组成功率高于3－4小时组（P＜0.05），与1－2小时组比较无显著性差异（P＞0.05）。前瞻组COPD及心衰组拔管成功率均较回顾组明显提高（P均＜0.05）。结论：应根据不同病种有用不同SBT。COPD患者SBT过短只能了解呼吸肌力，不能了解耐力；而心衰患者SBT过长会增加呼吸功而诱发心衰。     

自主呼吸试验在撤机中的应用

目的 对应用自主呼吸试验(SBT)撤机方式与逐渐降低机械通气支持水平撤机方式成功拔管的患者进行比较,以寻找最佳撤机方式.方法 选择57例机械通气患者,病情稳定后通过撤机试验前评估,然后准备撤机.采用前后对照的方法将患者分为两组,2004年6月-2005年12月的21例患者作为对照组,采用逐渐降低机械通气支持水平的撤机方式拔管;2006年1月-2007年3月的36例患者作用为试验组,采用SBT的撤机方式拔管.分别观察两组患者的机械通气时间、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、ICU病死率.结果 试验组与对照组的机械通气时间分别为(59.45±37.1)h和(111.4±59.8)h(P=0.001),住ICU时间分别为(8.0±5.5)d和(15.3±14.3)d(P=0.034),VAP发生率分别为16.7%和38.0%(P=0.070),48 h内再插管率分别为19.4%和5.0%(P=0.253),ICU病死率分别为25.0%和24.0%(P=0.920).结论 SBT的撤机方式比逐渐降低机械通气支持水平的撤机方式具有机械通气时间和住ICU时间短的优点,而两组VAP发生率、48 h内再插管率、ICU病死率基本相同.     

两种自主呼吸试验方法在气管插管患者撤机中的应用和研究

目的 两种自主呼吸试验方法在ICU气管插管患者撤机中的应用及观察研究。方法 采用随机对照试验,将符合标准的外科术后机械通气患者分为两组,分别采用T管试验和低水平PSV模式进行SBT,比较两组患者拔管前的气道保护能力、撤机时间、撤机成功率、撤机失败率和再插管率。结果 低水平PSV模式SBT较T管试验在首次SBT成功率上高,差异有统计学意义(P＜0.05)。在气道内分泌物及吸痰频率评估中T管试验少于低水平PSV,差异有统计学意义(P＜0.05)。在撤机成功率、撤机失败率、撤机时间和再插管率的差异无统计学意义(P＞0.05)。结论 两种SBT试验均适合在外科术后机械通气病人撤机中应用,但T管试验组患者的气道保护能力评估总体要优于低水平PSV模式,用于辅助判断拔管风险,减少拔管后并发症的发生。     

重症监护病房机械通气病人撤离呼吸机的护理

总结52例重症监护病房机械通气病人撤离呼吸机的护理,强调机械通气病人达到撤机指证后做好撤机前后的准备、监测及护理,以保证病人顺利撤机。     

呼吸功对机械通气患者撤机的指导意义

目的：研究呼吸功（ＷＯＢ）对机械通气患者撤机的指导意义。方法：选择机械通气并准备撤机的患者２３例，应用ＢＩＣＯＲＥＣＰ１００呼吸监测仪床边监测患者ＷＯＢ及常规撤机指标〔呼吸频率（ＲＲ）、潮气量（ＶＴ）、每分通气量（ＶＥ）和最大用力吸气时口腔闭合压（ＭＩＰ）〕，观察其对撤机的指导意义。结果：１８例撤机成功，其中１０例ＷＯＢ正常（≤０．７５Ｊ／Ｌ），８例ＷＯＢ升高（１．００Ｊ／Ｌ～１．３１Ｊ／Ｌ）；撤机失败患者５例的ＷＯＢ〔（１．９６±０．７６）Ｊ／Ｌ（１．４５Ｊ／Ｌ～２．８６Ｊ／Ｌ）〕明显高于撤机成功的患者〔（０．７７±０．３６）Ｊ／Ｌ，Ｐ＜０．０５〕。常规撤机指标ＲＲ、ＭＩＰ、ＶＥ均显著高于撤机成功组，ＶＴ显著低于撤机成功组。结论：ＷＯＢ值对撤机有一定的指导意义，但并非敏感指标，需考虑肺部基础疾病，结合临床指标等综合因素判断是否撤机。     

