高频振荡通气与同步间歇指令通气在新生儿肺炎合并气胸患儿中的应用效果比较

目的:比较高频振荡通气(High-frequency oscillatory ventilation,HFOV)、同步间歇指令通气(Synchronized intermittent mandatory ventilation,SIMV)两种模式在新生儿肺炎合并气胸患儿中的应用效果.方法:回顾性分析我院2017年10月至2020年9月89例新生儿肺炎合并气胸患儿的临床资料,按所用通气模式不同分为HFOV组(n=47)和SIMV组(n=42).比较两组肺泡复张时间、通气治疗时间、住院时间、治疗前、治疗1 d后、治疗3 d后血气指标、血清炎性因子和心肌酶谱水平及并发症发生率.结果:两组肺泡复张时间比较差异无统计学意义(P>0.05),HFOV组通气治疗时间、住院时间均短于SIMV组(P<0.05);治疗1d后、3d后两组动脉血氧分压、血氧饱和度水平升高,HFOV组高于SIMV组,动脉血二氧化碳分压水平降低,HFOV组低于SIMV组(P<0.05);治疗1 d后、3 d后两组血清肿瘤坏死因子-α、白细胞介素-6水平及乳酸脱氢酶、肌酸激酶、肌酸激酶同工酶水平均降低,HFOV组低于SIMV组(P<0.05);两组并发症发生率无明显差异(P>0.05).结论:与SIMV比较,HFOV治疗模式在改善动脉血气状态、缓解机体炎症、减轻心肌损伤方面更具优势,可有效促进新生儿肺炎合并气胸患儿病情康复,临床应用价值较高.     

与高频震荡通气有关的潜在性危害及其防治

１概述［１］ 自从１９７２年ｌｕｎｋｅｎｈｅｉｍｅｒ等在用高频震荡器研究心肌阻抗的实验时发现高频震荡通气（ ｈｉｇｈ ｆｒｅ－ｑｕｅｎｃｅ　 ｏｓｃｉｌｌａｔｏｒｙ ｖｅｎｔｉｌａｔｉｏｎ， ＨＦＯＶ） 可以保持有效气体交换后，近十余年来人们不断通过对其作用机理、临床参数调节及肺力学参数监测等方面进行广泛研究，体会到ＨＦＯＶ在机械通气治疗方面确实起到一些独特的作用．如在呼吸窘迫综合征（ＲＤＳ）动物实验中，ＨＦＯＶ和常频机械通气（ＣＶ）两种方法相比，表明ＨＦＯＶ可以减少气漏发生，使肺均匀膨胀，改善气体交…     

高频振荡通气治疗新生儿呼吸衰竭的临床疗效分析

高频振荡通气（HFV）是一种高频通气辅助呼吸方法，具有高频率、小潮气量、低气道压、机械死腔小的通气特点，其通过与常频呼吸机完全不同的作用原理，改善患者的血氧分压和氧合情况，在国外应用于临床已有10余年。我科应用HFV治疗新生儿呼吸窘迫综合征及胎粪吸入综合征、重症肺炎、肺出血、气漏综合征等常频呼吸机械通气疗效差的Ⅱ型呼吸衰竭，     

几种高频呼吸通气模型的比较

高频呼吸是近十年来在临床上得到一定应用和推广的人工呼吸方式,但其使用上仍存在着一些问题如二氧化碳排除困难等。本文就高频呼吸的力学背景及其输运机理进行了探讨,对几种比较典型的高频呼吸的通气模型进行了分析,提出了一种新的自然呼吸和高频呼吸的统一通气模型——振荡模型。该通气模型认为:高频振荡呼吸的气体输运机制是气体轴向的对流流动和径向的扩散(包括分子扩散和由湍流、涡流引起的强化扩散)的相互作用,由此对二氧化碳排除困难的原因作出了解释,认为:现有高频呼吸过程中的压力梯度周期性变化的非对称性是导致高频呼吸中二氧化碳排出困难的主要原因。     

术侧不同通气方式对单肺通气期间肺保护作用的研究进展

良好的肺隔离技术是胸科手术顺利进行的保障,单肺通气可导致低氧血症和肺内分流及急性肺损伤。目前,改善低氧血症和肺内分流及急性肺损伤的方法主要有药物应用、麻醉方式、容量治疗和通气模式等方面。对非通气侧肺的研究较少,非通气侧实施持续正压通气或高频喷射通气是胸部手术的一种气道管理策略。该文将对非通气侧行持续正压通气和高频喷射通气两种不同的辅助通气方式对改善肺部并发症的最新研究进展做一综述。     

