Side effects and risks of a general anaesthetic

It is very common to have some side effects after an anaesthetic. Feeling hungry or thirsty, having a headache or nausea (feeling sick, sometimes with vomiting), and a sore throat are the most common. These are generally mild and can usually be treated effectively. Minor grazes to the lips are also common.

Other side effects include tiredness, dizziness, and confusion on waking. These generally just need time to wear off.

Younger children particularly can be very upset or even angry immediately after an anaesthetic. When this happens, it can last up to about an hour but will usually settle by itself.

It is very common to be nervous or worried about having an anaesthetic. Explanation and reassurance can help with this.

Some patients’ behaviour may change for a period after coming to hospital for a procedure – they may have separation anxiety and become anxious or distressed when away from a parent or carer, temper tantrums, changes in eating and sleep patterns, this could include bed wetting or nightmares. These will generally settle in a few weeks, although it can take longer.

Children and young people who have multiple procedures and experience significant anxiety are more likely to experience changes in emotions and behaviour for longer.

Find out more information about emotional and behavioural changes after surgery.

People often worry about the risk of awareness or being awake during anaesthesia. This can happen but it is uncommon. When it does happen, it is usually an awareness of sounds or of touch that is not painful. It is rare for children or young people to be upset by an episode of awareness, or to have subsequent ongoing distress. A large national study has shown that is very rare for a child or young person to report a painful, distressing experience under anaesthesia.

Find out more information about emotional and behavioural changes after surgery.

Serious problems are uncommon but include eye injuries (for example corneal abrasion), damage to teeth, an allergic or other reaction to a medicine, or breathing difficulties - either during or after an anaesthetic. If a child does need more support with breathing, maintaining their blood pressure, or anything else after their anaesthetic, there is an Intensive Care Unit in the hospital where they would be looked after.

Very serious problems are rare. These include severe allergic or other reactions to a medicine (for example anaphylaxis), or injury to nerves. Nerve injury from an operation or procedure can cause numbness or weakness, this usually gets better over days or weeks but can be long-term, visual loss, or, very rarely, hearing loss.

The most serious problems associated with anaesthesia are usually very rare indeed. Until recently these very rare risks were not routinely discussed. The General Medical Council (GMC) have updated their guidelines, and they are clear that we should make parents and young people aware of any risk of serious harm, however unlikely it is to occur.

These most serious harms can potentially involve brain damage, disability, or death. However, it is very rare for a problem related to anaesthesia to result in brain damage leading to long-term disability or for a child to die.

Deaths that do occur around the time of surgery are not usually directly caused by the anaesthetic but by other problems connected with the patient’s health or the operation they are having. The risk of death due to a general anaesthetic for a child or young person who is well and without any underlying health problems is thought to be somewhere between one in 100,000 and one in a million. This is similar to the lifetime risk of being killed by lightning.

In babies and in children with underlying health conditions, especially those with significant heart disease, the risks may be substantially higher.

There is also ongoing research into possible long-term effects of anaesthesia in babies and very young children. At present there is no strong evidence that anaesthetics are harmful to development.

Anaesthetists are doctors who give anaesthetics. They are highly trained to avoid, anticipate and treat any problems that may arise. Risks cannot be removed completely but modern equipment, training and medicines continue to make anaesthesia safer.

An anaesthetist will be with your child throughout their anaesthetic to monitor their progress and to help them to wake up as comfortable as possible.

Risks should always be balanced against the overall importance of having a procedure or surgery.

If you are concerned about the risks of anaesthesia, or want to discuss this or anything else in more detail, please ask us at your appointment with the Anaesthetic Pre-Operative Assessment clinic (APOA). We can also discuss any other worries or concerns you may have.

Telephone: 020 7829 8686

Email: anaesthetic.pre-op@gosh.nhs.uk

Find out more about your child’s general anaesthetic | Great Ormond Street Hospital (gosh.nhs.uk)

Risks are a normal part of life. Decisions we make every day involve balancing risk and benefit.

For example:

• should I cross the road here - quicker but more risky?
• should I walk to the zebra crossing - safer but slower?

Your decision will depend on many things:

• How busy is the road?
• Are you alone, or do you have your children with you?
• Are you in a hurry?
• As well as how you feel about taking risks generally

Having a procedure or operation under general anaesthetic is no different. It will involve hoped-for benefits but will also involve some side effects and risks. You have to balance the potential benefits against the risks in order to come to your own decision. This leaflet is designed to help you with this by giving you information about anaesthesia.

Describing risks

People vary in how they interpret words and numbers. In this information sheet, we have linked numbers to words. For example, when it says that feeling thirsty after an anaesthetic is very common – you know that it means that the chance of feeling thirsty is more than one in 10. The definitions we have used are below, along with examples from everyday life:

• Very Common - more likely than a one in 10 chance of happening. For example, when flipping a coin, it is very common for it to land on heads - one in two
• Common - less likely than one in 10, but more likely than one in 100. For example, it is common for a pregnancy to be twins - one in 65.
• Uncommon - less likely than one in 100, but more likely than one in 1,000. For example, it would be uncommon for your child to have the same birthday as their anaesthetist - one in 365.
• Rare - less likely than one in 1,000, but more likely than one in 10,000. For example, it is rare for a pregnancy to be triplets - one in 5,000.
• Very rare - less likely than one in 10,000, but more likely than one in 100,000.For example, it would be very rare to be killed in a road traffic accident in a 12-month period - one in 32,000 in the UK.
• Extremely rare - less likely than one in 100,000. For example, it would be extremely rare to be killed by lightning in the UK - one in 200,000 lifetime risk.

More exact numbers are used in some places, to give you the best information available.

This information sheet includes text taken from the Royal College of Anaesthetists (RCoA) publication, ‘Your child’s general anaesthetic (2020)’ but the RCoA has not reviewed this information sheet as a whole.