Anesthesia controls pain during surgery or other medical procedures. It includes using medicines, and sometimes close monitoring, to keep you comfortable. It can also help control breathing, blood pressure, blood flow, and heart rate and rhythm, when needed.
An anesthesiologist takes charge of your comfort and safety during surgery. This topic focuses on anesthesia care that you get from these specialists.
Anesthesia may be used to:
Other medicines also may be used to relax your muscles during surgery.
The type of anesthesia used depends on several things:
Your doctor may prefer one type of anesthesia over another for your surgery. In some cases, your doctor may let you choose which type to have. Sometimes, such as in an emergency, you do not get to choose.
Major side effects and other problems of anesthesia are not common, especially in people who are in good health overall. But all anesthesia has some risk. Your specific risks depend on the type of anesthesia you get, your health, and how you respond to the medicines used.
Some health problems increase your chances of problems from anesthesia. Your doctor will tell you which of your health problems could affect your care.
Make sure you get a list of instructions to help you prepare for your surgery. Your surgeon will also let you know what will happen when you get to the clinic or hospital, during surgery, and afterward.
Your doctor will tell you when to stop eating and drinking before your surgery. When you stop depends on your health problem and the type of anesthesia that will be used. If you take any medicines regularly, ask your doctor if you should take your medicines on the day before or the day of your surgery.
You have to give your consent to be given anesthesia. Your doctor will discuss the best type of anesthesia for you and review risks, benefits, and other choices.
Many people are nervous before they have anesthesia and surgery. Mental relaxation methods as well as medicines can help you relax.
Right after surgery you will be taken to the recovery room. Nurses will care for you there under the direction of an anesthesiologist. A nurse will check your vital signs and any bandages and ask about how much pain you have. If you are in pain, don't be afraid to say so.
Some effects of anesthesia may last for many hours after surgery. If you had local or regional anesthesia, you may have some numbness or reduced feeling in part of your body. Your muscle control and coordination may also be affected.
Other common side effects of anesthesia are closely watched and managed to reduce your discomfort. These side effects include:
For minor surgeries, you may go home the same day. For more complicated surgeries, you may have to move to a hospital room to continue your recovery. If you stay in the hospital, your doctor will visit you to check on your recovery from anesthesia and answer any questions you have.
Planning for anesthesia:
Risks and possible problems:
Preparing for anesthesia:
What happens during anesthesia:
Recovering from anesthesia:
Being well-prepared for anesthesia may help you remain calm and relaxed. If you take the time to learn about your procedure and the anesthesia, you will be better able to understand the information and instructions you are given. Knowing what to expect can help decrease tension and anxiety.
Usually, your surgeon's office, clinic, or hospital will contact you in advance to give you information about what to do the evening before and the day of the procedure. Your surgeon will also provide information about what will happen when you arrive at the clinic or hospital, during the procedure, and afterward.
As part of getting ready for your procedure, you are not allowed to eat or drink anything for a certain time period before anesthesia. The following times are averages. In some cases, such as in those people with gastroesophageal reflux disease (GERD), the restrictions must be started earlier for safety.
Food and fluids are restricted to reduce the risk of aspiration by reducing the contents of your stomach. Aspiration occurs when an object or liquid is inhaled into the respiratory tract when a person regurgitates contents into the throat. Aspiration during anesthesia is very uncommon, but it can cause severe complications.
If you take any medicines on a regular basis, such as diabetes medicines or heart medicines, ask your surgeon whether you should take your medicines on the day before or the day of your procedure. Some medicines may interact with the anesthetics and other medicines used for anesthesia.
Before any non-emergency surgery or procedure, most surgery centres and hospitals have a surgery consent for you to sign. This is called an informed consent, because your surgeon will explain why your surgery is needed, what it will involve, its risks and expected outcome, and how long it will take you to recover. After discussing this information, you may be asked to sign the informed consent. It needs to be signed before you receive any medicines that could affect your state of mind.
