Information following a caudal block

What is caudal anaesthesia?

When your child has an operation, the general anaesthetic will make your child unconscious. Pain relief before and during the operation can be provided using pain relieving medicines that will affect the whole body or alternatively by injecting local anaesthetic to numb (block) the area of the operation.

What is a caudal block?

  • This is an injection of local anaesthetic (numbing agent) into the caudal space, at the base of your child’s spine
  • It is a good form of pain relief for children who are having operations below the level of their belly button
  • It provides pain relief both during and after the operation
  • It may last for up to six hours or more
  • Your anaesthetist will discuss this with you before your child goes to have their operation


  • Numbing the nerves at the base of the back , means your child will feel little or no pain
  • Avoids needing to use strong pain relief which have side effects
  • Reduce sickness and usually decreases recover time after the operation


Your anaesthetist will discuss these with you before the operation.


Weak / heavy legs

  • This is the most common side effect and occurs as the block affects the nerves supplying the legs. It is temporary and strength to the legs will return to normal as the block wears off

Inadequate pain relief

  • In about 1 in 20 children the block does not  work
  • If this is the case the anaesthetist will give your child other forms of pain relief

Difficulty passing urine

  • Usually, this is not a problem and patients manage to pass urine when they have had enough fluid to drink
  • Rarely, a catheter needs to be inserted temporarily into your child’s bladder to empty it



This may occur if your child has been given other pain relief along with the local anaesthetic (caudal block).


This may occur if your child has been given morphine like pain relieving medication in addition to local anaesthetic.


Nerve damage

This occurs in less than 1 in 10,000 and may be temporary or permanent.

Very rare

The following are very rare recognised complications and checks are taken throughout the process to prevent these

Your child’s anaesthetist will discuss them in more detail

  • Infection
  • Haematoma (bruise)
  • Injection of local anaesthetic in blood / spinal space

Advice at home

It is safe for children to be discharged the same day as having had a caudal block.

Pain relief      

It is important to give your child regular mild pain relief (Paracetamol/ Ibuprofen) as advised by your clinician, even if your child is comfortable. This will help as the caudal block starts to wear off and can be gradually reduced in frequency over the next couple of days.


  • Key safety information is listed overleaf

Key points

Continue regular mild pain relief at home and decrease slowly.

It may take 12 hours for the normal feeling to return to your child’s legs.

  • Avoid hot baths / hot water bottles
  • supervise your child while crawling

Keep child well hydrated

  • Encourage your child to drink water

Monitor for difficulty passing urine

  • Inability to pass any urine
  • Pain in the lower tummy
  • Bloated lower tummy

If your child has not passed urine in 8-10 hours after the operation or has these problems please contact your GP or go to your local Emergency Department.


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