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。     

适应性支持通气在部分支持通气中对呼吸力学和呼吸功的影响

目的探讨适应性支持通气(ASV)在部分支持通气过程中对呼吸力学和呼吸功的影响。方法30例有自主呼吸的危重症机械通气患者,在同样的分钟通气量和呼气末正压(PEEP)的设置下,先给予AC1模式通气45min后改为ASV模式通气,时间为45min,结束后改为AC2模式(参数设置与AC1一致),通气时间为45min。记录上述三个45min后的呼吸力学和呼吸做功的参数。结果ASV模式下的气道峰值压和平均气道压下降明显,P分别小于0.01和0.05。ASV下的内源性PEEP(PEEPi)发生率为23.3%,明显低于AC1的PEEPi发生率46.7%(P<0.05)。ASV的器械附加功(WOBimp)和吸气压力时间乘积(PTP)明显降低(P<0.01)。而两种呼吸模式的血气分析和血液动力学,以及前后两次AC模式的各种参数变化无统计学意义(P>0.05)。结论在危重症的部分支持机械通气过程中,ASV较常规通气模式有利于实施保护性通气策略,同时降低呼吸负荷和呼吸做功,因而能降低呼吸氧耗。     

测定患者呼吸功对调整压力支持通气水平的意义

目的：评价患者呼吸功（ＷＯＢｐ）对调整压力支持通气（ＰＳＶ）水平的意义。方法：观测不同水平ＰＳＶ时，ＷＯＢｐ、呼吸机做功（ＷＯＢｖ）及呼吸频率（ＲＲ）、潮气量（ＶＴ）等指标的变化。结果：随ＰＳＶ水平增高，ＷＯＢｐ逐渐降低，ＷＯＢｖ逐渐增高；ＰＳＶ０时，ＷＯＢｐ为１．２２±０．４７Ｊ／Ｌ，ＰＳＶ在１．４７ｋＰａ时，ＷＯＢｐ和ＷＯＢｖ分别为０．３８±０．３１Ｊ／Ｌ和１．２９±０．１４Ｊ／Ｌ；ＷＯＢｐ与ＰＳＶ水平呈负相关（ｒ＝０．９９３；Ｐ＜０．０５），ＷＯＢｖ与ＰＳＶ水平呈正相关（ｒ＝０．９９９，Ｐ＜０．０５）；ＲＲ随ＰＳＶ增高而仅从２２．０次／分降至１７．２次／分，ＶＴ仅从０．３６Ｌ增至０．４９Ｌ。结论：随ＰＳＶ支持水平的提高，ＷＯＢｐ逐渐降低，以ＷＯＢｐ水平指导ＰＳＶ水平的调整，比ＲＲ、ＶＴ等常规监测指标更有意义。     

机械通气患者的舒适度及其影响因素

目的：测评机械通气患者的舒适度,了解影响其舒适度的相关因素,探讨提高患者舒适度的对策。方法：以43名接受机械通气治疗的患者作为研究对象,采用美国国立卫生研究院制定的视觉模拟评分法（visual analoguescale,VAS）测评患者的舒适度,采用自制调查表调查影响患者舒适度的相关因素。结果：机械通气患者VAS平均得分为（5.12±1.26）,影响机械通气患者舒适度的主要因素有沟通障碍、气管插管、吸痰、呼吸机不合拍、口干、口渴、活动受限、害怕、焦虑、缺乏医务人员支持、周围环境差等。结论：机械通气患者承受着中度不舒适,影响患者舒适度的因素包括内源性和外源性。医务人员应正确评估患者的舒适度,准确把握影响患者舒适度的因素,提供必须的医疗护理支持,提高患者的生活质量。     

