- What is a Nerve Block?
- Common Types of Nerve Blocks
- How Long Does the Procedure Last?
- Side Effects and Risks
- Is a Nerve Block Procedure Painful?
A nerve block is an injection of an anesthetic to “turn off” pain signals being sent to a specific organ or part of the body. It is a common procedure used for situations like when a patient needs temporary relief from pain or help to manage chronic pain during a healing process, to name a couple of situations. In some cases, certain types of nerve block procedures can provide permanent pain relief.
What is a Nerve Block?
Every part of the body is served by a system of nerves that send pain signals. A nerve cluster is called a ganglion or plexus. To stop the pain signals requires blocking the nerve signaling.
The nerve block for pain is a procedure administered by a physician in which a medication is injected into the designated set of nerves to numb them. For temporary pain relief, the medication used in a local nerve block is an anesthetic, steroid or opioid. The medication used for permanent pain relief in a neurolytic block is phenol or alcohol, which purposefully damages the nerve pathways. Thermal agents that freeze nerves can also be used to treat chronic nerve pain on a permanent basis.
There are several reasons nerve blocks are administered:
- Therapeutic nerve blocks for the treatment of acute pain due to a condition.
- Prognostic nerve blocks to determine if a permanent nerve block would treat the pain.
- Diagnostic nerve blocks to identify sources of pain.
- Preemptive nerve blocks are given before a procedure that is known to cause pain.
Surgery is a last resort procedure for cases of severe chronic pain.
Common Types of Nerve Blocks
The nerve block procedure can treat a variety of areas and organs in the body. They include:
- Face – trigeminal nerve block
- Forehead – supraorbital nerve block
- Eyelids and scalp – ophthalmic nerve block
- Upper jaw – maxillary nerve block
- Neck – cervical epidural
- Middle back – thoracic nerve block
- Lower back – lumbar epidural block
- Shoulder and upper neck – cervical plexus block and cervical paravertebral block
- Shoulder into an armpit, arm, hand – brachial plexus block
- Elbow – elbow block
- Wrist – wrist block
- Abdomen and pelvis – subarachnoid block and celiac plexus block
There are several types of common diagnostic nerve blocks:
- Sympathetic nerve block – determines if there is damage to the sympathetic network of nerves that are found along the length of the spine.
- Facet joint block – determines whether a facet joint in the spine is a source of pain.
- Stellate ganglion block – determines if there is damage to the sympathetic network of nerves supplying nerve signals to the head, chest, neck or arms.
This is not a comprehensive list but gives a good idea as to the many ways nerve blocks are used. The nerve blocks most familiar to people are the epidural given to women during childbirth and dental novocaine used to numb the mouth during a painful dental procedure.
Other common conditions qualifying for a nerve block include:
- Low back pain;
- Migraine or chronic headaches;
- Cancer-causing pain;
- Arthritis pain;
- Trigeminal neuralgia;
- Pain after surgery;
- Pain with an unidentified source.
How Long Does a Nerve Block Last?
Except for a surgical nerve block, the nerve blocking procedure is usually done on an outpatient basis and takes approximately 20 minutes. Sometimes the physician decides to do the procedure in the hospital, depending on the patient’s health.
There are no special pre-procedure preparations required. The only exception is if the physician will be administering a mild sedative when the patient is nervous about the procedure. In that case, the patient is asked to fast 6-8 hours before the procedure.
First, the patient is asked to lay on his or her back, side or stomach on an ultrasound or fluoroscopy table that makes it easy for the physician to reach the site where the injection will take place. An anesthetic is applied to the area where the injection will be given. Using the ultrasound or fluoroscopy to guide the injection, the physician will administer the medication.
Typically, the temporary nerve block will last from a few days to several weeks. In some cases, a patient may require more than one nerve block over a period of time. Each case is different, and the length of time a patient feels pain relief is not predictable.
Side Effects and Risks
Nerve block injection side effects are normally minimal. They may include a small feeling of discomfort or soreness at the injection site like the soreness felt when getting a flu shot.
