hello I'm Eric strong from the Palo Alto 你好，我是Palo Alto的Eric强者
Veterans Hospital and Stanford 退伍军人医院和斯坦福大学
University this is the first lecture in 大学这是第一次演讲
this series on mechanical ventilation 本系列机械通气
and this will serve as a bit of an 这将作为一个
introduction to the topic and provide a 介绍该主题并提供一个
little historical context as well here 这里的历史背景也很少
are the learning objectives of this 这是学习目标
initial lecture first to know the 初步讲座首先要了解
general indications for intubation and 插管的一般适应症和
mechanical ventilation and the second to 机械通气和第二
understand the conceptual differences 理解概念上的差异
between positive and negative pressure 在正压和负压之间
ventilation as I begin discussing 我开始讨论通风
mechanical ventilation in this first 首先是机械通气
lecture the most obvious place to start 讲座最明显的起点
is simply to ask what is it in the most 只是问最多的是什么
general sense mechanical ventilation is 一般意义上的机械通气是
any means in which physical devices or 物理设备或物理设备的任何手段
machines are used to is either assist or 机器习惯是辅助或
replace spontaneous respiration there 在那里取代自发呼吸
are four major indications for 有四个主要适应症
mechanical ventilation first the need 机械通风首先需要
for high levels of inspired oxygen that 对于高水平的吸入氧气
might accompany hypoxic respiratory 可能伴有缺氧性呼吸
failure 失败
second the need for assisted ventilation 第二，需要辅助通气
this can be seen with either hypercapnia 这可以从高碳酸血症中看出
respiratory failure or more commonly as 呼吸衰竭或更常见的
part of routine protocol for surgical 手术常规方案的一部分
procedures done under general anesthesia 在全身麻醉下完成的程序
third protection of the airway against 第三次保护呼吸道
aspiration this could be an issue for 这可能是一个问题
patients with neurologic attached rafi 神经系统附着的rafi患者
or drug overdose and finally relief of 或药物过量，最后缓解
upper airway obstruction in situations 上呼吸道阻塞情况
such as anaphylaxis soft tissue 如过敏性软组织
infections of the neck or severe head 颈部或严重头部感染
and neck trauma on the most fundamental 和颈部创伤最根本
level the first distinction to make when 等级时要做的第一个区别
classifying mechanical ventilation into 机械通气分类
different categories is whether the 不同的类别是否
ventilator relies on positive or 呼吸机依赖于阳性或
negative pressure to move the chest wall 负压移动胸壁
and diaphragm and to create the pressure 和隔膜并产生压力
gradients that drive gas in and out of 驱动气体进出的梯度
the lungs with negative pressure 肺部有负压
ventilation which was the first to be 通风是第一次
developed pressure lower than 发展压力低于
atmospheric pressure is applied to the 大气压力适用于
extra thoracic space during inspiration 灵感来自额外的胸腔
while with positive pressure ventilation 同时采用正压通气
pressure higher than atmospheric 压力高于大气压
pressure is applied to the intra 压力施加在内部
alveolar space during inspiration those 灵感来自那些肺泡腔
of you who have 你有谁
her negative pressure ventilation may 她的负压通气可能
know that it is almost never used in the 知道它几乎从未用过
cube medicine anymore it may wonder why 立方体医学它可能想知道为什么
I'm even going to spend time discussing 我甚至会花时间讨论
it however aside from the historical 然而，它除了历史
context it will provide a quick review 它将提供快速审查
of the physiology of negative pressure 负压生理学
ventilation will help to better 通风有助于改善
understand the physiology of positive 了解积极的生理学
pressure ventilation let's look at some 压力通风让我们看看一些
illustrations here's a schematic of the 这里的插图是一个示意图
lung external to the lung is the outside 肺外的肺是外面的
world where we will set the atmospheric 我们将设定大气层的世界
pressure to zero for reference the 压力为零以供参考
single oval cavity in the middle 中间有一个椭圆形腔
represents all the intra alveolar space 代表所有肺泡内空间
where at rest and at equilibrium the 在休息和平衡的地方
pressure is also zero the orange shell 橙壳的压力也是零