持续气道正压通气,T管及压力支持通气等条件下患者呼吸功…

目的：探讨从呼吸功角度评价呼吸机脱机方式优劣的可能性及其意义。方法：通过Ｂｉｃｏｒｅ ＣＰ－１００呼吸监测测定２２例患者在压力支持通气（ＰＳＶ）、持续气道内正压（ＣＰＡＰ）通气、Ｔ管及拔管后２小时等条件下的呼吸功的变化。结果：ＣＰＡＰ０．４９ｋＰａ（１ｋＰａ＝１０．２０ｃｍＨ２Ｏ）Ｔ管、ＰＳＶ０．４９ｋＰａ时，患者呼吸功依次逐渐降低。ＣＰＡＰ０．４９ｋＰａ时呼吸功（９．９８Ｊ／ｍｉｎ）比ＰＳＶ０．     

呼吸功的评价及临床意义

呼吸功的评价及临床意义邱海波（综述）陈德昌（审校）作者单位：１００７３０中国医学科学院中国协和医院大学北京协和医院ＩＣＵ近年来，机械通气作为重要的器官功能支持手段，已广泛应用于临床。但呼吸支持的程度及何时脱机等仍是临床上常见的棘手问题。危重患者呼吸支...     

机械通气患者的舒适度及其影响因素

目的 测评机械通气患者的舒适度,了解影响其舒适度的相关因素,探讨提高患者舒适度的对策.方法 以43名接受机械通气治疗的患者作为研究对象,采用美国国立卫生研究院制定的视觉模拟评分法(visual analogue scale,VAS)测评患者的舒适度,采用自制调查表凋查影响患者舒适度的相关因素.结果 机械通气患者VAS平均得分为(5.12±1.26),影响机械通气患者舒适度的主要因素有沟通障碍、气管插管、吸痰、呼吸机不合拍、口干、口渴、活动受限、害怕、焦虑、缺乏医务人员支持、周围环境差等.结论 机械通气患者承受着中度不舒适,影响患者舒适度的因素包括内源性和外源性.医务人员应正确评估患者的舒适度,准确把握影响患者舒适度的因素,提供必须的医疗护理支持,提高患者的生活质量.     

长期机械通气患者撤机主要影响因素的临床研究

目的分析ICU病房长期机械通气（≥7d）患者撤机的主要影响因素，探讨长期机械通气撤机的策略。方法回顾性调查45例ICU长期机械通气患者入院时一般情况、早期气管切开、原发病，通气前生命体征、辅助检查以及APACHEⅡ评分。根据撤机成败判定标准，将全部病例分为撤机成功组和撤机失败组，依照设定的临床资料调查指标对两组资料进行对比分析。结果撤机成功23例，撤机失败22例，分别占病例总数的51．1％和48．9％；APACHEⅡ评分撤机失败组明显高于撤机成功组，两组间比较差异有显著性（P〈0．01）；早期气管切开比例撤机成功组高于撤机失败组（P〈0．05）；血浆白蛋白（Alh）水平、心功能状态撤机成功组优于撤机失败组。结论长期机械通气患者原发病加重和（或）出现较严重并发症是导致其撤机成功率较低、死亡率较高的重要原因。其中上机前患者的基础状态、血浆Alb水平、心功能状态、APACHEⅡ评分等对撤机成败有一定的预测意义。     

持续气道正压通气、T管及压力支持通气等条件下患者呼吸功的比较性研究

目的：探讨从呼吸功角度评价呼吸机脱机方式优劣的可能性及其意义。方法：通过ＢｉｃｏｒｅＣＰ１００呼吸监测仪测定２２例患者在压力支持通气（ＰＳＶ）、持续气道内正压（ＣＰＡＰ）通气、Ｔ管及拔管后２小时等条件下的呼吸功的变化。结果：ＣＰＡＰ０．４９ｋＰａ（１ｋＰａ＝１０．２０ｃｍＨ２Ｏ）、Ｔ管、ＰＳＶ０．４９ｋＰａ时，患者呼吸功依次逐渐降低。ＣＰＡＰ０．４９ｋＰａ时呼吸功（９．９８Ｊ／ｍｉｎ）比ＰＳＶ０．４９ｋＰａ时高２３．７％（Ｐ＜０．００１），比拔管后２小时高４８．５％（Ｐ＜０．０１），与Ｔ管时比较无显著性差异。Ｔ管时呼吸功（９．３１Ｊ／ｍｉｎ）比ＰＳＶ０．４９ｋＰａ时高１５．４％（Ｐ＜０．０５），比拔管后２小时高３８．５％（Ｐ＜０．０１）。结论：患者呼吸功因脱机方式不同而显著不同，ＰＳＶ０．４９ｋＰａ比ＣＰＡＰ０．４９ｋＰａ和Ｔ管更有利于脱机。     

