肺不张时采取啥策略进行肺复张？

本文由“小麻哥的日常”授权转载

摘要译文（供参考）

肺复张的可变通气复张与逐步肺复张操作：

一项实验性肺不张模型的比较研究

背景：

可变通气在肺不张症肺中可复张肺泡，但尚不清楚它与常规复张策略相比效果如何。

目的：

测试具有可变潮气量的机械通气和常规肺复张对肺功能的影响是否相似。

设计：

随机交叉研究。

实施：

大学医院研究设施。

动物：

11只幼年机械通气猪，盐水肺灌洗导致肺不张。

干预措施：

采用两种策略进行肺复张，两者都具有个体化的最佳呼气末正压（PEEP），该压力与PEEP试验期间的最佳呼吸系统弹性相关： 常规肺复张组：在压力控制模式下逐步增加PEEP，随后50分钟采取恒定潮气量的容量控制通气（VCV）

可变通气肺复张组：采取潮气量随机变化的VCV，时长50分钟。

主要结局指标：

在每次复张策略之前和之后50分钟，通过计算机断层扫描评估肺通气，通过电阻抗断层扫描确定相对肺灌注和通气（0%=背侧，100%=腹侧）。

结果：

50分钟后，可变通气和逐步肺复张 降低了通气不良和未通气肺组织的相对质量（肺质量百分比：35.3±6.2对34.2±6.6，P=0.003）； 与基线相比，通气不良的肺质量减少，（分别为-3.5±4.0%，P=0.016和-5.2±2.8%，P<0.001）， 未通气的肺质量降低，分别为-7.2±2.5%，P<0.001；-4.7±2.8%，P<0.001）， 而相对灌注的分布几乎没有受到影响 可变通气：-0.8±1.1%，P=0.044； 逐步肺复张：-0.4±0.9%，P=0.017）。 与基线相比，可变通气和逐步肺复张 增加了PaO2（分别为172±85mmHg，P=0.001；213±73mmHg，P<0.001）， PaCO2降低（分别为-9.6±8.1 mmHg，P=0.003；-6.7±4.6 mmHg，P<0.001），

弹性下降（分别为-11.4±6.3 cmH2O，P<0.001；-14.1±3.3 cmH2O，P<0.001）。

在逐步肺复张期间，平均动脉压降低（-24±8 mmHg，P=0.006），但可变通气组无动脉压降低。

结论：

在该肺不张模型中，可变通气和逐步肺复张都可有效地复张肺，但仅可变通气不会对血流动力学产生不利影响。

试验注册：

本研究由德国德累斯顿州政府注册并批准（DD24-5131/354/64）。

原文摘要

Variable ventilation versus stepwise lung recruitment manoeuvres for lung recruitment: 

A comparative study in an experimental model of atelectasis

Background: 

Variable ventilation recruits alveoli in atelectatic lungs, but it is unknown how it compares with conventional recruitment manoeuvres.

Objectives: 

To test whether mechanical ventilation with variable tidal volumes and conventional recruitment manoeuvres have comparable effects on lung function.

Design: 

Randomised crossover study.

Setting: 

University hospital research facility.

Animals: 

Eleven juvenile mechanically ventilated pigs with atelectasis created by saline lung lavage.

Interventions: 

Lung recruitment was performed using two strategies, both with an individualised optimal positive-end expiratory pressure (PEEP) associated with the best respiratory system elastance during a decremental PEEP trial: conventional recruitment manoeuvres (stepwise increase of PEEP) in pressure-controlled mode) followed by 50 min of volume-controlled ventilation (VCV) with constant tidal volume, and variable ventilation, consisting of 50 min of VCV with random variation in tidal volume.

Main outcome measures: 

Before and 50 min after each recruitment manoeuvre strategy, lung aeration was assessed by computed tomography, and relative lung perfusion and ventilation (0% = dorsal, 100% = ventral) were determined by electrical impedance tomography.

Results: 

After 50 min, variable ventilation and stepwise recruitment manoeuvres decreased the relative mass of poorly and nonaerated lung tissue (percent lung mass: 35.3 ± 6.2 versus 34.2 ± 6.6, P = 0.303); reduced poorly aerated lung mass compared with baseline (-3.5 ± 4.0%, P = 0.016, and -5.2 ± 2.8%, P < 0.001, respectively), and reduced nonaerated lung mass compared with baseline (-7.2 ± 2.5%, P < 0.001; and -4.7 ± 2.8%, P < 0.001 respectively), while the distribution of relative perfusion was barely affected (variable ventilation: -0.8 ± 1.1%, P = 0.044; stepwise recruitment manoeuvres: -0.4 ± 0.9%, P = 0.167). Compared with baseline, variable ventilation and stepwise recruitment manoeuvres increased PaO2 (172 ± 85mmHg, P = 0.001; and 213 ± 73 mmHg, P < 0.001, respectively), reduced PaCO2 (-9.6 ± 8.1 mmHg, P = 0.003; and -6.7 ± 4.6 mmHg, P < 0.001, respectively), and decreased elastance (-11.4 ± 6.3 cmH2O, P < 0.001; and -14.1 ± 3.3 cmH2O, P < 0.001, respectively). Mean arterial pressure decreased during stepwise recruitment manoeuvres (-24 ± 8 mmHg, P = 0.006), but not variable ventilation.

Conclusion: 

In this model of lung atelectasis, variable ventilation and stepwise recruitment manoeuvres effectively recruited lungs, but only variable ventilation did not adversely affect haemodynamics.

Trial registration: 

This study was registered and approved by Landesdirektion Dresden, Germany (DD24-5131/354/64).

免责声明：

文中所涉及药物使用、疾病诊疗等内容仅供医学专业人士参考。

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编辑：MiSuper.米超

校对：Michel.米萱

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