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DR MARK FREEDMAN M.B.BCh. DA(SA) FFA(SA) PG Cert Clinical Ultrasound  


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Patients Guide to Local & Regional Anaesthesia
Patient's Guide to General Anaesthesia
An Associate of the Northern Anaesthetic Group
Professional Details and Curriculum Vitae:

ANAESTHETIC RISKS AND COMPLICATIONS

Post Operative Nausea and Vomiting

Sore Throat

Shivering

Damage to Teeth, Lips or Tongue

Eye Damage during General Anaesthesia

Post Operative Chest Infection

Mental Confusion after Anaesthesia and Surgery

Awareness during General Anaesthesia

Serious Allergy + Anaphylaxis

Nerve Damage after General Anaesthesia

Nerve Damage after Spinal / Epidural Anaesthesia

Nerve Damage after Peripheral nerve Blocks

Equipment Failure

Death or Brain Damage

Headache after Spinal or Epidural anaesthesia

Nausea and Vomiting

This sections t explains the causes of sickness following anaesthesia and surgery, what can be done to prevent it occurring, and treatments available if it does happen to you.

Nausea is an unpleasant sensation,usually in the stomach, also described as feeling queasy or feeling sick. It is often felt with the urge to vomit.

Vomiting: This means being sick. It is the act of forcefully emptying the stomach, or throwing up.

PONV: These letters are used to mean post-operative nausea and vomiting. Postoperative: means that it happens after the operation.

Anti-emetic drugs. These are medicines that help to prevent or treat nausea and vomiting.

Will I feel sick after my operation?

Not everyone feels sick after an operation or anaesthetic, although it is a very common problem. Overall, about one third of people (1 in 3) will experience a feeling of sickness after having an operation, but it depends very much on who you are (see below), and on what operation and anaesthetic you are having.

Why do some people feel sick after operations?

There are a number of factors that we know affect how likely you are to feel sick after an operation. Some operations cause more sickness than others, for example: Operations in the abdomen or genital area, ear, nose or throat operations (e.g. removal of tonsils), surgery to correct a squint of the eye, very long operations may all be contributory factors.

Some drugs are known to cause sickness: These may include anaesthetic drugs,some anaesthetic gases, drugs that target pain receptors (especially morphine-like pain relieving medicines, including codeine).

Some people are more likely to suffer from post-operative sickness: these include:

Children, Women, non-smokers, those who suffer from ‘travel sickness’, anyone who has suffered from postoperative sickness before, prolonged starvation or not drinking, being very anxious about what is happening can make you more likely to feel sick. Travelling shortly after receiving a general anaesthetic

How long does the feeling of sickness last?

Usually the sensation of sickness is short-lived or stops following treatment. Uncommonly, it can be prolonged and last for more than a day.

Can feeling sick after an operation harm me?

Feeling sick or vomiting after an operation is distressing and unpleasant. It can make the pain of your operation feel worse, particularly if you are retching or vomiting, and it can delay when you start eating and drinking after your operation. This may keep you in hospital longer. Rarely, if vomiting is severe and lasts a long time, it can result in other more serious problems, such as damage to your operation site, tears to your oesophagus (gullet), or damage to your lungs..

What can be done to prevent it occurring, and what treatments are available?

Although the risk of sickness can never totally be removed. Your anaesthetist will assess your risk of experiencing sickness when they visit you before your operation. There are various ways in which your anaesthetist can change your anaesthetic in order to reduce your chance of suffering sickness.
You may be able to have your operation performed under a regional anaesthetic rather than general anaesthetic, as this may reduce the sickness that you feel.

You may be given one or several‘anti-sickness’ medicines, called antiemetics, as part of your anaesthetic. Some anaesthetic drugs are less likely to cause sickness than others. Your anaesthetist may decide that you are suitable to receive them.

You may receive intra-venous fluids via a cannula (fluid goes into a thin plastic tube placed in a vein – often called a ‘drip’). This may be given for other reasons, but has been shown to help prevent sickness.

If you are worried about sickness, or have experienced it following a previous operation, it is important that you inform your anaesthetist. It is much easier to relieve the feeling of sickness if it is dealt with before it gets too bad. So, you should ask for help as soon as you feel sick.

What drugs may I be given and do they have side effects?

Anti-emetic drugs can be given as a tablet or as an injection. Injections can be given intra-venously into your cannula or into your leg or buttock muscle. Intra-venous injections work more quickly and reliably and avoid the need for another needle. The same drugs are used to prevent and treat sickness after surgery. There are several different types. A combination of anti-emetic drugs may be given, as this is more effective than one drug given on its own. All medicines have some side effects, although with anti-emetics these are generally minor and temporary, or rare.

The following are commonly used antiemetic drugs:

Ondansetron (Zofran) or granisetron (Kytril) or tropisetron (Navoban). Dexamethasone. Although a steroid drug, the single dose given to prevent nausea and vomiting does not seem to be associated with the side effects seen with long-term steroid use. Prochlorperazine (Stemetil). This may cause tremors or uncontrolled body movements, known as an extrapyramidal reaction (rare).

Maxolon (metachlopramide) is effective both is decreasing nausea and emptying the stomach buty may also be associated with uncontrolled body movements.

Can I do anything to avoid feeling sick?
Yes. After your surgery, avoid sitting up or getting out of bed too quickly. Avoid drinking and eating immediately after your operation. Start with small sips of water and slowly build up to bigger drinks and light meals. Your nurse will give you advice about this. Good pain relief is important. Although some pain relieving medicines can make you feel sick, severe pain will too. You should ask for help if you are not sure. Taking slow deep breaths can help to reduce any feeling of sickness.

 

 

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Sore Throat

After a general anaesthetic you may develop a sore throat. This can range between a minor discomfort and a more severe continuous pain. You may also have a very dry throat or feel pain on speaking or swallowing. These symptoms may disappear after a few hours but may take two days or more to settle down. Recent advances in anaesthetic equipment mean that having a very sore throat is less common than before.

Why does a sore throat happen?
During any general anaesthetic your anaesthetist must make sure that you can breathe freely. He/she must also make sure that secretions or stomach contents, which can collect in your throat during an anaesthetic, do not get into your trachea (windpipe) or your lungs. Your anaesthetist will choose one of several methods to achieve these things after you are anaesthetised. The choice will depend on your medical condition and on what operation you are having. He or she may use the following:
A face mask: This is held firmly onto your face by your anaesthetist.
Sometimes a separate plastic Guedel airway that sits over the tongue is needed as well.
A laryngeal mask airway: This is a different shaped tube, with a soft cuff, which sits in the back of the throat above the opening to the trachea. When in place it allows gases to move freely in and out of the lungs but it does not protect the lungs from secretions or stomach contents. It is not suitable for some operations.
A tracheal tube: This is positioned in your trachea (windpipe) and has a soft cuff, which is inflated to prevent leakage of gases or movement of secretions. During your anaesthetic it is occasionally necessary to use an additional tube placed in your nose or mouth to empty your stomach. All of these tubes or masks are placed after you are anaesthetised and you are not usually aware of their use. However, any of them may contribute to a sore throat as follows. During insertion, any of the tubes or equipment used to insert them in the mouth may cause irritation or damage to your throat.The tracheal tube and the laryngeal mask airway both have a cuff, which may press on parts of your throat or airway causing swelling and discomfort.
Anaesthetic gases and some drugs can dry your throat. This may also contribute to a sore throat following your anaesthetic.
Uncommonly, placement of an airway tube is difficult. It is possible that more significant damage to the vocal cords and other structures can occur occasionally in these circumstances.
How likely is it to occur?
After a general anaesthetic with a tracheal tube the risk of developing a sore throat is estimated to be around 2 in 5.
After a general anaesthetic with a laryngeal mask airway the risk is estimated at about 1 in 5
After a general anaesthetic you may develop a sore throat. This can range between a minor discomfort and a more severe continuous pain. You may also have a very dry throat or feel pain on speaking or swallowing. These symptoms may disappear after a few hours but may take two days or more to settle down. Recent advances in anaesthetic equipment mean that having a very sore throat is less common than before.
Women are more likely to get a sore throat than men, and younger patients are more likely than older people.
What can be done about it?
There is some limited evidence that sore throat can be prevented or reduced by the use of local anaesthetic or steroid applied to the throat before the tube is placed. However, for long operations local anaesthetic is likely to have stopped working before the end of the operation.
If sore throat occurs, symptoms disappear without any specific treatment over the course of a few days. If the pain is severe, pain relief medicines and gargling may help to reduce inflammation and pain.
What happens if the symptoms do not disappear?
If your symptoms have not disappeared after two days or if you are having problems with breathing, coughing up blood or persisting hoarseness in your voice, you should contact your general practitioner or anaesthetist for further advice.

 

 

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Shivering

At the end of your operation, you will be taken to the recovery room. Staff in the recovery room will be with you at all times and will continue to monitor your blood pressure, oxygen levels, pulse rate and temperature. Some people shiver during this period. This section provides information about shivering after an anaesthetic and how it can be prevented and treated.

Shivering after an anaesthetic is a very common problem. It can cause a great deal of discomfort. Although it can be extremely distressing, shivering is not usually dangerous and should stop within 20 to 30 minutes. It can occur after a general anaesthetic and during or after a regional anaesthetic (for example, an epidural or spinal).
What causes it?
Most shivering after an operation is due to a fall in your core (central) body temperature. This occurs because parts of your body may be exposed to a cool environment during your operation.
Anaesthetic drugs and gases can contribute to this fall by reducing your body’s natural ability to regulate your own temperature. Epidural and spinal anaesthetics increase heat loss by dilating (opening up more widely) blood vessels in the skin.
Shivering may also occur without a fall in core body temperature. It can be caused by anaesthetic drugs and gases, and is more likely if you have pain following your operation.
What is done to prevent it?
Care is taken to keep you warm before, during and after your operation. If you are kept warm before your operation, you are less likely to be cold afterwards. There are some things that you can do to help you stay warm before your operation.
Remember that the hospital may be colder than your own home. Bring warm clothing, such as a dressing gown, to keep you comfortably warm before your operation. Tell the staff if you feel cold at any time during your hospital stay. By keeping warm before your operation, you can help avoid shivering afterwards.
Depending on the length and type of your operation, your anaesthetist and recovery nurses may use some other ways to keep you warm. These can include heating any intra-venous fluids that you may receive and using a heated blanket filled with warm air.
How often does shivering happen?
Shivering following an anaesthetic is a very common problem. Even using measures to prevent a fall in body temperature, shivering may still occur in up to 1 in 4 patients following a general anaesthetic. The risk of shivering is increased in younger patients and during long operations and orthopaedic operations. Shivering may also be more common when epidural or spinal anaesthesia is used. A t the end of your operation, you will be taken to the recovery room. Staff in the recovery room will be with you at all times and will continue to monitor your blood pressure, oxygen levels, pulse rate and temperature. Some people shiver during this period.
What can be done if shivering occurs?
When you get to the recovery room, your temperature will be measured. If you are cold, the nurses will use warming blankets to help warm you up again. This is usually all that is required to stop shivering, although it may take some time for your temperature to return to normal. There are also a number of drugs which can be used to treat shivering, although it is usually considered best to wait until the shivering stops on its own. None of the drugs is 100% effective and all may have side effects. The most effective drugs include pethidine, clonidine and doxapram. If you are in pain following your operation, treatment of your pain may also help to reduce your shivering. Shivering will stop on its own and, although distressing, it is generally not dangerous. It does, however, increase your body’s requirement for oxygen so you may be given additional oxygen via a mask.
A nurse will be with you at all times in the recovery room and they will make sure that you are warm and as comfortable as possible following your operation. If you have suffered from post-operative shivering in the past this does not indicate that you will definitely shiver with surgery and anaesthetics in the future.

