So when we talk about ischemia, we’re usually talking about this lack of blood flow to a 因此，当我们谈论局部缺血时，我们通常会谈论缺乏血液流动
specific area of tissue, so maybe like with a heart attack, a coronary artery in the heart 特定的组织区域，所以可能像心脏病发作一样，是心脏中的冠状动脉
gets blocked that supplies the left ventricle with blood...so that localized area of heart 被阻塞，为左心室提供血液......使心脏的局部区域
tissue doesn’t get enough blood and oxygen and that damage is localized to that left 组织不能获得足够的血液和氧气，并且损伤局限于左侧
ventricle. 心室。
Shock is like ischemia...but on a global scale, in other words it’s a whole body circulatory 休克就像缺血......但在全球范围内，换句话说，它是一个全身循环
failure, where blood flow to tissues is dangerously low, leading to cellular injury, possibly 失败，血液流向组织的危险性很低，可能导致细胞损伤
damaging multiple organs and even leading to multiple organ failure if not treated immediately. 如果不立即治疗，会破坏多个器官甚至导致多器官衰竭。
Ok, so with shock, the body’s tissues aren’t getting enough oxygen via the blood, right? 好吧，震惊的是，身体的组织没有通过血液获得足够的氧气，对吗？
Normally, blood perfuses through tissue and delivers oxygen because there’s enough pressure 通常情况下，血液通过组织灌注并输送氧气，因为有足够的压力
in the circulatory system to push it through; so blood pressure’s a major determinant 在循环系统中推动它;所以血压是一个主要的决定因素
for the amount of blood perfusing through tissues. 通过组织灌注的血液量。
Now blood pressure’s determined by two components, the resistance to blood flow in the blood 现在血压由两个组成部分决定，血液中的血流阻力
vessels, things like vessel length, blood viscosity, and vessel diameter, and the cardiac 血管，血管长度，血液粘度，血管直径，心脏等
output which is the volume of blood pumped by the heart through the body per minute. 输出是心脏每分钟通过身体泵送的血液量。
And you can break that into heart rate, the number of beats per minute, times stroke volume, 你可以将其分解为心率，每分钟心跳次数，每次心搏量，
the amount pumped out each beat. 每次击败的数量。
Going further, the stroke volume is found by taking the total volume of blood left over 更进一步，通过获取剩余的血液总量来找到每搏输出量
after contraction, the end-systolic volume, and subtracting it from the total volume in 收缩后，收缩末期容积，并从总体积中减去
the heart after filling, the end-diastolic volume. 填充后的心脏，舒张末期容积。
Alright, now keeping those in mind, shock can be caused by whole bunch of different 好吧，现在记住这些，震惊可能是由一堆不同造成的
things, but we can categorize the different types of shock into the three main categories, 事情，但我们可以将不同类型的冲击分为三大类，
along with some subcategories here and there. 以及一些子类别。
The first category is called hypovolemic shock. 第一类称为低血容量性休克。
Hypo- means “low”, -vol- refers to “volume”, and -emia refers to the blood, so hypovolemic 低 - “低”，-vol-指“体积”，-emia指血液，所以低血容量
shock is shock induced by a low fluid volume of blood, and this could be either non-hemorrhagic 低流量的血液可引起休克，这可能是非出血性的
or haemorrhagic. 或出血性。
Non-hemorrhagic means that the loss of fluid volume isn’t from bleeding, so this could 非出血意味着液体量的减少不是出血，所以这可能
be like if you were stranded in a desert and suffered severe dehydration, eventually your 如果你被困在沙漠中并遭受严重脱水，最终你的
loss of fluid in sweat would reduce blood volume to where it wouldn’t be enough to 汗液中的液体流失会使血液量减少到不足的程度
supply your body’s organs and you’d develop hypovolemic shock. 供给你的身体器官，你会发展低血容量休克。
Hemorrhagic hypovolemic shock on the other hand is loss of blood volume through ruptured 另一方面，出血性低血容量性休克是通过破裂导致的血容量减少
