General Anaesthesia

1 What is a General Anaesthesia?

When you are under anaesthesia, you are completely unconscious and unable to feel man durin surgery or other medical procedures.

General anaesthesia commonly uses a mixture of intravenous drugs and inhaled gasses (anaesthetics). General anaesthisia is is more than just being asleep, in this condition, the anaesthesized brain does not respond to pain signals or reflexes.

An anaesthesiologist is a specially trained doctor who specializes in anaesthesia. While you are unconcious, the anaesthesiologist monitors your body's vitals and manages your breathing.

In most hospitals, an anaesthesiologist and a certified registered nurse anaesthetist (CRNA) work together during your procedure.

2 Reasons for Procedure

Here are the most common reasons to receive general anaesthesia.

Your anaesthesiologist or nurse anaesthetist together with your doctor will recommend the very best anaesthesia option for you.

This is based on the kind of operation you are having, your overall health and finally, your individual preferences.

Procedures that require general anaesthesia include:

  • Procedures that require a lot of time to complete,
  • procedures that result in significant blood loss,
  • procedures that expose you to cold temperatures
  • procedures that affect your breathing (particularly chest and abdominal surgery).

Other forms of anaesthesia, like light sedation mixed with local anaesthesia (for a small area) or regional anaesthesia (for a larger part of your body), may not be appropriate for more involved procedures.

3 Potential Risks

Overall, general anaesthesia is safe, most people, even those with serious health conditions, are capable of undergoing general anaesthesia itself without any potential risks.

In general, the risks are more related to the kind of procedure you are undergoing and your general physical health rather than to the kind of anaesthesia.

Older adults, or individuals with significant medical problems, specifically, those undergoing very serious procedures, may be at a risk of  postoperative confusion, pneumonia or even stroke and heart attack.

Specific conditions that can increase your risk of complication during surgery include:

  • smoking
  • obesity
  • high blood pressure
  • seizures
  • obstructive sleep apnea
  • drug allergies
  • history of heavy use of alcohol
  • medications such as aspirin, that can increase bleeding
  • a history of adverse reaction to anaesthesia
  • other medical conditions involving your heart, lungs and kidneys

Anaesthesia awareness

Although estimates vary, about 1 to 2 individuals out of 10,000 may be partially awake during general anaesthesia and experience what is known as unintended intraoperative awareness. It is even rarer to experience pain, but this can also occur.

People are unable to move or speak to let the doctors know they are awake or feeling pain because of the muscle relaxants administered to them prior to the procedure. For some patients, this may result in long-term psychological problems, similar to post-traumatic stress disorder.

This phenomenon is so rare that it makes it difficult to make clear connections.

Some factors that may be involved include:

  • emergency surgery
  • depression
  • cesarian delivery
  • use of certain medications
  • heart or lung problems
  • daily use of alcohol
  • lower anaesthesia doses than necessary during the procedure
  • errors by the anaesthesiologist, such as not monitoring the patient or not measuring the amount of anaesthesia in the patient's system during the procedure

4 Preparing for your Procedure

In preparing for your general anaesthesia, you must follow your doctor’s orders. 

In general, anaesthesia relaxes the muscles in your digestive tract and airways that keep food and acid from passing from your stomach to your lungs.

Always follow your doctor's instructions about avoiding any food and drink before surgery. Fasting is recommended to start about six hours before the surgery. You  may be able to drink clear fluids until a few hours before.

Your doctor will also encourage you to keep on taking some of your regular medication with a small sip of water during your fasting period. It is important to discuss your medication with your doctor.

Some medications should also be avoided, these include aspirin and other over-the-counter blood thinners.

Some vitamins and herbal medicines such as:

  • ginseng
  • garlic
  • Ginko Biloba
  • St John's wort
  • kava and others may cause problems during surgery.

If you are diabetic, talk to your doctor about any changes  to your medications during the fasting period. You will not usually take oral diabetes medication in the morning of your surgery.

If you have sleep apnea, discuss the condition with your doctor. The anaesthesiologist will carefully monitor your breathing during and after the surgery.

5 What to Expect

Here’s what you can expect before, during, and after your general anaesthesia.

Before your procedure

Prior to undergoing anaesthesia, your anaesthesiologist will talk with you and may ask questions about:

  • your health history
  • your prescription medications
  • over-the-counter medications and herbal supplements
  • allergies
  • your experiences with anaesthesia

This information will assist the anaesthesiologist in choosing the best medication for you.

During the procedure

Your anaesthesiologist usually administers your anaesthesia medications intravenously. In some cases, you can be given a gas that you inhale from a mask. Once you are asleep, the anaesthesiologist may insert the tube in your mouth and down you trachea.

The tube makes sure you receive enough oxygen and protects your lungs fro blood or other fluids such as stomach fluids. Muscle relaxants will be administered before the tube is inserted to relax the muscles in your windpipe.

Your doctor may utilize other options, these may include a laryngeal airway gas mask, to help manage your breathing uring surgery.

Someone from the anaesthesia care team monitors you continuously while you are asleep. He or she will make adjustments to your:

  • breathing
  • temperature
  • fluids and blood presure as required

Blood transfusions may be necessary especially during complex surgeries. The anaesthesia care team monitors your condition and delivers the blood transfusion when needed. Blood transfusion may involve risks. This risks are more likely in individuals who are older, have low red blood cell volume or are undergoing complex heart surgery.

After the procedure

When the surgery has been completeed, anaesthesia medication is stopped being administered and you slowly wake either in the operating room or recovery room. You will possibly feel groggy and a little confused when you first wake.

The following side effects may be experienced:

Other side effects can inlude pain.

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