Are nerve blocks safe? It is considered one of the safer medical treatments. Depending on the area of the body treated, there may be some specific side effects in that area. For example, a nerve block in the neck area may cause hoarseness and difficulty swallowing.
There are some other general risks associated with the nerve block:
- Injected medication spreads to other nerves;
- Infection develops at the injection site;
- Bleeding occurs at the injection site;
- Rash and/or itching develops;
- Medication is accidentally delivered into the bloodstream;
- Medication is injected into the wrong nerve while trying to block a different nerve;
- Exposure to low-level radiation during the imaging process;
- Blood sugars are elevated.
Is a Nerve Block Procedure Painful?
The nerve block requires the insertion of a small needle through the skin and into the area believed to contain the nerves causing the pain. The needle is not any bigger than a typical syringe. The use of imaging equipment, like fluoroscopy or CT, helps the physician guide the needle to the right area as quickly as possible, minimizing the time it takes to place the needle.
The skin area is numbed before the needle is inserted. The only pain felt might be a small sting or pinch similar to the feeling when getting any shot. There is no pain from the imaging process. There may some minor discomfort during the procedure, depending on how deep the needle must go.
If the needle comes too close to a major nerve, like the sciatic nerve, there may be a sudden shot of pain, but this is not likely to happen. In these cases, the physician will remove the needle and re-insert it in a different position. This rarely happens thanks to sophisticated imaging equipment.
Can it cause nerve damage?
One of the questions people ask is whether the procedure can cause nerve damage. There is a risk a temporary nerve block may cause permanent nerve damage. If that happens, the patient may experience side effects like weakness, numbness that never subsides or muscle paralysis.
Surgical nerve blocks are often designed to either destroy a damaged peripheral nerve or nerve roots. As previously mentioned, a neurolytic block uses medications, like thermal agents, so permanently damage nerves, so the procedure is used mostly when a person is experiencing chronic pain.
What to expect after a nerve block injection?
Knowing what to expect after a nerve block injection is important to the patient’s peace of mind. After the injection, a patient will hopefully experience almost immediate pain relief in the area treated, but it can take up to 45 minutes for the medication to take affect. The patient will rest after the procedure to give the medication time to take affect.
If the nerve block was given to reduce the pain of surgery or an injury or other medical condition, for example, the relief may be permanent once the person heals or recovers. Typically, the relief, as mentioned, may last for up to three weeks. In some cases, permanent pain relief is experienced even with a temporary nerve block.
They physician doing the procedure is usually a radiologist or anesthesiologist who will follow up with the patient to determine if the injection helped with pain relief and the degree of relief experienced. The physician will also determine if additional injections are needed, which is often the case.
If the patient received a sedative before the procedure, he or she wouldl have to remain at the outpatient clinic or hospital until the sedative wears off. It will also be necessary to have someone drive the patient home. If no sedative was administered, patients can drive themselves home after consultation with the physician.
In many cases, the nerve block does bring temporary pain relief by numbing the nerves, often reducing inflammation that may be contributing to the pain. If there is pain after nerve block, the procedure will either be repeated in a different location of the body or a new treatment plan is developed. Most people can return to their normal routine the next day.
Procedure has Limitations
It is important to maintain reasonable expectations as to what the nerve block may or may not accomplish. Nerve block complications are not common. A temporary nerve block brings, at best, temporary relief in most cases. Though some people may experience long-term pain relief, it is not a certainty. It may also take a series of injections to experience the desired pain relief. Sometimes, nerve blocks bring no relief.
Surgical nerve blocks do usually bring long-term relief. Like any surgery, the recovery period is longer. It is hoped that permanent nerve destruction relieves the pain permanently.
It is important to approach any nerve block with reasonable expectations. People living with pain are sometimes desperate to find relief, so it is tempting to view the nerve block as the answer. However, any medical procedure has limitations, including the nerve block. A nerve block is not a good procedure for everyone.