无创通气在机械通气撤离中的作用

目的 探讨无创通气(Noninvasive positive pressure Ventilation,NNPV)在多种原因导致的急性呼吸衰竭机械通气患者撤机流程中的有效性.方法 前瞻性分析2007年1月至2008年12月浙江大学医学院附属邵逸犬医院ICU人选的71例急性呼吸衰竭机械通气患者.经气管插管机械通气治疗48 h后,达到临床撤机条件,但末能完成自主呼吸试验,排除NPPV禁忌证,将患者随机(随机数字法)分成无创通气序贯撤机(NPPV组,n=36)和传统撤机方法(IPPV组,n=35)两组.NPPV组拔管前予提高压力支持水平休息30 min,拔管后立即给予NPPV作为撤机方法;IPPV组传统方法撤机.观察两组患者自主呼吸试验前后呼吸力学参数、动脉血气、循环指标的变化,以及分组后两组机械通气2 h后的心肺参数,同时比较两组患者的转归.结果 分绀后机械通气2 h后心肺参数差异无统计学意义.与IPPV组相比,NPPV组机械通气时间、ICU住院时间、总住院时间明显缩短,分别为[(14.88 ±3.76)d vs.(20.68±2.79)d,P<0.01);(14.16±3.45)d vs.(2.57±7.71)d,P<0.01);IPPV组分别为(23.39±5.19)d vs.(33.89±8.58)d,P<0.01)],NPPV组并发症发生率明显低于IPPV组(22.9%vs.72.2%,P<0.01),特别是肺部感染发生率较低(6.1%vs.36.1%,P<0.01).结论 NPPV适用于多种原因导致的呼吸衰竭的撤机过程.把握无创通气NPPV的适应证,以及在撤机过程中及早进行NPPV干预,可以提高NPPV住序贯撤机中的成功率.     

Inspiratory pressure/maximal inspiratory pressure ratio: a predictive index of weaning outcome

Objective To compane the accuracy of P_I/ P_Imax ratio and other commonly used indices in predicting weaning outcome.Design A prospective study.Setting Intensive care unit.Patients 31 stable intubated patients ready to undergo weaning trial.Methods A simple method was developed to measure the P_I and P_Imax in intubated patients. The accuracy of P_I/P_Imax ratio and other commonly used indices in predicting outcome were compared. All indices were measured prior to weaning trial using standardized methods.Measurements and results Minute ventilation of the successful patients (13.00±0.67 (SE) l/min) was not significantly different from the failure patients (10.64±1.26 l/min,p=0.10). The P_I and P_Imax for the successful patients (11.48±1.25 cmH₂O and 47.77±4.48 cm H₂O, respectively) and the unsuccessful, patients (14.32±2.31 cmH₂O and 40.16±4.55 cmH₂O respectively) were also not significantly different (p=0.28 and 0.24 respectively). The P_I/P_Imax ratio was lower for the weaning successes (0.26±0.03) than for the weaning failures (0.36±0.04,p<0.05). The threshold value of 0.3 for P_I/P_Imax provided the best separation between weaning success and failure patients. The combined usage of rapid shallow breathing index and P_I/P_Imax ratio provided the highest accuracy with sensitivity of 0.81 and specificity of 0.93.Conclusion The P_I/P_Imax ratio provided a good separation between the patients who were successfully weaned and those who failed. It provides additional discriminative power to f/V_T.     

A weaning protocol administered by critical care nurses for the weaning of patients from mechanical ventilation

Purpose

The primary objective of this clinical trial of patients on mechanical ventilation was to determine if a weaning protocol implemented solely by nurses could reduce the weaning time relative to usual care (UC).

Materials and Methods

This study is a prospective, randomized, controlled trial conducted from January 2007 to January 2009 that compared protocol-based weaning (PBW) with UC. A total of 122 patients who received invasive ventilation in the medical ICU of the Asan Medical Center were examined. Nurses operated the mechanical ventilators according to a predesigned ventilator-weaning protocol for the PBW group (n = 61), and intensive care unit (ICU) physicians managed weaning in the UC group (n = 61).

Results

There were no significant differences in the 2 groups at baseline. The number of patients who successfully discontinued mechanical ventilation was similar in the 2 groups (PBW, 46 patients, 75.4%; UC, 47 patients, 77.0%; P = .832). The weaning time was 47 hours (interquartile range, 24-168 hours) in the UC group and 25 hours (interquartile range, 5.75-134 hours) in the PBW group (P = .010).

