休克

title: 对休克的研究史.
content: 18世纪,Henri Francois Le Dran提出休克一词,并指这是机体创伤后的一种状态。  19世纪,Grile通过实验,提出“休克是由血管运动中枢麻痹所致。”  20世纪,系统的研究表明,休克乃循环功能急剧障碍所致。1960年代,Lillehei提出,休克的关键环节是微循环衰竭。  现在,通过生物化学和病理生理学对休克的研究,人们更清楚了解到休克的机制和发生过程。
title: 休克种类与原因.
content: 休克可分为四种类型,但实际中经常遇到的是其混合形式。
title: 征候.
content: 由于导致休克的原因不同,其征候也有不同之处。以下的症状并不一定全部出现:  作为诊断依据可以使用到"休克指数"值 (=脉搏/收缩压)。但现在几乎被放弃使用,因为很多因素会影响脉搏和血压。
title: 休克三期.
content: 休克的过程可根据其微循环特征分为三期:缺血缺氧期,淤血缺氧期和DIC(弥散性血管内凝血)期。但有些休克并不一定都经历了这三期。
title: 缺血缺氧期.
content: 即休克早期。缺血缺氧期指的是由于失血、失液、烧伤等导致机体有效循环血量绝对不足引起的组织供血供氧不足。机体实行“自我输血”和“自我输液”,保证回心血量。除心脑血管外,全身血管收缩。心脑供血并无明显障碍。
title: 淤血缺氧期.
content: 休克病因未消。组织持续缺血缺氧,乳酸等扩血管物质增多,微血管和后微动脉痉挛减弱而出现淤血。血液滞留在腹腔器官中,心脑供血下降明显。此期又称休克期。
title: DIC期.
content: 又称微循环衰竭期或休克难治期。该期中微循环血管平滑肌麻痹扩张,血流停止。凝血系统被激活,广泛微血栓形成,继而引起多功能系统衰竭。微血管对血管活性物质无反应性。
title: 微血管收缩.
content: 微血管的收缩是休克的重要环节,其在休克中有以下变化:  导致其出现的化学物质有:
title: 器官功能衰竭.
content: 由于休克过程中,血流量的变化,身体器官因缺血缺氧会出现各种病理变化甚至衰竭。
title: 肺休克.
content: 肺休克指严重休克患者晚期发生的呼吸衰竭。肺部出现肺出血,肺水肿,肺不张,微血栓形成,肺泡透明膜形成和飞虫量增加。
title: 肾休克.
content: 肾休克指机体在持续致病因素作用下,交感-肾上腺系统持续兴奋,儿茶酚胺分泌增多而引起腹腔血管痉挛,导致的急性肾功能衰竭。
title: 胰腺和心脏.
content: 胰因在休克过程中严重缺血,导致外分泌腺细胞溶酶体膜破裂,释放心抑制因子。它具有抑制心肌收缩性,抑制单核吞噬细胞,收缩腹腔内脏小血管的作用,使病情进一步恶化。而由外科疾病引起的休克,往往都需要手术处理造成休克的原发病变,如内出血的止血、切除已坏死的肠道,或对于伤口组织感染进行清创及脓疡引流等

Summary: 休克(Shock)为一急性的综合症。其顾名思义,为临床上常面临到的一种急性病症,一般人普遍认为休克专指低血压的状况,然而,以定义而言,休克其实为指身体的血液循环不够,造成组织氧气供应不足,所造成的一种状态。在这种状态下,全身有效血流量减少,微循环出现障碍,导致重要的生命器官缺血缺氧。即是身体器官需氧量与得氧量失调。休克不但在战场上十分常见,同时也是内外妇儿科常见的急性危重病症。

Shock (circulatory): Shock is the state of insufficient blood flow to the tissues of the body as a result of problems with the circulatory system. Initial symptoms of shock may include weakness, fast heart rate, fast breathing, sweating, anxiety, and increased thirst. This may be followed by confusion, unconsciousness, or cardiac arrest, as complications worsen. Shock is divided into four main types based on the underlying cause: low volume, cardiogenic, obstructive, and distributive shock. Low volume shock, also known as hypovolemic shock, may be from bleeding, diarrhea, or vomiting. Cardiogenic shock may be due to a heart attack or cardiac contusion. Obstructive shock may be due to cardiac tamponade or a tension pneumothorax. Distributive shock may be due to sepsis, anaphylaxis, injury to the upper spinal cord, or certain overdoses. The diagnosis is generally based on a combination of symptoms, physical examination, and laboratory tests. A decreased pulse pressure (systolic blood pressure minus diastolic blood pressure) or a fast heart rate raises concerns. The heart rate divided by systolic blood pressure, known as the shock index (SI), of greater than 0.8 supports the diagnosis more than low blood pressure or a fast heart rate in isolation. Treatment of shock is based on the likely underlying cause. An open airway and sufficient breathing should be established. Any ongoing bleeding should be stopped, which may require surgery or embolization. Intravenous fluid, such as Ringer's lactate or packed red blood cells, is often given. Efforts to maintain a normal body temperature are also important. Vasopressors may be useful in certain cases. Shock is both common and has a high risk of death. In the United States about 1.2 million people present to the emergency room each year with shock and their risk of death is between 20 and 50%.