Anaesthetic awareness: the dangers of waking up during surgery

Posted: 18/09/2019

A 43-year old woman has been awarded damages of £28,000 after suffering a period of ‘anaesthetic awareness’ during bowel surgery.

Although it is widely recognised that all surgery carries risk, the risk of anesthetic awareness, where a patient is conscious during surgery, is less well known. It is thought to happen to one to two patients per thousand undergoing surgery.

Anaesthetic awareness can be a painful and frightening ordeal, causing long-term psychiatric injury. When cases do occur, they are most often the result of the sedative not working properly or having worn off too early. The patient may then have normal sensation and be wide awake, but remain paralysed and unable to alert their surgical team. Patients may report having fleeting memories of conversations amongst the surgical team or the sound of machines in the operating theatre. However, in severe cases, the patient is completely aware of their surroundings and they may experience all the pain of surgery without anaesthesia; a terrifying ordeal. The anaesthetist looking after the patient may have no idea of what is happening.

In another scenario, neither the sedative nor the paralytic agent given may be working properly. The patient is then neither sedated nor paralysed, and can move around. They may sit up, try to remove tubes and attempt to speak. It is then at least evident that the patient requires additional medication before the surgery continues.

When the sedative is working but the paralytic agent is not, the patient may move but is not aware of anything. An additional dose of paralytic agent can be given to allow surgery to proceed safely.

In some scenarios a lower dose of sedative will be given intentionally, perhaps when a patient cannot safely tolerate full general anaesthesia, due to their medical condition. The risk of anaesthetic awareness is then greater, but it will be a balanced risk.

It is very important that risk factors for anaesthetic awareness are discussed before surgery. Patients should be open with their anaesthetist and surgeon about any history of alcohol or drug use, any previous difficulty with anaesthesia and any heart or lung problems, as these can increase the risk.

An episode of anaesthetic awareness can cause a psychiatric injury, often post-traumatic stress disorder and hospital phobia. The woman who suffered anaesthetic awareness during her bowel surgery reported intrusive thoughts, flashbacks and night terrors. She was diagnosed with PTSD and hospital phobia and required cognitive behavioural therapy. She needed further surgery but was unable to put herself through that after her terrifying experience of having been awake for 15 minutes during her first operation and hearing the surgeons discuss serious complications that had arisen, meaning that it had become dangerous to proceed with her surgery. She was unable to speak or to move so could not alert her surgeon to the fact that she was fully conscious.  

Alison Johnson, partner in the clinical negligence team at Penningtons Manches Cooper, says: “Incidents of anaesthetic awareness are rare but when they happen, they can be terrifying. Patients have reported extreme panic at being able to feel a scalpel cutting through their skin and a surgeon’s hands inside them. They can feel tremendous pain and fear and that can affect them considerably for a long time afterwards. They may then not be able to complete the medical treatment they require and are very likely to require psychiatric therapy. It can take months or even years for them to recover from what has happened to them.

“It is possible to bring a clinical negligence claim when anaesthetic awareness has been caused by a lack of reasonable medical care. It may be that there have been failures in administering the correct dose of medication to ensure adequate anaesthetisation, in managing the anaesthesia during surgery, or in recognising signs of anaesthetic awareness and reacting promptly to them.”

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