blood vessels, in other words, from bleeding. 血管，换句话说，就是出血。
A loss of about 20% of your total blood volume, roughly one liter, can be enough to induce 损失约20％的总血量，大约一升，足以诱导
hypovolemic shock, and when that liter of blood leaves the circulation, the total volume 低血容量休克，当那升血液离开循环时，总体积
filling into the heart goes down, meaning the end-diastolic volume goes down, this means 填充到心脏下降，意味着舒张末期容量下降，这意味着
stroke volume goes down as well, which causes cardiac output to go down, and finally we 每搏输出量下降，导致心输出量下降，最后我们
see blood pressure goes down. 看血压下降。
When cardiac output goes down, catecholamines like epinephrine and norepinephrine, ADH, 当心输出量下降时，儿茶酚胺如肾上腺素和去甲肾上腺素，ADH，
and angiotensin II are released, all of which cause vasoconstriction of blood vessels which 和血管紧张素II被释放，所有这些都引起血管的血管收缩
increases of vascular resistance, and increased heart rate, which, increases cardiac output, 增加血管阻力，增加心率，增加心输出量，
and these combined effects increase blood pressure. 这些综合效果会增加血压。
A super important indicator of tissues not getting enough oxygen due to hypovolemia, 由于血容量不足导致组织氧气不足的一个非常重要的指标，
is a decreased mixed venous oxygen saturation, or MVO2. 是降低的混合静脉血氧饱和度，或MVO2。
MVO2 is the amount of oxygen bound to to hemoglobin in blood coming to the right side of the heart, MVO2是血液中与血红蛋白结合的氧气量，来自心脏右侧，
from the tissues. 从组织。
So it’s like the amount of oxygen left over, or not extracted and used by the tissues. 因此，它就像残留的氧气量，或者组织未提取和使用的氧气量。
So if blood volume’s down, that means oxygen’s down, and there’s going to be less left 因此，如果血量下降，这意味着氧气下降，并且会减少血量
over, right? 对吧？
So MVO2 will be down with hypovolemic shock. 所以MVO2会因低血容量休克而下降。
Since blood flow provides heat to the tissues as well, when it’s down, the skin starts 由于血液流动也为组织提供热量，当它下降时，皮肤开始出现
to feel cool and clammy; and so hypovolemic shock is considered a cold shock. 感到凉爽和湿冷;所以低血容量性休克被认为是一种冷休克。
A second main category of shock is cardiogenic shock, cardio - genic means produced by the 第二个主要类型的休克是心源性休克，由心脏产生的有氧运动手段
heart, right? 心，吧？
So this is when something happens to the heart such that now it can’t pump enough blood 所以这就是当心脏发生某些事情时，现在它无法抽出足够的血液
to the body’s tissues. 到了身体的组织。
The most common cause is acute myocardial infarction, or heart attack. 最常见的原因是急性心肌梗塞或心脏病发作。
Hold on a second, though...didn’t I say at the beginning that was more along the lines 坚持一秒钟，但是...我不是说在开始时更多的是沿着这条线
of localized ischemia? 局部缺血？
Well, the heart attack itself reflects ischemia, right? 那么，心脏病发作本身就反映了缺血，对吗？
But the effects of the initial cardiac damage eventually leads to a state of shock. 但最初的心脏损伤的影响最终导致休克状态。
When the heart’s muscle cells die, it can’t contract as hard, which means the amount of 当心脏的肌肉细胞死亡时，它不能收缩，这意味着它的数量
blood pumped out, or stroke volume, goes down, and therefore cardiac output goes down as 血液泵出，或每搏输出量下降，因此心输出量下降
well. 好。
In the same way as with hypovolemic shock, the body releases vasoconstrictors to increase 与低血容量性休克相同，身体释放血管收缩剂增加
vascular resistance help maintain blood pressure. 血管阻力有助于维持血压。
Also, as with hypovolemic shock, MVO2 will be down since there’s less oxygen being 此外，与低血容量休克一样，由于氧气较少，MVO2会下降
pumped out, and so less will be left over. 抽出来，剩下的就少了。
