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Surgery Complications

Exploring the effects of anaesthesia awareness

Updated: 22nd Feb 2022
the effects of anaesthesia awareness
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Medical Negligence Solicitor and Partner - LLB (Hons) University College London

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Since the 19th century, patients undergoing surgery have benefitted from the medical miracle of anaesthesia. As the decades have passed, the application of anaesthetic during surgery has become safer and more straightforward, making incidents of problems caused as a result of anaesthesia highly uncommon.

However, it is not a fail-safe process. While anaesthetic is usually administered appropriately, equipment failure, incorrect dosage or negligence can occur leading to the possibility of the patient waking up mid-operation – known as anaesthesia awareness.

Here we will breakdown what anaesthesia awareness is and how it can occur, how frequently this happens and what effects waking up during surgery can have on a patient.

How do anaesthetics work?

An anaesthetic is designed to put a patient who is to undergo surgery into a state of controlled unconsciousness, so the patient is unaware of what is taking place and they feel no pain during their operation.

While the precise nature of why it works is still a mystery, it is known that anaesthetics temporarily interrupt signals passing through the nerves, meaning anything that happens to the body is not recognised or registered by the brain.

Complications with general anaesthetic are rare, but risks still exist, ranging from allergic reactions and the potential of the patient waking up during surgery to, in the most unfortunate cases, death (although this only occurs in 1 in every 100,000 cases).

A surgeon or anaesthetist should discuss the risks and provide guidance on how these can be minimised in the lead up to an operation.

How long does anaesthesia last?

The length of time anaesthesia last will depend on the type of surgery. General aesthetic will typically only be used for longer or notably painful operations, and an anaesthetist will be present to ensure the patient receives a safe, maintained level of anaesthetic required to keep them under for the duration of the surgery.

Other forms of anaesthesia include:

  • Local anaesthesia
  • Epidural anaesthesia
  • Spinal anaesthesia
  • Nerve blocks

With these options, the patient will not lose consciousness as they would under general anaesthetic, and the anesthesia will only last for the duration of the procedure in question.

Is anaesthesia awareness real?

Anaesthesia awareness is when a patient regains consciousness during surgery. They are unlikely to feel pain, although may experience the sensation of the procedure. They will often be unable to move or let the anaesthetist know that they are awake. The thought of waking up during surgery is a fear for many people, and sadly it is one that can become a reality.

How a patient experiences anaesthesia awareness varies from patient-to-patient. For some, this will be a fleeting occurrence that they do not recall by the time they are back in their hospital bed; for others, it can be a traumatic episode that leads to lasting psychological issues and PTSD. Some will not feel any pain; others may suffer severely.

What is the likelihood of waking up during surgery? A study conducted in 2014 by NAP5 into Accidental Awareness during General Anaesthetic (AAGA) came to the conclusion that anaesthesia awareness is very uncommon, taking place in just 1 in 19,000 cases. This rose to 1 in 8,000 for patients who had been given paralysing drugs as part of the operation, as this meant they were unable to signal to the surgeon what was happening sooner.

However, other studies have disputed this, saying that anaesthetic awareness occurs significantly more often. Some have this at approximately 1 in 1,000 cases, while others claim that 1 in 20 people will be awake during surgery at some point, but that the vast majority will not recall this at all.

Other notable anaesthesia awareness statistics gathered by NAP5 include:

  • Most events would last no longer than 5 minutes
  • 51% of cases resulted in the patient suffering distress
  • 41% of incidents resulted in moderate to severe psychological harm for the patient

Fundamentally, it is highly unlikely that during surgery you would wake up, be aware of your surroundings and recall the incident following the operation. However, it is not an impossibility, and can cause a great deal of fear, panic and stress for affected individuals.

Reasons why anaesthesia may not work

There are numerous reasons why general anaesthesia does not perform as it should do during an operation, resulting in the patient being aware at some point during the procedure.

If the patient is notably poorly or weak, a lower dose of anaesthesia might be used, which may lead to a greater likelihood of them regaining consciousness, in particular during cardiothoracic surgery. Or during a Caesarean section, as the anaesthetist will have to balance the amount used to support both mother and baby.

Similarly, if a person is more resistant to the anaesthesia used, it might not have the same effect on them as it would on another person. Research has shown that:

The anaesthetist or surgeon should conduct a thorough interview with a patient prior to surgery in order to establish any factors that might make it more or less likely a patient will wake up during surgery. If this is not carried out, it could result in an incorrect level of anaesthetic being administered, leading to anaesthesia awareness.

Other causes of anaesthesia awareness include if there has been an interruption in the delivery of anaesthetic when a patient is transferred into the operating theatre, if any emergency drugs were used at the time, or if there was difficulty managing the patient’s airway. Interviews with people who have been through anaesthetic awareness often describe how they can feel like they are suffocating, which can lead to experiences of PTSD following the event.

Anaesthetic awareness may also be the result of surgical negligence, particularly in regards to the anaesthetist monitoring the patient’s intake during the procedure. The WHO Surgical Safety Checklist was created to outline the steps professionals should take to avoid acts of surgical negligence.

What can happen as a result of waking up during surgery?

As set out above, the experience of anaesthetic awareness can vary significantly from patient to patient. Some may have no memory of it ever taking place, or even if they do it may not have any long-term repercussions. Unfortunately, for others it can leave lasting emotional and psychological damage.

Recounts of people who have been affected by anaesthetic awareness illustrate how panic-inducing being awake during surgery can feel. If they feel any pain from the surgery, suffer from breathing difficulties or, as the result of muscle-relaxing drugs, are unable to move any part of their body or get anyone’s attention, there is a greater likelihood that they will experience PTSD or comparative psychological damage.

When this happens, it is critical that the patient is provided with relevant counselling and psychological therapy to treat their feelings of distress as a result of the incident. With nightmares, panic attacks and significantly increased stress as potential outcomes of anaesthetic awareness, timely intervention can be crucial in supporting the patient’s recovery.

If a patient believes that a negligent act was the cause of anaesthetic awareness, the patient should instruct an experienced medical negligence firm, like our team at Gadsby Wicks, to make a claim for any emotional or physical damage suffered as a result.

Have you been affected by problems under anaesthetic?

Anaesthesia has been a blessing to the safety and performance of surgery worldwide, and in most cases this is administered responsibly and there are no issues. But mistakes do happen, and when they do, it is critical the person affected is fairly compensated for any harm they endure.

If you have been affected by anaesthetic awareness or any other surgical complication due to the negligence of your healthcare providers, we are here to help.

With decades of combined experience in a range of complex cases, we commit to investigating your case, advising you on the strength of your claim, and guiding you to secure the compensation, answers and justice you are entitled to.

If you would like to make an anaesthetic awareness claim, or claim for another act of surgical negligence, get in touch with our experts today.


All content contained within this article is meant for general information only – this should not be treated as a substitute for medical advice from your doctor or another healthcare provider. If you require legal advice specific to your situation, please contact our team directly.

Gadsby Wicks is not liable for any diagnosis made from the content of this article, nor does it endorse any service or external site linked to within the article.

Always consult your GP if you are concerned about your health and wellbeing, or speak to us if you require legal advice.