 

 

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Damage to Teeth, Lips or Tongue

During a general anaesthetic, it is possible for your teeth to be damaged. This happens in about 1 in 4,500 general anaesthetics. Serious damage to the tongue is rare. Minor damage to the lips or tongue is very common. This section tells you more about why damage can happen, what makes damage more likely, what you can do to help prevent it and what will happen if it does occur.

Why does damage happen?
General anaesthesia is a state of controlled unconsciousness. When you are anaesthetised, you become less able to breathe freely through your nose or mouth. Your anaesthetist will choose a way of making sure that you can breathe properly. This is essential for your safety, and usually requires an artificial airway or breathing tube to be placed in your mouth or throat. Insertion of these devices can cause damage to the teeth or soft tissues of the mouth or nose.
What type of damage may occur?
Lacerations (minor cuts) or bruising to the lips and tongue are very common, probably occurring in about 1 in 20 general anaesthetics. These injuries heal very quickly and can be treated with simple ointments such as Vaseline.
Teeth or dental work such as crowns, bridges or veneers may be broken, chipped, loosened or completely removed by accident. The most frequently damaged teeth are the upper maxillary incisors (top front teeth). Damage to a tooth requiring subsequent removal or repair occurs in about 1 in 4,500 general anaesthetics.
Rarely, pressure from an airway device causes damage to nerves which control movement and sensation (feeling) in the tongue. This causes numbness and loss of normal movement of the tongue for a period of time. These changes are almost always temporary, with recovery taking a few weeks or months.
How does damage to teeth occur?
The use of artificial airway devices to keep you breathing safely after you are anaesthetised is not always straightforward. Anaesthetists are trained in the use of airway devices, but, even in skilled hands, there may be some difficulty and a certain amount of force is used. This can sometimes lead to damage to teeth, lips or tongue.
For major operations on the chest, abdomen, head, neck or spine, and sometimes for other surgery, you will need a tracheal tube to be placed through your mouth or nose into your trachea (windpipe). This is usually done after you are anaesthetised. The instruments used to place this tube may cause damage, especially if placement is difficult. Other types of tube may be used for other operations and these carry less risk of damage to teeth.
During a general anaesthetic, it is possible for your teeth to be damaged. This happens in about 1 in 4,500 general anaesthetics. Serious damage to the tongue is rare. Minor damage to the lips or tongue is very common. This section tells you more about why damage can happen, what makes damage more likely, what you can do to help prevent it and what will happen if damage does occur.
The surgeon can also damage your teeth, lips or tongue during operations in the mouth or throat, including examinations under anaesthetic of the throat, the lungs or the oesophagus (gullet).
What about false teeth?
You will usually be asked to remove false teeth before a general anaesthetic. This is because they may be dislodged or damaged as your anaesthetist places the artificial airway device as described above.
Occasionally your anaesthetist may ask you to leave your false teeth in place. This is most likely to be if you have teeth of your own in amongst the false teeth and your anaesthetist thinks that the false teeth will help protect your own teeth. In this case there is a risk that the false teeth may be damaged.
Who is at increased risk of damage to teeth?
Anyone undergoing a general anaesthetic is at some risk. Wherever possible, your anaesthetist will assess your airway before the anaesthetic starts. He/she may look in your mouth. ask you to move your neck and ask you about your teeth and any caps, crowns or loose teeth that you may have. He/she will then be able to tell you if you have any features that predict difficulty in inserting tubes into the airway. However, difficulties can also arise unexpectedly. Certain factors are associated with difficulty. These include: reduced mouth opening. reduced neck movement, prominent upper teeth or small lower jaw, certain medical conditions such as rheumatoid arthritis and ankylosing spondylitis, pregnant women requiring an emergency general anaesthetic, people who are very overweight.
The following have a higher risk of damage to teeth. Anyone with one or more of the above factors.
Any person with teeth in poor condition (large amounts of decay or failing dental work). Nearly two thirds of injuries to teeth happen in people with teeth in a poor condition. Anyone with caps, crowns, cosmetic veneers or a bridge on their front teeth. Anyone having an operation or examination of the mouth, neck, jaw or oesophagus (gullet). Anyone who needs to have a tracheal tube inserted after the operation has started. This is sometimes necessary if the existing airway becomes unsatisfactory during the operation, and insertion of the endotracheal (breathing) tube may be more difficult.
What steps are taken to prevent damage to my teeth?
All anaesthetists are trained to be aware of the potential for damage to teeth. Your anaesthetist will take care during the insertion of airway devices and force will be avoided as much as possible. If you have any features that predict difficulty with airway devices, your anaesthetist will choose a suitable technique which will allow safe insertion. This should be discussed with you beforehand.
Teeth may be protected with mouthguards similar to those used in contact sports. A study of the use of mouthguards found no evidence to support their routine use. However, if you have a high risk of damage to your teeth, your anaesthetist or surgeon may choose to use a mouth-guard, as there is some evidence that this helps protect your teeth in these circumstances.
Is there anything I can do to prevent damage to my teeth?
If your teeth or gums are in poor condition or any teeth are loose, it is advisable to visit your dentist before a planned operation for a check-up and dental assessment. Please alert the anaesthetist to any loose teeth or dental work before your operation. If you know there have been difficulties with placing a tube in your airway or you have had damage to your teeth during a previous anaesthetic, it is important to tell your anaesthetist. You should tell someone involved in your care as early as possible, as it may be necessary to find previous anaesthetic records to find out exactly what happened. Your GP, your surgeon or your nurses (on the ward or in the clinic) will be able to help you organise this. If your anaesthetist tells you that there were difficulties, it is very helpful if you know what the difficulties were. If you are not sure, ask your anaesthetist to write them down so that you can show the letter to anaesthetists in the future.
What happens if my teeth are damaged during an operation?
Your operation should proceed as planned. If a tooth has become completely dislodged it must be secured or removed before you wake up. If there is chipping or cracking of a tooth, the anaesthetist will record the damage and you will be informed when you have recovered. Immediate treatment will involve pain relief if required and an explanation of what has happened. The tooth may require repair, re-implantation or extraction depending on the nature of the injury and pre-existing health of the tooth.
Damage to veneers, crowns or bridges may require repair.
If you are treated by your own dentist, you may be able to claim assistance with the cost of repairs from the hospital or from your anaesthetist. However, if you were informed that there was a risk of damage to your teeth and the anaesthetist took a reasonable amount of care, then you may need to accept that this was an unavoidable risk and meet the cost of treatment yourself. If you have no features which place you at increased risk of damage to your teeth (as listed above,) then it is normal practice not to give you a specific warning. However, teeth may still be damaged.
How likely is damage to teeth, lips and tongue?
Minor injuries to the lips or tongue are very common and are usually unreported which means accurate figures do not exist. A small study of 404 patients suggested that minor injuries occur in about 1 in 20 patients. Damage to a tooth which requires subsequent repair or extraction happens in about 1 in 4,500 general anaesthetics. This figure comes from a large study of just under 600,000 patients. Nerve damage to the tongue due to pressure from airway devices is reported, but accurate figures do not exist. It is likely to be rare or very rare.
Summary:
Serious damage to the tongue is rare. Minor injuries to the lips or tongue are very common. The overall risk for serious damage to teeth is around 1 in 4,500 general anaesthetics. If you have an increased risk for damage to teeth, this may be identified before the anaesthetic starts. The majority of damage happens in people with teeth in previously poor condition. Mouth-guards can reduce but not eliminate the chance of damage in high-risk patients.
A visit to the dentist before a routine operation is advisable if your teeth are not in good condition.

 

 

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Damage to the Eyes during General Anaesthesia

During a general anaesthetic it is possible for your eyes to be damaged. This is an uncommon or rare event. The types of damage that can occur, and its consequences and treatment are described in this section.