Your anesthesia specialist will discuss the anesthesia care for your surgery so that you will understand what is involved. You can then give your informed consent. You will be able to ask questions and express any concerns.
If the person to have anesthesia is a child or is mentally incompetent to sign a consent form, the consent may be signed by a responsible family member or guardian.
Many people experience anxiety before medical procedures, especially surgery. Mental relaxation techniques can help reduce anxiety. If you will be awake during the procedure, you also can use these techniques to relax while it is being done. They can also be used to help reduce pain and anxiety after your procedure.
Some mental relaxation techniques that may be useful include:
You may be given a medicine before anesthesia. Medicines may be given by mouth or by injection immediately before anesthesia. Or sometimes the doctor will apply medicine to part of your body, such as your nose or mouth.
Medicine is given before anesthesia for many reasons, including:
For many procedures, medicines are given through a vein (intravenously, IV). An IV is usually inserted into a vein in the hand or lower arm. When the IV is in place, medicines or fluids can be given quickly into your bloodstream. Children and some adults may find insertion of the IV painful and stressful. In these cases, the IV may be inserted after they have been sedated or after an inhaled anesthetic has been given through a mask.
Some of the instruments used to watch your breathing, blood pressure, and heart function may be placed on your body while you are being prepared for your surgery.
Children do better when receiving anesthesia if they know what to expect. You can help relieve your child's anxiety or fears by being calm and explaining what will happen at the clinic or hospital. Explain to your child that he or she will be in unfamiliar surroundings but that many doctors and nurses will be there to help.
It is best to be honest and explain that there may be some discomfort or pain after the procedure. But reassure your child that you will be close by. Bringing familiar items such as books or toys may help comfort and distract your child.
Anesthesia involves the use of medicines to block pain sensations (analgesia) during surgery and other medical procedures. Anesthesia also reduces many of your body's normal stress reactions to surgery.
The type of anesthesia used for your surgery depends on:
Based on your medical condition, your anesthesia specialist may prefer one type of anesthesia over another for your surgery. When the risks and benefits of different anesthesia options are equal, your anesthesia specialist may let you choose the type of anesthesia.
There are several ways that anesthesia can be given.
For some minor procedures, a qualified health professional who is not an anesthesia specialist may give some limited types of anesthesia, such as procedural sedation. Procedural sedation combines the use of local anesthesia with small doses of sedative or analgesic agents (painkillers) to relax you.
A wide variety of medicines are used to provide anesthesia. Their effects can be complex. And they can interact with other medicines to cause different effects than when they are used alone. Anyone receiving anesthesia—even procedural sedation—must be monitored continuously to protect and maintain vital body functions. The complex task of managing the delivery of anesthesia medicines as well as monitoring your vital functions is done by anesthesia specialists.
Medicines used for anesthesia help you relax, help relieve pain, induce sleepiness or forgetfulness, or make you unconscious. Anesthesia medicines include:
Other medicines that are often used during anesthesia include:
The three main phases of anesthesia are induction, maintenance, and emergence.
The first phase of anesthesia, when you first begin receiving an anesthetic, is called induction.
For local anesthesia and many types of regional anesthesia, induction occurs when a local anesthetic is injected into the part of your body that needs to be anesthetized. Local and regional anesthesia often are given with other medicines that make you relaxed or sleepy (sedatives) or relieve pain (analgesics). These medicines are often given through a vein (intravenously, IV) before the local anesthetic is given.
Induction of epidural and spinal anesthesia may require the insertion of a needle into the space around the spinal nerves in the lower back. You will receive an injection of local anesthetic to reduce discomfort before the needle is inserted.
The second phase of anesthesia is called maintenance. During maintenance, the anesthesia specialist keeps a balance of medicines while carefully watching your breathing, heart rate, blood pressure, and other vital functions. Anesthesia is adjusted based on your responses during the procedure.
With local anesthesia and regional nerve blocks, maintenance frequently requires additional injections of sedatives to prolong the effects for more lengthy procedures.
