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Anaesthetic awareness: Will it happen to me?

March 29, 2008

Following his recent interview on This Morning (ITV 1 27.03.08) Professor Michael Wang has made available further advice and information to anyone who is concerned about the possibility of unintended awareness during forthcoming surgery.

What is my risk of being awake during my operation with a general anaesthetic?

The risk of awareness is around 1 in 600. This means it is not likely that you will be aware, but it is possible – there is a small risk. Some operations carry greater risk for awareness than others: for example, open heart surgery and operations that last several hours.

What is the experience of awareness like?

In the film “Awake”, a man is portrayed as conscious from the very beginning of the operation and is aware and in excruciating pain during the first phase when the surgeon is cutting into his chest. This is NOT what usually happens: most commonly in awareness cases, people wake after the early part of the operation, when the operation is well advanced. Often the period of wakefulness is relatively short – perhaps a matter of a few minutes. Nevertheless this can seem like an eternity and be very traumatic. Some patients are awake for much longer periods. Patients in this situation can hear everything going on in the operating theatre but usually cannot see. Some (but not all) feel the pain of the operation. Most people find they cannot move or speak (see below). Many people who suffer from severe psychological problems after awareness have had no pain.

So why do they have problems?

Because it is the paralysis they have experienced which leads to psychological problems. Most operations involving a general anaesthetic include a muscle relaxant. This type of drug paralyses the whole body so that if you become wakeful you will not be able to move. When people become conscious during surgery, they try to move or to speak and find they cannot. They may then believe that something catastrophic has happened – for example, that the surgeon has accidentally cut their spinal chord or that there has been some unusual drug interaction – meaning that they will be paralysed for the rest of their life. Sometimes people believe they are in a preparatory phase before death or even that they are, quite literally, in hell. It is this kind of belief during the experience of awareness that often leads to severe psychological problems afterwards. Some medical students and doctors have experienced anaesthetic awareness, but they rarely suffer severe psychological problems afterwards, probably because during their experience, they have understood what was happening and why they were unable to move. This is not to say that if one fully understands a traumatic situation when it is happening, one will always be protected from its effects. But misunderstandings will make the situation a whole lot worse.

Why does it happen?

There are commonly three different types of drug used together in a general anaesthetic: one to cause unconsciousness, one to deal with pain, and a muscle relaxant. The muscle relaxant paralyses the body and is used to help with the surgery: obviously if the patient were to move, the surgeon might accidentally cause unintended injury to you. Also if the operation involves cutting through muscle (as in abdominal surgery) it is much better if the muscle is relaxed. If it is taut, the cut will tear, and afterwards will not heal as well as it should. Anaesthetic awareness usually occurs when sufficient muscle relaxant has been given, but insufficient of the drug or drugs intended to cause unconsciousness. Unfortunately, in this situation it is very hard for the anaesthetist to tell that the patient is awake, because the muscle relaxant stops all movement and makes you appear as though you are unconscious.

What types of psychological problem can arise afterwards?

Studies suggest that more than half of patients who have had this experience will develop psychological problems. The most common type of disturbance is known as Post-Traumatic Stress Disorder (PTSD). This includes three types of problem: Re-experiencing the awareness: this may be in the form of flashbacks (daytime or waking experiences in which the person relives the awareness vividly and in detail) and recurrent nightmares. Phobic avoidance: this may involve avoidance of hospitals, doctors and anything that reminds the person of the awareness such as hospital TV programmes. Sometimes this can be so severe that it develops into a pervasive phobia such as agoraphobia or claustrophobia. Chronic anxiety: People are often left with persistent anxiety symptoms such as palpitation, rapid heart rate, sweating, shaking, etc. Often people will also experience panic attacks, especially when reminded of the experience. In addition, clinical depression, anxiety and other phobias are common in the aftermath of awareness. The duration of these problems is also variable. For some, these problems will last just a few days or weeks. Many others will be troubled with the symptoms for years or even a lifetime. But there are successful treatments for these difficulties. It is important to be referred to a clinical psychologist or psychiatrist who is able to offer Cognitive Behaviour Therapy (CBT) or Eye Movement Desensitisation and Reprocessing (EMDR), especially if the problems persist for more than a few weeks.

Can I do anything now, before my operation? Is there anything the anaesthetist can do to reduce the chances of this happening?

You should have an opportunity to talk with your anaesthetist before your surgery, at a pre-admission clinic or on the ward immediately before your procedure. If you are particularly worried about awareness, you should ask to speak to your anaesthetist before you go to hospital, perhaps on the telephone. You should discuss you concerns and ask the anaesthetist about how he or she is going to prevent you becoming wakeful and how he or she is going to monitor your consciousness level during the operation. You should be honest with your anaesthetist. If you are a particularly anxious type of person, or you consume quite a lot of alcohol or use tranquilisers or opiate drugs, you should make sure your anaesthetist is aware of this, because all these things mean you will need a higher dose of anaesthetic than the average person. Most anaesthetists believe that they can tell if a patient is awake during an operation from the patient’s heart rate, blood pressure, sweating and tear production. Unfortunately there is much evidence that these are unreliable indicators. You could ask your anaesthetist about brain monitors which are based on brain waves, but even these are not yet foolproof.

So can NOTHING be done to ensure the anaesthetist knows I’m awake?

There is ONE very simple way of virtually guaranteeing you will not suffer from awareness, and that is the Isolated Forearm Technique (IFT). This involves placing a tourniquet on the arm just before the muscle relaxant is given, so that the hand and forearm are not paralysed. If you become conscious during the operation, you will be able to move your hand to signal to the anaesthetist and he or she will then be able to increase the anaesthetic and put you back to sleep. Unfortunately most anaesthetists are reluctant to use this simple technique for a number of reasons: partly because of misinformation that has spread amongst anaesthetists and also because they (wrongly) believe they can detect awareness without it. But you may be able to persuade your anaesthetist to do this. If your anaesthetist seems open to this idea but uncertain because he or she has no previous experience or training in the IFT, ask them to contact Dr Ian Russell at Hull Royal Infirmary.

You can find more information about general anaesthesia and anaesthetic awareness from the Royal College of Anaesthetists’ patient information leaflet here.

Prof Michael Wang March 2008