What is Anesthesia? - Definition & Types

Instructor: Sarah Friedl

Sarah has two Master's, one in Zoology and one in GIS, a Bachelor's in Biology, and has taught college level Physical Science and Biology.

Can you imagine having surgery without being put to sleep or getting stitches without numbing the skin? Anesthesia allows us to have painful procedures without feeling pain, and in this lesson you'll learn about the different types used in medicine today.

What is Anesthesia?

Have you ever had a surgical procedure? How about a cavity filled at the dentist? Or maybe you simply fell down and needed a few stitches at urgent care. If so, you probably had anesthesia at the time. This is medicine that prevents you from feeling pain. Can you imagine going through any of these situations without anesthesia? That doesn't sound fun at all!

The first anesthesia used in operating rooms was in 1846. Patients would inhale ether fumes, go to sleep, and then doctors could do the procedure without the patient feeling any pain. How terrible it must have been for those who needed any surgical procedures before this time! But ether itself wasn't fool-proof. There was no way to administer a certain amount of ether so it was possible that the patient would inhale too little and wake up during surgery, or inhale too much and not wake up at all! Ether is also highly flammable, so a spark might cause an explosion in the operating room.

The first anesthesia. Doctors would have patients inhale ether to become unconscious.
ether anesthesia

Since its inception, anesthesia has come a long way. Today, doctors called anesthesiologists become specially trained in administering and monitoring anesthesia in patients. If you ever have a surgical procedure where they put you under, you will likely meet your anesthesiologist beforehand so they can make sure you are safe, comfortable, and have had all of your questions answered about the medicine you're going to receive.

Types of Anesthesia

Because anesthesia is used for so many different things, it makes sense that there should be different types. Something as minor as stitches shouldn't require that you go to sleep, but something like knee replacement surgery requires that you sleep for several hours. Therefore, the type and amount of anesthesia used will depend on what you are having done.

If you are only getting some stitches you will likely receive local anesthesia. This is just what it sounds like - anesthesia in one specific place. Why use a local anesthetic? Well, you don't need your entire arm to be numb to get stitches in your hand, just the place where you're getting the stitches. You will also receive local anesthesia for minor procedures at the dentist, like getting a cavity filled because you don't need your entire mouth to be numb, just where the dentist is working.

Regional anesthesia is a bit different. Here, a larger area of your body will be numbed from pain (like maybe your entire lower body) but like with local anesthesia you are still conscious during the procedure. You might receive regional anesthesia if you are having surgery on a specific body part like your hand, if you are receiving a nerve block to temporarily block pain to a specific nerve group, or if you are receiving a spinal epidural.

If neither local nor regional anesthesia is appropriate for your procedure, you will then receive general anesthesia, which knocks you out completely. If the procedure is going to be long, painful, and require that you do not move at all, general anesthesia will make sure that you are asleep the entire time. It is common for patients to receive this type of medication intravenously through a vein, which will quickly put you to sleep.

General anesthesia is used for major operations so that you can sleep through the entire procedure.
general anesthesia

Risks & Side Effects of Anesthesia

Because each type of anesthesia is a medicine, there are of course both risks and side effects. For local and regional anesthesia the most important thing is to make sure the medicine is administered to the correct location (you'll quickly find out if it's not!). Some people have allergies or bad reactions to the medications, and I can tell you from experience that the medication itself doesn't feel very good when they're giving it to you!

But in general, local and regional anesthesia tend to have fewer side effects and risks because they don't interact with the brain the way general anesthesia does. You're also only blocking pain in a small portion of the body, so there is less stress from the anesthesia itself. You may be able to go about your daily life within a few hours of the procedure instead of having to spend an entire day recovering from general anesthesia. Being conscious during the procedure means the doctors can see how you are responding and feeling, too.

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