What is the most common type of damage?
The most common type of damage to the eye that can occur during or after a general anaesthetic is a corneal abrasion.
The cornea is a superficial clear layer of the eye. An abrasion is a tear or graze of this layer. Corneal abrasions often heal without long-term effects on vision, but a scar may remain on the cornea. This may not be noticed during normal vision or it may cause a dark or blurred spot in the affected eye.
What other damage can occur?
Eye injuries leading to loss of eyesight are very rare. These include:
Pressure may be accidentally placed on the eyeball during surgery. This could cause an injury to the eye or block the eye’s blood supply. Pressure may be more likely if you are positioned face down to facilitate your operation. Anaesthetists are trained to take a great deal of care to position your head and neck, but it can be difficult to achieve a good position when you are face down, especially in people who are overweight. Operations on the spine have been particularly linked with sudden loss of vision, although this remains uncommon.
The eye’s blood supply may be affected for another reason, such as a low blood pressure during the operation.
Overall, it is very rare to suffer any of these problems and lose sight in an eye.
Loss of sight following general anaesthesia is so rare that it is difficult to give an accurate figure for the risk: one large study found that it occurred in 1 of over 60,000 patients studied.
Other possible eye problems following a general anaesthetic may include:
Pressure on nerves in the eyebrow area may cause a droopy eyelid. Protective tape or eye ointments used to protect your eyes from corneal abrasions may cause temporary bruising of the eyelids or irritation of the eyes. Redness of the eye, blurred vision and the feeling that there is something in the eye may last for up to eight hours.
A few operations are performed in an extreme head down position (for example, some gynaecology
operations). This can lead to swelling of your eye lids which usually resolves within a short time.
If you have glaucoma (giving you high pressures inside your eye) your anaesthetist will need to take extra care to protect your eyesight during surgery.
During a general anaesthetic it is possible for your eyes to be damaged. This is an uncommon or rare event. The types of damage that can occur, and its consequences and treatment are described in this section.
Damage caused during surgery to the eye itself or associated with anaesthesia for eye surgery is not described here. You can talk about this with the eye surgeon or specialist anaesthetist who is looking after you.
How do corneal abrasions happen?
Most abrasions happen because your eye does not close fully during the anaesthetic and the cornea becomes dry. The dry cornea may stick to the inside of the eyelid and the abrasion occurs when the eye opens again.
Approximately 6 out of 10 people (60%) do not close their eyes naturally when they have a general anaesthetic. In addition, fewer tears are produced during an anaesthetic causing dryness in the eyes.
Corneal abrasion can also occur because something rubs against the exposed cornea while you are anaesthetised. This may be a surgical drape or other equipment.
Care is taken to protect your eyes, and to ensure that they are fully closed during a general anaesthetic.
What is done to prevent corneal abrasions?
Corneal abrasions can usually be prevented by careful protection of the eyes.
To prevent your eyes becoming dry, small pieces of sticking tape are used to help your eyelids close properly during your anaesthetic. This has been shown to reduce the chances of a corneal abrasion
occurring. Bruising of the eyelid can occur when the tape is removed, especially if you have thin skin and bruise easily. Sometimes, your anaesthetist may use a gel, an ointment or eye-drops to moisten your eyes during your anaesthetic. These may be helpful if tape cannot be used or if your eyes need to be opened briefly during some types of surgery. Eye ointments can sometimes cause temporary eye irritation or blurring of vision following an anaesthetic.
Anaesthetists are trained to take care that nothing rubs against your eyes. If your surgery requires you to be positioned lying on your front (e.g. back surgery), special goggles, cushions or eyepads may be used to protect your eyes.
How often do corneal abrasions occur?
Following a general anaesthetic, it is uncommon to suffer from a corneal abrasion that causes symptoms. A large study of over 60,000 patients having general anaesthetics found that about 1 in 1,750 patients suffered from a corneal abrasion that caused symptoms. The risk may be higher during certain types of surgery. A study of over 4,500 patients having brain or spinal surgery found that about 1 in 580 patients suffered from a corneal abrasion. Other studies, using a microscope to examine the eyes following an anaesthetic, have found that small corneal abrasions may occur more commonly than this.
Around 1 in 25 patients may have small, otherwise un-noticeable corneal abrasions, even when protective eye tape or ointment is used. You may be more likely to suffer from a corneal abrasion if your surgery requires you to be positioned lying on your front or your side, if your operation lasts a long time, or if you are having surgery on your head or neck.
What if I already have poor vision?
If you have poor vision, it is helpful if you tell your anaesthetist about it. This is because he/she can give you any extra information that you need to help you feel at ease if you cannot see well. However, this will not make any difference to the risk of getting a corneal abrasion, or to the ways in which your anaesthetist cares for your eyes while you are anaesthetised.

What happens if I have a corneal abrasion?
Corneal abrasions may be very painful. Treatment is aimed at reducing pain and preventing an eye infection. It may involve eye drops, ointments and an eye patch, as well as pain-relieving medicines. No surgical treatment is necessary. Healing usually takes a few days, after which the pain will stop completely.
When it is healed there may be a scar on the cornea. The effect of the scar on vision will depend on how big it is and where it is on the cornea. Many corneal abrasions heal and leave no effect on vision, although an eye specialist will be able to see the scar through a microscope.
Contact lens users should take advice before using contact lenses again.
Occasionally the abrasion will be right in the centre of the cornea and there may be some long-term blurring of vision.

 

 

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Post Operative Chest Infection

After an anaesthetic and an operation there is a risk that you may develop a chest infection. This is called ‘post-operative’ because it happens after the operation. This section tells you about these infections, including information about what you can do to help prevent them

Why or how do chest infections occur?
Anaesthesia and surgery interfere with the normal ways in which the lungs keep themselves clear of secretions and infection. Pain from the surgical wound (especially after chest or abdominal operations) can make breathing and coughing more difficult. This increases the risk of developing a chest infection.
How likely is it that I will get a post-operative chest infection?
In one survey, 1 in 5 patients who had abdominal surgery developed some degree of chest infection, although most of these were not severe. Chest infections are less likely with most other types of surgery.
Who is most at risk?
How likely you are to develop a chest infection depends on your state of health before the operation, in particular whether you have chest trouble already or are currently a smoker. The type of operation you are having (chest and abdominal operations increase your risk of a chest infection). How how long you spend lying in bed and unable to sit in a chair or walk about; this is why your nurses and physiotherapists will be encouraging you to get up. How urgent your operation is – there is more time to get you into the best possible condition if the operation is planned some time in advance, the type of anaesthetic you are having. Your age. Very young children and older people have a higher risk of chest infection but if in good health this increase is small.
What does it feel like if this happens to me?
If you are developing a chest infection you may feel feverish – hot and cold all over– and find breathing more difficult than usual. You are also likely to have a cough with green or yellow coloured phlegm.
Depending on your surgical wound, coughing may be painful and not powerful enough to clear the phlegm properly.
Some people get a dry but persistent cough after an anaesthetic. This is common and does not mean you are getting a chest infection. It normally lasts only a day or two.
What treatment can be given?
Chest infections are usually treated with antibiotics. These may be given as tablets or a liquid to swallow but are often given intra-venously (an injection into a vein) if you are in hospital.
Physiotherapy is also an important part of treatment. There are different types of chest physiotherapy including deep breathing exercises and techniques to help you cough and breathe more comfortably, and to get rid of phlegm. Oxygen may often need to be given. This is usually given through a light plastic facemask. Alternatively, small tubes can be placed just under the nose, which some people find more comfortable.
This method cannot always be used– it depends on how much oxygen you need.
Occasionally, the physiotherapist, nurse or doctor will ask you to use oxygen under pressure by breathing through a mouth piece (like a snorkel) or through a mask, which covers the mouth and/or nose. This helps to expand the lungs better.
You will also be encouraged to get out of bed as soon as it is safe for you to do so.
How quickly would I get better?
Would there be any after effects?
Most people recover from the chest infection with the treatments described above within a few days. It may take a couple of months for your chest to feel back to normal again but most people have no long-term after effects. Occasionally, the chest infection can become very serious and breathing is extremely difficult. This mostly happens if you have had previous lung disease, are a heavy smoker, were already ill from other causes. In this situation more direct ways of helping with breathing may be required.
Sometimes oxygen is given continuously under pressure through a tight fitting mask or hood. This is known as noninvasive ventilation. This treatment is usually given on a High Dependency or Intensive Care Unit.
Alternatively full ventilation (support of breathing) may be required. This is done on an Intensive Care Unit. A general anaesthetic is given and a breathing tube is inserted into your trachea (windpipe). This tube is attached to a ventilator (breathing machine) which gives support as required with your breathing. Where ventilation is required, the chest infection is usually very serious and, despite this treatment, some patients may die.
What precautions are used to prevent a chest infection?
Good pain relief after surgery is important to make sure you can breathe and cough easily. The anaesthetist may suggest using an epidural to give good pain relief following chest, abdominal and lower limb operations.
Getting your health, and particularly your chest, into the best possible condition beforehand will also help. When you are admitted to hospital the doctors may ask you to take extra medicines and have chest physiotherapy before your surgery.
Is there anything I can do to prevent this risk from happening?
These are some simple measures to help decrease your risk before you come into hospital.
If you are a smoker, the most useful thing you can do to protect yourself is to stop smoking. You need to stop smoking at least six weeks before your operation to get the full benefit.
If you have chest disease already, it would be wise to get your chest in the best possible condition before the operation. Your own doctor and chest specialist can help with this – extra medication may be necessary for a short period before surgery.
If your chest is better during a particular time of year it may help to arrange your operation for that time. Again you and your doctors will need to work together to arrange this.
Whatever your situation, you are more likely to avoid a chest infection and recover better from your operation if you are as fit as possible. Taking as much exercise as you are able to take in the months and weeks leading up to your operation will help.

 

 

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Mental Confusion after Anaesthesia and Surgery

Some people become confused after an operation and anaesthetic. Their memory may fail and their behaviour is quite unlike their normal selves. This can be very upsetting for you, and your family, friends or carers. However, as you recover from the effects of the operation, the confusion will also get better.
In addition to feeling generally confused, some people find that their higher mental functions are not quite as good as they were before the operation and anaesthetic. For example, they cannot do the crossword as easily, or they find it difficult to cope with complex mental work such as problem solving or tasks needed to do their job. These changes are called Post-Operative Cognitive Dysfunction or POCD. The changes can be: ‘early’ (noted at one week after the operation and anaesthetic) or ‘late’ (still present three months or more afterwards)
These changes are not the same as dementia, although some of the symptoms may be the same. People with dementia can become even more confused if they have an operation. These changes are not the same as mental illness (e.g. schizophrenia), although some of the symptoms may be similar.

