Very Low Tidal Volume Ventilation with Associated
Hypercapnia - Effects on Lung Injury in a Model for Acute
Respiratory Distress Syndrome
Hans Fuchs
1
*, Marc R. Mendler
1
, Dominik Scharnbeck
1
, Michael Ebsen
2
, Helmut D. Hummler
1
1 DivisionofNeonatologyandPediatricCriticalCare,DepartmentofPediatricsandAdolescentMedicine,UlmUniversity,Ulm,Germany,2 Medizinisches
Versorgungszentrum Sta¨dtisches Krankenhaus Kiel, Kiel, Germany
Abstract
Background: Ventilation using low tidal volumes with permission of hypercapnia is recommended to protect the lung in
acute respiratory distress syndrome. However, the most lung protective tidal volume in association with hypercapnia is
unknown. The aim of this study was to assess the effects of different tidal volumes with associated hypercapnia on lung
injury and gas exchange in a model for acute respiratory distress syndrome.
Methodology/Principal Findings:In this randomized controlled experiment sixty-four surfactant-depleted rabbits were
exposedto6 hoursofmechanicalventilationwiththefollowingtargets:Group1:tidalvolume = 8–10 ml/kg/
PaCO 2 = 40 mmHg;Group2:tidalvolume = 4–5 ml/kg/PaCO 2 = 80 mmHg;Group3:tidalvolume = 3–4 ml/kg/
PaCO 2 = 120 mm Hg; Group 4: tidal volume = 2–3 ml/kg/PaCO 2 = 160 mm Hg. Decreased wet-dry weight ratios of the
lungs, lower histological lung injury scores and higher PaO 2 were found in all low tidal volume/hypercapnia groups (group
2, 3, 4) as compared to the group with conventional tidal volume/normocapnia (group 1). The reduction of the tidal volume
below4–5 ml/kgdidnotenhancelungprotection.However,oxygenationandlungprotectionweremaintainedat
extremely low tidal volumes in association with very severe hypercapnia and no adverse hemodynamic effects were
observed with this strategy.
Conclusion: Ventilation with low tidal volumes and associated hypercapnia was lung protective. A tidal volume below 4–
5 ml/kg/PaCO 2 80 mm Hg with concomitant more severe hypercapnic acidosis did not increase lung protection in this
surfactant deficiency model. However, even at extremely low tidal volumes in association with severe hypercapnia lung
protection and oxygenation were maintained.
背景：
低潮气量机械通气复合允许性高碳酸血症在急性呼吸窘迫综合症治疗中有肺保护作用。然而在允许性高碳酸血症下，最佳肺保护潮气量是不清楚的。本研究是在呼吸窘迫综合症模型中，允许性高碳酸血症下，不同潮气量对肺损伤和气体交换的影响。
方法学以及试验结果：
在随机选择64只表面活性物质耗尽的兔子行6小时机械通气，以下面分组：G1:TV = 8–10 ml/kg, PaCO 2 = 40 mmHg;G2: TV = 4–5 ml/kg ,PaCO 2 = 80mm Hg;G3: TV= 3–4 ml/kg, PaCO 2 = 120 mmHg; G4: TV = 2–3 ml/kg, PaCO 2 = 160 mmHg，去除肺干湿比重，降低组织学上肺损伤分值。较高的氧分压在所有低潮气量复合高碳酸血症组（2.3.4组与传统潮气量和正常碳酸血症患者）。潮气量减少到低于4-5ml/kg并没有增加肺保护作用。然后，氧化作用和肺保护仍然存在在极低潮气量以及严重的高碳酸血症是，没有观察到对血流动力学造成副作用。
结论：
低潮气量机械通气以及允许性高碳酸血症有肺保护作用。在肺表面活性物质缺乏的模型中，当潮气量低于4-5ml/Kg, PaCO 2 = 80 mm Hg伴随着呼吸性酸中毒，并不增加肺保护作用。然后，即便在极低的低潮气量复合高碳酸血症仍然有肺保护作用以及氧合作用。
文章见于：plos one 2011.08.6(8) 1-7
Maternal anaesthesia risk coefficient
产妇的麻醉风险系数
Tachpnea is not always associated with hyperventilation, which is defined by increased alvealar ventilation resulting in a lower arterial carbon dioxide level. 呼吸急促不是都伴有过度换气，过度换气的定义是肺泡通气量增高引起动脉血二氧化碳水平降低
困难气道：具有五年以上临床麻醉经验的麻醉科医师在面罩通气时遇到了困难（上呼吸道梗阻），或气管插管时遇到了困难，或两者兼有的一种临床情况。
The definition of difficult spirit way is:Have for more than five years the clinical anaesthesia is empirical anaesthesia doctor Ke met a difficulty(up breath way block) when the mask ventilates, or the windpipe met a difficulty while putting a tube, or both and a kind of clinical circumstance for having.
An understanding of the components of the anaesthetic system is essential for the safe practice of anaesthesia
了解麻醉装置的组成部分对安全实施麻醉非常重要
A man\'s life is limited, but there is no limit to serving the people.
I will dedicate my limited life to the limitless job of serving the people.
人的生命是有限的,可是,为人民服务是无限的,我要把有限的生命,投入到无限的为人民服务之中去.
A man\'s life is limited, but there is no limit to serving the people.
I will dedicate my limited life to the limitless job of serving the people.
人的生命是有限的,可是,为人民服务是无限的,我要把有限的生命,投入到无限的为人民服务之中去
此文出自毛泽东“纪念张思德”一文。
人的生命是有限的,可是,为人民服务是无限的,我要把有限的生命,投入到无限的为人民服务之中去
错了，抱歉。此文出自，雷锋日记。是雷锋同志的一句名言。
During insertion , there was no difficulty , needle advanced until " give " sensation was felt
穿刺进针时，没有困难，进针直到有“落空”的感觉停止进针。
During insertion , there was no difficulty , needle advanced until " give " sensation was felt
穿刺进针时，没有困难，进针直到有“落空”的感觉停止进针。
出自：Broken Spinal needle ( 腰麻针折断)
During insertion , there was no difficulty , needle advanced until " give " sensation was felt
穿刺进针时，没有困难，进针直到有“落空”的感觉停止进针。
出自：Broken Spinal needle ( 腰麻针折断)
{:4_101:} {:4_101:} Objective To explore the possibility and security of tracheal e xtubation in the operation room afte ...
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