呼吸重症监护室机械通气患者拍背操作所致疼痛状况及影响因素及对睡眠的影响

目的:探讨呼吸重症监护室(Respiratory Intensive Care Unit,RICU)护士在为机械通气患者进行拍背操作时所致疼痛现况,并分析引发患者疼痛的影响因素,简要探讨对患者的睡眠影响.方法:选取2019年1月至2019年12月山东大学齐鲁医院收治的术后机械通气患者98例作为研究对象,采用中文版行为疼...     

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     

Effect of PEEP on work of breathing in mechanically ventilated COPD patients

Objective: To study the effects of PEEP on the inspiratory work done per breath on the respiratory system (W_I,rs) in patients with chronic obstructive pulmonary disease (COPD).¶Design: Physiological study.¶Setting: Fourteen-bed Medical ICU of a 1000-bed teaching tertiary hospital.¶Patients and participants: Ten patients with COPD intubated and mechanically ventilated for acute respiratory failure.¶Interventions: PEEP of 0 (ZEEP), ¶5, 10, and 15 cm H₂O were applied randomly and measurements done at the end of a 15–20 min period.¶Measurements and results: Using the rapid airway occlusion technique during constant flow inflation, we partitioned W_I,rs into its static and dynamic components. On ZEEP, the mean ± SD values of W_I,rs amounted to 15.1 ± 5.7 cm H₂O × l. With increasing PEEP, W_I,rs was significantly reduced to 12.6 ± 5.7, 11.1 ± 4.1, and 10.4 ± 2.8 cm H₂O × l at PEEP of 5, 10, and 15 cm H₂O, respectively (P < 0.05). This reduction was entirely due to the decline of the work due to intrinsic PEEP (PEEPi) and was abolished when the applied PEEP counterbalanced PEEPi. The other components of W_I,rs were not affected by PEEP. By increasing PEEP up to the level of PEEPi on ZEEP, no further increase in end-expiratory lung volume was observed.¶Conclusions: In COPD patients the application of PEEP levels close to PEEPi can substantially reduce W_I,rs without promoting further dynamic pulmonary hyperinflation.     

Helium-oxygen reduces work of breathing in mechanically ventilated patients with chronic obstructive pulmonary disease

Objective To evaluate whether helium-oxygen mixture reduces inspiratory work of breathing (WOB) in sedated, paralyzed, and mechanically ventilated patients with acute exacerbation of chronic obstructive pulmonary disease (COPD).Design and setting Open, prospective, randomized, crossover study in the medical intensive care unit in a university hospital.Patients and participants 23 patients admitted for acute exacerbation of COPD and mechanically ventilated.Measurements Total WOB (WOBt), elastic WOB (WOBel), resistive WOB (WOBres), and WOB due to PEEPi (WOBPeepi) were measured. Static intrinsic positive end expiratory pressure (PEEPi), static compliance (Crs), inspiratory resistance (Rins), inspiratory (tinsp) and expiratory time constant (texp) were also measured. These variables were compared between air-oxygen and helium-oxygen mixtures.Results WOBt significantly decreased with helium-oxygen (2.34±1.04 to 1.85±1.01 J/l, p<0.001). This reduction was significant for WOBel (1.02±0.61 J/l to 0.87±0.47, p<0.01), WOBPeepi (0.77±0.38 J/l to 0.54±0.38, p<0.001), and WOBres (0.55±0.19 J/l to 0.44±0.24, p<0.05). PEEPi, Rins, tinsp and texp significantly decreased. Crs was unchanged.Conclusions Helium-oxygen mixture decreases WOB in mechanically ventilated COPD patients. Helium-oxygen mixture could be useful to reduce the burden of ventilation.     

