A general anaesthetic uses medicines to make you unconscious so you will not feel pain, move or be aware during surgery.
During a general anaesthetic, medicines are used to send you to sleep, so you're unaware of surgery and do not move or feel pain while it's carried out. General anaesthesia is used for surgical procedures where it's safer or more comfortable for you to be unconscious.
General anesthesia is an anesthetic used to induce unconsciousness during surgery. The medicine is either inhaled through a breathing mask or tube, or given through an intravenous (IV) line. A breathing tube may be inserted into the windpipe to maintain proper breathing during surgery.
Most people are awake during operations with local or regional anesthesia. But general anesthesia is used for major surgery and when it's important that you be unconscious during a procedure. General anesthesia has 3 main stages: going under (induction), staying under (maintenance) and recovery (emergence).
While there are many types and levels of anesthesia — medication to keep you from feeling pain during surgery — general anesthesia is most commonly used for major operations, such as knee and hip replacements, heart surgeries, and many types of surgical procedures to treat cancer.
The process of waking up from anesthesia is known as emergence. During emergence, the anesthesiologist will slowly reduce the amount of anesthetic drugs in the body. This helps to reduce the intensity of the effects of anesthesia and allows the patient to regain consciousness.
Delayed emergence from general anesthesia (GA) is a relatively common occurrence in the operating room. It is often caused by the effect of drugs administered during the surgery. It can also be caused by other etiologies such as metabolic and electrolyte disturbances.
The condition, called anesthesia awareness (waking up) during surgery, means the patient can recall their surroundings, or an event related to the surgery, while under general anesthesia. Although it can be upsetting, patients usually do not feel pain when experiencing anesthesia awareness.
Patients that are under general anesthesia feel nothing, and are unaware that any time has passed during the procedure. For the patient under general anesthesia, it seems as though they blink and the procedure is over.
Waking up from anesthesia can take anywhere from a few minutes to several hours, depending on the type of anesthesia used and the individual's response to it. Generally, most people wake up within 30 minutes of the anesthesia being administered.
After the procedure
You'll slowly wake either in the operating room or the recovery room. You'll probably feel groggy and a little confused when you first awaken. You may experience side effects such as: Sleepiness.
Most general anesthetics will last between 1-2 hours. However, some procedures may require longer periods of anesthesia. For instance, complex surgeries such as spinal surgeries may require 3-4 hours of anesthesia. The length of time a person is under anesthesia also depends on the type of anesthesia used.
Anesthesia won't make you confess your deepest secrets
It's normal to feel relaxed while receiving anesthesia, but most people don't say anything unusual. Rest assured, even if you do say something you wouldn't normally say while you are under sedation, Dr. Meisinger says, “it's always kept within the operating room.
He says for children, crying after anesthesia is very common – it happens in about 30 to 40 percent of the cases. For adults, the numbers are much lower – he estimates them to be around three percent – but crying is not even something that gets written down in the patient notes.
Coming out of general anesthesia is not the same sensation as waking up from a good night's sleep. But sometimes, after sedation, people wake up with a good feeling and interpret it as being well-rested. That's because sedative drugs can induce the release of dopamine, which gives you a sense of feeling good.
Some people feel sleepy but otherwise fine as the anesthesia wears off; others have side effects such as nausea or chills, and sometimes vomiting. Your throat may be sore from a tube that helped you breathe during surgery.
When the sedative does not work or wears off, the patient may have normal sensation and be wide awake, but the medications given to paralyze the body during surgery prevent them from alerting anyone to their problem.
You will be taken into an area where you will be asked to remove all of your clothing and jewelry and you will be given a hospital gown. This is sometimes called the Pre-Operative Holding Area. The staff will help secure your belongings, or have you give them to your family for safekeeping.
Some patients may be more resistant to the effects of anesthetics than others; factors such as younger age, obesity, tobacco smoking, or long-term use of certain drugs (alcohol, opiates, or amphetamines) may increase the anesthetic dose needed to produce unconsciousness.
In most cases, a delayed awakening from anesthesia can be attributed to the residual action of one or more anesthetic agents and adjuvants used in the peri-operative period. The list of potentially implicated drugs includes benzodiazepines (BDZs), propofol, opioids, NMBAs, and adjuvants.
Failure to arouse and delayed awakening are the most common early neurologic problems following general anesthesia. True prolonged postoperative coma is relatively uncommon, with estimates ranging from 0.005 to 0.08 percent following general surgery, but with higher rates reported after cardiac surgery.
Stages of Anesthesia
Eyelash reflex disappear but other reflexes remain intact and coughing, vomiting and struggling may occur; respiration can be irregular with breath-holding.
3: A measurement of three fingers between the upper and lower teeth of the open mouth of a patient indicates the ease of access to the airway through the oral opening. A typical patient can open their mouth sufficiently to permit placement of three of their fingers between the incisors.
Anesthetic drugs cause brain circuits to change their oscillation patterns in particular ways, thereby preventing neurons in different brain regions from communicating with each other. The result is a loss of consciousness—an unnatural state that he compares to a “reversible coma”—that differs from sleep.