Anaesthesia for Limb Surgery

Your anaesthetic for limb surgery may be:

  • A ‘block’
  • A general anaesthetic
  • A combination of both

A ’block’ usually used for surgery on an arm or leg in orthopaedics, plastic surgery or vascular surgery
A ‘block’ is a type of anaesthetic where we numb an area of the body instead of a general anaesthetic (full unconsciousness) or for pain relief as well as a general anaesthetic.

  • It involves numbing the arm or the leg.
  • It can be used as the only anaesthetic for your operation.
  • It also serves as excellent pain relief during and after your operation.

During your operation

Block with no or minimal sedation

  • You will be lying flat.
  • A screen will separate you from the area of operation.
  • You will not be able to see the operation.
  • You may hear people talking and/or noise from equipment or drills.
  • You will be awake during the operation.
  • You might receive sedation during the procedure.

Block combined with general anaesthesia

  • The “block” can be performed before or after you are put to sleep under general anaesthetic.
  • On waking from anaesthetic following the procedure, the limb that was “blocked”, will be numb and will stay so for number of hours providing pain relief.


  • Excellent pain relief for a few hours after your operation
  • Avoids high dose, strong pain relief during your operation.
  • Avoids nausea, itch and constipation associated with high dose pain relief.
  • Possibility of discharge straight back to your ward as soon as your operation is finished
  • No anaesthetic delay in eating, drinking and going home.
  • Can be used as the sole form of anaesthetic therefore avoiding the sleepiness of a general anaesthetic

How is a block performed?

To ‘block’ your arm or leg we inject a drug called local anaesthetic beside the nerves that supply your arm or leg. The local anaesthetic soaks into nerves, numbs them, and you will lose all feeling and power in that arm or leg.

The block may be performed before you get to theatre in a designated area, in the anaesthetic room, which is connected to the theatre, or in the theatre itself. When you arrive, we will place a drip. We will attach routine monitors to observe your heart rate, blood pressure and oxygen.

All blocks are performed in a sterile manner.

  • We clean the area with antiseptic.
  • We place some cold jelly on your arm/leg and use the ultrasound to scan the area and identify the nerves as they lie beside muscles and veins
  • Following this, a small needle is inserted through the skin, down toward the nerve, watching it continuously on the ultrasound screen
  • We inject a small amount of local anaesthetic drug beside the nerve
  • It is normal to feel discomfort at the site of injection and mild unpleasant pressure as we are doing the injection.
  • Please tell us if you feel pain or tingling down your arm/leg

Your arm/leg may start to feel warm, tingle and go numb within minutes.
Often, the pain of a fracture, if present, goes within 5 minutes.
It may take approximately 20 minutes for the arm/leg to go completely numb and heavy.

We will check that the areas specific to your operation are fully numb before you proceed with the surgery. If your ‘block’ is not fully effective, we may add an extra injection to ensure full numbness, or if needed, change to a general anaesthetic

After your nerve block

Your arm or leg will be numb and weak/heavy for up to 24 hours.
It is possible to do further injury to it before full power and feeling return.

  • Protect it – leave it in your sling or supported/elevated
  • Do not lift your arm above your head, let it fall off the side off the bed/trolley, or move it out of direct sight
  • If you have a numb leg/foot, do not stand until you have been shown how to mobilize safely with crutches by the physiotherapists.
  • Take care near falling objects, sharp, hot or cold objects or anything that might put pressure or injure it.

Pain Relief after your Block

As the block starts to wear off, usually there is a feeling of pins and needles, or tingling, prior to dull ache/soreness and full feeling.
Please take the pain medication prescribed before you start to feel any pain.
Ask a member of staff if you are not sure about the pain relief prescribed for you before you leave the hospital

What are the risks and side effects with my block?

Side effects are secondary effects of drugs or treatment. They can often be anticipated but are sometimes unavoidable. Complications are unexpected and unwanted events due to a treatment.

For a block performed on the neck there is also a very rare risk of

  • Lung puncture
  • Subarachnoid injection (spinal tap)
  • Subdural/Epidural injection