Measuring the breathing workload in mechanically ventilated patients

Conclusion All the methods for the evaluation of the breathing workload in mechanically ventilated patients are subject to serious theoretical criticisms, due to the numerous assumptions and approximations on which they are based. Nevertheless they are of great interest in providing an objective evaluation of the ability of different forms of partial support ventilation to reduce the breathing workload. They have been applied successfully to assist-controlled ventilation [29, 30], SIMV [31], and pressure support ventilation [10, 11].Supported by a grant INSERM CNEP 89 CN 24     

Evaluation of respiratory system resistance in mechanically ventilated patients: The role of the endotracheal tube

Objective To investigate the role played by the endotracheal tube (ETT) in the correct evaluation of respiratory system mechanics with the end inflation occlusion method during constant flow controlled mechanical ventilation.Setting General ICU, university of Rome La Sapienza.Patients 12 consecutive patients undergoing controlled mechanical ventilation.Methods We compared the values of minimal resistance of the respiratory system (i.e. airway resistance) (RRS min) obtained: i) subtracting the theoretical value of ETT resistance from the difference between P max and P1, measured on airway pressure tracings obtained from the distal end of the ETT; ii) directly measuring airway pressure 2 cm below the ETT, thus automatically excluding ETT resistance from the data.Results The values of RRS min obtained by measuring airway pressure below the ETT were significantly lower than those obtained by measuring airway pressure at the distal end of the ETT and subtracting the theoretical ETT resistance (4.5±2.8 versus 2.5±1.6 cm H₂O/l/s,p<0.01).Conclusion When precise measurements of ohmic resistances are required in mechanically ventilated patients, the measurements must be obtained from airways pressure data obtained at tracheal level. The in vivo positioning of ETT significantly increases the airflow resistance of the ETT.     

Helium-oxygen decreases inspiratory effort and work of breathing during pressure support in intubated patients with chronic obstructive pulmonary disease

Objective To evaluate the impact of helium-oxygen (He/O₂) on inspiratory effort and work of breathing (WOB) in intubated COPD patients ventilated with pressure support.Design and setting Prospective crossover interventional study in the medical ICU of a university hospital.Patients and participants Ten patients.Interventions Sequential inhalation (30 min each) of three gas mixtures: (a) air/O₂, (b) He/O₂ (c) air/O₂, at constant FIO₂ and level of pressure support.Measurements and results Inspiratory effort and WOB were determined by esophageal and gastric pressure. Throughout the study pressure support and FIO₂ were 14±3 cmH₂O and 0.33±0.07 respectively. Compared to Air/O₂, He/O₂ reduced the number of ineffective breaths (4±5 vs. 9±5 breaths/min), intrinsic PEEP (3.1±2 vs. 4.8±2 cmH₂O), the magnitude of negative esophageal pressure swings (6.7±2 vs. 9.1±4.9 cmH₂O), pressure-time product (42±37 vs. 67±65 cmH₂O s^–1 min^–1), and total WOB (11±3 vs. 18±10 J/min). Elastic (6±1 vs. 10±6 J/min) and resistive (5±1 vs. 9±4 J/min) components of the WOB were decreased by He/O₂.Conclusions In intubated COPD patients ventilated with pressure support He/O₂ reduces intrinsic PEEP, the number of ineffective breaths, and the magnitude of inspiratory effort and WOB. He/O₂ could prove useful in patients with high levels of PEEPi and WOB ventilated in pressure support, for example, during weaning.Funding was provided by the Swiss National Scientific Research Fund (grant #32-63501.00)     

Work of breathing during successful spontaneous breathing trial

Objective

The aim of this study was to evaluate the work of breathing (WOB) behavior during a 120-minute successful spontaneous breathing trial (SBT) with T-tube trial, and its predictive value for extubation outcome.

