麻醉是如何運作的？- Steven Zheng：英語精讀講義

If you've had surgery, 文法

如果你做過手術，

you might remember starting to count backwards from 10, 片語搭配

你可能還記得從10開始倒數，

9,

9，

8,

8，

and then waking up with the surgery already over 文法

然後醒來時手術已經結束了，

before you even got to five.

你甚至還沒數到5。

And it might seem like you were asleep, 表達脈絡

看起來你好像睡著了，

but you weren't.

但其實並沒有。

You were under anesthesia, 用詞

你處於麻醉狀態，

which is much more complicated.

這是一個複雜得多的過程。

You were unconscious,

你失去了意識，

but you also couldn't move,

同時你也不能移動，

form memories, 片語搭配

無法形成記憶，

or hopefully feel pain.

並且理想情況下也感覺不到疼痛。

Without being able to block all those processes at once, 文法

如果不能同時阻斷所有這些過程，

many surgeries would be way too traumatic to perform. 文法

許多手術就會因為創傷太大而無法進行。

Ancient medical texts from Egypt,

來自埃及、

Asia,

亞洲，

and the Middle East all describe early anesthetics containing things like opium poppy, 片語搭配

和中東的古代醫學文獻都記載了早期的麻醉劑，它們含有罌粟、

mandrake fruit,

曼德拉草果實，

and alcohol.

以及酒精等成分。

Today,

如今，

anesthesiologists often combine regional, 用詞

麻醉醫師通常會將局部麻醉劑、

inhalational,

吸入性麻醉劑，

and intravenous agents to get the right balance for a surgery. 片語搭配

和靜脈注射麻醉劑結合使用，以達到手術的合適平衡。

Regional anesthesia blocks pain signals from a specific part of the body from getting to the brain. 片語搭配

局部麻醉會阻斷身體特定部位的疼痛信號傳遞到大腦。

Pain and other messages travel through the nervous system as electrical impulses. 文法

疼痛和其他訊息以電脈衝的形式在神經系統中傳遞。

Regional anesthetics work by setting up an electrical barricade. 講解

局部麻醉劑透過設置電氣路障起作用。

They bind to the proteins in neurons' cell membranes that let charged particles in and out 講解

它們與神經元細胞膜上控制帶電粒子進出的蛋白質結合，

and lock out positively charged particles. 片語動詞

並將帶正電的粒子擋在門外。

One compound that does this is cocaine,

一種能做到這點的化合物是古柯鹼，

whose pain-killing effects were discovered by accident when an ophthalmology intern got some on his tongue. 片語搭配

它的鎮痛作用是一位眼科實習生不小心弄到舌頭上時偶然發現的。

It's still occasionally used as an anesthetic,

它現在偶爾仍被用作麻醉劑，

but many of the more common regional anesthetics have a similar chemical structure and work the same way. 片語搭配

但許多更常見的局部麻醉劑具有相似的化學結構，作用原理也相同。

But for major surgeries where you need to be unconscious, 文法

但對於需要你失去意識的大型手術，

you'll want something that acts on the entire nervous system, 片語搭配

你會需要一種作用於整個神經系統的藥物，

including the brain.

包括大腦。

That's what inhalational anesthetics do. 表達脈絡

這就是吸入性麻醉劑的作用。

In Western medicine, 文化背景

在西醫中，

diethyl ether was the first common one.

乙醚是第一種常用的吸入麻醉劑。

It was best known as a recreational drug 片語搭配

它作為一種消遣性藥物而廣為人知，

until doctors started to realize that people sometimes didn't notice injuries they received under the influence. 慣用語

直到醫生們開始意識到，人們在受其影響時有時察覺不到自己受的傷。

In the 1840s,

在19世紀40年代，

they started sedating patients with ether during dental extractions and surgeries. 用詞

他們開始在拔牙和手術期間用乙醚給病人進行鎮靜。

Nitrous oxide became popular in the decades that followed 片語搭配

笑氣在隨後的幾十年裡開始流行，

and is still used today,

並且沿用至今，

although ether derivatives like sevoflurane are more common. 文法

儘管像七氟醚這樣的乙醚衍生物更為常見。

Inhalational anesthesia is usually supplemented with intravenous anesthesia, 片語搭配

吸入性麻醉通常輔以靜脈麻醉，

which was developed in the 1870s.