For general anesthesia, after you are unconscious, anesthesia may be maintained with an inhalation anesthetic alone, with intravenous anesthetics, or most commonly with a combination of the two. Very often, inhalation anesthetics are given through an endotracheal (ET) tube or a laryngeal mask airway (LMA), which is an airway placed at the back of your throat but not in your windpipe like an ET tube. The airway is inserted after you become unconscious.
It also is common during general anesthesia for you to be given other medicines intravenously to maintain stable vital functions and to help prevent or decrease pain or nausea after the procedure.
The final phase of anesthesia is called emergence. When your procedure is completed, the anesthesia specialist will stop giving the anesthetic. As your body clears the anesthetic medicines from your system, the effects begin to wear off, and your body functions begin to return. How quickly you emerge from anesthesia depends on the anesthetics and other medicines used and on your response to the medicines.
With local and regional anesthesia, emergence occurs as the effect of the injected anesthetic wears off and sensation returns. How long it takes for sensation to return depends on the type of anesthetic used, how much you were given, and the area of your body that was affected. Local anesthesia and some regional nerve blocks may wear off within 1 to 2 hours. Emergence from epidural or spinal blocks may take longer.
Emergence from general anesthesia begins when the intravenous or inhalation anesthetic is stopped. It may take a short time before your body clears the anesthetic from your system. You will be closely watched during emergence to make sure that you are breathing well on your own; your heartbeat, blood pressure, and other vital functions stay at normal levels; and your muscle control has returned. If an endotracheal tube or laryngeal mask airway was used, it will be removed as soon as you are breathing on your own.
In some cases, to help speed emergence, reversal agents are used to counteract, or reverse, the effects of certain anesthetics. These agents may help reduce the time it takes for you to recover from anesthesia.
Emergence does not mean you will have completely recovered from all the effects of anesthesia. Some effects may persist for many hours after anesthesia has ended. For example, you may have some numbness or reduced sensation in the part of your body that was anesthetized until the anesthetic wears off completely. Even if you feel alert and normal, your judgment and reflexes may still be affected for some time after your procedure, especially if you continue to take medicines, such as those to control pain or nausea. If you have numbness or reduced sensation longer than expected, contact your anesthesia specialist or doctor.
Although all types of anesthesia involve some risk, major side effects and complications from anesthesia are uncommon. Your specific risks depend on your health, the type of anesthesia used, and your response to anesthesia.
Your age may be a risk factor. In general, the risks associated with anesthesia and surgery increase in older people.
Certain medical conditions, such as heart, circulation, or nervous system problems, increase your risk of complications from anesthesia.
If you smoke, drink alcohol, or use illegal drugs, you may be more likely to have problems from anesthesia. It's important that you are honest when you talk with your surgeon and anesthesia specialist.
When used properly, local anesthetics are safe and have few major side effects. But in high doses, local anesthetics can have toxic effects caused by being absorbed through the bloodstream into the rest of the body (systemic toxicity). This may significantly affect your breathing, heartbeat, blood pressure, and other body functions. Because of these potential toxic effects, equipment for emergency care must be immediately available when local anesthetics are used.
For regional anesthesia, an anesthetic is injected close to a nerve, a bundle of nerves, or the spinal cord. In rare cases, nerve damage can cause persistent numbness, weakness, or pain.
Regional anesthesia (regional nerve blocks, epidural and spinal anesthesia) also carries the risk of systemic toxicity if the anesthetic is absorbed through the bloodstream into the body. Other complications include heart or lung problems, and infection, swelling, or bruising (hematoma) at the injection site.
Spinal anesthesia medicine is injected into the fluid that surrounds the spinal cord (cerebrospinal fluid). The most common complication of spinal anesthesia is a headache caused by leaking of this fluid. It is more common in younger people. A spinal headache may be treated quickly with a blood patch to prevent further complications. A blood patch involves injecting a small amount of the person's own blood into the area where the leak is most likely occurring to seal the hole and to increase pressure in the spinal canal and relieve the pull on the membranes surrounding the canal.