Mental confusion is common after major operations in elderly and infirm people, but can happen to people of any age. Mental changes commonly go along with being generally unwell. For example, you may have an infection, or have slightly lower oxygen levels than normal. Or you may be in pain, or be receiving strong pain relief medicines. These medical events will be treated, and the mental changes are likely to improve as the body recovers.
What are the symptoms?
Some people become agitated and confused in their thinking and behaviour, whereas others become quiet and withdrawn. Symptoms can vary greatly, but here are some typical symptoms.
Not knowing your own name or where you are.
Not knowing what has happened to you or why you are in hospital.
Difficulty in concentrating.
Loss of memory – you may even become unable to recognise family members.
Reversal of day and night sleep patterns – sleeping during the day and being wakeful at night.
Being illogical or incoherent, shouting and swearing.
Emotional changes such as tearfulness, anxiety, anger or aggression.
Some people become confused after an operation and anaesthetic. Their memory may fail and their behaviour is quite unlike their normal selves. This can be very upsetting for you, and your family, friends or carers. However, as you recover from the effects of the operation, the confusion will also get better.
In addition to feeling generally confused, some people find that their higher mental functions are not quite as good as they were before the operation and anaesthetic. For example, they cannot do the crossword as easily, or they find it difficult to cope with complex mental work such as problem solving or tasks needed to do their job. These changes are called Post-Operative Cognitive Dysfunction or POCD. The changes can be: ‘early’ (noted at one week after the operation and anaesthetic) or ‘late’ (still present three months or more afterwards)
Abnormal behaviours may include: Trying to climb out of bed and pulling out drips and tubes. Appearing indifferent to whatever is going on. Becoming paranoid and thinking that people are trying to harm you. This can be particularly distressing for friends and relatives. Occasionally, people experience visual or auditory hallucinations (seeing and hearing things that don’t exist). Becoming aggressive, shouting and abusing the staff and other patients.
Why does this happen?
In the first few days and weeks after your operation, your body is repairing itself, and the physical challenges associated with this process can cause you to become confused.
Some things which can lead to you becoming confused are listed below:
Causes that can be treated include Infections, such as chest, wound and urine infections. Poor pain control. Side effects of pain relief medicines and other medicines (which can then sometimes be changed for different ones).
Dehydration.
Low oxygen levels due to: the after effects of the anaesthetic, the effects of medicines on breathing, especially pain relief medicines, a chest infection and other lung problems.
Inadequate nutrition. Prolonged constipation. Sleep disturbance. Not taking drugs that you were taking before the operation. Loss of vision and hearing sometimes simply due to lack of glasses or hearing aids.
How likely am I to become confused?
This kind of confusion is common in elderly people. One author says that up to half of elderly patients having hip surgery become confused afterwards for a period of time.
The highly vulnerable person (for example, someone who already has dementia) may require only a minor trigger (for example, a hearing aid not working) to start an episode of confusion and altered behaviour.
The following things increase your chance of becoming confused:
Advanced age. Previous ill health. Previous poor memory, dementia, stroke or other brain disease such as Parkinson’s disease. Previous poor mobility (you were unable to walk about easily). Previous high alcohol intake.Being disorientated due to the unfamiliar hospital environment (although support from nurses and relatives can help with this).
If you have none of these things, then you are unlikely to become confused.
Does the type of anaesthetic make a difference?
You can reduce your risk of becoming confused if you have a regional anaesthetic and stay awake for your operation. This does not remove the risk however, as the confusion can still occur during the recovery period, perhaps related to an infection or the use of strong pain relief medicines or any of the other causes given above. Your anaesthetist will be able to tell you if your operation can be done with a regional anaesthetic
How is it treated?
The good news is that the great majority of people who become confused make a full recovery.
If a physical reason is found, it will be treated (for example, antibiotics, oxygen, pain relieving medicines, nutrition and fluids, drugs to help with constipation etc).
Other than that, the simplest measures can be the most helpful. The support of family and friends is vital in tackling this problem. Frequent reorientation and reassurance are important for recovery. The involvement of family, friends and even pets can help to reassure you that you are safe. The use of familiar objects such as your own pillows and clothes helps. Clocks and calendars are useful to help keep track of time. Making sure that glasses and hearing aids are used is essential. For people who do not speak English, an interpreter should be used as much as possible.
The room lighting should follow a day/ night cycle. At night, the room should be quiet. This will help promote uninterrupted sleep.
Normal eating and drinking should be encouraged. This may not be possible immediately after an operation. Intravenous fluids (a drip) or intra-venous feeding can be used. Unnecessary bed rest should be avoided.
Despite these measures, it is occasionally necessary to give a sedative (calming) medicine to you if you are at risk of injuring yourself or someone else because of confusion. This can be done either by a tablet or injection.
How long does it take to recover?
Most people recover within a few days.
Occasionally it may take up to three months. If you have complications after the operation, the confusion may get worse again. Occasionally you may not recover fully. This may be because POCD has developed, which is described below.
Can I do anything to help with this problem?
Before the operation try and be as healthy as possible. Eat a good diet and take a sensible amount of exercise. Talk to your anaesthetist about alternatives to a general anaesthetic, but these alternatives do not guarantee you will not become confused.
If your operation is not major, and you have someone at home to look after you, you may be able to go home on the same day. This reduces the risk of becoming confused.
Make sure that you have any glasses or hearing aids with you and that spare batteries are available if needed. Ensure you take all your medications into hospital with you so that your doctors know what you are taking and so they are not stopped unnecessarily.
If you drink a lot of alcohol you should take advice about how to cut down safely. Your GP or practice nurse will be able to help you with this. You should also tell your doctors in hospital how much you drink.
You may wish to warn your family and friends about the possibility of becoming confused, and tell them how they can help you. Motivation is important. When you are allowed out of bed, your nurses and physiotherapists will tell you how much you should try and do for yourself. You should aim to be increasingly independent. As you recover, you may feel upset and sad about what has happened to you and worry that you may never get back to normal. Remember that it is very common and most people make a good recovery.
Who can I talk to before my operation about the possibility of being confused afterwards?
Your surgeon, anaesthetist and nurses will be able to discuss these issues with you before and after the operation. You may have the opportunity to do this at a surgical pre-assessment clinic before your operation. It can also help to talk to family and friends and involve them from the outset. They are important in helping you make a full recovery.
Who will be able to help me afterwards if this happens to me?
There is a team of: doctors, nurses, physiotherapists (who help you exercise normally), occupational therapists (who give practical help to help you get back your independence in hospital and at home), social workers, who will work with you to help you return safely home.


Post-Operative Cognitive Dysfunction (POCD) is detected in clinical trials by memory tests, mood assessments and tests of ability to manage the activities.
There are many difficulties in designing tests that can detect accurately the changes in people’s ability to carry out all the many tasks of daily life. Some people score well in tests, but still find that they cannot return to their old job or complete the crossword as well as they used to. Therefore it is difficult to say how often permanent POCD happens. Experts disagree on how valid tests are and how results should be analysed.
1 in 5 patients over 60 has measurable POCD one week after major surgery (other than heart surgery). This is sometimes called ‘early’ POCD. It is not always severe and may not even be noticed except by close friends and family or by specific testing. The studies also suggest that 1 in 20 patients over 60 having major surgery (other than heart surgery) will still have this brain impairment three months later. (‘late’ POCD). However, this fact has been called into question due to some doubt about how test results were analysed. After a major operation, the type of anaesthetic used does not seem to affect whether you might get‘late’ POCD. However, there is less risk of ‘early’ POCD with a regional anaesthetic (such as a spinal anaesthetic) than with a general anaesthetic.
The cause of POCD is not understood. For heart surgery there is some evidence that POCD does happen and that it can be prolonged or permanent.
If you think that you may have POCD it is important that you visit your GP and talk about it. There may be things that can be done to help you.

 

 

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Awareness during General Anaesthesia

When you have a general anaesthetic, you become unconscious. The anaesthetist decides how much anaesthetic you need to keep you unconscious during your operation. Awareness is when you become conscious during your operation and can remember things that happened. This is an uncommon event, but it can be very distressing. This section tells you more about how it can occasionally happen, what steps are taken to prevent it and what to do if you think it has happened to you.

Awareness is becoming conscious during some part of your operation. The majority of patients who are aware do not feel any pain, but may have memories of events in the operating theatre. Dreaming around the time of an operation is very common (6 in 100) but this is not awareness. Some patients recall events from the recovery room after their operation and mistakenly believe them to be memories from during the surgery.
How and why does it happen?
You are not receiving enough anaesthetic to keep you unconscious.
Anaesthetics have side effects that increase as more anaesthetic is given. These include falling blood pressure and reduced breathing. Your anaesthetist is present throughout the whole operation. He/she uses clinical judgement and experience to ensure that you are receiving enough anaesthetic to keep you unconscious, but not so much that you suffer serious side effects.
Anaesthetists sometimes use muscle relaxing drugs as part of the anaesthetic. These drugs stop your breathing and your anaesthetist will use a ventilator (breathing machine) to do the breathing for you. For some operations these drugs are essential as they allow the surgeon access to parts of your body that he/she could not reach without muscle relaxants. These drugs also allow lighter levels of anaesthetic to be used, and this reduces dangerous side effects. Muscle relaxants also prevent movement, and your anaesthetist uses information coming from monitors (heart rate, blood pressure, anaesthetic gas levels etc) to judge whether you are unconscious or not.
Awareness occurs if your anaesthetist misjudges the amount of anaesthetic needed to keep you unconscious. It can also happen if the equipment that delivers the anaesthetic to your body is malfunctioning, or there may be a combination of these.
How likely is it?
Careful studies, which include interviews with many thousands of patients, have been done. Most studies suggest that between 1 and 2 people per 1,000 anaesthetics experience some kind of awareness. Only a third of these people feel pain, although the experience can still be very distressing. However, a recent survey of over 80,000 patients, published in 2007 found that only 1 in 14,000 people having a general anaesthetic experience awareness. Most of the cases they found happened to people who had certain risk factors. If no risk factor is present, the risk was 1 in 42,000 anaesthetics. Awareness is more likely, (but still rare) if you are having open heart surgery, obstetric surgery (childbirth) or surgery after a major accident.
What does it feel like if it happens to me?
Over half of aware patients recollect sounds and conversations within the operating theatre.You may be unable to move and have feelings of anxiety and panic. Approximately a quarter of aware patients are aware of the insertion or presence of the endotracheal (breathing) tube in their throats.
Pain is experienced by about one third of aware patients.
Are there any long-term effects?
Many people who have been aware during a general anaesthetic suffer longterm effects. These include anxiety, fear of anaesthesia, sleep disturbances, nightmares, flashbacks and in some cases post-traumatic stress disorder.
If I think I have been aware, what should I do?
Your anaesthetist should be informed as soon as possible. You can ask your nurses, or, if you are already at home, your GP, to contact him/her. Your anaesthetist will want to know about it, and you will benefit from talking about it and understanding how it might have happened. Studies have shown that some people do not realise that they have been aware until several days later. You can still report the fact that you think you have been aware, even days later.
The anaesthetist who conducted the anaesthetic will talk to you. He/she will ask you to explain exactly what you remember. He/she will talk to you about your memories and try to work out if you have been aware or if your memories are dreams or relate to things that happened while your anaesthetist is allowing you to wake up. If you have been aware when you should not have been aware, your anaesthetist will explain to you how this might have happened. You will be offered counselling.
How can awareness be avoided totally?
If you do not have a general anaesthetic, then you cannot have unintentional awareness. Some operations can be carried out using a local or regional anaesthetic to numb part of the body. You will not need a general anaesthetic and you will be awake during the operation. Your anaesthetist will be able to tell you if these anaesthetics are suitable for you.
You can choose to have sedation with a local or regional anaesthetic. Sedation is medicine that makes you drowsy and mentally relaxed, but not unconscious. You will probably remember events in the operating theatre.
How is awareness prevented during a general anaesthetic?
At the start of the day, your anaesthetist will check all equipment to ensure it is functioning properly. Misconnections and disconnections of the breathing tubes can cause awareness. All anaesthetists are trained to spot these problems, hopefully before awareness occurs. Before the start of your anaesthetic you will be connected to a monitor that tells the anaesthetist how you are responding during the operation. Another monitor will usually be used which shows the amount of anaesthetic in your body. This monitoring equipment helps the anaesthetist judge whether you are having the right amount of anaesthetic. Monitors, which try to detect awareness by analysing brain activity, have been developed. These have been studied in a number of trials of varying size and quality.The results of the different trials do not agree. At the present time these monitors are not in routine use.
If I have had an episode of awareness, is it more likely to happen during my next anaesthetic?
Yes, you are at a slightly increased risk during your next anaesthetic. It is very important you tell your anaesthetist about your previous episode of awareness. He/she will try to ensure that you receive adequate doses of anaesthetic throughout surgery. If available, he/she may make use of additional monitors that help to decrease the likelihood of awareness.
Are there any circumstances in which awareness is more or less likely?
If you are very ill, awareness is more common.Very ill patients have a low blood pressure and anaesthetics can decrease the blood pressure further which may cause harm (e.g. heart attack or stroke). The anaesthetist may use a lighter general anaesthetic to reduce the risks to you. However, the risk of you being aware of what is going on is increased. If you take certain medications you will require more anaesthetic. These include alcohol (prolonged, heavy use), some types of sleeping tablets and morphinelike drugs. It is very important that you inform the anaesthetist of all your regular medications. Some types of general anaesthetic are more likely to be associated with awareness than others. There is not usually any choice in which kind of anaesthetic you have – it depends on what operation you are having and on your general health. Most cases of awareness leading to serious psychological upset occur in people who have received muscle relaxants. Only one study in the last 50 years has shown awareness in people who were breathing for themselves. None of these people suffered serious psychological upset as a result.
In some types of surgery the side effects of anaesthetic drugs may be particularly dangerous to you (or, if you are pregnant, to your unborn child). The risk of awareness is increased because your anaesthetist may need to use less anaesthetic. For example:
cardiac surgery (the risk may be 1 in 100)
emergency surgery for major trauma (1 in 20)
emergency Caesarean section under a general anaesthetic (4 in 1,000).
Is there anything I can do to prevent it from happening?
Ask your anaesthetist if it is possible to avoid having a general anaesthetic and have your operation performed with a local anaesthetic. You can have sedation as well to help you feel drowsy and mentally relaxed. Tell the anaesthetist about all your regular medications or drugs, especially those mentioned above, and about your alcohol intake. Also tell him/her if you think you may have been aware during any previous anaesthetic

 

 

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Serious Allergy + Anaphylaxis

When you have an anaesthetic you will receive a number of medicines, drugs or injections. During the anaesthetic you may receive injections into a vein or a muscle and anaesthetic gases. Before or after the anaesthetic, you may receive pills, tablets or liquids to swallow, injections or suppositories. You may also be given fluids into a vein to prevent dehydration and you will be in contact with anti-septics and equipment in the operating theatre.
All these things can occasionally cause allergic reactions of varying severity.

Anaphylaxis is a severe, life-threatening allergic reaction. Allergic reactions can happen in response to many things– pollen, dust, bee stings, nuts and antibiotics are common causes. These things are called antigens. Rarely, anaphylaxis can happen during an anaesthetic, either caused by one of the anaesthetic drugs or by other substances used during surgery. We meet thousands of antigens in everyday life and they usually do us no harm whatsoever. Sometimes, for reasons we don’t fully understand, the body makes substances called antibodies.
The purpose of antibody production is to help eliminate antigens, which may be harmful, from the body. Each antibody is a unique match for its own antigen, and will be produced rapidly if the antigen appears in the body in the future. This is known as sensitization. If they meet the same antigen or a very similar antigen again at a later date, the antibody-antigen combination may cause the release of histamine and other chemicals. These chemical substances released are called mediators and they can cause the symptoms of allergy. If only small amounts of mediators are released the symptoms are minor – for example, hay fever or skin rashes. If very large amounts are released very rapidly there may be severe difficulty with breathing (wheezing), low blood pressure or swelling inside the throat, and this is called anaphylaxis. Severe anaphylaxis is life threatening but, with prompt treatment, death from anaphylaxis is very rare.
Other similar types of reaction There are some reactions that cause similar symptoms, but are not due to antibody production. It can be more difficult to identify the exact cause of these reactions.
How is anaphylaxis treated?
Any medicine that might have caused the reaction should be stopped immediately.
If the pulse is weak, the affected person should be laid flat on their back and their legs should be raised. This is the quickest way to improve the blood pressure. Adrenaline is the most effective drug treatment and is given as a series of injections. In hospitals, oxygen and an intravenous drip are also used. Antihistamines, steroids and asthma treatments might be needed.
When you have an anaesthetic you will receive a number of medicines, drugs or injections. During the anaesthetic you may receive injections into a vein or a muscle and anaesthetic gases. Before or after the anaesthetic, you may receive pills, tablets or liquids to swallow, injections or suppositories. You may also be given fluids into a vein to prevent dehydration and you will be in contact with anti-septics and equipment in the operating theatre. All these things can occasionally cause allergic reactions of varying severity.
This section gives information about these reactions.
Usually the symptoms will settle down quite quickly, but continued observation will be required, often necessitating an overnight stay in hospital. Very serious reactions will require treatment in the Intensive Care Unit (ICU). If the operation has not already started, surgery will almost certainly be postponed unless it is very urgent. All anaesthetists are trained in how to treat anaphylaxis. Adrenaline is immediately available in every operating theatre.
It is extremely important that any episode of anaphylaxis is investigated in detail, so that the drug or other substance responsible can be identified and avoided in the future. Investigations include blood tests taken at the time of the reaction and then skin testing at a later date.
How frequently do anaesthetics cause anaphylaxis?
Nobody knows this exactly. At the moment, the best estimate is that a lifethreatening allergic reaction (anaphylaxis) happens during 1 in 10,000 to 1 in 20,000 anaesthetics. Most people make a full recovery from anaphylaxis. We do not know how many anaphylactic reactions during anaesthesia lead to death or permanent disability. One review article suggests that 1 in 20 serious reactions can lead to death, but this is only one person’s estimate. This would mean that the chance of dying as a result of an anaphylactic reaction during anaesthesia is between 1 in 200,000 and 1 in 400,000 anaesthetics.
What can cause anaphylaxis during an anaesthetic?
During any operation and anaesthetic, it is normal to have contact with a wide range of antigens (unfamiliar substances). Many of these could potentially cause an allergic reaction, but some are more likely to do so than others. Anaphylaxis is more likely when drugs are given intravenously.
The four most common causes of anaphylaxis during anaesthesia are:
Drugs used to prevent movement during surgery (called muscle relaxants or neuromuscular blocking agents). These drugs are only given to patients who are already anaesthetised. Antibiotics – these are often needed during surgery. Chlorhexidine, a skin antiseptic often used before surgery. Latex (a type of rubber). For many years latex has been used in the manufacture of surgical rubber gloves and other equipment used in operating theatres. Most hospitals are taking steps to reduce the number of latex containing products they use.
Your anaesthetist will choose drugs for your anaesthetic taking into account many different factors, in particular the type of operation, your physical condition and whether you are allergic to anything. All drugs, including anaesthetic drugs, are carefully tested before they are licensed for general use.
What factors could make anaphylaxis more likely?
Anaphylactic reactions during anaesthesia seem to occur more in women than in men. Allergy to certain fruits and nuts, particularly bananas, avocados and chestnuts is seen more commonly in patients who are allergic to latex. Latex allergy is also seen more often in people who have frequent exposure to latex, e.g. hospital workers and those who have had several surgical operations. Some people who have multiple allergies or allergic asthma may be more likely to experience anaphylaxis than people who have no known allergies. Most severe reactions are unpredictable.
Is allergy to anaesthetics hereditary?
No. If you are allergic to an anaesthetic drug, your children are no more likely to have the same allergy than any other person. Some very rare non-allergic problems with anaesthetic drugs can occur in families, for example ‘suxamethonium apnoea’ where some muscle relaxant drugs can last longer than usual, and ‘malignant hyperthermia’ where the body can become very hot. These are NOT allergic conditions.
Can I be tested for anaphylaxis before I have my anaesthetic?
Routine skin testing is not currently recommended. The most important reason is that a negative skin test to a particular drug does not guarantee that you will not experience an anaphylactic reaction to the same drug in the future. Skin tests are only a guide because the response of the skin to a tiny amount of the drug is not necessarily the same as giving a much larger dose of the drug directly into a vein during the anaesthetic.
A second reason is that it is possible to become sensitised to some anaesthetic drugs without ever having received the drug previously. Some common chemicals are similar to certain anaesthetic drugs. It is possible to become sensitised to these anaesthetic drugs in everyday life after the skin test has been done.
An important exception is latex allergy. If you have any symptoms of latex allergy– for example, itching or a rash after exposure to latex rubber in children’s balloons, rubber gloves or condoms – then you should be tested for latex allergy before your surgical operation.
You may already know that you are allergic to certain medicines or substances. When you come into hospital, you will be asked several times if you are allergic to anything. It is very important that you pass on this information to the health professionals looking after you. If your allergy is serious, you may be advised to wear a Hazard Warning bracelet.
If I am allergic to an anaesthetic drug, are alternative drugs available?
Yes, there are many different anaesthetic drugs and alternative drugs can almost always be given. Just occasionally a person is allergic to several muscle relaxant drugs and we advise the avoidance of all drugs of this type. If a person is allergic to an antibiotic or a skin antiseptic, suitable alternatives are available.
What should I do if I think I have had an allergic reaction during an operation in the past?
If you think you might have had an allergic reaction during or after previous surgery, it is important to try to find out whether it was an allergic reaction and what caused it. It may be possible for your GP to find out from your hospital consultant what was the cause of the problem. If your GP thinks it is appropriate, you may be referred to an allergy clinic to help to find the cause.

 

 

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Nerve Damage after General Anaesthesia

Significant nerve damage is uncommonly associated with a general anaesthetic (less than 1 in 1,000 patients). This section provides information about how nerves can be damaged during an operation under general anaesthesia, what kinds of nerve damage can happen, how likely this is, and what recovery can be expected.