is the pleural space which in reality is 是实际上是胸膜的空间
actually quite thin much more so than it 实际上比它更薄
appears from this picture there are some 从这张照片看，有一些
mechanical forces at work here even with 机械力在这里工作甚至与
the lungs at rest these will be 这些将是休息的肺部
discussed more detail in a later lecture 在后面的讲座中讨论了更多细节
but I will simply simplify it by stating 但我会简单地通过陈述来简化它
that the lungs themselves exert an 肺部自身发挥作用
inward force on the pleural space 胸膜上的内力
due to their elastic recoil likewise the 由于它们的弹性后坐力同样如此
chest wall exerts an outward force on 胸壁施加向外的力量
the pleural space due to its own elastic 胸膜腔由于其自身的弹性
recoil therefore the pressure at the 因此反冲压力
pleural space is negative at rest five 静息空间在休息时是负面的
centimeters of water is a relatively 厘米的水是相对的
typical value I'm now going to go 典型的价值我现在要走了
through how these pressures change 通过这些压力如何变化
during a respiratory cycle with both 在两者的呼吸循环期间
negative and positive pressure 负压和正压
ventilation while leaving in the 离开时通风
intrapleural pressure and including its 胸膜内压力及其包括
effects at various times will lead to a 在不同时间的影响将导致a
more complete understanding of this 更全面地了解这一点
physiology it will make things difficult 生理学会让事情变得困难
more complicated so I'm just going to 更复杂所以我只是去
leave it out for now so first with 现在就把它留出来
negative pressure ventilation the basic 负压通气基本
principle is that either the thorax or 原则是胸部或胸部
more commonly the entire torso is 更常见的是整个躯干
enclosed in an airtight chamber leaving 封闭在一个密闭的室内离开
the head and neck exposed inspiration is 头部和颈部暴露的灵感是
triggered by application of negative 由负面的应用引发
pressure within that chamber 那个房间内的压力
this increases the outward pull on the 这增加了对外的拉力
chest wall which is transmitted through 穿过的胸壁
the pleural space to the lungs to expand 肺部扩张的胸膜腔
them physical expansion of the lungs 他们的肺部物理扩张
leads to increased internal builder 导致内部建设者增加
volume which drops the intra alveolar 体积下降肺泡内
pressure you may notice that the 压力你可能会注意到
external negative pressure doesn't 外部负压不会
equal the intra alveolar pressure this 等于肺泡内压力
discrepancy is because the inward 差异是因为向内
elastic recoil of the lungs somewhat 有点弹性后坐的肺部
blunts the outward pulling force now if 如果，现在减弱向外的拉力
you remember that the patient's mouth 你记得病人的嘴巴
and nose are at atmospheric pressure 和鼻子处于大气压力下
which is at zero you'll realize that the 这是零，你会意识到
pressure gradient will drive the flow of 压力梯度会驱动流量
air into the lungs 空气进入肺部
thus inspiration as air flows into the 因此空气流入的灵感
lungs the intra alveolar pressure which 肺内肺泡压力
is in equilibrium with atmospheric 与大气平衡
pressure and when that occurs air flow 压力以及何时发生空气流动
will cease you'll notice that the inward 将停止你会注意到内向
force at this point still roughly equals 此时的力量仍然大致相等
the outward force despite the pressures 尽管有压力，但外在的力量
being quite different that's because of 与众不同的是因为
that elastic recoil of the lung again 那种弹性后坐力再次出现
which is accentuated when higher volumes 当数量增加时，这会更加突出
stretch it further just like a rubber 像橡胶一样伸展它
band or a coiled spring now exploration 乐队或盘绕的弹簧现在探索
is then triggered by the pressure in the 然后是由压力引发的
chamber returning to atmospheric 室返回大气层
pressure now the inward force with the 压力现在与内在的力量
additional recoil from inflation is 通货膨胀带来的额外后坐力
greater than the outward force this 比这更大的向外力量
pulls the lungs back in deflation of the 在通缩的情况下拉回肺部
lungs increases intra alveolar pressure 肺增加肺泡内压
and the pressure gradient drives gas 压力梯度驱动气体
back out again for another perspective 从另一个角度再次退出
on this let's take a look at a graph of 在这个让我们来看看图表
pressure as a function of time for one 压力随时间的变化而变化
