What Is Anesthesia?

No doubt about it, getting an operation can be stressful. If you're scheduled for surgery, you may have questions or concerns about anesthesia. The thought of being unconscious or temporarily losing sensation can be downright unnerving.

From a minor procedure with a shot to numb the area to a more serious surgery in which you will be "asleep," knowing the basics about anesthesia may help answer your questions and ease some concerns.

Basically, anesthesia is the use of medicine to prevent the feeling of pain or another sensation during surgery or other procedures that might be painful (such as getting stitches or having a wart removed). Given as an injection or through inhaled gases or vapors, different types of anesthesia affect the nervous system in various ways by blocking nerve impulses and, therefore, pain.

In today's hospitals and surgery centers, highly trained professionals use a wide variety of safe, modern medications and extremely capable monitoring technology. An anesthesiologist is a doctor who specializes in giving and managing anesthetics — the medications that numb an area of the body or help you fall and stay asleep.

In addition to administering anesthesia medications to prepare you for the surgery, the anesthesiologist will:

• monitor your major bodily functions (such as breathing, heart rate and rhythm, body temperature, blood pressure, and blood oxygen levels) during surgery
• address any problems that might arise during surgery
• manage any pain you may have after surgery
• keep you as comfortable as possible before, during, and after surgery

A specially trained certified registered nurse anesthetist (CRNA), resident physician, or student nurse anesthetist, who work with the anesthesiologist and surgeon, may assist in giving you anesthesia. CRNAs may work under the supervision of a anesthesiologist or on their own — it all depends on the state or hospital.

What Are the Types of Anesthesia?

Anesthesia is broken down into three main categories: general, regional, and local, all of which can be administered using various methods and different medications that affect the nervous system in some way. The American Society of Anesthesiologists (ASA) compares the nervous system to an office's telephone system — with the brain as the switchboard, the nerves as the cables, and the body parts feeling pain as the phones.

General anesthesia. The goal is to make and keep the person completely unconscious (or "asleep") during the operation, with no sensations, feeling of pain, awareness, movement, or memory of the surgery. General anesthesia can be given through an IV (which requires a needle stick into a vein, usually in the arm) or by inhaling gases or vapors.

Regional anesthesia. An anesthetic drug is injected near a cluster of nerves, numbing a larger area of the body (such as below the waist). A person who receives regional anesthesia is usually asleep before the procedure is done. However, older children or those who would be at unacceptable risk by being asleep may be awake or sedated during the procedure. For example, if a person is overweight, it may be difficult for the anesthesiologist to feels the bones that help guide correct placement of the needle. This type of anesthesia includes things like epidurals, caudal blocks (which are similar to epidurals, but are placed in the tailbone), and spinal blocks (which further numb the lower body).

Local anesthesia. An anesthetic drug numbs only a small, specific part of the body (for example, a hand or patch of skin). Depending on the size of the area, local anesthesia can be given as a shot, spray, or ointment. With local anesthesia, a person may be awake, sedated, or asleep. Local anesthesia is often used for minor surgeries and outpatient procedures (when patients come in for an operation and can go home that same day). If you are having surgery in a clinic or doctor's office (such as the dentist or dermatologist), this is probably the type of anesthetic that will be used.

The type and amount of anesthesia will be specifically tailored to your needs and will depend on various factors, including your age and weight, the type and area of the surgery, any allergies you may have, and your current medical condition.

What Are the Common Side Effects?

You will most likely feel disoriented, groggy, and a little confused when waking up after surgery. Some other common side effects, which should go away fairly quickly, include:

• nausea or vomiting, which can usually be alleviated with anti-nausea medication
• chills or shakiness
• sore throat (if a tube was used to help with breathing)

What Are the Risks?

Anesthesia today is very safe. In very rare cases, anesthesia can cause complications (such as strange heart rhythms, breathing problems, allergic reactions to medications, and even death). The risks depend on the kind of procedure, the condition of the patient, and the type of anesthesia used. Be sure to talk to your doctor, surgeon, and/or anesthesiologist about any concerns.

Most complications can usually be prevented by simply providing the anesthesiologist with complete information before the surgery about things like:

• your current and past health (including diseases or conditions such as recent or current colds, or other issues such as snoring or depression)
• any medications (prescription and over-the-counter), supplements, or herbal remedies you are taking
• any allergies (especially to foods, medications, or latex) you may have
• whether you smoke, drink alcohol, or take any recreational drugs
• any previous reactions you or any family member has had to anesthesia

To ensure your safety during the surgery or procedure, it's extremely important to answer all of the anesthesiologist's questions as honestly and thoroughly as possible. Things that may seem harmless could affect how you react to the anesthesia.

It's also important that you follow the doctor's recommendations about what not to do before the surgery. You probably won't be able to eat or drink (usually nothing after midnight the day before) and may need to stop taking herbal supplements or other medications for a certain period of time before surgery.

You can rest assured that the safety of anesthetic procedures has improved a lot in the past 25 years, thanks to advances in technology and the extensive training anesthesiologists receive. The more informed, calm, and reassured you are about the surgery and the safety of anesthesia, the easier the experience will probably be.

Reviewed by: Judith A. Jones, MD
Date reviewed: April 2012