Conclusions

The weaning protocol administered by the nurses was safe and reduced the weaning time from mechanical ventilation in patients who were recovering from respiratory failure.     

长期机械通气老年患者撤机的影响因素分析

目的探讨长期机械通气的老年患者撤机的影响因素。方法回顾性分析2006年1月至2010年6月内科重症监护病房（MICU）收治的136例长期机械通气的老年患者。根据撤机成败判定标准将全部病例分为撤机成功组（72例）和撤机失败组（64例）,比较两组患者机械通气时间、年龄、住院时间、气管切开例数、基础疾病和入科第1天及第10天的急性病生理学和长期健康评价（APACHE）Ⅲ评分及各项生理指标,采用logistic回归分析法对各指标进行分析,并运用受试者工作特征（ROC）曲线对第10天的APACHEm评分及血乳酸水平预测长期机械通气的老年患者撤机成功与否作评价。结果两组患者住院时间比较差异有统计学意义（P〈0．05）,撤机成功组患者第1天仅APACHEⅢ评分、白蛋白水平优于撤机失败组（P均〈0．05）;第10天APACHEⅢ评分、氧合指数、平均动脉压、肺泡一动脉血氧分压差、血乳酸、白细胞、血小板、总胆红素、丙氨酸转氨酶、肌酐、白蛋白、血糖、血钠水平均优于撤机失败组（P均〈0．05）。logistic分析示第10天APACHEm评分〉60分、第10天血乳酸〉2．0mmol／L是影响撤机成功与否的独立危险因素,其ROC曲线下面积分别为0．894（95％可信区间：0．836～0．951）、0．738（95％可信区间：0．648～0．828）。结论APACHEm评分、血乳酸水平对预测长期机械通气患者能否成功撤机有一定影响。     

呼吸功作为慢性阻塞性肺病患者撤机指标的评价

目的　评价呼吸功 (WOBp)对慢性阻塞性肺病 (COPD)机械通气患者撤机的指导作用 ,探讨预计撤机的标准。方法　应用Bicore -cp10 0呼吸监护仪床边监测 2 7例COPD呼吸衰竭患者通气治疗不同时期及撤机时及 12例COPD缓解期患者 ,分析不同WOBp标准预计撤机的敏感性和特异性。结果　撤机成功组 2 1例 ,均值为 ( 1 19± 0 2 6 )J/L ,撤机失败组 6例均值为 ( 1 6 5± 0 39)J/L ,高于撤机成功组和对照组 ( 1 14± 0 2 8)J/L ,二组比较差异有显著性 (P <0 0 1)。动态观察 14例患者 ,急性加重期和撤机时 ,随病情改善 ,均值由 ( 2 0 7± 0 6 2 )J/L ,下降至 ( 1 13± 0 36 )J/L (P <0 0 1)。以常规的WOBp≤ 0 8J/L作为撤机标准 ,敏感性仅为 19% ,以≤ 1 1J L作为撤机标准 ,敏感性为 71% ,特异性为 10 0 % ,以WOBp≤1 3作为撤机标准 ,敏感性为 85 % ,特异性为 83%。结论　患者基础增高 ,常规撤机指标不适用于COPD患者 ,对COPD可适当提高判断标准。若以≤ 1 1J/L为撤机标准 ,可以提高预计撤机敏感性。动态监测有助于预测撤机     

序贯器官衰竭评价在评估呼吸机撤机中的应用

目的：应用序贯器官衰竭评价（SOFA）评估急诊监护室内行机械通气的患者,来评估其对机械通气患者撤机预后的价值。方法：收集既往急诊监护室行机械通气患者的临床资料92例,按照撤机成功与否,分为成功组和失败组,分别行SOFA,进行临床对比和统计学分析。结果：成功组的SOFA^2为（2.59±2.10）分,失败组的SOFA^2为（15.32±3.56）分,两者比较差异具有显著性（P〈0.05）。而成功组的机械辅助通气时间（6±4）d相对于失败组的（10±7）d较短,成功组与失败组在机械通气时间方面相比差异具有显著性（P〈0.05）。结论：SOFA既可用于评估患者多脏器功能衰竭情况,在一定程度上也为机械通气撤机提供参考。     

