How Does Anesthesia Work?

While you probably have a vague understanding of anesthesia, you likely have some questions. What is it, exactly? And how does anesthesia work? Take a look at this overview to find out.

WHAT IS ANESTHESIA?

In the simplest sense, anesthesia is a medication that helps alleviate pain or discomfort during a procedure. There are numerous types and delivery methods. Additionally, different drugs can be used in combinations as appropriate for the patient and the procedure.

• Analgesia—Pain reduction or elimination
• Amnesia—which is temporary and may include unconsciousness
• Muscle relaxation

While you already know that anesthesia is used during major surgeries, that’s not the only use. It’s also administered for noninvasive procedures that may otherwise be uncomfortable. Dr. Ma says anesthesia may be used when obtaining magnetic resonance imaging (MRI) from a child or a patient who’s claustrophobic, for example.

“Having a near motionless patient is critical for obtaining optimal MRI images.”

“Having a near motionless patient is critical for obtaining optimal MRI images,” she explains. “An anesthetized patient would be essentially motionless.”

WHAT ARE THE DIFFERENT TYPES OF ANESTHESIA?

While there are numerous medications anesthesiologists use in different combinations, Dr. Ma highlights four main types. Each of these categories is used for different types of care. This is by no means an exhaustive explanation, but it should give you an idea of what you can expect should you or a loved one need a procedure.

1. General anesthesia is used to render a patient unconscious and is administered for invasive operations like a laparoscopic hernia repair. Dr. Ma further adds that the anesthesiologist controls the patient’s breathing.

2. Sedation anesthesia is used for minimally invasive procedures like colonoscopies. “This includes light-to-moderate IV sedation with the patient breathing independently,” Dr. Ma explains.

3. Local anesthesia involves injection into a surgical site, but the patient remains awake. It’s often used to numb the area before a patient gets stitches.

4. Regional anesthesia numbs a large area of the body while the patient remains awake. Perhaps the most widely recognized use is an epidural to make childbirth more comfortable for women.

HOW DOES ANESTHESIA WORK?

Based on the information above, it’s clear there aren’t one specific way anesthesia works. And researchers are really just starting to gain a sense of how different medications used to numb or induce unconsciousness work. They think the drugs target different proteins in the membranes around nerve cells.

Propofol is one of the most common medications used for general anesthesia. A 2018 study focused specifically on propofol to dig into what mechanisms are at play. The research found this type of anesthesia restricts the movement of a type of protein in a way that inhibits communication between neurons. But the study’s authors also note there’s still a lot yet to learn.

And remember, different drugs achieve different results. The question of how anesthesia works is further complicated by the fact that different types often need to be used in combination with each other. A single medication may not be sufficient for a given procedure.

“A drug such as propofol can induce unconsciousness, but has no analgesic effects.”