儿科高频通气的历史回顾与现状

近十年来，在儿科领域，一种新的通气手段──高频通气（ｈｉｇｈ－ｆｒｅｑｕｅｎｃｙ ｖｅｎｔｉｌａｔｉｏｎ，ＨＦＶ）引起了医学界的兴趣．ＨＦＶ定义为一组独特的，包括使用超生理的通气频率（ｆｒｅｑｕｅｎｃｙ，ｆ），通常＞ ６０次／ｍｉｎ（１Ｈｚ），和控制潮气量小于生理死腔两个必要组成的复合通气技术、首先，它以低换气量（均小于潮气量Ｖｔ以及生理死腔），高频率为主要特征，在气道压力波动甚微的条件下使肺泡持续维持在复张状态；其次，特殊的气体交换模式能改善肺泡气体的混合与通气／灌注比（Ｖ／Ｑ）．常作为治疗常规…     

高频振荡通气治疗新生儿呼吸衰竭的对比性研究

目的探讨高频震荡通气对新生儿重症呼吸衰竭治疗的疗效。方法对比分析36例新生儿重症呼吸衰竭使用传统机械通气失败后改用高频震荡通气治疗前后动脉血氧分压（PaO2）,二氧化碳分压（PCO2）,血氧饱和度（SaO2）,动脉血氧分压与吸入氧浓度之比（PaO2/FiO2）,动脉-肺泡氧张力比值（a/APaO2）,氧合指数（oxygenation index,OI）。结果改高频通气治疗后二氧化碳分压（PaCO2）、氧合指数（OI）下降,（P〈0.01）。动脉血氧分压（PaO2）、动脉血氧分压与吸入氧浓度之比（PaO2/FiO2）、动脉-肺泡氧张力比值（a/APaO2）上升,（P〈0.01）。结论高频震荡通气能更好地改善重症呼吸衰竭新生儿的通气和气体交换,减少气压伤,对治疗新生儿重症呼吸衰竭具有较好的疗效。     

新生儿先天性食管闭锁合并食道气管瘘高频震荡通气治疗的机理与临床(附9例报告)

目的总结一年多来先天性食管闭锁９例术后高频震荡通气治疗的效果．方法对９例合并肺炎患儿均在术后使用高频震荡呼吸机通气治疗,加强呼吸、循环功能监测,并根据血气分析等结果调整参数,及早发现并治疗合并症．结果９例中治愈 ７例（７７．８％）,死亡１例（１１．１％）,放弃１例,高频震荡通气过程中无一例合并气胸,合并吻合口狭窄和吻合口瘘及肺不张分别１例．结论　高频震荡通气可促进食道闭锁术后患儿肺炎吸收,减少合并症,提高治愈率,而加强监护是关键．     

高频喷射通气治疗婴幼儿重症肺炎呼吸衰竭的临床观察及护理

高频喷射通气(HFIV)是以通气频率高、潮气量低,平均气道压低为特征的机械通气通过加速弥散和对流等机制进行气体交换迅速排出CO2,提高PaO2阻断呼吸衰竭因缺氧和CO2潴留而发病的恶性循环,以获得抢救治疗的时间,我院自2004～2006年期间,用HFIV抢救婴幼儿重症肺炎并呼吸衰竭患者76     

左右肺间相互通气的高频通气机制研究

传统观念认为充足潮气量是满足呼吸的必要条件,但低气潮气量的高频通气仍能满足呼吸病患者的通气需求。为探究其通气机制,本文提出了高频通气下左右肺间存在相互通气这一观点,并开发设计了基于新鲜绵羊肺的高频通气实验平台,以测验高频通气下左右肺间的通气气流。同时,还建立了基于呼吸道对气流的黏性阻力(R)、惯性阻力(I)和肺顺应性(C)的肺通气模型,并进行通气仿真分析,进一步从理论上探讨进入左右肺内的通气气流特征。本文实验与仿真结果均表明,在一定频率的高频震荡通气条件下,进入左右肺内的气流存在相位差,因而可以引起相互通气;即使进入肺部的总气流为0,左右肺间仍存在彼此气流交换现象。本文研究证实了高频通气下左右肺间相互通气气流的存在,这一现象将有利于肺部通气更为均匀,并提高肺内氧气的利用率。     

Neonatal ventilatory techniques – which are best for infants born at term?

Few studies have examined ventilatory modes exclusively in infants born at term. Synchronous intermittent mandatory ventilation (SIMV) compared to intermittent mandatory ventilation (IMV) is associated with a shorter duration of ventilation. The limited data on pressure support, volume targeted ventilation and neurally adjusted ventilatory assist demonstrate only short term benefits in term born infants. Favourable results of high-frequency oscillatory ventilation (HFOV) in infants with severe respiratory failure were not confirmed in the two randomised trials. Nitric oxide (NO) in term born infants, except in those with congenital diaphragmatic hernia (CDH), reduces the combined outcome of death and requirement for extracorporeal membrane oxygenation (ECMO). In infants with severe refractory hypoxaemic respiratory failure, ECMO, except in infants with CDH, reduced mortality and the combined outcome of death and severe disability at long-term follow-up. Randomised studies with long term outcomes are required to determine the optimum modes of ventilation in term born infants.     

