General anesthesia is a combination of medicines that you inhale or receive through a needle in a vein to cause you to become unconscious. It affects your whole body. Under anesthesia, you should be completely unaware and not feel pain during the surgery or procedure. General anesthesia also causes forgetfulness (amnesia) and relaxation of the muscles throughout your body.
General anesthesia suppresses many of your body's normal automatic functions, such as those that control breathing, heartbeat, circulation of the blood (such as blood pressure), movements of the digestive system, and throat reflexes such as swallowing, coughing, or gagging that prevent foreign material from being inhaled into your lungs (aspiration).
Because these functions are suppressed, an anesthesia specialist must carefully keep a balance of medicines while watching your heart, breathing, blood pressure, and other vital functions. An endotracheal (ET) tube or a laryngeal mask airway device is usually used to give you an inhaled anesthetic and oxygen and to control and assist your breathing.
General anesthesia is commonly begun (induced) with intravenous (IV) anesthetics. But inhaled anesthetics also may be used. After you are unconscious, anesthesia may be maintained with an inhaled anesthetic alone, with a combination of intravenous anesthetics, or a combination of inhaled and intravenous anesthetics.
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.
Risks and complications from general anesthesia
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.
People are instructed not to eat or drink anything for up to 8 hours before anesthesia so that the stomach is empty. The amount of time depends on the procedure. This will help to prevent food from being inhaled (aspirated) into the lungs. The breathing tube inserted during general anesthesia can also prevent stomach contents from entering the lungs.