SPINAL ANAESTHESIA

For many operations, patients receive a general anaesthetic, which produces a state of controlled unconsciousness during the operation.

As an alternative, for operations below the waist, you can have a spinal anaesthetic. This is when an injection is placed in your back, which makes you numb from the waist downwards. This means you cannot feel the operation being done. Depending on your medical condition and the operation you are having, this may be safer or more comfortable for you.

During your spinal anaesthetic, you can be:

fully awake,
sedated – drugs make you relaxed and sleepy but not unconscious,
fully anaesthetized (unconscious).

Your anaesthetist can help you decide which of these would be best for you. Almost any operation below the waist is suitable for a spinal anaesthetic. Depending on your personal health, there may be benefits to you from having a spinal anaesthetic. Your anaesthetist is there to discuss this with you and help you make a decision as to what suits you best.

A spinal anaesthetic is often used for:

Orthopedic surgery on joints or bones of the leg.
Groin hernia repair, varicose veins, hemorrhoid surgery (piles).
Vascular surgery: operations on the blood vessels in the leg.
Gynecology: prolapse repairs and some kinds of hysterectomy.
Obstetrics: caesarean section.
Urology: prostate surgery, bladder operations, genital surgery.

What is a spinal?

A local anaesthetic drug is injected through a needle into the middle of your lower back, to numb the nerves from the waist down to the toes for two to three hours. Other drugs may be injected at the same time that prolong pain relief for many hours.

How is the spinal performed?

1. Your anaesthetist will discuss the procedure with you beforehand on the ward.
2. In the anaesthetic room, you will meet an anaesthetic assistant who will stay with you during your time in the theatre.
3. The spinal may be done in the anaesthetic room or in the operating theatre.
4. Your anaesthetist will use a needle to insert a thin plastic tube (a ‘cannula’) into a vein in your hand or arm.

5. You be helped into the correct position for the spinal. You will either sit on the side of the bed with your feet on a low stool or you will lie on your side, curled up with your knees tucked up towards your chest.
6. The anaesthetic team will explain what is happening, so that you are aware of what is taking place ‘behind your back’.
7. The anaesthetist will give you the spinal injection. Local anaesthetic is used in the skin to make the spinal injection more comfortable. A nurse or healthcare assistant will support and reassure you during the injection.
8. As the spinal begins to take effect, your anaesthetist will test its effectiveness.

What will I feel?

A spinal injection is often no more painful than having a blood test or having a cannula inserted. It may take several minutes to perform.

Most patients feel no abnormal sensation but as the injection is made you may feel pins and needles or a sharp pain in one of your legs – if you do, try to remain still, and tell your anaesthetist.
When the injection is finished, you will be asked to lie flat. The spinal works quickly and is usually effective within five to ten minutes.
To start with your skin feels warm, then numb to touch and then gradually your leg muscles become weak.
When the injection is working fully, you will be unable to move your legs or feel any pain below the waist.

Testing the block

Your anaesthetist may use a range of simple tests to see if the block is working properly.
He/she may spray a very cold liquid on your skin and ask you what you can feel. He/she may ask you to distinguish between cold and wet sensations from the spray. Please try and simply describe what you can feel and where. If the feeling of cold is lost at this early stage, this is a good sign that the spinal will work well for the surgery.
He/she may also ask you to try and move your legs. If you cannot move them, then the spinal is working very well. If you still have some movement, the anaesthetist will decide if this is significant.

Only when the anaesthetist is satisfied that the anaesthetic has taken effect will he/she allow the surgery to begin.

During the operation

In the operating theatre, a full team of staff will look after you. If you are awake, they will introduce themselves and try to put you at your ease.
You will be positioned for the operation. Please tell your anaesthetist if there is something simple that will make you more comfortable, such as an extra pillow or armrest.
You may be given oxygen to breathe via a lightweight, clear plastic mask, to improve oxygen levels in your blood.
You will be aware of the ‘hustle and bustle’ of the operating theatre when you come in. Once surgery starts, noise levels drop. You will be able to relax, with your anaesthetist looking after you.
You can listen to music if you wish during the operation. Feel free to bring your own music, with headphones.
You can communicate with the anaesthetist during the operation. If an operating camera is used, and there is an extra screen, you may be able to watch the operation on the screen, if you want to.
Alternatively, you may be receiving sedation during the operation. You will be relaxed and sleepy but not unconscious.

However, you may still need a general anaesthetic if:

Your anaesthetist cannot perform the spinal to his/her satisfaction.
The spinal does not work adequately in the area of the operation.
The surgery is more complicated or takes longer than expected.

After the spinal

It takes one to four hours for sensation (feeling) to return to the area of your body that is numb. You should tell the ward staff about any concerns or worries you may have.
As sensation returns, you may experience some tingling in the skin as the spinal wears off. At this point, you may become aware of some pain from the operation site and you should ask for more pain relief before the pain becomes too obvious.
You may be unsteady on your feet when the spinal first wears off. Please ask for help from your nurse when you first get out of bed.
You can normally drink fluids within an hour of the operation and may also be able to eat a light diet.

Why have a spinal?

Advantages compared to having a general anaesthetic. There may be:

less risk of a chest infection after surgery,
less effect on the lungs and the breathing,
excellent pain relief immediately after surgery,
less need for strong pain-relieving drugs. This is because the local anaesthetic and any pain relief drugs given in the spinal reduce the need for pain relief medicines given in other ways, which tend to have many more side effects, including nausea, confusion, drowsiness and constipation,
less sickness and vomiting,
earlier return to drinking and eating after surgery,
less risk of becoming confused after the operation, especially if you are an older person.

Side effects and complications

As with all anaesthetic techniques, there is a possibility of unwanted side effects or complications.

Very common and common side effects:

These may range from trivial to unpleasant, but can be treated and do not usually last long.

Low blood pressure – as the spinal takes effect, it can lower your blood pressure. This can make you feel faint or sick. This will be controlled by your anaesthetist with the fluids given through
your drip and by giving you drugs to raise your blood pressure.
Itching – this can occur as a side effect of using morphine-like drugs in combination with local anaesthetic drugs in the spinal anaesthetic. If you experience itching, it can be treated. Please let the staff know if you are itchy.
Difficulty passing water (urinary retention) – you may find it difficult to empty your bladder normally for as long as the spinal lasts. Your bladder function returns to normal after the spinal wears off. You may require a catheter to be placed in your bladder temporarily, while the spinal wears off and for a short time afterwards. Bowel function is not affected by the spinal.
Pain during the injection – if you feel pain in places other than where the needle is – you should immediately tell your anaesthetist. This might be in your legs or bottom, and might be due to the needle touching a nerve. The needle will be repositioned.
Headache – there are many causes of headache after an operation, including the anaesthetic, being dehydrated, not eating and anxiety. Most headaches get better within a few hours and can be treated with pain relieving medicines.

A severe and important headache can occur after a spinal injection. In young women having a spinal for childbirth it happens in around 1 in 200 or 300 spinals. It is much less common in older people having a spinal. This headache gets worse on sitting or standing and improves if you lie down. If this happens to you, you need to see an anaesthetist for assessment. If you are still in hospital, your nurses and the surgical team will organise this for you. If you have left hospital, you should seek help from your GP or by attending the emergency department.

Rare complications

Nerve damage – this is a rare complication of spinal anaesthesia. Temporary loss of sensation, pins and needles and sometimes muscle weakness may last for a few days or even weeks but almost all of these make a full recovery in time.

Permanent nerve damage is rare (approximately 1 in 50,000 spinals). It has about the same chance of occurring as major complications of having a general anaesthetic.

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Spinal Anaesthesia