The Central Nervous System comprises the brain, which acts as the‘central processor’ and the spinal cord. which carries electrical signals away from the brain to nerves supplying muscles and organs. It also carries signals from nerves which supply the sense organs towards the brain. These signals allow you to feel touch, pain, position and hot or cold.
The Peripheral Nervous System includes motor nerves (controlling muscles) and sensory nerves (bringing information about touch, pain, and other sensations). Some nerves are mixed nerves– partly motor and partly sensory.
What symptoms can be caused by nerve damage?
Peripheral nerve damage. If sensory nerves are damaged, you may feel numbness, tingling or pain.
The pain can be a continuous aching pain or a sharp shooting pain. You may also get inappropriate warm or cold sensations. If motor nerves are damaged, there may be weakness or paralysis (loss of movement) of muscles in that area. If mixed nerves are damaged, there will be a mixture of the symptoms given above.
The area varies according to the nerves affected, from a very small patch of numbness, to most of a limb being affected.
Damage to the spinal cord usually affects both muscle power and sensation, depending on where the damage has happened. Unfortunately, spinal cord damage is often extensive, with pain being a frequent feature.
Significant nerve damage is uncommonly associated with a general anaesthetic (less than 1 in 1,000 patients). This section section provides information about how nerves can be damaged during an operation under general anaesthesia, what kinds of nerve damage can happen, how likely this is, and what recovery can be expected. Control of the bowels and the bladder can also be affected.
How long do these effects last?
Peripheral nerves: This is variable.If the changes you notice are slight, they may resolve within a few days, but often it will take several weeks. Most symptoms resolve within three months. Full recovery can sometimes take up to a year or even longer. Rarely, (less than 1 in 10,000 general anaesthetics) nerve damage occurs that is permanent.
Unfortunately, damage caused by an injury to the spinal cord is usually permanent. This is very rare, occurring in less than 1 in 50,000 anaesthetics.
What are the most common nerve injuries?
The ulnar nerve of the arm is by far the most commonly reported nerve injury. It can be compressed at the elbow, where it is very close to the skin. Ulnar nerve damage causes numbness in the fourth and fifth fingers and/or weakness of the hand muscles.
The common peroneal nerve can be damaged on the outside of the leg, just below the knee. This can cause foot drop (an inability to raise the foot off the ground), and/or numbness on the front of the foot.
What can be done if there is nerve damage?
Your anaesthetist or surgeon may arrange for you to see a neurologist (a doctor specialising in nerve diseases). Tests may be done to try and find out exactly where and how the damage has occurred. This might involve nerve conduction studies (very small electrical currents are applied to the skin or muscles and recordings made further up the nerve. This shows whether the nerve is working or not.
Magnetic Resonance Imaging (MRI), Computed Tomography (CT) scanning.
The neurologist will suggest a treatment plan, which might include physiotherapy and exercise. If you have pain, drugs that relieve pain will be used. This may include drugs that are normally used for treating epilepsy or depression. These drugs help because of the way in which they change electrical activity in nerves.
Drug treatment is not always successful in relieving pain. Occasionally an operation can be done, either to repair a nerve or to relieve pressure on a stretched nerve.
How does peripheral nerve damage happen?
Compression and stretching. During the operation, you will be placed in a certain position to allow the operation to be done. For example, you may need to lie on your front to allow surgery on your back. If a nerve is stretched or compressed (pressed on or squashed), there can be nerve damage. If you were awake, you would feel this and move to relieve the discomfort. During an anaesthetic, you cannot do this.
If a tourniquet is used to reduce surgical bleeding there can be nerve damage due to compression. The pressure of the tourniquet and the time it is used should be carefully controlled to reduce the chance of this happening.
Very rarely, the nerves to your tongue can be compressed by the tube used to ensure your airway is clear, or by the process used to place the tube. The surgeon might cut a nerve, or injure it with the diathermy (cautery) instrument used to stop bleeding. Surgical instruments can also compress and/or stretch a nerve. During some operations, this may be difficult or impossible to avoid. If this is likely, the surgeon should discuss it with you beforehand.
Inadequate blood supply: Every nerve is supplied by blood vessels which keep it healthy. If these blood vessels are damaged during the operation, or if the blood supply is reduced due to pressure or stretching, the nerve can be starved of oxygen. This type of damage is slightly more likely if you have narrowing of your blood vessels generally – you may know that you have coronary heart disease or narrowed blood vessels elsewhere.
Nerves can be damaged by needles used to place an intra-venous cannula (‘your drip’) or a cannula into large veins or arteries.
Unfortunately, the mechanism of injury is unclear in the majority of cases of nerve injury associated with surgery and general anaesthesia
What is done to prevent peripheral nerve damage?
Your anaesthetist, surgeon and theatre staff take care to try and prevent nerve damage. They share the responsibility of minimising the risks by: careful padding of vulnerable areas, positioning you in a way which avoids stretching nerves as much as possible and avoiding prolonged bed rest.
What increases the risk of nerve damage?
Certain positions required for the operation, for example: lying on your front for an operation on your back, lying on your side for some operations on the chest or kidney lying on your back with your legs raised and separated – for operations in the genital area (this is called the lithotomy position), your arm being placed in position for some shoulder operations.Certain operations, including: operations on the spine or brain, cardiac or vascular operations (on the heart or major blood vessels), operations on the neck or parotid (a gland in the face, some kinds of breast operationl operations where a tourniquet is used to reduce bleeding (knee, foot, hand operations mainly).
Previous disease – a few examples. Diabetes, Rheumatoid or osteo-arthritis, Atherosclerosis (hardening and/or narrowing of the arteries), Increasing age, Being very overweight or extremely thin.
Being male – men have a higher risk of ulnar nerve damage. The reason for this is not known.
How does spinal cord damage happen?
Spinal cord damage is very rare. Unfortunately, compared to peripheral nerve injury, it is more likely to result in permanent serious disability. This is because the spinal cord cannot grow back and heal, unlike peripheral nerves which can re-grow.
Compared to peripheral nerve injury, spinal cord damage is: much more rare, more likely to be disabling, more likely to be permanent, more often associated with pre-existing disease.
How does it happen?
The main cause of spinal cord damage associated with a general anaesthetic is an inadequate blood supply to the spinal cord. Other causes of spinal cord damage during an operation are not related to the anaesthetic and happen during surgery on or near the spine itself. Inadequate blood supply to the spinal cord can happen due to: low blood pressure, a clot blocking the blood vessels, compression or stretch of blood vessels, making them narrower. These may cause oxygen starvation of the spinal cord, leading to damage. The ‘anterior spinal artery syndrome’ is caused by one or more of these factors reducing blood flow in the anterior spinal artery. If the flow of blood in this artery is very low, the front part of the spinal cord becomes starved of oxygen and may be damaged. If this is not corrected, nerve cells will die. This will result in permanent lower limb paralysis.
If you have disease of your blood vessels elsewhere (for example coronary heart disease) the risk of this happening is higher. But the risk remains very rare.
How likely is peripheral nerve and spinal cord damage?
The exact risk of nerve damage is not known. The following figures are the best information available.
The risk of a significant peripheral nerve injury lasting more than three months, is estimated to be less than 1 in 2,000 patients having a general anaesthetic.Permanent damage, lasting more than a year, is estimated to be less than 1 in 5,000. Spinal cord damage occurs in less than 1 in 50,000 patients having a general anaesthetic. More minor symptoms may occur much more frequently, perhaps as high as 1 in 100 people having a general anaesthetic, but most recover completely.

 

 

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Nerve Damage associated with Spinal or Epidural Anaesthesia

Your anaesthetist may suggest that you have a spinal or epidural injection. These injections can rarely be associated with nerve damage. This section gives you information about:
Risks associated with your anaesthetic and answers the following questions:
What is Spinal or epidural anaesthesia?
How nerve damage can happen?
What are the symptoms?
How likely is it that this will happen to me?
What recovery can be expected?

What is a spinal injection?
A needle is inserted between the bones of your back, through ligaments and then through the dura. The dura is a membrane which encloses the nerves and spinal cord. Spinal injections are usually performed near the lowest part of the spine. At this level, the spinal cord itself has ended and a bundle of nerves is present which supplies the legs and genital area. Nerves in this area are bathed in cerebro-spinal fluid (CSF). A single injection of local anaesthetic is given and the needle is removed. This injection makes you feel numb in the lower part of the body for about two hours.

What is an epidural?
A needle is used to introduce a fine catheter (tube) into your back. The needle is passed between the bones, through ligaments and into a space outside the dura. The catheter is passed through the needle into this space and the needle is removed. The catheter is taped securely to your skin. Local anaesthetic can be given through this catheter for a period of time – perhaps several days.
An epidural is used for operations which are longer than two hours or when pain relief is needed for several days.
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This section describes nerve damage associated with spinal and epidural injections. It is aimed at patients having all kinds of operations.
What types of nerve damage can happen?
Nerve damage is a rare complication of spinal or epidural anaesthesia. Nerve damage is usually temporary. Permanent nerve damage resulting in paralysis (loss of the use of one or more limbs) is very rare.
A single nerve or a group of nerves may be damaged. Therefore the area affected may be small or large.
In its mildest form you can get a small numb area or an area of ‘pins and needles’ on your skin. There may be areas of your body that feel strange and painful. Weakness may occur in one or more muscles. The most severe (and very rare) cases give permanent paralysis of one or both legs (paraplegia) and/or loss of control of the bowel or bladder. The majority of people make a full recovery over a period of time between a few days and a few weeks. Permanent damage is very rare.
How does nerve damage happen?
The ways in which nerve damage can be caused by a spinal or epidural injection are listed below:.

Direct injury caused by the needle or the catheter.
Haematoma (a blood clot).
Infection.
Inadequate blood supply.
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Direct injury can occur if the epidural or spinal needle or the epidural catheter damages a single nerve, a group of nerves or the spinal cord. Contact with a nerve may cause ‘pins and needles’ or a brief shooting pain. This does not mean that the nerve is damaged, but if the needle is not repositioned, damage can occur. If this happens you should try to remain still and tell your anaesthetist about it. The anaesthetist will change the position of the needle and the sensations will usually improve immediately. Most cases of direct damage are to a single nerve and temporary. Injecting drugs right into the nerve rather than into the area surrounding it can also cause direct damage.
Haematoma is a collection of blood near the nerve, which collects due to damage to a blood vessel by the needle or the catheter. Small amounts of bleeding or bruising are common, and do not cause damage to the nerve. A large haematoma may press on a nerve or on the spinal cord and cause damage. Occasionally an urgent operation is required to remove the haematoma and relieve the pressure. If your blood does not clot normally or you take a blood-thinning medicine (anticoagulants) such as warfarin or heparin, you are more likely to get a haematoma. You will need to stop these medicines before you can have an epidural or spinal injection. It is important that you tell your anaesthetist about any problems with blood clotting that you have had in the past as you may not be able to have an epidural or spinal injection.
Most infections related to a spinal injection or an epidural are local skin infections and do not cause nerve damage. Very rarely, an infection can develop close to the spinal cord and major nerves. There may be an abscess (a collection of pus) or meningitis. These infections are very serious and require urgent treatment with antibiotics and/or surgery to prevent permanent nerve damage. If you already have a significant infection elsewhere, or if you have a weak immune system, you have a higher risk of these serious infections. You may not be offered an epidural or spinal injection.
Inadequate blood supply: Low blood pressure is very common when you have an epidural or spinal injection. This can reduce the blood flow to nerves and, rarely, this can cause nerve damage. Anaesthetists are aware of this risk and use both drugs and intravenous fluid to prevent large drops in blood pressure.
Other causes: There have been cases of the wrong drug being given in an epidural or spinal injection. This is an exceptionally rare event.
What else can cause nerve damage?
If you have nerve damage, you should not assume that it is caused by the epidural or spinal injection. The following list shows other causes of nerve damage related to having an operation.
Your nerves can be damaged by the surgeon. During some operations, this may be difficult or impossible to avoid. If this is the case, your surgeon should discuss it with you beforehand.
The position that you are placed in for the operation can stretch a nerve and damage it.
The use of a tourniquet to reduce blood loss during the operation will press on the nerve and may damage it as may swelling in the area after the operation.
Pre-existing medical conditions, such as diabetes or atherosclerosis (narrowing of your blood vessels), can make damage more likely.
What is done to prevent nerve damage?
Anaesthetists are trained to be aware of nerve damage. Steps taken to prevent each kind of damage are described here.
All anaesthetists performing epidural and spinal injections are trained in these techniques.
Spinal injections are placed below the expected lower end of the spinal cord. This should prevent damage to the spinal cord itself. Spinal injections are usually performed while you are awake or lightly sedated.
If there is pain or tingling due to contact with a nerve, you will be able to warn the anaesthetist. Your anaesthetist may wish to do your epidural injection while you are awake. Direct nerve injury after an epidural injection is rare, and so there is no clear evidence about whether it is safer to do the epidural while you are awake or after the general anaesthetic has been given.
Haematoma: If you take an anti-coagulant (a drug which thins the blood, such as warfarin), you will be asked to stop it several days before surgery If your doctors think it is safe to do so. The anaesthetist and surgeon together will decide if and when the drug should be stopped. A blood test will allow your anaesthetist to decide if it is safe to have a spinal or epidural injection. If your anti-coagulation cannot be safely stopped, then you will not be able to have an epidural or spinal injection. If you take aspirin, you can have an epidural or spinal injection. However, your surgeon may ask you to stop taking the aspirin to help prevent bleeding during or after the operation.
Infection: All epidural and spinal injections are performed under sterile conditions, similar to those used during the operation. Your back should be kept clean and regularly checked over the next few days.
General care
If you have an epidural or spinal injection, the nurses will make regular checks until everything returns to normal. This should help spot possible nerve damage very early and if treatment is needed it can be started immediately.
If I think I have nerve damage, what can be done about it?
Your anaesthetist or surgeon may arrange for you to see a neurologist (a doctor specialising in nerve diseases). Tests may be done to try and find out exactly where and how the damage has occurred. This might involve: nerve conduction studies (very small electrical currents are applied to the skin or muscles and recordings made further up the nerve. This shows whether the nerve is working or not). He/she may also recommend that you be investigated with Magnetic Resonance Imaging (MRI) or Computed Tomography (CT) scanning.
The neurologist will suggest a treatment plan, which might include physiotherapy and exercise. If you have pain, drugs that relieve pain will be used. This may include drugs that are normally used for treating epilepsy or depression because of the way that they change electrical activity in nerves. Drug treatment is not always successful in relieving pain. Occasionally an operation can be done, either to repair a nerve or to relieve pressure on a stretched nerve.
How likely is permanent nerve damage?
The number of people known to have nerve damage is very small. The following figures are a guide:
Estimated frequency (cases per spinal/ epidural injection):
The risk of damage to nerves is between 1 in 1,000 and 1 in 100,000.
In many of these cases the symptoms improve or resolve within a few weeks or months.
The risk of longer lasting problems is (Permanent harm) is 1 in 23,500 to 50,500
The risks of Paraplegia or death are 1 in 54,500 to 1 in 141,500
Summary
Nerve damage is a rare complication of spinal or epidural injection. In the majority of cases, a single nerve is affected, giving a numb area on the skin or limited muscle weakness. These effects are usually temporary with full recovery occurring within days or a few weeks. Significant permanent nerve damage resulting in the loss of the use of your legs is very rare.
Your anaesthetist will balance this against the benefits of an epidural or spinal injection. He/she will also be able to describe the alternatives.

