This section explains:

  • what a spinal anaesthetic is
  • how it works
  • the benefits and risks of having one for your operation

For many operations, patients receive a general anaesthetic that will help you fall into a deep state of controlled unconsciousness.

Spinal anaesthetic, or spinal is a type of anaesthetic usually used for operations below the waist.

This is done with an injection in your back that makes you numb from the waist downwards, meaning that you will not feel the operation being done.

This is often safer and more comfortable for patients but this will depend on your medical conditions and the operation you are having.

Some common operations that are suitable for spinal anaesthetic include:

  • Orthopaedic surgery involving your leg, e.g. hip and knee joint replacements, leg bone or ankle surgery
  • General surgery for groin hernias, haemorrhoids
  • Vascular surgery involving blood vessels in your legs such as varicose vein surgery
  • Gynaecological surgery
  • Urological surgery such as bladder or prostate surgery and any genital surgery such as circumcision
  • Obstetric surgery – caesarean section

For patients who have their operations under spinal anaesthetic, they can be:

  • Fully awake
  • Sedated using drugs to help you feel relaxed and sleepy but still able to respond
  • Fully anaesthetised (controlled unconsciousness under general anaesthetic)

Your anaesthetist will help you decide which of the above would be most suitable for you.

Why have a Spinal?

Advantages over a general anaesthetic include:

  • Less risk of chest infection after surgery
  • Less harmful effect on your lungs and breathing
  • Good pain relief after surgery with lower need for strong pain killers, which can sometimes cause sickness, drowsiness and confusion
  • Earlier return to eating and drinking after surgery
  • Less risk of confusion after surgery, especially if you are an older person

When is a Spinal not suitable?

Even though your operation may be suitable for a spinal anaesthetic, there are some medical conditions or medications that make a spinal unsuitable or unsafe for you.

Your pre-operative assessment nurse will usually highlight this to the anaesthetist and your anaesthetist will discuss this with you before your operation.

What does a Spinal involve?

A local anaesthetic drug is injected through a small needle in your lower back to numb the nerves from the waist down. Generally, the spinal lasts around 2 to 3 hours. This can be changed depending on the drug we use. How much you get depends on the type of operation you are having and how long you are having it for.

Additional pain killers can also be taken to help with the pain relief after your operation.

How is a Spinal performed?

Your anaesthetist will discuss this with you on the day of the operation beforehand.

The spinal is usually done in an anaesthetic room but may be done in the operating theatre. Your anaesthetist will place a small plastic tube (a “cannula” or “drip”) into a vein, usually in the back of your hand or arm.

The anaesthetic assistant will apply monitoring equipment to observe your heart rate, blood pressure and oxygen level. You will then be helped into position for the spinal anaesthetic to be performed; this is either sitting up on the side of the bed with your feet resting on a stool or lying on your side with your chin tucked in and knees brought up to your chest.

Your back will be cleaned with a cold disinfectant. A local anaesthetic injection is then made at the skin to make the spinal injection more comfortable for you.

Your anaesthetist will explain the procedure as it occurs and a nurse or healthcare assistant will also be there to assist and reassure you during the injection.

It usually takes around 5 to 10 minutes to perform the procedure, occasionally individual factors make it harder to find the correct place for the spinal injection and may take longer.

Will I feel anything during the Spinal?

Spinal anaesthetic is no more painful than having a blood test, especially with a local anaesthetic injection at the skin.

Most patients do not feel anything other than a warm sensation in their legs or buttocks as the spinal anaesthetic takes effect.

Occasionally, pins and needles or an electric sensation may be felt as the spinal needle brushes next to a nerve.

It is important to try to stay still and avoid sudden movement throughout the injection. If you experience any abnormal sensation, tell your anaesthetist.

Once the spinal injection is made, you will usually be asked to lie flat or on a particular side. It can take 5 to 20 minutes for the spinal anaesthetic to be fully effective for your operation.

Your legs will gradually go from numb to touch to completely weak. You will not be able to move your legs or feel pain below the waist when the spinal anaesthetic is working.

Testing the Spinal

Your anaesthetist will use a range of simple tests to assess whether your spinal is working effectively.

This may be asking you to try and move your legs to testing your legs with cold spray on the skin.

During the operation

Once the spinal anaesthetic is working effectively, the team will help move you into the correct position for the operation.

Oxygen through a plastic facemask may be used to improve the oxygen levels in your blood.

If the decision is made to stay awake or to use light sedation during the operation, you may be aware of the normal background noise in the operating theatre.

You are invited to bring your own music and headphones to listen with during the operation.

A general anaesthetic may still be needed if:

  • The spinal anaesthetic cannot be performed
  • The spinal anaesthetic does not work adequately
  • The surgery is more complicated or takes longer than expected

After the Operation

It can take a few hours before the spinal anaesthetic wears off and normal feeling returns. As it wears off, you may feel a tingling sensation in the areas that were previously numb.

It is important to ask for help from the ward nurse to help get out of bed when the spinal first wears off.

If you start to experience discomfort or pain around the surgical area whilst the spinal is wearing off, it is important to ask for pain killers early before it becomes too sore.

Side Effects and Complications

Like all anaesthetic techniques, there is a risk of side effects or complications.

Very common to common side effects

  • 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 nurses 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. If there is difficulty in passing urine, 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 happen 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.

Common Questions

Can I eat and drink before my spinal?

You will be asked to follow the same rules as if you were having a general anaesthetic (see Fasting for Surgery section). This is because there is a chance of changing from a spinal to a general anaesthetic for your operation.

Will I see what is happening to me?

A screen is usually placed across your body at chest level so that you cannot see the surgery. Some operations that involve cameras and telescopes may be projected to a screen and some patients like to see what is happening if there is a spare screen.

Do I have a choice and can I refuse a spinal?

Your anaesthetist will discuss with you your preference and needs for surgery. Your overall medical conditions will be assessed and your anaesthetist may advise why a spinal anaesthetic may be a safer option and better for your recovery.

He/She will answer any questions about the anaesthetic you have and discuss any worries you might have about a spinal anaesthetic.

If after this you are still unhappy about a spinal anaesthetic, you can always say no.

Will I feel anything during the operation?

Your anaesthetist will not let surgery to begin until he/she is satisfied that the spinal is working properly. You should not feel any pain during the operation but you may be aware of movement or pressure as the surgical team carry out their work.

Should I tell the anaesthetist anything during the operation?

Yes, your anaesthetist will want to know about any sensations or other feelings you experience during the operation. They will make adjustments to your care throughout the operation and be able to explain things to you.

For more information about spinal and other anaesthetic related topics, please visit: