What are they?
A caudal block is used to give pain relief to children having an operation. It is as an injection of pain-relieving medicine into the caudal space which is a little gap at the bottom of the back.
It is given whilst the child is asleep under general anaesthetic.
How does it work?
Nerves send pain messages to the brain via the spinal cord. The medicine used in a caudal injection temporarily blocks these messages before they get to the spinal cord and so reduces any pain felt.
The medicine injected is a local anaesthetic, a similar medicine to the one given by dentists when they remove your teeth. Sometimes other medicines will be given with it to reduce pain.
Why do we use caudal blocks?
A caudal block numbs the lower half of the body, from the belly button down. It can therefore be used for pain relief in hernia repairs, urology procedures such as hypospadias repair, circumcision, orchidopexy and penile surgery, and orthopaedic surgery on the hip, knee or foot.
How long does a caudal block last?
A caudal block can give pain relief for 3 to 12 hours. Using a caudal block will reduce the need for strong painkillers during and after the operation and so will reduce the side effects of strong painkillers such as itching, vomiting and drowsiness.
What are the side effects of a caudal block?
The caudal block numbs the nerves of the leg muscles and so your child may feel like they have numb, weak or tingly legs. As the effects of the local anaesthetic wears off, strength in the legs will gradually return.
Difficulty passing urine
After a caudal block, children may find it difficult to pass urine. Occasionally a catheter needs to be inserted to help them pass urine.
Inadequate pain relief
In a small number of children, the caudal block does not work or it may be not be possible to perform.
Could there be any complications?
Caudal blocks have been carried out very safely for many years. Complications are rare after a caudal block but they can include:
This is very unlikely as a caudal injection is done under sterile conditions.
This is rare unless the child has a bleeding condition or is on medications that interfere with bleeding. Sometimes there may be bruising at the site of injection.
- Nerve damage
This can range from a small numb patch that lasts a few days to something more serious. This is very rare.
- Injection into the blood stream
Checks are carried out before the injection to prevent this from happening. If this does happen the anaesthetist will manage it appropriately in theatre.
- Injection into the spinal fluid
If this was to happen, the numbness would spread above the middle of the body and your child may need extra breathing support until the local anaesthetic wears off. Your anaesthetist will perform checks to prevent this from happening.
Can everyone have a caudal block?
Caudal blocks may not be suitable for everyone and if your child has any abnormalities of their back or spine, a caudal block is not suitable. You should let the anaesthetist know if you think you child may have a back or spine problem.
Care after a caudal block
The lower half of the body will be numb and so needs to be protected from heat, sharp objects or similar hazards as the child will not feel an injury.
It is important to take the regular pain medicine prescribed to reduce any pain or discomfort as the numbness wears off.
The ward nurses will need to see your child move around before they will let you go home if they have had a caudal block. In some cases they may also want to check that your child has been to the toilet or had a wet nappy.
I have questions?
The anaesthetist will discuss the caudal block with you before the operation. They will be happy to answer any questions you may have.
If you decide not to proceed they will also be able to discuss alternative pain relief plans with you and help you make the best choice for your child.
South Tees Hospitals NHS Foundation Trust would like your feedback. If you wish to share your experience about your care and treatment or on behalf of a patient, please contact The Patient Experience Department who will advise you on how best to do this.
This service is based at The James Cook University Hospital but also covers the Friarage Hospital in Northallerton, our community hospitals and community health services.