 

 

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Nerve Damage associated with Peripheral nerve Block

Your anaesthetist may suggest that you have a peripheral nerve block. This is an injection placed near to a nerve or group of nerves. Rarely, this may result in damage to these nerves. This section explains:
What a peripheral nerve block is?
How nerve damage can happen?
What the symptoms of nerve damage may be and how likely this is to happen as well as what recovery can be expected.

What is a peripheral nerve block?
This is an injection of local anaesthetic near to the nerves which go to the area of your operation, making the area feel numb. The injection may be used on its own, as the sole anaesthetic, or you may receive sedation or a general anaesthetic as well.
There are many types of nerve block, each one aimed at a different group of nerves. Your anaesthetist will tell you if there is a block suitable for your operation. Having talked about the benefits, risks and your preferences, you can decide together whether you would like a nerve block.
How long does the block last?
A nerve block can give pain relief for two to 18 hours depending on the site and on the drugs used. Sometimes a catheter (a very thin tube) can be passed through the needle and left in place. More local anaesthetic can then be given for a longer period – perhaps up to a few days.
Benefits of a nerve block may include a shorter recovery period, and better pain relief after your operation. This allows you to be mobile more quickly after your operation. You may not need as many strong pain relieving medicines such as morphine. This will help reduce your risk of the side effects associated with these medicines, which include nausea (feeling sick) and drowsiness.
This section describes nerve damage after a peripheral nerve block.
Permanent nerve damage is a rare complication of peripheral nerve block. Nerve damage is usually temporary, and most patients with nerve damage make a full recovery within a few days or weeks.
How does it feel to have nerve damage and what recovery can one expect?
Some people have mild changes in sensation (feeling). There may be an area of numbness or ‘pins and needles’. Sometimes there may be strange sensations or there may be pain. Uncommonly, there may be weakness in one or more muscles. Most nerve injuries are temporary, and will recover over a period of about three months. Permanent injury does occur on rare occasions. In the most serious cases there can be severe pain or permanent paralysis of the area involved.
How does nerve damage happen and what is done to prevent nerve damage?
The ways in which a nerve can be damaged are listed here, and explained below.
All anaesthetists performing nerve blocks are trained in the technique and will take steps to prevent these types of nerve damage.
Direct injury: this may happen if the needle or catheter damages the nerve. Contact with the nerve may cause ‘pins and needles’ or a brief shooting pain. This does not mean the nerve is damaged but if the needle is not repositioned damage can occur. If you are having a peripheral nerve block and a general anaesthetic, your anaesthetist may wish to do the nerve block while you are awake, before giving the general anaesthetic. This allows you to report any tingling or shooting pains that you feel. If you notice these, you should tell the anaesthetist immediately. The anaesthetist will reposition the needle and the feelings should disappear. If you have the nerve block after you are anaesthetised, the anaesthetist will take other precautions to avoid nerve damage.
Intra-neural injection (injecting drugs directly into the nerve rather than very near to the nerve) can also cause nerve damage. This would cause feelings similar to those described above. The anaesthetist may use a nerve stimulator (a small electrical gadget which is connected to a sticky pad on your skin and to the needle) to help find the correct spot for injection and to help avoid intra-neural injection. Your anaesthetist may also use an ultrasound machine to show the nerve and nearby structures on a screen. This can help to find the nerve and to place local anaesthetic near to the nerve.
Haematomas is a collection of blood near the nerve due to damage to a blood vessel by the needle or the catheter. Small amounts of bleeding or bruising are common, and do not cause damage to nerves. A large haematoma may press on a nerve and cause damage. Rarely, an urgent operation is required to remove the haematoma and stop it pressing on the nerve.
If you take blood-thinning medicines such as warfarin or clopidogrel, you are more likely to get a haematoma. Your anaesthetist will take this into account before he/she offers you a nerve block.
Inadequate blood supply: Every nerve is supplied by blood vessels, which keep it healthy. If the blood supply is damaged or reduced, the nerve may be starved of oxygen, which leads to damage. Infections are very rare. They are slightly more likely if a catheter is left in place. Sterile conditions similar to those used for the operation itself are used to help prevent infection. If a catheter is used the site should be kept clean and checked regularly by a nurse. If you have infection elsewhere or a weak immune system, you are more likely to get an infection. The anaesthetist will take this into account before he/she offers you a nerve block.
What else can cause nerve damage?
If you have nerve damage, you should not assume that it is caused by the nerve block. The following list shows other causes of nerve damage related to having an operation. Your nerves can be damaged by the surgeon. During some operations, this may be difficult or impossible to avoid. If this is the case, your surgeon should discuss it with you beforehand. The position that you are placed in for the operation can stretch a nerve and damage it. The use of a tourniquet to reduce blood loss during the operation will press on the nerve and may damage it. Swelling in the area after the operation can damage nerves. If it is a limb, elevation of the limb will help reduce any swelling.
Pre-existing medical conditions, such as diabetes or atherosclerosis(narrowing of your blood vessels), can make damage more likely.
If I think I have nerve damage, what can be done about it?
Your anaesthetist or surgeon may arrange for you to see a neurologist (a doctor specialising in nerve diseases). Tests may be done to try and find out exactly where and how the damage has occurred. This might involve: nerve conduction studies (very small electrical currents are applied to the skin or muscles and recordings made further up the nerve. This shows whether the nerve is working or not). Magnetic Resonance Imaging (MRI) or Computed Tomography (CT) scanning may help localise the injury.
The neurologist will suggest a treatment plan, which might include physiotherapy and exercise. If you have pain, drugs that relieve pain will be used. This may include drugs that are normally used for treating epilepsy or depression because of the way that they change electrical activity in nerves. Drug treatment is not always successful in relieving pain. Occasionally an operation can be done, either to repair a nerve or to relieve pressure on a stretched nerve.
How likely is permanent nerve damage?
There have been many studies looking at how often nerve damage happens in various peripheral nerve blocks. Nerve damage occurs in less than 3 out of every 100 nerve blocks (<3%). The risk varies between the different blocks. The vast majority of those affected (92–97%), recover within four to six weeks. 99% of these people have recovered within a year. Permanent nerve damage is rare and precise numbers are not available A possible estimate from the information that we do have suggests it might happen in between 1 in 5,000 and 1 in 30,000 nerve blocks. A recent review of 16 large studies reported only 1 case of permanent nerve damage.
Summary:
Permanent nerve damage after a peripheral nerve block is very rare. The most common type of nerve damage causes an area of numb skin which is very likely to resolve within a few weeks.

 

 

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Equipment Failure

This section describes the equipment used by anaesthetists. It gives information about the ways in which equipment is made as safe as possible and it describes what is done to protect you if equipment failure occurs. It also deals with the possibility of equipment transmitting an infection from patient to patient.

