Anesthesia

Approved by the Cancer.Net Editorial Board, 09/2017

Listen to the Cancer.Net Podcast: Anesthesia - What to Expect, adapted from this content

Anesthesia is medicine that blocks the awareness of pain. It is used during certain medical procedures. The type depends on the procedure and your overall health.

Types of anesthesia

There are 4 main types of anesthesia:

Local anesthesia. Local anesthesia is an injection that numbs the procedure site. It is typically used for small procedures. These include a breast biopsy and a mole removal. The numbing lasts for a short time, potentially several hours. You might remain awake and alert. Or your doctor may use sedation to make you relaxed and sleepy (see “Sedation” below).

Regional anesthesia. Regional anesthesia blocks pain in 1 part of the body. Sometimes the injection provides pain relief during and after surgery. This makes recovery easier.

Two common types of regional anesthesia:

  • Peripheral nerve block anesthesia prevents sensation in the limbs. For example, the arms, hands, legs, or feet.

  • Epidural and spinal anesthesia prevents midsection and lower-body pain. Areas include the abdomen, pelvis, rectum, or lower limbs. 

Sedation. Sedation uses medicine to make you relaxed and sleepy. You may receive these medicines by mouth in a liquid or pill form. Or the medicines may be given into a vein. This is called intravenous (IV) medication. Sedation may be used with a local or regional anesthesia to reduce pain. 

There are different levels of sedation based on how aware and awake you are: 

  • Minimal sedation makes you relaxed and reduces anxiety. You remain awake, and you can speak during the procedure. Typically, this type is used for uncomfortable tests or procedures such as a colonoscopy.  

  • Moderate sedation is also called conscious sedation. It reduces pain and lowers your awareness. Some people under conscious sedation can still speak and respond. Others fall into a light sleep. It is often used for minor surgeries. You may not remember the procedure afterwards. 

  • Deep sedation makes you unaware of the procedure. Usually, people under deep sedation cannot speak or answer questions. They can respond to pain, but pain medicines reduce discomfort. You may also receive drugs that affect your memory. This means you will not remember the procedure afterward. Under deep sedation, you may receive assistance breathing. 

General anesthesia. General anesthesia uses a combination of drugs. This makes you unconscious during a major procedure, like surgery. Being unconscious is different from sleeping. You cannot wake up until the anesthesia wears off or until you receive medication to help you wake up.

Who gives anesthesia?

The anesthesia care team typically includes the following professionals: 

  • An anesthesiologist. This doctor specializes in giving anesthesia and related care. He or she will lead your anesthesia care team.

  • Certified registered nurse anesthetists, also called CRNAs. These registered nurses are trained in anesthesia.

  • Anesthesia assistants, also called AAs. These health care professionals have undergone graduate-level training. They specialize in anesthesia care and advanced patient monitoring techniques. 

Getting ready for anesthesia

Evaluations. Before receiving general anesthesia, you may meet with the anesthesiologist. And you will receive a questionnaire. The discussion may include the following topics:

  • Your health history

  • Prescription and over-the-counter medicines, vitamins, and herbal supplements you take

  • Allergies, including foods, medicines, and substances such as latex

  • Previous experiences with anesthesia

  • Drug, alcohol, and tobacco use

It is important to answer these questions accurately and honestly.

You may also need blood tests or other examinations beforehand. The information helps identify the safest type of anesthesia for you.

Restrictions. You will learn about food, drink, and medicine restrictions. Typically, you should fast for about 6 hours before the procedure. You should not eat or drink anything other than clear liquids. And you may need to temporarily stop taking current medications. Some medications could interfere with the anesthesia or the procedure. However, do not stop taking medication without first asking your doctor.

What happens during general anesthesia?

You will receive general anesthesia in 1 of these ways:

  • Through an IV line inserted in a vein in your arm

  • Through a face mask that helps you inhale the medicine

  • Through a combination of both

Most likely, you will become unconscious in less than 1 minute.

Beforehand, your care team will attach monitoring devices to your body. These devices track your vital signs. Vital signs include temperature, blood pressure, and heart rate.

During the procedure, team members will monitor the devices. They will ensure that vital signs stay at appropriate levels. They will also monitor your level of consciousness.

The anesthesiologist may choose to give additional medicine for these reasons:

  • To increase the strength of the anesthesia

  • To provide additional pain relief

  • To further relax the muscles to help the surgeon complete the procedure

  • To reduce the risk of side effects after the procedure

After the procedure ends, the anesthesiologist will gradually stop the anesthesia. And you may receive other medications to help you wake up.

Specially trained nurses will monitor you as you regain consciousness. This typically takes place in a recovery room or a post-anesthesia care unit.

Potential side effects of anesthesia

  • Grogginess, sleepiness, or confusion

  • Nausea or vomiting

  • Chills

  • Dry mouth or sore throat. Particularly if a tube went through your mouth and airway. The tube helps you breathe during your procedure.

These side effects are temporary. And the care team will help you manage them.

Rare complications of anesthesia include serious injury and death. These risks are often higher for older adults. Especially patients who have severe heart or lung disease.

Another rare complication is anesthesia awareness. This means a person briefly wakes up during the procedure. It occurs in 1 or 2 out of every 1,000 people.

Risk factors for anesthesia awareness:

  • Undergoing emergency surgery

  • Having a long history of anticonvulsant, opiate, or tranquilizer use

  • Having cardiovascular problems

  • Drinking alcohol daily

For most people, anesthesia causes no harm.

Recovering from anesthesia

Avoid these activities for at least 24 hours after waking up: 

  • Driving a car

  • Operating heavy machinery

  • Making important decisions

Your reaction speed and judgment may be temporarily impaired by the anesthesia.

If your recovery is not going well, contact your doctor immediately. 

Ask your doctor when to restart regular medicines. And ask about temporary restrictions on eating and drinking. Initially, you may have trouble digesting heavy foods. You may start with liquids, followed by light foods.

Examples of light foods: 

  • Broth or soup

  • Yogurt

  • Gelatin

  • Toast, crackers, or plain rice

Questions to ask your health care team

Before receiving anesthesia, you may want to ask these questions:

  • Do I have a choice about the type of anesthesia I receive?

  • What are the risks and complications with each type of anesthesia?

  • How can I prevent or minimize risks and complications?

  • Do I need any tests before undergoing anesthesia?

  • May my family come with me to the operating room?

  • Can I bring any electronic devices and headphones to the operating room?

  • What care will I receive before, during, and after my procedure?

Related Resources

What is Cancer Surgery?

What to Expect When Having Surgery

Side Effects of Surgery

More Information

American Society of Anesthesiologists: Anesthesia 101

MedlinePlus: Anesthesia