Skip to main content

Guide to General Anesthesia: What You Need to Know Before Going Under

  • Author:
  • Updated date:

I am a board-certified anesthesiologist in Lake Tahoe, California. I write from the perspective of both a doctor and a patient.

Your anesthesiologist monitors vital signs and adjusts anesthetic throughout your surgery.

Your anesthesiologist monitors vital signs and adjusts anesthetic throughout your surgery.

General Anesthesia: What You Need to Know

For some procedures and surgeries, you may have a choice regarding the type of anesthesia used. Many times, though, the only good choice will be general anesthesia.

In this article I will give you a broad introduction to terminology, procedure, and what to expect.

What to Expect Before Surgery

After checking in with a nurse and having an IV placed, you will meet your anesthesiologist to discuss your anesthetic. Midazolam or other sedatives are often given prior to other medications to "take the edge off." You may get this type of drug before you even leave the pre-op room. These drugs kick in within a minute and make you forget anything that happens for a period of time afterward, although the effect varies from person to person. For this reason, you may have no recollection (or only vague memories) of entering the operating room.

After you go to the operating room, you will be given oxygen to breathe and will have monitors such as a blood pressure cuff, an oxygen monitor, and EKG stickers placed.

Agents for Induction

Most commonly, your general anesthetic is induced with medicines injected into your IV. Anesthesia providers use a combination of medications that function as sedatives, pain relievers, and hypnotics for the induction (getting you to sleep) phase of general anesthesia. You may or may not remember this if you were given a sedative in the pre-op phase.

After You Are "Sleeping"

Once you are unconscious, your anesthesiologist will make sure you are getting enough oxygen and anesthesia. To do this, he or she may need to use a breathing device to help keep your airway open. There are various ways to do this, including using just an oxygen mask, an LMA (a soft rubber mask that sits inside of your mouth, just over the opening to your windpipe), or a breathing tube that slides into the windpipe between the vocal cords. The decision regarding the type of airway device is based on many factors, including any medical problems that you have and the type of surgery planned.

(Note: Although we use the word "sleeping," anesthesia is not like sleep in that you cannot be awakened until the drugs are removed from or metabolized by your body. Recent studies reiterate that it is better thought of as a controlled, reversible, coma-like state.)

Oxygen levels are monitored and maintained the whole time you are "asleep."

Oxygen levels are monitored and maintained the whole time you are "asleep."

Maintenance of General Anesthesia

"Maintenance" refers to the process of keeping you "asleep"/"under" for the entire surgery. Usually a combination of gas, IV hypnotics, and strong pain medication are used for this important stage.

During this phase, your anesthesiologist stays with you, carefully monitoring your vital signs and keeping you safe. Your anesthesia is adjusted throughout the operation based on what is going on in the surgery. For example, it will be "lighter" during the time that the nurse is washing the surgical area with sterilizing soap—you need less then because this is not painful or disruptive for your body. Too much anesthesia when it is not needed causes the heart rate and blood pressure to drop. When the surgeons are ready to begin, your anesthesiologist will make adjustments to make sure you have enough.