A comparison of clinical efficacy between high frequency oscillatory ventilation and conventional ventilation with lung volume recruitment in pediatric acute respiratory distress syndrome: A randomized controlled trial

Purpose:

To determine the efficacy of lung volume recruitment maneuver (LVRM) with high frequency oscillatory ventilation (HFOV) on oxygenation, hemodynamic alteration, and clinical outcomes when compared to conventional mechanical ventilation (CV) in children with severe acute respiratory distress syndrome (ARDS).

Materials:

We performed a randomized controlled trial and enrolled pediatric patients who were diagnosed to have severe ARDS upon pediatric intensive care unit (PICU) admission. LVRM protocol combined with HFOV or conventional mechanical ventilation was used. Baseline characteristic data, oxygenation, hemodynamic parameters, and clinical outcomes were recorded.

Results:

Eighteen children with severe ARDS were enrolled in our study. The primary cause of ARDS was pneumonia (91.7%). Their mean age was 47.7 ± 61.2 (m) and body weight was 25.3 ± 27.1 (kg). Their initial pediatric risk of mortality score 3 and pediatric logistic organ dysfunction were 12 ± 9.2 and 15.9 ± 12.8, respectively. The initial mean oxygen index was 24.5 ± 10.4, and mean PaO₂/FiO₂ was 80.6 ± 25. There was no difference in oxygen parameters at baseline the between two groups. There was a significant increase in PaO₂/FiO₂ (119.2 ± 41.1, 49.6 ± 30.6, P = 0.01*) response after 1 h of LVRM with HFOV compare to CV. Hemodynamic and serious complications were not significantly affected after LVRM. The overall PICU mortality of our severe ARDS at 28 days was 16.7%. Three patients in CV with LVRM group failed to wean oxygen requirement and were cross-over to HFOV group.

Conclusions:

HFOV combined with LVRM in severe pediatric ARDS had superior oxygenation and tended to have better clinical effect over CV. There is no significant effect on hemodynamic parameters. Moreover, no serious complication was noted.     

Exhaled Nitric Oxide Increases During High Frequency Oscillatory Ventilation in Rabbits

This study compared the effects of high frequency oscillatory ventilation (HFOV) and intermittent mandatory ventilation (IMV) on the homeostasis of nitric oxide (NO) in the lower respiratory tract of healthy rabbits. The mechanisms underlying a putative stretch response of NO formation in the airways were further elucidated. Male New Zealand White rabbits were anaesthetized, tracheotomized and ventilated with IMV or HFOV in random order. Total NO excretion increased from 9.6 +/- 0.8 nl min-1 (mean +/- S.E.M.) during IMV to 22.6 +/- 2.7 nl min-1 during HFOV (P < 0.001). This increase was not explained by changes of functional residual capacity ([Delta]FRC). A similar increase in NO excretion during HFOV was seen in isolated buffer-perfused lungs under constant circulatory conditions (P < 0. 05, n = 4). Intratracheal mean CO2 and NO concentrations, measured at 2.5, 5, 7.5 and 10 cm below tracheostomy, increased significantly with increasing distance into the lung during both IMV and HFOV (P < 0.001 for each comparison). At every intratracheal location of the sampling catheter, particularly low in the airways, both CO2 and NO concentrations were significantly higher during HFOV than during IMV (P < 0.01 for each comparison). We conclude that HFOV increases pulmonary NO production in healthy rabbits. Increased stretch activation of the respiratory system during HFOV is suggested as a possible underlying mechanism. The increase in mean airway NO concentrations may have biological effects in the respiratory tract. Whether it can account for some of the benefits of HFOV treatment needs to be considered.     

加温加湿经鼻导管高流量氧疗的研究

氧疗在呼吸系统疾病的治疗中占有重要地位,其包括有创机械通气及无创通气。有创机械通气是指通过行气管插管或气管切开的有创操作给予呼吸机通气支持。无创通气是指经口鼻、面罩或鼻导管连接呼吸机进行呼吸通气支持。近年来,经鼻高流量加温加湿氧疗作为一种新型氧疗方式,因其装置简便易行及独特的生理学效应得到广泛关注。本文对国内外经鼻高流量加温加湿氧疗的研究现状作一综述,为经鼻高流量氧疗在临床中的应用提供参考。     

Fluid Dynamics of Gas Exchange in High-Frequency Oscillatory Ventilation: <Emphasis Type="Italic">In Vitro</Emphasis> Investigations in Idealized and Anatomically Realistic Airway Bifurcation Models

The objective of this work is to develop understanding of the local fluid dynamic mechanisms that underpin gas exchange in high-frequency oscillatory ventilation (HFOV). The flow field during HFOV was investigated experimentally using particle image velocimetry in idealized and realistic models of a single bifurcation. Results show that inspiratory and expiratory fluid streams coexist in the airway at flow reversal, and mixing between them is enhanced by secondary flow and by vortices associated with shear layers. Unsteady flow separation and recirculation occurs in both geometries. The magnitude of secondary flow is greater in the realistic model than in the idealized model, and the structure of secondary flow is quite different. However, other flow structures are qualitatively similar.     

