A nerve block, also called a ‘peripheral nerve block’, is where a specific nerve or bundle of nerves to a specific area of the body can be made numb. This can be used as the sole form of anaesthetic or combined with sedation or a general anaesthetic. This form of anaesthesia is used to provide long-lasting pain relief, during and after surgery. It can last from 2 to 24 hours, depending on the site and the drugs used. Sometimes a very fine tube is put through the needle and left in place. This means that the local anaesthetic can be given for a longer period of time – at times up to a few days. The fine tube can also be connected to a pump called a Patient Controlled Analgesia (PCA) machine. This is where you can be in charge of your own pain relief.
Types Of Nerve Blocks
There are many types of nerve blocks each aimed at different nerves. Your Anaesthetist will explain the particular block that is selected for your surgery.
An Ultrasound machine or nerve stimulator is frequently used to guide the needle as close as possible to the nerve reducing the risk of nerve trauma.
Nerve blocks have many benefits and these include:
- Better pain relief after your surgery
- You may need less strong pain relieving drugs such as morphine
- Less morphine related side effects such as nausea and itchiness
- Shorter recovery time after your surgery
- Nerve Blocks are a very safe procedure
Side Effects And Risks Of A Nerve Block
- Nerve damage: Nerve damage, if this occurs it is usually temporary and will get better over a period of weeks to months. Damage may cause weakness and/ or numbness of the body part that the nerve goes to. Permanent nerve damage is rare.
- Bruising (haematoma): If you take blood thinning drugs such as aspirin, warfarin, clopidogrel, you are more likely to get a haematoma as it may affect your blood clotting. Your Anaesthetist will discuss this with you at your pre-operative consultation.
- Failure of block: This may require a further injection of anaesthetic or a different method of anaesthesia to be used
Less Common And Rare Risks
- Lung collapse (only associated with some blocks)
- Damage to surrounding structures such as blood vessels, nerves and muscles
- Overdose of local anaesthetic which may result in seizures
- Cardiac Arrest