respiratory cycle the grey line at zero 呼吸循环灰线为零
represents atmospheric pressure and the 代表大气压力和
red line will represent the external 红线代表外部
pressure set by the ventilator during 呼吸机设定的压力
inspiration when the ventilator provides 呼吸机提供的灵感
negative external pressure there is a 负外部压力有一个
smooth transition from an intra alveolar 从肺泡内平滑过渡
pressure of zero to some negative value 零压力到一些负值
a little shy of that set pressure then 那个压力有点害羞
as air flows into the lungs the pressure 当空气流入肺部的压力
gradient resolves in intraocular 梯度在眼内消退
pressure turns to atmospheric during 在此期间压力变为大气压
expiration the step pressure goes to 到期压力变为
zero this triggers a smooth increase in 零这会触发平稳增加
intraocular pressure to some positive 眼压有些积极
value which pushes gas back out until 将气体推回去的价值
the pressure then again returns to zero 然后压力又回到零
the first negative pressure ventilator 第一个负压呼吸机
to enter a clinical use was invented by 进入临床使用是由发明的
two Harvard professors in 1928 it was 1928年，有两位哈佛大学教授
initially called the drinker respirator 最初称为饮水器呼吸器
after one of the inventors but quickly 一位发明者之后但很快
became known as the iron lung here's a 这里被称为铁肺
picture of it the patient's body would 病人身体的照片
lie supine in the tube with their head 用他们的头仰卧在管子里
sticking out of the hole at the top 伸出顶部的洞
resting on that comfortable looking 靠着那舒服的样子
metal tray you can see a mirror above 金属托盘，你可以看到上面的镜子
where the head would lie which would be 头部会撒谎的地方
the what the patient used to look at 病人过去看的东西
their care providers and visitors since 他们的护理人员和访客
they couldn't move themselves though 他们虽然无法动弹
removable panels on the sides allow 两侧可拆卸面板允许
doctors and nurses to perform 医生和护士表演
rudimentary examinations and provide 初步检查和提供
hygiene without having to remove the 卫生而不必去除
patient from the chamber now during the 病人现在在房间里
polio outbreaks of the 1940s and 50s 20世纪40年代和50年代的小儿麻痹症爆发
entire wards of hospitals were filled 医院的整个病区都被填满了
with children and iron lungs as polio 患儿童和肺部肺炎为脊髓灰质炎
commonly affects the diaphragm and can 通常影响隔膜和罐头
reduce the patient's ability to take in 降低患者的摄入能力
breasts although images such as this may 乳房，虽然这样的图像可能
seem 似乎
depressing today without the iron lung 今天没有铁肺就郁闷了
probably every single patient in this 可能每个患者都在这
ward would would have died it may seem 病房本来会死的
to you to look quite uncomfortable and 让你看起来很不舒服
restrictive to being in an iron lung and 限制在铁肺和肺部
you may wonder how long a person could 你可能想知道一个人能做多久
possibly tolerate such an intervention 可能会容忍这种干预
here's a picture of a woman her name's 这是一张她名字的女人的照片
Diane Odell mrs. O'Dell was 3 years old Diane Odell夫人。奥戴尔3岁
when she contracted polio unfortunately 当她不幸感染小儿麻痹症时
unlike most polio patients who recover 不像大多数脊髓灰质炎患者康复
most if not all of the lung function she 大多数，如果不是所有的肺功能她
did not and instead she lived remarkable 没有，而是她的生活非凡
58 years in this iron lung much of it 这个铁肺已经58年了
spent in a family home in Tennessee 在田纳西州的一个家庭度过
unfortunately she passed away in 2008 不幸的是，她于2008年去世
after the homes emergency generator 家庭应急发电机后
failed during a power outage it's kind 在停电期间失败是件好事
of a unfortunate end to a very sad and 一个不幸的结局，一个非常悲伤和
tragic life while they are quite rare 悲惨的生活虽然很少见
these days for reasons we'll get to our 这些天我们会找到我们的理由
lungs no longer need to look like a 肺不再需要看起来像一个
contraption from a Jules Verne novel 朱尔斯凡尔纳小说的装置
here is the picture of a modern negative 这是现代否定的图片
pressure ventilator known as a port a 压力呼吸机称为端口a
lung and no I'm not kidding about that 肺，不，我不是在开玩笑
amusing name let's now look at positive 有趣的名字让我们看看积极的