Sometimes there might be an obstruction that doesn’t allow the heart to fill properly 有时候可能会有阻塞，使心脏无法正常填充
with blood. 带血
For example, we might have the pericardial sac fill up with fluid from an infection or 例如，我们可能会让心包囊充满感染的液体或
blood from a traumatic accident like getting stabbed in the chest. 来自创伤性事故的血液，如被刺入胸部。
If this sac fills up, it physically constricts the heart from expanding and contracting normally 如果这个囊充满，它会使心脏正常收缩，不会正常扩张和收缩
and also reduces the stroke volume. 并且还减少了每搏输出量。
This is sometimes “sub” classified as obstructive shock, but you can see that the 这有时被“分”归类为阻塞性休克，但你可以看到
cause is still due to the heart’s inability to do its job, right? 原因仍然是由于心脏无法完成其工作，对吧？
Similarly to hypovolemic shock, a reduction in cardiac output leads to lowered blood flow, 与低血容量性休克相似，心输出量减少导致血流量降低，
so the skin gets cool and clammy and so cardiogenic shock is also considered a kind of cold shock. 因此，皮肤变得凉爽和湿冷，因此心源性休克也被认为是一种冷休克。
Alright, the third main category of shock is called distributive shock, where there’s 好吧，第三类主要的冲击被称为分配冲击，其中有
typically “leakiness” of blood vessels and an excessive amount of arteriole vasodilation, 典型的血管“渗漏”和过量的小动脉血管扩张，
or widening of the peripheral blood vessels, which remember is one of the components of 或扩大外周血管，记住是其中一个组成部分
vascular resistance. 血管阻力。
If arterioles dilate, vascular resistance to blood flow goes down and blood pressure 如果小动脉扩张，血管对血流的抵抗力下降和血压升高
goes down, leading to less perfusion and distribution of blood to organs and tissues. 下降，导致血液灌注和血液分布到器官和组织。
Now the most common type of distributive shock is septic shock, from pathogens in the blood. 现在最常见的分配性休克类型是脓毒性休克，来自血液中的病原体。
What happens with septic shock is endotoxins, these large clunky lipopolysaccharide molecules, 脓毒性休克会发生什么，内毒素，这些大笨重的脂多糖分子，
sometimes just called LPSs, found in the outer membrane of gram-negative bacteria causes 有时只是称为LPSs，发现在革兰氏阴性菌的外膜上
a crazy cascade of events. 疯狂的一系列事件。
that ultimately leads to lowered perfusion. 这最终导致灌注降低。
First these guys directly damage endothelial cells and cause them to release vasodilators 首先，这些家伙直接损伤内皮细胞并使其释放血管扩张剂
like nitric oxide. 像一氧化氮。
They also activate the complement pathway in the blood, which stimulates mast cell release 它们还激活血液中的补体途径，刺激肥大细胞释放
of histamine, another vasodilator. 组胺，另一种血管扩张剂。
The LPS molecules also activate immune cells like macrophages and neutrophils, which help LPS分子还激活免疫细胞，如巨噬细胞和中性粒细胞，这有助于
create a bunch of pro-inflammatory cytokines like tumor necrosis factor and interleukin 产生一系列促炎细胞因子，如肿瘤坏死因子和白细胞介素
1. 1。
These help the immune system destroy the invaders...but also stimulates the endothelial cells to release 这些有助于免疫系统摧毁入侵者......但也刺激内皮细胞释放
more inflammatory molecules like platelet activating factor and reactive oxygen species. 更多的炎症分子，如血小板活化因子和活性氧。
All of these inflammatory chemicals damage the endothelial cells and increases their 所有这些炎症化学物质都会破坏内皮细胞并使其增加
vascular permeability, making the blood vessels “leaky”. 血管通透性，使血管“渗漏”。
Also, endothelial cells express a procoagulant called tissue factor, procoagulants are molecules 此外，内皮细胞表达称为组织因子的促凝血剂，促凝血剂是分子
that increase blood coagulation, or blood clotting; this, in combination with an overall 增加血液凝固或血液凝固;这与整体相结合