Serious side effects of general anesthesia are uncommon in people who are otherwise healthy. But because general anesthesia affects the whole body, it is more likely to cause side effects than local or regional anesthesia. Fortunately, most side effects of general anesthesia are minor and can be easily managed.
General anesthesia suppresses the normal throat reflexes that prevent aspiration, such as swallowing, coughing, or gagging. Aspiration occurs when an object or liquid is inhaled into the respiratory tract (the windpipe or the lungs). To help prevent aspiration, an endotracheal (ET) tube may be inserted during general anesthesia. When an ET tube is in place, the lungs are protected so stomach contents cannot enter the lungs. Aspiration during anesthesia and surgery is very uncommon. To reduce this risk, people are usually instructed not to eat or drink anything for a certain number of hours before anesthesia so that the stomach is empty. Anesthesia specialists use many safety measures to minimize the risk of aspiration.
Insertion or removal of airways may cause respiratory problems such as coughing; gagging; or muscle spasms in the voice box, or larynx (laryngospasm), or in the bronchial tubes in the lungs (bronchospasm). Insertion of airways also may cause an increase in blood pressure (hypertension) and heart rate (tachycardia). Other complications may include damage to teeth and lips, swelling in the larynx, sore throat, and hoarseness caused by injury or irritation of the larynx.
Other serious risks of general anesthesia include changes in blood pressure or heart rate or rhythm, heart attack, or stroke. Death or serious illness or injury due solely to anesthesia is rare and is usually also related to complications from the surgery. Death occurs in about 1 out of 200,000 healthy people who get anesthesia.1
Some people who are going to have general anesthesia express concern that they will not be completely unconscious but will "wake up" and have some awareness during the surgical procedure. But awareness during general anesthesia is very rare. Anesthesia specialists devote careful attention and use many methods to prevent this.
Some anesthetic medicines may cause allergic or other abnormal reactions in some people, but these are rare. If you suspect you may have such a problem, you should tell both your surgeon and anesthesia specialist well before your surgery. Testing will then be arranged as needed.
A rare, potentially fatal condition called malignant hyperthermia (MH) may be triggered by some anesthetics. The anesthetics most commonly associated with malignant hyperthermia include the potent inhalation anesthetics and the muscle relaxant succinylcholine. For more information, see the listing for the Malignant Hyperthermia Association of the United States (MHAUS) in the Other Places to Get Help section of this topic.
Recovery from anesthesia occurs as the effects of the anesthetic medicines wear off and your body functions begin to return. Immediately after surgery, you will be taken to a post-anesthesia care unit (PACU), often called the recovery room. There, nurses will care for and observe you. A nurse will check your vital signs and bandages and ask about your pain level.
How quickly you recover from anesthesia depends on the type of anesthesia you received, your response to the anesthesia, and whether you received other medicines that may prolong your recovery. As you begin to awaken from general anesthesia, you may experience some confusion, disorientation, or difficulty thinking clearly. This is normal. It may take some time before the effects of the anesthesia are completely gone.
Your age and general health also may affect how quickly you recover. Younger people usually recover more quickly from the effects of anesthesia than older people. People with certain medical conditions may have difficulty clearing anesthetics from the body, which can delay recovery.
Some of the effects of anesthesia may persist for many hours after the procedure. For example, you may have some numbness or reduced sensation in the part of your body that was anesthetized until the anesthetic wears off completely. Your muscle control and coordination may also be affected for many hours following your procedure. Other effects may include:
When your normal body functions have returned, you either will be transferred to another location in the hospital to complete your recovery or allowed to go home.
In many cases minor surgical procedures are done on an outpatient basis. This means you will go home the same day. Before you are discharged from an outpatient clinic, you should be alert and able to understand and remember instructions. You will also want to make sure you have regained muscle control and coordination enough to walk safely, take fluids without vomiting, and take oral pain medicines safely. Depending on your medical history, your surgeon may also want you to be able to urinate before you are discharged.
