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In partnership with Camden MSK, our department has agreed to provide ultrasound-guided Caudal Epidural injections to patients referred by the Camden community MSK services.

Why an injection?

Caudal Epidural can be used as a treatment for low back pain caused by inflamed nerves in the spine. The pain can travel down one or both legs. In some cases, your condition may respond to an injection to help settle your symptoms. Injections are usually given in addition to physiotherapy in order to help your recovery. 

What is in the injection?

Your doctor will inject a combination of local anaesthetic and corticosteroids. Local anaesthetic works in the short term. Corticosteroids aim to reduce inflammation – they can take longer to take effect but should provide longer term pain relief. The improvement of symptoms after receiving this injection can vary from person to person. 

What are corticosteroids?

Corticosteroids are anti-inflammatory medicines used to treat different conditions (e.g., corticosteroids inhalers can be used to treat asthma). When given as an injection they can be used to reduce pain and swelling in a joint. Corticosteroids are not the same as anabolic steroids, which are used illegally to increase muscle bulk.

What area is injected?

The injection is into the epidural space which lies between the lining of the spinal cord and the nerves. The space is accessed through the sacrum (sitting bone) under the guidance of ultrasound.

Is the injection painful?

The injection can be uncomfortable, but this tends to resolve quickly. Sometimes it can be sore for a few days after, and you will be advised by your doctor how to best manage this.

What are the risks?

Caudal epidurals overall are considered a safe procedure. Adverse reactions are rare, but may include:

More common (<10%):

  • A change in sensation in both your legs (this should resolve quickly if it occurs).
  • Vasovagal reaction.
    • Transient dizziness/fainting due to blood pressure drop (this typically resolves within 15-30 minutes after the injection).
  • Bruising/bleeding in & around the injection site.
  • Temporary loss of bladder control and sensation of a full bladder.
  • Steroid flare – increase in pain for a few days after the injection.

Rare (<1%):

  • Severe allergic reaction that requires emergency treatment (anaphylaxis).
  • Headache.
  • Spinal cord or nerve damage.
  • Infection. 
  • Facial flushing.
  • Skin discolouration or skin fat reduction (atrophy) at site of injection.
  • If you are diabetic, you blood sugar may be slightly higher for one to two weeks.
  • Irregular menstrual cycle (usually for 1-2 months).

Extremely Rare (<0.1%):

  • Pain permanently worse.
  • Paralysis. 
  • Cauda equina syndrome.
  • Blindness.
  • Hiccups.

Your doctor will take every necessary precaution to reduce the risk of complications and will discuss these with you.

How is the injection done?

Firstly, the skin is cleaned with antiseptic liquid. Under ultrasound-guidance a small needle is then gently put into epidural space through the sacrum (sitting bone), and the solution is injected through the needle (see picture). 

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Why ultrasound-guided?

The use of ultrasound allows your doctor to see the area that needs to be injected an accurately place the needle. This improves both accuracy and safety of the injection. 


If you are taking Warfarin, please ensure your INR is less than 3.0. Other blood thinning medications (e.g., rivaroxaban, dabigatran, apixaban, aspirin & clopidogrel) can usually be taken as normal before the procedure. Please seek advice from your consultant or medical team if unsure.


After the injection it is advised you rest in the waiting room for 20-30 minutes before walking out of the clinic. Your doctor will discuss how look after yourself after the injection and how to spot signs of complications.

How to contact us

Patient Services
The Royal London Hospital for Integrated Medicine (RLHIM)
60 Great Ormond Street, London WC1N 3HR

Tel: 020 3448 2000
Switchboard: 020 3456 7890 
Email: (not for referrals)