Nerve blocks

Related:   Patient guide to anesthesia   

Nerve blocks are safe and commonly used to temporarily numb many areas of the body, particularly the legs, arms and chest wall. It involves injection of local anesthesia near nerves. Nerve blocks are also called regional anesthesia. It can be used as a sole anesthetic agent or as part of an anesthetic for pain relief. Once the injection has been done, it is common for the area to feel weak and heavy until the medication wears off. This can take up to 24 hours. 

Anesthesiologists are specialist doctors who have undergone many years of training to perform these procedures. Your treating anesthesiologist will discuss what they believe is the best way to care for you during your procedure. 

They’ll discuss with you what their plan for the anesthetic involves and answer any questions you have. 

The nerve block can be administered before going into the operating room, or in the operating room or in the recovery area depending on your situation. 

An ultrasound will often be used by your anesthesiologist to locate the nerves involved. They will first clean the area with cold cleaning solution and then place local anesthetic under your skin first. They will then carefully move a needle near your nerves to inject the medication for the nerve block. It is common to feel a pressure sensation while they do this, but a nerve block should not be a painful procedure. The procedure normally takes about 5 minutes to complete. 

You will have an opportunity to ask questions if you have any prior to the procedure. While we have asked you to review this information, your anesthesiologist will review their personalized plan for your care with you on the day of surgery and discuss any risks that are relevant to you. 

• Can help you go home sooner, as there are fewer side effects like nausea and drowsiness  
• Reduce side effects of pain medications 
• Sometimes you can avoid a general anesthetic if you have a nerve block
• Better control of pain after surgery

See a video from Regional Anaesthesia UK of a nerve block being performed if you wish to view it.

View nerve block video

Common complications of nerve blocks 

Temporary nerve symptoms (tingling, a patch of numbness or weakness) after nerve block occur to about 2 in 100 patients who have a nerve block. 

Rare complications of nerve block

Permanent nerve injury after nerve block is so rare that it is difficult to know the exact rate. It occurs to about 1-1.5 in 10 000 (0.01 - 0.015%) patients who have a nerve block.

Toxicity or allergic reaction from local anesthetic is very rare.

Infection at the injection site from a nerve block is very rare.

Depending on the type of nerve block performed, there is a risk of damage to the structures near the nerve. This is why ultrasound is commonly used to carefully find where the needle is at all times during a nerve block. 

Quoted risks on this website are for the general population.  Your personal risk may differ somewhat from the general population, depending on your medical history and what type of surgery you are having.  All patients will have the chance to discuss their personal risks and benefits related to having an anesthetic and surgery with their care providers prior to their procedure.  

The Anesthesiologist conducting your anesthetic on the day of your surgery will finalize your care plan with you before the procedure starts. This final care plan may differ somewhat from what was discussed in the Pre-Admission Clinic and what is outlined on this website.