pressure ventilation the first serious 压力通气第一严重
research on positive pressure 关于正压的研究
ventilation didn't occur in the hospital 在医院没有发生通气
but rather in a research lab where the 而是在一个研究实验室里
military was investigating better ways 军方正在调查更好的方法
to deliver oxygen the high altitude 在高海拔地区输送氧气
pilots during the nineteen 十九岁的飞行员
Ortiz positive-pressure ventilators Ortiz正压式呼吸机
didn't enter the medical setting until 直到没有进入医疗机构
the 1960s and we're still quite rare 20世纪60年代，我们仍然非常罕见
into the 1970s which I still find 进入20世纪70年代，我仍然发现
amazing considering how ubiquitous these 考虑到这些无处不在，令人惊叹
life life-saving devices are just a 生命救命设备只是一个
generation later with positive pressure 后来有正压力
ventilation instead of the body being 换气而不是身体
placed in the chamber a small tube 在室内放置一个小管
called an endotracheal tube is 称为气管插管
introduced into the trachea usually via 通常通过气管引入气管
the mouth and the airtight seal is made 嘴和气密密封
between the endotracheal tube and the 气管导管与导管之间
trachea by means of a soft sided cuff 气管采用柔软的袖口设计
that is inflated once the tube is in 一旦管进入就会膨胀
place with positive pressure ventilation 有正压通气的地方
positive pressure is applied to the air 正压力施加在空气中
within the endotracheal tube this 在气管插管内
pressure gradient drives the flow of air 压力梯度驱动空气流动
into the lungs which then expand once 进入肺部然后扩张一次
the inter alveolar pressure is equalized 肺泡间压力相等
with the endotracheal tube pressure air 用气管内压力空气
flow stops you'll notice that here at an 流量停止你会注意到在这里
inspiration although there is positive 灵感虽然有积极意义
pressure in the intra alveolar space an 肺泡腔内的压力
atmospheric pressure in the extra 额外的大气压力
thoracic space the forces on the 胸部空间上的力量
respiratory apparatus are balanced 呼吸器是平衡的
that's because the additional outward 那是因为额外的外在
force from the positive pressure is 来自正压的力量
balanced by the inward elastic recoil 由向内弹性反冲平衡
once again expiration is triggered by 再次到期是由触发的
removal of the positive pressure being 去除正压力
applied to the tube now the pressure 现在适用于管子的压力
gradient drives gas out of the lungs as 梯度将气体排出肺部
equilibrium is reached and the intra 达到平衡并且在内部
alveolar pressure reaches zero the net 肺泡压力达到零净值
force on the long down favors elastic 长时间的力量有利于弹性
recoil leading to long deflation let's 反冲导致长期通货紧缩
took a look at a graph of intra alveolar 看了一下肺泡内图
pressure as a function of time once 压力作为时间的函数一次
again the dashed gray line will be 虚线灰色线将是
atmospheric pressure set at zero for 大气压设定为零
reference the dashed red line will be 参考虚线红线将
the extrinsic pressure applied via the 外在的压力通过
endotracheal tube you can see that 你可以看到气管插管
application of a constant pressure 施加恒定压力
because it has a constant positive 因为它有一个持续的积极因素
pressure that is at the beginning of 开始时的压力
inspiration results in the intra 灵感来自于内部
alveolar pressure reaching equilibrium 肺泡压力达到平衡
with it towards the end of inspiration 随着它走向灵感的尽头
with release of that extrinsic pressure 释放出那种外在的压力
the intra alveolar pressure quickly 肺泡内压很快
drops back down to zero 降回零
before we move on I want to point out 在我们继续之前，我想指出
that what I've shown you with these 我用这些给你看的东西
schematics and graphs is a substantial 原理图和图表是一个实质性的
simplification of the actual process 简化实际过程
respiration doesn't happen in a sequence 呼吸不会按顺序发生
of well delineated steps like I went 像我去的那样描绘得很好的步骤
through but rather as a continuous 通过而是作为一个连续的
smooth process volumes and pressures 平稳的过程量和压力
change simultaneously not in a series 同时改变不是一系列的
like these animations might make it 像这些动画可能会成功
appear let's take a look at some 看来我们来看看吧
positive pressure ventilator x' first 正压通气机x'首先