When you are discharged, make sure you have:
If you are not ready to go home, you will be transferred to another area in the hospital to complete your recovery. The length of your stay will depend on your response to your surgery.
|American Society of Anesthesiologists Patient Page|
This Web site, sponsored by the American Society of Anesthesiologists, has information to help adults and children before and after anesthesia. This Web site has videos, articles, patient stories, and more.
|American Society of Anesthesiologists (ASA)|
|520 N. Northwest Highway|
|Park Ridge, IL 60068-2573|
The American Society of Anesthesiologists (ASA) is an educational, research, and scientific association of physicians organized to raise and maintain the standards of the medical practice of anesthesiology and to improve patient care. The ASA Web site offers educational materials for the general public.
|Canadian Anesthesiologists' Society (CAS)|
|1 Eglinton Avenue East|
|Toronto, ON M4P 3A1|
The Canadian Anesthesiologists' Society (CAS) is an organization for medical professionals. The CAS website also provides basic information about anesthesia for the general public.
|KidsHealth for Parents, Children, and Teens|
|4600 Touchton Road East, Building 200|
|Jacksonville, FL 32246|
This Web site is sponsored by Nemours Foundation. It has a wide range of information about children's health, from allergies and diseases to normal growth and development (birth to adolescence). This Web site offers separate areas for kids, teens, and parents, each providing age-appropriate information that the child or parent can understand. You can sign up to get weekly e-mails about your area of interest.
|Malignant Hyperthermia Association of the United States (MHAUS)|
|11 East State Street|
|P.O. Box 1069|
|Sherburne, NY 13460|
MHAUS is a nonprofit group that strives to reduce illness and death from malignant hyperthermia, a rare, life-threatening genetic disorder that can be triggered by anesthesia. Its Web site has information about symptoms, testing, and more.
- Wiener-Kronish JP (2008). Overview of anesthesia. In L Goldman, D Ausiello, eds., Cecil Medicine, 23rd ed., pp. 2904–2907. Philadelphia: Saunders Elsevier.
Other Works Consulted
- American Society of Anesthesiologists (2006). Guidelines for patient care in anesthesiology. Available online: http://www.asahq.org/publicationsAndServices/standards/13.pdf.
- Brown DL (2010). Spinal, epidural, and caudal anesthesia. In RD Miller et al., eds., Miller's Anesthesia, 7th ed., pp. 1611–1638. Philadelphia: Churchill Livingstone.
- Dalens BJ (2010). Regional anesthesia in children. In RD Miller et al., eds., Miller's Anesthesia, 7th ed., pp. 2519–2700. Philadelphia: Churchill Livingstone.
- Hilton L, et al. (2009). Anesthesia, local. In B Narins, ed., Gale Encyclopedia of Surgery and Medical Tests: A Guide for Patients and Caregivers, 2nd ed., vol. 1, pp. 68–72. Farmington Hills, MI: Gale.
- Miller RD (2006). Anesthesia. In GM Doherty, LW Way, eds., Current Surgical Diagnosis and Treatment, 12th ed., pp. 170–181. New York: McGraw-Hill.
- White PF, Eng MR (2010). Ambulatory (outpatient) anesthesia. In RD Miller et al., eds., Miller's Anesthesia, 7th ed., pp. 2419–2459. Philadelphia: Churchill Livingstone.
- Yip P, et al. (2009). Non-pharmacological interventions for assisting the induction of anaesthesia in children. Cochrane Database of Systematic Reviews (3).
|Primary Medical Reviewer||Anne C. Poinier, MD - Internal Medicine|
|Specialist Medical Reviewer||John M. Freedman, MD, MD - Anesthesiology|
|Specialist Medical Reviewer||C. Dale Mercer, MD, FRCSC, FACS - General Surgery|
|Last Revised||April 14, 2010|
Last Revised: April 14, 2012
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