Having a spinal anaesthetic for an operation
(Also known ‘a spinal’.)
What is a spinal anaesthetic?
A spinal anaesthetic is an injection into the lower back. A local anaesthetic numbing drug is injected into the fluid that surrounds the nerves at the base of the spine. The lower half of the body becomes numb for two to three hours. A spinal anaesthetic can be used instead of a general anaesthetic for a number of operations on the abdomen (tummy) and legs. You can normally choose either to remain fully conscious during the operation, or to have some sedation that makes you relaxed and drowsy.
What does it involve?
Your anaesthetist will tell you what he/she is going to do:
- First a needle is used to insert a small plastic tube (a drip) into your hand or arm.
- You will be helped into the correct position for the spinal injection; either sitting, or lying on your side, curled up with knees tucked up towards your chest.
- When the injection is finished, you normally lie flat as it works quickly. The skin becomes numb and the leg muscles are weak. You will be unable to move your legs or feel any pain below the waist.
What will I feel?
- Your anaesthetist will clean the lower back with an antiseptic cleaning solution that feels very cold. Then some local anaesthetic is injected into the skin that may sting but afterwards you should just feel pushing when the spinal injection is performed. Your anaesthetist will ask you to remain still during the procedure. If you feel any pins and needles or sharp tingles in one of your legs during the injection you should try to remain still and tell your anaesthetist about it.
- Your anaesthetist will check that you are numb enough for the operation to start. They will give you sedation if that has been planned with you. The sedative drugs are given into the tube in your hand or arm.
What are the benefits to me of a spinal anaesthetic?
- You will not need so much strong pain relieving medicine in the first few hours after the operation.
- It helps to avoid blood clots in the legs and lungs (deep vein thrombosis).
- There may be less bleeding during surgery and you may be less likely to need a blood transfusion.
- Compared to a general anaesthetic, there is less effect on the lungs and reduced risk of chest infection after surgery. There is also less sickness and drowsiness immediately after the operation and less confusion in older people.
Are there any risks to me?
As with all anaesthetic techniques there is a possibility of unwanted side effects and complications: -
Very Common and common side effects:
- Low blood pressure. This often occurs as the spinal anaesthetic takes effect and occasionally can make you feel sick or faint. Fluids or drugs are put into your drip to treat this.
- Itching. Itchy skin can occur as a side effect of the painkillers that are sometimes combined with the local anaesthetic drugs. Let your nurse or doctors know if is a problem. It can be treated.
- Headache. Headaches are quite common after surgery, particularly if you normally have frequent headaches or if your normal caffeine consumption is high. There is also a risk of headache due to the spinal injection (about 1 in 100) that is eased by lying flat. This usually settles with bed rest and ensuring you have plenty to drink.
- Difficulty passing water (urinary retention). It can be difficult to pass water while you are still numb from the spinal injection. Bladder function returns to normal quite quickly, but you may require a catheter to be placed in your bladder temporarily. Difficulty passing urine can also occur after a general anaesthetic.
- Back ache. Back pain is common after surgery (particularly after long operations), and is very rarely due to the spinal injection.
- Inadequate numbness. It is sometimes difficult for the anaesthetist to put the spinal needle in a satisfactory position or the numbness produced is inadequate for surgery. In this case, you will usually need a general anaesthetic. Occasionally the surgery is more complicated than expected and takes longer; again a general anaesthetic may be given.
- 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 with time. Permanent nerve damage is very rare.
(Incidences; Temporary problems: about 1 in 2,500. Long-term problems: less frequently than 1 in 25,000. Permanent nerve damage (e.g. resulting in loss of the use of legs): less frequently than 1 in 100,000).
What should I expect after my operation and spinal anaesthetic?
- Your nurses will make sure that the numb area is protected from pressure and injury until sensation returns.
- It can take several hours for normal feeling to return. You may experience some tingling as this occurs. You should ask for some painkillers as soon as you start to become aware of pain from the operation site.
- Please ask for help the first time you get out of bed after a spinal anaesthetic. (Your legs may still be a little ‘wobbly’)
Are there any reasons I may not have a spinal anaesthetic?
Yes, sometimes a spinal anaesthetic may be dangerous or undesirable, and your anaesthetist will ask you about any medical conditions you may have. This could include patients who need to remain on ‘blood thinning’ drugs such as warfarin and heparin during surgery and people with severe back problems. If you are overweight it can be more difficult to perform the spinal injection but it may still carry fewer risks for you than a general anaesthetic.
Frequently asked Questions
Can I eat and drink before a spinal anaesthetic?
No. You need to have an empty stomach. This is because it is sometimes necessary to change from a spinal anaesthetic to a general anaesthetic. The hospital should give you clear instructions about fasting on the day of your operation.
Do I have to stay awake?
Before the operation you can decide with your anaesthetist whether you remain fully awake or lightly sedated. A screen is positioned so that you cannot see the operation. You will be aware of the ‘ hustle and bustle’ of the operating theatre. You may choose to bring a personal stereo or ‘MP3’ player to help you relax. You may feel movements or vibrations but will not feel any pain. Your anaesthetist will stay with you throughout the operation. If you have sedation you may have very little memory of events afterwards, but it is normal to remember some noises or conversations.
Can I choose not to have a spinal anaesthetic?
Your anaesthetist will carefully consider what they think is the best procedure for you and explain and discuss this with you. You will never be forced to have any anaesthetic procedure that you don’t want.
Is a spinal anaesthetic the same as an epidural?
No, although they both involve an injection of local anaesthetic between the bones of the spine in the small of your back, the injections work in a slightly different way and should not be confused.
How can I get more information?
Your anaesthetist will be able to answer any questions you have. You should have been given a copy of our general leaflet ‘Information About Your Anaesthetic’. The Royal College of Anaesthetists and The Association of Anaesthetists have produced a number of useful information leaflets about anaesthesia, which can be accessed via the Internet at www.youranaesthetic.info.
Consent- What does this mean?
Before any doctor, nurse or therapist examines or treats you they must have your consent or permission. Consent ranges from allowing a doctor to take your blood pressure, (rolling up your sleeve and presenting your arm is implied consent), to signing a form saying you agree to the treatment or operation.
It is important before giving permission that you understand what you are agreeing to. If you do not understand – ask. More detailed information is available on request.
Information about you- The Data Protection Act 1998
Confidential records are kept about your health and the care you receive.These records are important, helping to make sure you receive the best possible care from us. The information may also be used to plan services and assist in the teaching and training of health professionals. To make sure that patient confidentiality is maintained a policy has been written informing all staff of their responsibilities.
How to comment on your treatment
We aim to provide the best possible service and staff will be happy to answer any questions that you have. However, if you have any concerns you can also contact firstname.lastname@example.org and we will be happy to assist.
Authors: Portsmouth Anaesthetic Department Governance Group February 2009
Review date: Feb 2011
References: Some of the text used in this leaflet has been extracted from the patient information leaflets; ‘Your spinal anaesthetic’ and ‘Anaesthetic choices for hip or knee replacement’, produced by the Royal College of Anaesthetists and The Association of Anaesthetists.