Placeholder Image

字幕列表 影片播放

  • If you've ever landed on the surgeon's slab, you're probably really grateful that

  • you won't remember or feel the operation.

  • Anesthesia is there to get you through it.

  • But what exactly happens when you go under?

  • Tens of thousands of people undergo anesthesia every day in the United States.

  • But here's the not so pleasant thought: surgery predates anesthetic drugs by thousands of

  • years.

  • Before the mid-1800s, surgeons turned to alcohol, narcotics, and even smacking their patients

  • upside in the head to induce unconsciousness.

  • That is not awesome bedside manner, so surgeries were often done when patients were totally

  • awake.

  • Some historians believe that before the advent of anesthetics, about

  • half of patients in surgery died of shock.

  • That's why, in 1846, the first public demonstration of a surgery performed with general anesthesia

  • took the medical world by storm.

  • Doctors at Massachusetts General Hospital in Boston administered the first-ever anesthetic:

  • diethyl ether.

  • In fact, the theater where the surgery took place received this totally awesome name:

  • the Ether Dome.

  • The landmark event was heralded in the press as theend of pain.”

  • But anesthetics don't just address pain; they also temporarily paralyze the body and

  • induce amnesia.

  • Fortunately for you, that means you have no memories of the procedure.

  • Today, doctors usually give their patients combinations of different drugs to ensure

  • a balance of these effects throughout a procedure.

  • These include inhaled substances like sevoflurane and nitrous oxide, as well as intravenous

  • drugs like propofol and ketamine.

  • Scientists know that anesthesia works, but they haven't worked out all the details

  • of how it works, or even more broadly, how consciousness itself works.

  • The current thinking goes that these drugs work to create the perfect operating conditions

  • by influencing neurotransmitters: those are the chemical messengers that transmit signals between nerve

  • cells.

  • Specifically, many anesthetics are thought to cut off access to receptors of a neurotransmitter

  • called gamma-Aminobutyric acidor GABA.

  • GABA is involved in sending signals for responsiveness from the cerebral cortex

  • that's the part of the brain responsible for our emotions and higher-level thinking.

  • When this path is blocked by anesthetics, the connections for arousal signals are lost

  • and its sleepytime.

  • But as you might imagine, bringing the brain down to such a low level of activity can be

  • a little dangerous.

  • Too much and the drugs could slow down activity not only in the consciousness-controlling

  • cortex but in the brainstem itself--which could stop a patient's heart and cause serious

  • brain damage or even death.

  • But too little drug and the patient could wake up.

  • Avoiding all that is where anesthesiologists and nurse anesthetists come in.

  • These medical professionals monitor a patient's breathing, heart rate, and other vital signs

  • to make sure they're delivering just the right amounts of anesthetic drugs in real

  • time.

  • That way you won't feel a thing as a skilled surgeon removes your funny bone for four hundred dollars.

  • Although, maybe next time you'll want to spring for doctors who don't use children

  • as assistants or, you know, drip cigarette ash on your face.

  • But maybe that's just me.

If you've ever landed on the surgeon's slab, you're probably really grateful that

字幕與單字

影片操作 你可以在這邊進行「影片」的調整,以及「字幕」的顯示

B2 中高級 美國腔

How Does Anesthesia Work?

  • 13 0
    nao 發佈於 2021 年 06 月 23 日
影片單字