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Anaesthesia is required to produce conditions that allow your surgery to take place. The conditions required include loss of sensation (inability to feel pain) and immobility (inability to move the shoulder and upper arm voluntarily). Not all types of anaesthesia make you unconscious and it can be directed to specific parts of the body. Drugs that cause anaesthesia work by blocking the signals that pass to your brain along nerves. As the drugs wear off you will start to feel sensations again including pain. Good pain relief is important. It prevents suffering, helps you recover more quickly and decrease complications. Your anaesthetist will provide a plan to ensure pain relief after the surgery.

Your anaesthetist will see you before your operation and discuss your anaesthetic with you. The choice of anaesthetic depends on many factors (your surgery, your physical health, your preferences, your anaesthetist's recommendations and the equipment, staff and other resources at your hospital).




General anaesthesia is a state of controlled unconsciousness most commonly produced by injecting drugs in to a vein. Occasionally people prefer to breathe anaesthetic gases instead. During this time of "sleep" you should be aware of nothing and feel no pain.

At the end of the surgery the drugs wear off and you will wake up and at this point you may feel pain. In order to minimise this pain relieving drugs (analgesics) are also given when you are asleep (morphine like drugs, paracetamol and anti-inflammatory drugs such as voltarol). Shoulder surgery can be very painful and but it is not possible to predict how much pain any individual will have before the surgery.

Once back on the ward pain relief will be given in tablet form and injections may also be required. Occasionally a special machine controlled by you will be used which allows you to administer a small dose of morphine according to your need (PCA, patient controlled analgesia). Severe pain and morphine often make people feel nauseous.




This involves directing anaesthesia specifically to the shoulder and arm. The procedure is called an Interscalene Block and involves an injection in the neck on the same side as the surgery is to be performed.

The skin is cleaned with a cold antiseptic solution. Next the skin at the site of injection is numbed using local anaesthetic and sedatives are given if required to minimise any discomfort during the procedure. A needle is then directed in the neck and the nerves supplying the shoulder are located. This is achieved by applying a tiny electrical current to the needle. When the needle is placed close to the nerve supply of the arm the muscles of the arm will twitch. This technique greatly enhances the effectiveness of the block and in conjunction with you being awake ensures maximum safety. The block becomes fully effective after about 20 minutes and lasts for up to 24 hours.

During this 24 hour period, usually the most painful, you will have excellent pain relief with no side effects of other pain relieving (analgesic) drugs such as morphine. Because of this it is essential to take other painkillers before the block has completely worn off so that pain relief is maintained beyond the first 24 hours.

It is also important to remember that your arm will be numb for 24 hours. You must therefore take care to protect it from burns, cold or pressure, as you will not have the sensations that normally warn you of such dangers.




Risks can be considered in many ways.

Very Common = 1 in 10

Common = 1in 100 = 3 balls in the UK lottery

Uncommon = 1 in 1000 = 4 balls in the UK lottery

Rare = 1 in 10 000 = death by traffic accident

Very Rare = 1 in 100 000 = death by murder

Extremely Rare = 1 in 1 000 000 = death by rail accident

The general and regional anaesthetic techniques used today are very effective however you must be aware that risks from the anaesthetic drugs and procedures exist.


Anaesthesia provides benefits of allowing surgery to take place, removing pain and other sensations. The benefits need to be considered against the risk and everyone varies in the risks they will accept. The risk to you as an individual depends on your general state of health and any pre-existing medical problems you have, lifestyle factors such as smoking or obesity and the complexity of surgery to be performed.

To understand risk you have to know the likelihood of the problem occurring, how serious the problem is and how the problem could be treated. Anaesthetic risks fall in to two categories: side effects and complications. Side effects are known effects of drugs or treatment that can often be predicted and anticipated but not always avoided e.g. nausea following administration of morphine. Complications are unexpected or unwanted effects of treatment that although known about cannot be predicted for any individual patient e.g. allergic drug reactions.


Below is a summary of the side effects and complications associated with anaesthesia for shoulder surgery. An estimate of the risk of each problem is given. Note that different risks exist for regional and general anaesthetic. If you would like to know more about a particular problem, its seriousness and treatment please ask your anaesthetist.


* Nerve damage can occur with both types of anaesthetic. Nerves can also be damaged as part of the surgery or as a result of previous shoulder injury, which may be the reason surgery is required. With respect to the anaesthetic the damage is usually temporary with recovery over a period of weeks to months. General anaesthetics and regional anaesthetics carry the same risk of temporary nerve damage (between 1 in 10 and 1in 100 cases). Occasionally the damage will not recover becoming permanent and the risk of this is about 1 in 5000 cases (uncommon / rare).

** Uncommonly (1 in 1000 cases) local anaesthetic can be injected in to the wrong place (a blood vessel or into the fluid that surrounds the spine). The chances of this happening are minimised through the use of a nerve stimulator to locate the nerve as described above. This is potentially a very serious complication, however if detected when little anaesthetic has been injected the effects are minimised. This is why the block is performed with you awake as the best way to detect the problem is through talking to you as the injection is performed.


More information about anaesthetics can be found in information leaflets entitled "You and your Anaesthetic" and "Anaesthesia Explained" these should be available in the hospital or can be found at on the Internet.