What is a peripheral nerve block?

A peripheral nerve block is a type of regional anaesthetic that involves injecting local anaesthetics and other painkillers near the major nerves to your arm (upper limb).

How does a nerve block work?

A nerve block works by temporarily numbing your nerves to give pain relief. Local anaesthetics and other painkillers are injected, using a fine needle, near the nerves to your arm. You may need more than one injection.

A nerve block can be used instead of a general anaesthetic for the operation and is also an effective form of pain relief afterwards. Depending on the operation, the injection may be given in the side of your neck, or near your collarbone or armpit, or in your elbow, forearm or wrist.

What does the procedure involve?

Your anaesthetist will usually use an ultrasound scanner or nerve stimulator to help guide them where to inject the anaesthetic.

Your anaesthetist will insert the needle and when they are certain that it is in the right position they will inject anaesthetic through it. They will usually remove the needle.

Sometimes your anaesthetist may insert a small tube (catheter) through the needle before they remove it, leaving the tube in place so they can inject more anaesthetic.

What effect does a nerve block have?

A nerve block has 2 main effects.

• Pain relief — The nerve block numbs the sensory nerves responsible for pain and touch.
• Weakness — The nerves supplying muscles may also be affected.

What complications can happen?

Some complications can be serious and can even cause death.

• change in your breathing
• the nerve block not working properly
• allergic reaction
• allergic reaction to the equipment, materials or medication
• bleeding
• nerve damage
• visual disturbance or loss of vision
• local anaesthetic toxicity
• pneumothorax
• droopy eyelid on the side of the nerve block
• developing a hoarse voice