A spinal injection can be used instead of going to sleep with a general anaesthetic. Some illnesses, like bad lung disease, may make a general anaesthetic unsuitable or more risky.
You may prefer to have a spinal injection, instead of going to sleep with a general anaesthetic.
What is a spinal?
A spinal is a type of anaesthetic. It makes part of the body pain free without you going to sleep. We put a small needle into your back, close to the spinal cord and the nearby nerves. The needle goes into the fluid that bathes the spinal cord, hence the name spinal.
We inject drugs through this needle to stop the spinal cord and nerves sending pain signals up to the brain. You will not feel any pain in either side of your body below a certain level. The level will depend on how far up the spinal cord the drugs are reaching.
The drugs will block other feelings apart from pain. They also block signals to the muscles. Your lower body will be numb and your legs will feel weak and clumsy. You may not be able to move your legs at all.
Once the drugs wear off, normal sensation and muscle power will return. This happens within an hour or two, after the operation is finished.
You will be awake during the operation. We can give sedative drugs into your arm vein drip, to make you feel more relaxed.
The aim is to numb your lower body to allow you to have a pain free operation without the risks of a general anaesthetic.
You can avoid the risks of a general anaesthetic, where you are asleep for the operation. Compared with a general anaesthetic, a spinal causes less sickness. It also allows you to keep a clear head so that you feel normal again more quickly. This allows you to eat, drink and be up and about as soon as possible.
You can have the spinal simply for preference if your surgery is suitable. Some patients prefer to be awake during their surgery.
Smokers benefit from a spinal, as they do not need to breathe the irritant gases of a general anaesthetic. They may upset the lungs and cause coughing after the operation.
Are there any alternatives?
There are several alternatives to a spinal:
Epidural - It may be suitable to perform an epidural, which also involves placing a needle into the spinal canal. This method involves threading a plastic tube (catheter) through the needle, which allows medications to be given down the tube several times. This allows longer operations to be performed than with a spinal. The tube lies just outside the covering of the spinal cord, which is called the dura, hence the name epidural. The epidural catheter can also be left for several days after the operation and can provide pain relief for this time.
General anaesthetic - You can have a general anaesthetic, where you are completely asleep throughout your operation. Strong painkillers, such as morphine, can be given to keep you comfortable when you wake up. There may be a medical reason why this is not suitable and this should be discussed with your anaesthetic doctor.
Regional anaesthetic - Another method is to make individual nerves go numb temporarily. This could be your whole leg. This makes a small region of the body numb, hence the name ‘regional anaesthetic’.
Local anaesthetic - Sometimes, if the surgery is minor, local anaesthetic injections can be used to numb the operation area only.
Hypnosis - More recently, some patients have used hypnosis to help them during an operation. Very few people can tolerate operations with hypnosis alone, but it may assist with the relief of anxiety, when used with other nerve blocking methods.
Whether any of these alternatives are suitable, depends on the part of the body to be operated on. The length of the procedure is also important. All of these methods can be used with sedation into a vein to help relieve anxiety.
If you are to have one of these procedures there is another information leaflet that will tell you more about it.
Who should have it done?
The general reasons for having a spinal are listed below:
Where you have had a previous problem with a general anaesthetic.
Where you have moderate to severe lung disease.
Where you have any other illness that may be made worse by a general anaesthetic, for example bad asthma or kidney disease.
There are some very specific reasons for performing a spinal. The most common reason is when a baby is delivered by caesarean section. The mother can bond with the child immediately after the operation because they are both awake. Also, the drugs given to the mother for a spinal do not affect the baby. A general anaesthetic would affect both mother and baby.
Another reason for using a spinal is when there is a definite history of allergy to the general anaesthetic gases. There is a relatively rare, but serious condition, that runs in families called ‘malignant hyperpyrexia’. Anaesthetic gases and other drugs used in a general anaesthetic can cause a severe temperature rise in patients who suffer from this disease.
Who should not have it done?
If you are unwilling to have a spinal and a general anaesthetic would be safe, then a spinal need not be performed.
Patients with the conditions listed below, should not have a spinal.
Medication that prevents your blood from clotting, such as Warfarin; this would lead to more bleeding than normal. Bleeding around the spine is a serious problem and must be avoided.
An illness that prevents your blood from clotting, such as haemophilia; this would lead to more bleeding than normal around the spine.
Infection of the skin over the site where the needle needs to be put in; this could lead to further infection in the deeper tissues and possibly blood poisoning. This could also cause infection around the spine.
A blood born infection from which you may be suffering e.g. MRSA. This is a bug that resists treatment with standard antibiotics. This also may infect the spinal cord area.
Unusual or difficult spinal anatomy; this would make it difficult to put the needle in the correct place.
A spinal cannot safely give pain relief above the upper part of the chest because it causes a fall in blood pressure at this level. It may also make breathing difficult, by blocking the nerves that work the chest muscles.
Author: Dr Sean White FRCA. Consultant in pain and anaesthesia
© Dumas Ltd 2006