Accidental awareness during general anaesthesia (AAGA)

• Accidental awareness can happen, but it is very rare for children or young people to tell us about something painful, distressing or frightening.^[1]
• There may be a higher risk of accidental awareness if someone has a serious cardiac condition.
• An anaesthetist will always be watching and monitoring someone having an anaesthetic.

Anaesthesia drugs are extremely reliable and are always monitored and controlled by a highly trained doctor. Sometimes, people can remember things that happened when they were supposed to be ‘asleep’. However, it is rare for a child or young person to say they have had a painful, distressing or frightening experience.

People often worry about waking up and not being able to move. This can happen if a muscle relaxant drug is used, and the sleep component of the anaesthetic is inadequate, but it is very rare. Muscle relaxant drugs temporarily stop muscles working and are a necessary part of some anaesthetics, however they are not given in all anaesthetics. Your anaesthetist will be able to tell you whether or not one is likely to be needed.

There are three main types of memory that children or young people can have following a general anaesthetic. These are:

1. Memories of events around the time of an anaesthetic, but when they were meant to be awake.
2. Memories of dreams during an anaesthetic.
3. Memories from when they were meant to be under anaesthetic (‘asleep’). This is genuine AAGA.

The most common situation is for people to recall voices, sounds or non-painful touch. These do not usually cause distress.

It is very rare for a child or young person to experience pain during surgery while being unable to move.

Some surveys suggest that AAGA in children could occur as often as 7 in every 1,000 anaesthetics (1 in every 135, or 0.7%)^[2] . The majority of these cases do not involve any distress.

An NHS survey of spontaneous reports estimated the incidence was 1 in every 60,000 anaesthetics given to a child (i.e. very rare).^[3]

We have had sporadic reports from patients at Great Ormond Street Hospital who may have had accidental awareness during general anaesthesia.^[4]

As discussed in the introduction, muscle relaxing drugs that are required for some operations can increase the risk of AAGA.

There is also a higher risk of AAGA if the dose of anaesthetic has to be limited because there is a severe heart or circulation problem

AAGA can also be more common under total intravenous anaesthesia (TIVA). TIVA is a technique where anaesthesia is maintained throughout the operation by drugs given into a vein. Anaesthetic gases are not used in this technique - all anaesthesia is given through the veins.

TIVA has special advantages but can also potentially increase the risk of AAGA. Giving anaesthesia through the veins relies on a having a reliable infusion through a secure intravenous cannula. Any problems with either of these may be difficult to detect quickly enough to prevent AAGA.

If you are a young person and remember something from when you think you were meant to be ‘asleep’/under anaesthetic (or if you are a parent and your child says they do), please tell us. We will believe you. Hopefully we will be able to explain what happened and provide reassurance about it. If the memory is distressing, we are able to offer psychological support.

If you are worried about the risk of AAGA and would like to talk to an anaesthetist about it in advance, before meeting your own anaesthetist on the day of your procedure, or if you think you or your child may remember something from your/their operation, then please contact the Anaesthetic Pre-Operative Assessment clinic (APOA):

Telephone: 020 7829 8686

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