decrease in anti-coagulants, which usually decrease clotting and seem to often be depleted 抗凝血剂减少，通常会减少凝血，似乎经常会耗尽
or used up during sepsis, leads to this net increase in coagulation and clotting in the 或在败血症期间用完，导致凝血和凝血的净增加
microvasculature, and of course clotting and blockages in the blood vessels further decreases 微脉管系统，当然血管中的凝血和阻塞进一步减少
perfusion, right? 灌注，对吧？
Okay so this widespread vasodilation means very little vascular resistance, and blood 好吧，这种广泛的血管舒张意味着很少的血管阻力和血液
can’t get the chance to unload as much oxygen as it cruises through the vasculature, and 没有机会在通过脉管系统的途中卸载尽可能多的氧气，并且
it gets back to the right side of the heart with leftover oxygen, so in this case, as 它用剩余的氧气回到心脏的右侧，所以在这种情况下，如同
opposed to cardiogenic and hypovolemic shock, MVO2 can be normal or even increased. 与心源性和低血容量性休克相反，MVO2可以正常甚至增加。
In contrast to hypovolemic and cardiogenic shock—now there’s an increase in flow 与低血容量和心源性休克相反 - 现在流量增加
in the peripheral blood vessels, and the skin becomes warm and flushed, so distributive 在外周血管中，皮肤变得温暖和冲洗，因此分配
shock is a kind of warm shock. 震惊是一种温暖的震撼。
The overall combined effects of widespread vasodilation, increased vascular permeability, 广泛血管舒张，血管通透性增加的总体综合效应，
and microvascular blood clotting, all contribute to decreased perfusion of blood to vital organs. 和微血管凝血，都有助于减少血液灌注到重要器官。
Now two kind of sub-types of distributive shock are anaphylactic shock, which is an 现在有两种分布式休克子类型是过敏性休克，这是一种过敏性休克
allergic reaction causing dangerously low blood pressure, and neurogenic shock, where 过敏反应导致危险的低血压和神经源性休克，在哪里
the nervous system gets damaged and can’t control the body’s blood pressure. 神经系统受损，无法控制身体的血压。
The treatment of shock depends on the cause. 休克的治疗取决于病因。
In general, the goal is to stabilize blood pressure so that vital organs like the heart 一般来说，目标是稳定血压，使重要器官像心脏一样
and the brain are perfused with blood. 并且大脑被血液灌注。
In order to stabilize blood pressure, fluid replacement and medications that increase 为了稳定血压，补液和增加药物
heart contractility, cause vasoconstriction, and retain fluid can be administered. 可以施用心脏收缩性，引起血管收缩和保留液体。
Oftentimes a person might need supplemental oxygen or have their airway protected, for 通常情况下，一个人可能需要补充氧气或保护气道
example with intubation. 插管的例子。
Alright, as a quick recap. 好吧，快速回顾一下。
Shock is ultimately a failure in tissue perfusion, and it affects the whole body, putting tissues 休克最终是组织灌注失败，它影响整个身体，组织
and organs at risk for injury and ultimately organ failure. 和器官有受伤和最终器官衰竭的风险。
Hypovolemic shock happens when dehydration or hemorrhage reduce the volume of blood in 当脱水或出血减少血液量时，就会发生低血容量性休克
the blood vessels. 血管。
Cardiogenic shock happens when a direct injury like a heart attack or an obstruction like 当心脏病发作或类似梗阻等直接损伤时，会发生心源性休克
a pericardial effusion prevents the heart from pumping blood efficiently. 心包积液可以防止心脏有效地抽血。
Distributive shock happens when something like an allergic reaction or damage to the 分配性休克发生在诸如过敏反应或损伤的情况下
nervous system - called neurogenic shock causes the blood vessels to vasodilate and become 神经系统 - 被称为神经源性休克导致血管血管扩张而变得神经衰弱
leaky which reduces the resistance and lowers the blood pressure. 泄漏会降低阻力并降低血压。