Comparison of respiratory indices in predicting response to high frequency oscillatory ventilation in very low birth weight infants with respiratory distress syndrome

To evaluate the predictive values of oxygenation index (OI), arterial-alveolar oxygen tension ratio (a/APO)2, and alveolar-arterial oxygen gradient ((A-a)DO2) for early recognition of responsiveness to high frequency oscillatory ventilation (HFOV) in very low birth weight infants with respiratory distress syndrome (RDS), 23 infants who received HFOV treatment for severe RDS after failing to be improved with conventional mechanical ventilation from July 1995 to February 1998 were included. Twelve infants survived with HFOV (Responder group), while 11 infants could not maintain oxygenation with HFOV and died (Non-responder group). Clinical record (of each patient) were retrospectively reviewed and compared with the respiratory indices. Mean (A-a)DO2 was significantly lower in the responder group than in the non-responder group at 2 hr after HFOV (p=0.024), and the difference was more remarkable at 6 hr (p=0.005). Death in the patient with (A-a)DO2 over 350 at 2 hr after HFOV therapy was 100% in sensitivity and 80% in specificity. The earliest significant difference of mean a/APO2 between two groups was noted at 6 hr after HFOV treatment (p=0.019). OI showed no significant differences between two groups. In summary, (A-a)DO2 was the most effective and sensitive respiratory index for predicting the responsiveness to HFOV in infants with severe RDS providing due as early as 2 hr.     

A review of high frequency oscillation ventilation in the neonate

In this study the use of high frequency oscillation (HFO) to treat neonates with respiratory failure is analysed. The theories behind gas exchange during HFO are reviewed and its specific application to neonatal care discussed. The mechanical performance of three HFO ventilators currently in use is compared with the views of medical staff operating them on a regular basis. The complex interactions between initial ventilator settings have led to difficulties in accurately comparing performance characteristics and ventilation strategies; each ventilator is seen to have its own strengths and weaknesses that contribute to the ventilator selection made. These interactions together with the specific HFO modes available on each ventilator should be taken into account when using a HFO for the first time or when switching from an alternative ventilation method. Medical staff who care for neonates suggest staff education and training into the variations of HFO will greatly improve its use in neonatal medicine.     

Large eddy simulation of high frequency oscillating flow in an asymmetric branching airway model

The implementation of artificial ventilation schemes is necessary when respiration fails. One approach involves the application of high frequency oscillatory ventilation (HFOV) to the respiratory system. Oscillatory airflow in the upper bronchial tree can be characterized by Reynolds numbers as high as 10⁴, hence, the flow presents turbulent features. In this study, transitional and turbulent flow within an asymmetric bifurcating model of the upper airway during HFOV are studied using large eddy simulation (LES) methods. The flow, characterized by a peak Reynolds number of 8132, is analysed using a validated LES model of a three-dimensional branching geometry. The pressures, velocities, and vorticity within the flow are presented and compared with prior models for branching flow systems. The results demonstrate how pendelluft occurs at asymmetric branches within the respiratory system. These results may be useful in optimising treatments using HFOV methods.     

A new sensor for monitoring chest wall motion during high-frequency oscillatory ventilation

The recently developed technique of fibre optic respiratory plethysmography (FORP) has been modified to monitor the rapid, small amplitude movements of the chest wall during high-frequency oscillatory ventilation (HFOV). The FORP sensor is an expandable belt encircling the chest, in which is housed a fibre optic loop that alters its radius of curvature as a function of chest perimeter. These curvature changes cause variations in macrobending losses of light transmitted through the fibre, which are proportional to the chest perimeter. Dynamic measurement of transmitted light intensity can hence be used to monitor chest wall motion (CWM). For application to HFOV, the design of the FORP belt was altered to increase sensitivity and the materials were chosen to maximise macrobending effects induced by the CWM. FORP was tested in four piglets ventilated with HFOV, both in the normal and surfactant-deficient lung. Measurement of CWM was possible over the full range of tidal volumes and ventilation frequencies used during HFOV. In all cases, the measured frequency of the CWM fell within 3% of the applied ventilation frequency. In addition, the technique was sufficiently sensitive to detect changes in the amplitude of CWM in response to changes in applied tidal volume. It is anticipated that application of this new non-invasive measurement device will lead to an increased understanding of the dynamics of chest and abdominal wall motion during HFOV.