What equipment will be used when I have an anaesthetic?
Pipes bring anaesthetic gas (nitrous oxide), piped air and oxygen to the operating theatre. More pipes run from the wall of the theatre to the anaesthetic machine. If you are having a general anaesthetic, the anaesthetic machine mixes these gases with a volatile anaesthetic agent (a vapour). This gas mixture is delivered to the patient through a breathing system made of light plastic tubing. A plastic bacterial and viral filter is placed at the end of the breathing system and this is connected to a face mask or to a tube placed in your throat.
The breathing system may include a chemical absorber to remove carbon dioxide from the gas you breathe out, allowing the remaining gas to be used again. During some anaesthetics, you will be breathing for yourself. However, in some general anaesthetics a machine is used to take over your breathing. This machine is called a ventilator. Your anaesthetist will be able to tell you if he/she plans to use a ventilator during your anaesthetic.
Monitors are used to measure your heart rate, blood pressure, blood oxygen level and the amount of anaesthetic gases, oxygen and carbon dioxide in your breath. These measurements will inform your anaesthetist of any change in your general condition.
How am I protected from equipment failure?
An anaesthetist and a trained technician/ assistant are present and pay constant attention to you and all the equipment being used throughout your anaesthetic. In this they are assisted by audible and visual alarms which the anaesthetist should set appropriately. If a problem occurs, the anaesthetist will be in a position to identify the cause immediately, and either correct it or change to an alternative anaesthetic and/or alternative equipment.
Equipment is designed to prevent misuse or mistakes. Gas pipe connections are colour coded and non-interchangeable, thus preventing accidental administration of the wrong gas. Other connections are of standard sizes to prevent misconnections. Anaesthetic gases cannot be administered without oxygen because anaesthetic machines are equipped with a device that prevents low oxygen levels in the gas mixture that you breathe. Other design features prevent injury from certain kinds of equipment failure. For example, pressure relief valves are built into anaesthetic machines to prevent high pressure gas reaching your lungs.
It is the responsibility of the anaesthetist to check anaesthetic equipment at the beginning of each operating session and before each new patient. The Association of Anaesthetists has published guidelines on checking anaesthetic machines and these form an important part of anaesthetic training and practice.
A record is kept, with the anaesthetic machine, that this has been done. All equipment failures that cause harm or could have caused harm should be reported as a ‘critical incident’. Critical incidents include any unwanted event that happens during hospital care which may or could have caused harm to a patient. All hospitals have important processes which monitor and investigate critical incidents looking for ways to improve patient safety.
Anaesthetic machines and monitors are fitted with comprehensive alarm systems. These emit both visual and audible signals, which are appropriate in terms of urgency, loudness and specificity. An alarm will go off when there has been a specific machine failure, or if a quantity being measured deviates from an expected normal value (e.g. a falling blood pressure).
If equipment fails, is alternative equipment available?
A back-up oxygen cylinder is attached to every anaesthetic machine and can be used immediately in the event of an oxygen supply failure.
If the anaesthetic gas supply fails, drugs may be given into a vein to maintain anaesthesia until the problem is resolved or the operation is over.
If the ventilator (the breathing machine) fails, a self inflating bag and valve system can be used by the anaesthetist to supply oxygen and air manually to the patient. Replacement equipment and technical assistance are also available in the theatre area.
If there is an electric power failure, a generator should take over immediately without any loss of power supply to the equipment. This is tested regularly. But, as already stated, oxygen and anaesthetic agents can be given using equipment that is operated manually and is not dependent on an electricity supply.
What type of failures can occur?
Unexpected equipment failure is uncommon. In an investigation of 83,154 anaesthetics given over a five-year period, equipment problems were found in 191 One third of problems involved the anaesthetic machine, with the most common being leakage from the breathing system or disconnection of the breathing system. The next most common problem was with blood pressure equipment. In one quarter of equipment problems, human error was involved. It is very rare for equipment failure to have serious consequences for the patient.
Is there a risk of infection from the equipment?
Anaesthetic equipment can transmit disease. Some items are used for only one patient and are then thrown away. Other items are cleaned in one of three ways. They may be: washed, disinfected, fully sterilised.
The method used will be determined by the hospital or national policies and depends on what the contamination is and what disease could possibly be transmitted. The breathing system attached to the anaesthetic machine is changed at least very week. The bacterial and viral filter is disposable and a new one is used for each patient. Filters have been shown to prevent bacterial and viral contamination of the breathing system. However, if the patient is known to a have a serious lung infection (such as TB), the complete breathing system is discarded after the anaesthetic.
New variant Creutzfeldt-Jakob disease is resistant to the methods of sterilisation currently used. No cases of infection with this very rare disease via anaesthetic equipment have been published so far.
Summary: Anaesthetic equipment can fail, however sophisticated it may be. Human error may play a part in equipment problems. The number of equipment problems is low, and they very rarely cause serious harm to patients.
The continued presence of a vigilant anaesthetist combined with equipment checks, appropriate monitoring and activated alarms, is the most important factor in keeping patients safe when equipment fails.

 

 

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Death or Brain Damage

This section provides information about the risk of dying or getting significant brain damage during an anaesthetic. It can be difficult to separate the risks of surgery and the risks of the anaesthetic when considering what happens during an operation.

Why do deaths occur during general anaesthesia?
There are four main reasons.
There may be things about your health or the type of operation you are having that increase the risk of dying during a general anaesthetic. For example, death is more likely if: you are older, you need major surgery on your heart or lungs, your brain, your major blood vessels, or your bowels or you need emergency surgery, including surgery for major trauma and if you are very unwell before your operation.
There may be an unexpected allergic reaction to the anaesthetic drugs that are given. Life-threatening allergic reactions occur in less than 1 in 10,000 general anaesthetics, and many are followed by a full recovery.
The surgeon may find that the surgery is very difficult to achieve without damage or he/she may make an error during the operation. Specific risks of your operation should be explained to you before you sign your consent form.
After the risks have been explained to you, you can decide whether you want to go ahead with the operation.
The anaesthetist may make a misjudgment or an error, perhaps by giving too much of a drug or giving the wrong drug. Modern anaesthetic techniques, training, monitoring and equipment mean that deaths caused by anaesthetic errors are very rare, occurring in about 1 in 185,000 general anaesthetics.
What is the risk of dying during a general anaesthetic?
If you are a healthy patient, who is having non-emergency surgery, the short answer is that death is very rare.
If you are having surgery as a day-case patient (going home the same day), the risk of death from general anaesthesia is even lower. This is because if you have been accepted for day-case surgery you will be reasonably healthy and you will not be having major surgery.
As already stated, the risk increases: l if you are older, if you are having major or emergency surgery.
Death or brain damage is more likely if you have previous problems with your health, especially heart or lung disease or if you were ill or injured before the operation. However, the risk of dying is still usually low. The risk of a child dying from a general anaesthetic is quoted as roughly 1 in 40,000. However, if the child is healthy and having nonemergency surgery, their risk of dying is approximately 1 in 100,000 general anaesthetics.
What is the risk of getting brain damage due to a general anaesthetic?
Dizziness, drowsiness, headache and confusion are relatively common shortly after general anaesthesia, and in a small number of patients may persist for days, weeks or even months. However, this does not mean that brain damage has occurred.
If you are a healthy patient having nonemergency surgery, severe brain damage is very rare. Exact figures for this risk do not exist. It can lead to permanent damage to the brain which can cause inability to think, feel or move normally. However, the risk of having a stroke that causes brain damage during general anaesthesia increases: for those who are elderly, for anyone who has had a previous stroke, for those having surgery to the brain or head and neck, carotid artery surgery or heart surgery.
Most strokes occurring around the time of surgery are not directly related to the general anaesthetic. Most strokes occur two to ten days after surgery and are due to the combined after-effects of the surgery and the anaesthetic together with the condition of the patient before the operation.
What precautions are used to prevent death and brain damage from occurring?
Drugs used by anaesthetists have effects not only on the brain (causing unconsciousness) but also on other body organs. They affect the heart, the blood pressure, breathing and lung function and other organs such as the kidney. It is usually these other effects that increase the risk of death or brain damage during the anaesthetic.
Anaesthetists are trained to use anaesthetic drugs with care, taking into account all relevant factors. Your anaesthetist will assess your condition before the operation to make sure that the drugs and techniques used are as safe as possible for you. He/she stays beside you throughout the whole anaesthetic and can adjust the anaesthetic and other treatments to keep you safe and healthy.
To help the anaesthetist, a number of monitors are used to measure heart and lung function. Your physical state is monitored before the anaesthetic starts, during the anaesthetic, and afterwards into the recovery period.
The anaesthetist chooses the appropriate doses of drugs according to the information obtained from the monitors and his/her experience and clinical judgement.
Is there anything I can do to prevent the risk of death or brain damage?
If you require emergency surgery, the short answer is: not much. However, if you are having nonemergency surgery, then anything that you can do to improve your physical condition will reduce the risks associated with anaesthesia.

 

 

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Headache after Spinal / Epidural Anaesthesia

Many people have epidurals or spinals for surgery. Uncommonly, a headache may develop following the procedure. This section explains the causes, symptoms and treatment of the headache

What is special about the headache?
Headaches after surgery or childbirth are common. However, after having an epidural or spinal anaesthetic, you have a 1 in 100 to 1 in 500 chance of developing a ‘post dural puncture’ headache depending on your age, procedure and other circumstances.
This typically occurs between one day and one week after having the epidural or spinal anaesthetic. It is usually a severe headache (felt at the front or back of your head) which gets better when lying down and worse on sitting or standing. Along with the headache you may experience neck pain, sickness and a dislike of bright lights.
Young patients and women during childbirth are more likely than other people to have a post dural puncture headache.
What causes the headache?
Your brain and spinal cord are contained in a bag of fluid. The bag is called the dura and the fluid is called the cerebro-spinal fluid (CSF).
When an epidural is given, a needle is used to inject local anaesthetic just outside the dura. Occasionally the needle passes through the dura: the chances of this happening depend on the experience of the anaesthetist and certain patient related circumstances.
When a spinal is given, a fine needle is inserted into the dura deliberately to inject local anaesthetic into the CSF.
If too much fluid leaks out through the hole in the dura, the pressure in the rest of the fluid is reduced. If you sit up, the pressure around your brain is reduced even more. This decreased pressure can cause the symptoms typical of a post dural puncture headache.
Some patients describe it as like a very bad migraine which is made worse when sitting or standing up.
What can be done about the headache?
Lying flat and taking simple pain relieving drugs (such as paracetamol and ibuprofen) may help. You should drink plenty of fluid (some people find tea, coffee or cola especially helpful) and avoid lifting and straining.
Although the hole in the dura will usually sealover in a number of weeks but it is not usually advisable to wait for this to happen. Rarely, further complications can occur due to the leaking fluid.
A new medical modality of treatment which entails the patient receiving 1 or 2 intravenous doses of "Neostigmine" and "Atropine" may be effective in a large percentage of post-dural puncture headaches, but if this fails - it is advisable to perform an ‘epidural blood patch’.
What is a blood patch?
The anaesthetist takes blood from your arm and injects it into your back, near to the hole in the dura. The blood will clot and tend to plug the hole. Relief of the headache may be instantaneous. The injected blod / clot may support the spinal cord until such time as the pressure within the CSF is sufficient. Having a "blood patch" feels similar to having the original epidural or spinal injection. It takes about half an hour to do. In 60–70% people who have this kind of headache, the blood patch will cure the headache within 24 hours. After this, if you still have a headache, you may be advised to have a second blood patch. It is very rare to need more than two blood patches. In some people, the headache goes away, but it then returns. A second blood patch may then help. After a blood patch, some anaesthetists recommend that you lie flat in bed for 4 hours and do not lift anything heavy for at least two days.
What problems are associated with a blood patch?
A blood patch may cause local bruising and backache which lasts for a few days. Neither epidurals nor blood patches cause chronic longterm backache.
There is a small chance that another accidental dural puncture could occur. Infection or bleeding into your back are very rare complications of epidurals, spinals and blood patches.
Difficulty passing urine, severe pain or loss of sensation in your back or legs is not normal and you should contact your anaesthetists or other doctor immediately.

 

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The Royal College of Anaesthetists