後者研發於19世紀70年代。

Common intravenous agents include sedatives like propofol,

常見的靜脈注射劑包括像異丙酚這樣的鎮靜劑，

which induce unconsciousness, 用詞

它可以導致無意識狀態，

and opioids like fentanyl,

還有像吩坦尼這樣的鴉片類藥物，

which reduce pain.

它可以減輕疼痛。

These general anesthetics also seem to work by affecting electrical signals in the nervous system. 表達脈絡

這些全身麻醉劑似乎也透過影響神經系統中的電信號來發揮作用。

Normally,

通常情況下，

the brain's electrical signals are a chaotic chorus 慣用語

大腦的電信號就像一場混亂的大合唱，

as different parts of the brain communicate with each other.

因為大腦的不同部分在相互交流。

That connectivity keeps you awake and aware. 文法

這種連通性讓你保持清醒和意識。

But as someone becomes anesthetized, 文法

但當人被麻醉時，

those signals become calmer and more organized,

這些信號變得更平靜、更有條理，

suggesting that different parts of the brain aren't talking to each other anymore. 表達脈絡

這表明大腦的不同部分不再相互對話。

There's a lot we still don't know about exactly how this happens. 表達脈絡

關於這到底是如何發生的，我們還有很多未知之處。

Several common anesthetics bind to the GABA-A receptor in the brain's neurons. 用詞

幾種常見的麻醉劑會與大腦神經元中的GABA-A受體結合。

They hold the gateway open, 慣用語

它們保持通道敞開，

letting negatively charged particles flow into the cell. 文法

讓帶負電的粒子流入細胞。

Negative charge builds up and acts like a logjam, 講解

負電荷不斷積累，就像堵塞的原木一樣，

keeping the neuron from transmitting electrical signals. 文法

阻止神經元傳遞電信號。

The nervous system has lots of these gated channels, 用詞

神經系統有許多這樣的門控通道，

controlling pathways for movement,

控制著運動、

memory,

記憶，

and consciousness.

和意識的通路。

Most anesthetics probably act on more than one,

大多數麻醉劑可能作用於不止一種通道，

and they don't act on just the nervous system. 文法

而且它們不僅僅作用於神經系統。

Many anesthetics also affect the heart,

許多麻醉劑也會影響心臟、

lungs,

肺，

and other vital organs,

以及其他重要器官，

just like early anesthetics,

就像早期的麻醉劑一樣，

which included familiar poisons like hemlock and aconite.

它們包含了熟悉的毒物，如毒芹和烏頭。

Modern drugs can have serious side effects. 片語搭配

現代藥物可能會有嚴重的副作用。

So an anesthesiologist has to mix just the right balance of drugs to create all the features of anesthesia 片語搭配

所以麻醉醫師必須混合出剛好達到平衡的藥物，以創造麻醉的所有特性，

while carefully monitoring the patient's vital signs 文法

同時仔細監測病人的生命徵象，

and adjusting the drug mixture as needed.

並根據需要調整藥物混合比例。

Anesthesia is complicated,

麻醉是複雜的，

but figuring out how to use it allowed for the development of new and better surgical techniques. 文法

但弄清楚如何使用它，促成了新的、更好的外科技術的發展。

Surgeons could learn how to routinely and safely perform C-sections, 用詞

外科醫生得以學會如何常規且安全地進行剖腹產、

reopen blocked arteries, 片語搭配

重新打通阻塞的動脈、

replace damaged livers and kidneys,

移植受損的肝臟和腎臟，

and many other life-saving operations. 片語搭配

以及許多其他拯救生命的手術。

And each year,

每年，

new anesthesia techniques are developed that will ensure more and more patients survive the trauma of surgery. 講解

都有新的麻醉技術被開發出來，這將確保越來越多的病人能在手術創傷中倖存下來。