Additional inspiratory work of breathing imposed by tracheostomy tubes and non-ideal ventilator properties in critically ill patients

Objective: To determine the tracheostomy tube-related additional work of breathing (WOB_add) in critically ill patients and to show its reduction by different ventilatory modes. Design: Prospective, clinical study. Setting: Medical ICU of a university teaching hospital. Intervention: Standard tracheostomy due to prolonged respiratory failure. Measurements and results: Ten tracheostomized, spontaneously breathing patients were investigated. As the tube resistance depends on gas flow, patients were subdivided according to minute ventilation into a low ventilation group ( = 10 l/min; n = 5) and a high ventilation group ( > 10 l/min; n = 5). The WOB_add due to tube resistance and non-ideal ventilator properties was calculated on the basis of the tracheal pressure measured. Ventilatory modes investigated were: continuous positive airway pressure (CPAP), inspiratory pressure support (IPS) of 5, 10, and 15 cm H₂O above PEEP, and automatic tube compensation (ATC). In the low ventilation group, WOB_add during CPAP was 0.382 ± 0.106 J/l. It was reduced to below 15 % of that value by ATC or IPS more than 5 cm H₂O. In the high ventilation group WOB_add during CPAP increased to 0.908 ± 0.142 J/l. In this group, however, only ATC was able to reduce WOB_add below 15 % of the value observed in the CPAP mode. Conclusions: The results indicate that, depending on respiratory flow rate, (1) tracheostomy tubes can cause a considerable amount of WOB_add, and (2) ATC, in contrast to IPS, is a suitable mode to compensate for WOB_add at any ventilatory effort of the patient. Received: 12 August 1998 Final revision received: 22 February 1999 Accepted: 24 February 1999     

1例脊柱侧凸伴呼吸衰竭患者延迟撤机的循证实践

总结了1例脊柱侧凸伴呼吸衰竭患者延迟撤机的循证实践方案。明确患者的临床问题,通过检索Cochrane图书馆、PubMed、中国知网等数据库,查找相关文献,评价证据级别后确定最佳临床证据。 结合患者实际情况,进行镇痛镇静谵妄护理、气道管理、早期运动安全管理,历时21d成功撤离呼吸机。     

Use of the oxygen cost of breathing as an index of weaning ability from mechanical ventilation

The oxygen cost of breathing (which is the difference in oxygen consumption measured during controlled ventilation and again during spontaneous ventilation) was measured in 30 patients between the ages of 17 and 96 years at the time of commencement of weaning from mechanical ventilation. There was a significant exponential correlation between the oxygen cost of breathing in ml/m²/min and the oxygen cost of breathing as a percentage of total oxygen consumption during spontaneous ventilation and the duration of weaning in days.     

Evaluation of indexes predicting the outcome of ventilator weaning and value of adding supplemental inspiratory load

Objective: To assess the diagnostic accuracy of several measured and calculated indexes for early prediction of weaning outcome, and to study the value of supplemental inspiratory load in improving the accurate prediction of successful weaning.Design: Prospective study.Setting: ICU of a University Hospital.Patients: Thirty consecutive patients under prolonged mechanical ventilation and without chronic obstructive pulmonary disease (COPD).Interventions: Forty weaning trials were performed. Data were recorded at 15, 30 (adding inspiratory flow resistance), 60 and 120 min.Measurements and main results: The threshold values and the accuracy of three indexes were determined: Inspiratory airway occlusion pressure at 0.1 sec. (P01) to maximum inspiratory pressure ratio (P01/MIP), inspiratory effort quotient (IEQ), and the ratio of respiratory frequency to tidal volume (F/Vt). All three were useful predictors for weaning success with a diagnostic accuracy between 82–87%. At 15 min of spontaneous breathing, a P01/MIP ratio <0.14 predicts weaning success with a sensitivity of 82% and specificity of 83%. In our group of patients no reintubation was necessary. The application of mechanical inspiratory load significantly increased P01 values (3.16±1.22 to 3.60±1.19,p<0.001). The degree of the P01 increase did not provide prediction of weaning outcome.Conclusions: a) P01/MIP, IEQ and F/Vt ratio were accurate, early predictors of weaning outcome. b) The addition of a moderate mechanical inspiratory load did not enhance the diagnostic accuracy of P01 measurements. c) In our patients, a period of two hours seemed to be sufficient for development and detection of weaning failure.