Reducing the risk of being aware during surgery

Reducing the risk of being aware during surgery

For many patients, going under anaesthesia can be as worrying as the surgery itself. Often this is caused by a fear of waking during their operation. Dr David Coates, Anaesthetist at Cromwell Hospital, talks about the machine he uses to prevent this happening.

Low risk of complications under general anaesthesia

General anaesthesia is very safe these days – the risk of anything going wrong is extremely low. As an anaesthetist, I spend time with all my patients before they go to theatre. I explain what I will be doing and what they can expect. A lot of patients are more concerned about the potential adverse effects of the anaesthetic than they are about the surgery, especially if they have chronic conditions such as high blood pressure, heart disease, or diabetes. It’s my job to reassure them and provide a good perspective of the overall relative risk versus the benefits.

Fear of waking during surgery

The possibility of being unintentionally aware or awake during surgery is a question that I am asked quite often and requires careful explanation. It is rare, but it can happen. A study of 80,000 patients published in the US in 2007 found that about 1 in 14,000 patients had some apparent recall of events that occurred during their operation. Anaesthetists strive to make sure this doesn’t happen and there are various ways this can be achieved. In essence, it relies on giving each patient an appropriate combination of the anaesthetic drugs to keep them safely under during the entire procedure.

Monitor helps to prevent awareness during surgery

I find using a cerebral function monitor (CFM) very beneficial for patients having surgery under general anaesthesia. The use of CFM not only reduces the likelihood of giving too little anaesthetic, which might result in awareness, but also allows the anaesthetist confidently to reduce the amount of anaesthetic when appropriate to minimise the risks of giving more drug than is necessary. This monitor is available in all theatres at Cromwell Hospital.

Four simple sensors are applied to the patient’s forehead. The monitor gives a constant indication of how the anaesthetic is affecting the brain and the anaesthetist interprets this information. The anaesthetic being delivered can be finely adjusted to achieve the desired effect. The precise amount required may vary quite widely throughout an operation. 

Recovery: the goal after anaesthesia

Modern anaesthetics wear off quickly. The achievement of a rapid, clear-headed recovery with good post-operative pain relief and no nausea is the target. I find the use of CFM helps me achieve this goal and so I use it routinely on my patients at Cromwell Hospital.

If you are interested in learning more about your anaesthetic, the Royal College of Anaesthetist's website (opens in a new window) has a useful ‘Patient FAQ section’ that you may find helpful.

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