This leaflet is provided by the Royal College of Anaesthetists, the professional body responsible for the speciality throughout the UK, ensuring the quality of patient care through the maintenance of standards in anaesthesia, critical care and pain medicine.
This leaflet provides information about the risk of dying or getting significant brain damage during an anaesthetic.
It can be difficult to separate the risks of surgery and the risks of the anaesthetic when considering what happens during an operation. This leaflet therefore includes some information about surgical risks too. However, your surgeon will be able to tell you more about the specific risks of your operation.
Why do deaths occur during general anaesthesia?
Most of the deaths that occur around the time of surgery are not directly caused by the anaesthetic.There are four main reasons.
- There may be things about your health or the type of operation you are having that increase the risk of dying during a general anaesthetic. For example, death is more likely if:
- You are older.
- You need major surgery on your heart or lungs, your brain, your major blood vessels, or your bowels.
- You need emergency surgery, including surgery for major trauma.
- You are very unwell before your operation.
The surgeon may find that the surgery is very difficult to achieve without damage or he/she may make an error during the operation. Specific risks of your operation should be explained to you before you sign your consent form. After the risks have been explained to you, you can decide whether you want to go ahead with the operation.
What is the risk of dying during a general anaesthetic?
Exact figures are not available. Some facts and figures are given below.
- If you are a healthy patient, who is having non-emergency surgery, the short answer is that death is very rare. An exact figure is not known, but it is around 1 death per 100,000 general anaesthetics.
- If you are having surgery and it is planned that you go home the same day, (day case surgery), the risk of death from general anaesthesia is even lower. This is because if you have been accepted for day-case surgery you will be reasonably healthy and you will not be having major surgery.
- As already stated, the risk increases:
- If you are older.
- If you are having major or emergency surgery.
- If you have previous problems with your health, especially severe liver disease, heart disease, lung disease, diabetes requiring insulin, or cancer which has spread beyond the primary tumor.
- If you were ill or injured before the operation.
However, the risk of dying is still usually low. An exact figure is difficult to quote, but your anaesthetist will be able to talk to you about it.
- For every 100,000 caesarean sections, one death happens which is said to be due to the anaesthetic alone. The rate is higher for emergency caesarean section with a general anaesthetic compared to planned caesarean section with a spinal or epidural anaesthetic. The overall death rate from all causes associated with caesarean section in England and Wales is approximately 17 in 100,000 caesarean sections.
- The risk of a child dying from a general anaesthetic is around 1 in 40,000. However if the child is healthy and having non-emergency surgery, the risk is much less, probably less than 1 in 100,000, and the risks may be even lower in children over the age of one year.
What is the risk of getting brain damage due to a general anaesthetic?
Dizziness, drowsiness, headache and confusion are relatively common shortly after general anaesthesia, and in a small number of patients may persist for days, weeks or even months. However, this does not mean that brain damage has occurred.
If you are a healthy patient having non-emergency surgery, severe brain damage is very rare. But on the very rare occasions when it does occur, the brain damage may be permanent and cause inability to think, feel or move normally. Exact figures for this risk do not exist.
Such permanent brain damage may be caused by a stroke that occurs during an anaesthetic. The risk of having a stroke that causes brain damage during general anaesthesia increases:
- For the elderly.
- For anyone who has had a previous stroke.
- For people having surgery to the brain or head and neck, surgery on the carotid artery (a major blood vessel which supplies the brain), or heart surgery.
Strokes occurring around the time of surgery are not often directly related to the general anaesthetic. Most strokes occur between two and ten days after surgery and are due to the combined after-effects of the surgery and the anaesthetic, together with the condition of the patient before the operation.
Very rarely, brain damage can happen because a complication or error has resulted in inadequate oxygen delivery to the brain for some time during the operation.
What precautions are used to prevent death and brain damage from occurring?
Drugs used by anaesthetists have effects on the brain (causing unconsciousness) but also on other body organs. They affect the heart, the blood pressure, breathing and lung function and other organs such as the kidney.
It is usually these other effects that increase the risk of death or brain damage during the anaesthetic.
Anaesthetists are trained to use anaesthetic drugs with care, taking into account all relevant factors. Your anaesthetist will assess your condition before the operation to make sure that the drugs and techniques used are as safe as possible for you. He/she stays beside you throughout the whole anaesthetic and can adjust the anaesthetic and other treatments to keep you safe and healthy.
To help the anaesthetist, a number of monitors are used to measure heart and lung function, and the amount of anaesthetic given. Your physical state is monitored before the anaesthetic starts, during the anaesthetic, and afterwards into the recovery period. The anaesthetist chooses the appropriate doses of drugs according to the information obtained from the monitors and his/her experience and clinical judgement.
There is continuing research aimed at making the drugs and techniques used by anaesthetists ever more safe for patients.
Is there anything I can do to prevent the risk of death or brain damage?
If you require emergency surgery, the short answer is: not much.
However, if you are having non-emergency surgery, then anything that you can do to improve your physical condition will reduce the risks associated with anaesthesia. This includes losing weight (if you are overweight), giving up smoking, eating well to improve your nutritional state, taking regular exercise and getting any long-term medical condition (such as asthma or diabetes) well controlled before the operation. Further information can be found in the leaflet Anaesthesia Explained.
Most of the deaths that occur around the time of surgery are not directly caused by the anaesthetic.
For healthy patients undergoing surgery which is not major and not an emergency, dying or getting brain damage from a general anaesthetic is very rare.
The risk of dying or brain damage from a general anaesthetic increases if you are older, if you are having major or emergency surgery, or if you were ill or injured before the operation, but it usually remains low.
These risks vary greatly depending on your individual circumstances. Your surgeon and anaesthetist will be able to tell you more about your individual risks and then you can decide whether you want to go ahead with the operation.
Content used with permission from the Royal College of Anaesthetists website: Death or Brain Damage (Third Edition, April 2013). Copyright for this leaflet is with the Royal College of Anaesthetists.