here is the endotracheal tube frequently 这里经常是气管插管
abbreviated ET tube the balloon on the 缩写ET管上的气球
right side is the cuff which creates the 右侧是创造的袖口
airtight seal within the trachea the 气管内的气密密封
cuff can be inflated or deflated through 袖带可以通过充气或放气
the blue port here is a woman with an ET 这里的蓝色港口是一个有ET的女人
tube 管
connected to a conventional positive 连接到传统的正面
pressure ventilator there are a variety 压力呼吸机有多种
of methods to keep the ET tube in place 保持ET管到位的方法
now this patient has a special strap 现在这个病人有一个特殊的表带
specifically designed for that purpose 专为此目的而设计
it's actually not all that uncommon to 它实际上并非罕见
see the ET tube simply taped the 看ET管只是录了一下
patient's face which I don't necessarily 病人的脸，我不一定
recommend but frequently is jerry-rigged 建议，但经常是偷工减料
when the special strap is not available 当特殊表带不可用时
the ET tube is attached to a Y connector ET管连接到Y连接器
off which run to larger caliber tubes 关闭哪个更大的口径管
one white one clear in this case one of 在这种情况下，一个白色清楚
the tubes is the inspiratory limb of the 管是吸气的肢体
ventilator circuit through which oxygen 呼吸机回路通过哪个氧气
rich gas travels to the patient's lungs 富含气体传播到患者的肺部
and the other tube is the expert ory 而另一支管是专家
limb through which carbon dioxide which 肢体通过哪个二氧化碳
gas travels away from the patient's 燃气远离病人
lungs in the back and partly cut off is 背部和部分切断的肺部是
the actual ventilator itself modern 实际呼吸机本身现代化
ventilators are quite sophisticated here 这里的呼吸机非常复杂
are two popular models that you will 你会选择两种流行的模特
likely see around the ICU now that we've 我们现在可能会看到ICU周围
reviewed a little of the physiologic 回顾了一点生理学
differences between negative and 负面和负面的差异
positive pressure ventilation what are 正压通气是什么
some of the practical differences let's 一些实际的差异让我们来
take a look at the major advantages of 看看主要优点
each negative pressure ventilation is 每个负压通风都是
non-invasive does not require sedation 非侵入性不需要镇静
allows the patient to still eat and talk 允许患者仍然吃饭和说话
relatively normally and it is probably 相对正常而且很可能
associated with a lower risk of 与风险较低有关
aspiration 心愿
positive pressure ventilation is able to 正压通气能够
provide higher levels of inspired oxygen 提供更高水平的吸入氧气
it is more effective for providing large 提供大型服务更有效
driving pressure gradients for patients 驱动患者的压力梯度
with poor lung compliance there is an 肺部依从性差，有一个
increased ability to individualize 提高个性化的能力
treatment as there are many more options 治疗因为有更多的选择
on positive-pressure ventilators than 在正压通风机上比
negative pressure ventilator x' and 负压呼吸机x'和
finally it can provide full vent support 最后它可以提供全面的通风支持
for unconscious patients the bottom line 对于无意识患者的底线
is that negative pressure ventilator 是负压呼吸机
where a near-perfect solution to dealing 处理近乎完美的解决方案
with large numbers of children with 有大量的孩子
polio and subsequent diaphragmatic 脊髓灰质炎和随后的膈肌
paralysis the patients are cognitively 患者瘫痪是认知的
intact and with normal lung parenchyma 完整和正常的肺实质
unfortunately they really only work for 不幸的是，他们真的只是为之努力
patients with neuromuscular disease and 神经肌肉疾病患者
its associated hypoventilation that 其相关的通气不足
specific type of respiratory failure 特定类型的呼吸衰竭
makes up a tiny tiny percentage of all 占所有人的一小部分
patients requiring mechanical 需要机械的患者
ventilation 通风
therefore the portal unga side negative 因此门户网站unga负面
pressure regulators are rarely used in 压力调节器很少用于
practice today and have been relegated 今天练习并且已经降级了
to museum exhibits I hope you have found 到博物馆展品我希望你找到了
this introduction to mechanical 这个机械的介绍
ventilators to be both interesting and 呼吸机既有趣又有趣
useful please continue now to lesson two 有用请继续第二课
on normal lung mechanics 关于正常的肺力学
you 您