Design

A prospective cohort study.

Setting

2 medical-surgical intensive care units.

Patients

Fifty-one consecutive patients mechanically ventilated for more than 48 hours after a successful SBT were extubated based on the institutional protocol and followed for the occurrence of postextubation respiratory distress during 48 hours.

Measurements and Main Results

All cases were serially monitored during 120 minutes of SBT using the respiratory monitoring system Ventrak 1500 (Medical Novametrix Systems, Wallingford, CT). Successful extubation occurred in 38 (74.5%) of 51 of the sample. Respiratory and hemodynamic parameters, APACHE II score, sex, days on mechanical ventilation, and cause of respiratory failure were unable to predict extubation outcome. The WOB significantly increased during SBT in extubation failure patients (WOB at 1st minute 0.24 ± 0.06 J/L vs WOB at 120th minute = 0.39 ± 0.07 J/L; P < .01) when compared to successfully extubated patients (WOB at 1st minute 0.21 ± 0.08 J/L vs WOB at 120th minute = 0.24 ± 0.11 J/L; P = .12).The WOB variation was able to predict extubation outcome only after the 90th minute of SBT (extubation failure = 0.35 ± 0.08 J/L vs extubation success = 0.22 ± 0.11 J/L; P = .01).

Conclusion

An increase in the WOB could predict extubation failure during a T-tube trial of 120 minutes.     

Early tracheotomy in neutropenic,mechanically ventilated patients: rationale and results of a pilot study

Despite substantial advances in the management of such patients, the prognosis of ventilated neutropenic patients remains grim. The objective of our study was to evaluate the benefit of tracheotomy in this category of patients, in terms of mortality while they were in the intensive-care unit and nosocomial pneumonias. The charts of 53 consecutive, ventilated, neutropenic patients, or those destined to be imminently neutropenic, admitted to our intensive-care unit during a 4-year period, have been retrospectively reviewed. Tracheotomy was performed at the bedside or in the operating room: 20 patients underwent tracheotomy within 48 h of mechanical ventilation (ET group), while 33 were tracheotomized later or remained intubated (INT group). The two groups were comparable with regard to the underlying disease, respiratory failure, mechanical ventilation patterns and severity scores, but neutropenia was more profound in the ET group. Mortality while in the intensivecare unit was similar (ET:70%; INT:78.8%). However, the survival curves showed a trend towards longer survival in the ET group, even after adjustment for the degree of neutropenia (log-rank test: P=0.07). The incidence of pneumonias was similar in both groups. No major complications of tracheotomy were reported. These findings suggest that a tracheotomy could be proposed for neutropenic patients requiring mechanical ventilation, in order to prologn their survival beyond the end of the neutropenic period. A prospective study is underway to confirm these preliminary results.     

鼻空肠管在机械通气患者早期肠内营养中的应用

目的探讨对机械通气(MV)患者留置鼻空肠管行早期肠内营养的应用价值。方法将ICU收治的50例机械通气患者随机分为A组(25例)和B组(25例),A组留置鼻空肠管,B组留置鼻胃管,观察两组肠内营养可以耐受的起始时间、达目标喂养量所需时间、并发症情况和机械通气时间。结果A组肠内营养可以耐受起始时间、达目标喂养量所需时间明显比B组短(P＜0．01),并发症发生率和呼吸机相关肺炎(VAP)发生率明显减少(P＜0．05),机械通气时间较B组明显缩短(P＜0．05)。结论机械通气患者留置鼻空肠管实施早期肠内营养比鼻胃管更为有效、安全,并有助于减少VAP发生,有助于尽早脱机。