Nerve block

Overview

A nerve block involves the administration of medication near a specific nerve or group of nerves, aiming to provide temporary relief from pain. In some cases, these injections can offer prolonged pain relief. When anti-inflammatory medication is combined with a local anesthetic in the injection, it may help damaged nerves heal by reducing inflammation.

Nerves can be likened to cables transmitting electrical signals between your brain and the rest of your body, facilitating sensations such as touch and pain, as well as muscle movement. Additionally, they play a role in essential bodily functions like breathing, sweating, and digesting food. Nerve blocks primarily target issues related to pain signaling, but they can also impact other nerve functions.

Typically, the effects of a nerve block are swift, but they are often a short-term solution. While some individuals find relief with a single injection, others may require multiple injections. There are cases where individuals do not experience any noticeable effects from the nerve block, necessitating alternative treatment methods to manage their symptoms.

Types

There are various types of nerve blocks that target specific nerves in the body to alleviate pain and provide relief for various conditions:

• Epidural nerve block: Commonly used for pain relief during childbirth or surgery, it numbs specific regions of the body, such as the legs or abdomen.
• Celiac plexus nerve block: Relieves pain in the upper abdomen, often caused by pancreatic cancer or chronic pancreatitis.
• Occipital nerve block: Used for occipital neuralgia, chronic migraines, and headache management.
• Lumbar sympathetic nerve block: Eases lower back and leg pain, including sciatica and complex regional pain syndrome (CRPS).
• Genicular nerve block: Addresses chronic knee pain or postoperative knee pain.
• Intercostal nerve block: Provides temporary relief for rib fractures and treats neuralgia.
• Pudendal nerve block: Relieves pain in the pelvic, genital, tailbone, and rectal areas, often during labor or for pudendal neuralgia.
• Stellate ganglion block: Alleviates pain in the head, neck, upper arm, and upper chest while improving circulation.
• Trigeminal nerve block: Treats various facial pain conditions, including trigeminal neuralgia.

Reasons for undergoing the procedure

There are three main uses for nerve blocks:

• Therapeutic nerve blocks: These nerve blocks aim to provide temporary pain relief for either acute (sudden and short-term) or chronic (long-term) pain. By reducing inflammation and promoting nerve healing, these blocks alleviate pain.
• Diagnostic nerve blocks: When the exact source of pain is uncertain, healthcare providers may perform diagnostic nerve blocks. If the injection results in pain relief, it indicates that the targeted nerves are likely responsible for the pain. Conversely, if there is no relief, the pain is likely originating from a different source. Diagnostic nerve blocks help guide future treatment plans.
• Anesthetic nerve blocks: Anesthesiologists or surgeons commonly administer nerve blocks before surgeries to effectively manage postoperative pain. These blocks are used in conjunction with general anesthesia for complex surgeries. In some cases, for less extensive procedures like carpal tunnel surgery or trigger finger release surgery, patients may opt for a nerve block instead of general anesthesia.

Risk

Nerve blocks are generally considered safe procedures with low rates of complications. However, it’s important to note that the risks and side effects associated with nerve blocks can vary depending on the specific type of block being performed. For instance, a stellate ganglion block may result in difficulties with swallowing, drooping eyelids, or hoarseness, while a celiac plexus block might lead to delayed stomach emptying (gastroparesis).

In general, potential risks and complications of nerve blocks can include:

• Infection at the site where the injection is administered.
• Bleeding at the injection site.
• Accidental introduction of the medication into the bloodstream.
• Unintended spread of the medication to adjacent nerves or into the spinal canal, depending on the type of block being performed.

Procedure

Nerve blocks function by interrupting the transmission of coded electrical signals from nociceptors, specialized nerve receptors that monitor for injury or damage. These signals, not actual pain itself, are sent to the brain and decoded into the sensation of pain. Nerve block anesthetics prevent nerve cells from relaying these signals, effectively blocking the perception of pain. Additionally, in cases of prolonged inflammation following an injury, these medications can also reduce inflammation within the affected nerve, facilitating healing and subsequently reducing pain.

Before the procedure

Typically, there is no specific preparation required for a nerve block procedure, but in certain situations, your healthcare provider might advise sedation, which would entail fasting for six to eight hours before the appointment and arranging for someone to drive you home afterward. Your healthcare provider will provide you with any necessary instructions, and it’s important to adhere to their guidance while also seeking clarification if you have any questions.

During the procedure

Nerve blocks are commonly administered by doctors for pain management in an outpatient setting, which means you won’t need to be admitted to a hospital and can return home shortly after the procedure. Although there are numerous types and variations of nerve blocks, the general process typically involves the following steps:

• The healthcare provider will position you on an examination table in a specific manner to facilitate access to the injection site.
• To help you relax, you may be given a mild sedative through an intravenous (IV) line in your arm.
• Your skin will be cleaned with an antiseptic solution, and a local anesthetic will be injected to numb the area where the nerve block will be administered. You might still experience a slight pinch or some discomfort as the needle penetrates your skin.
• In some cases, the provider may utilize imaging guidance, such as ultrasound or X-ray, to precisely locate the target spot for the injection. They will then inject the medication as close as possible to the affected nerve.
• Following the procedure, you will rest until the medication takes effect.

After the procedure

Following the injection, a period of rest lasting 15 to 30 minutes will be necessary to allow the medication to take effect. During this time, a healthcare provider will closely monitor you to ensure there are no unforeseen side effects. Afterward, you will be permitted to return home.

Outcome

The duration and effectiveness of pain relief from a nerve block can vary widely among individuals, ranging from a few days to several weeks, months, or even years. While some may find relief after a single injection, others might require multiple treatments. It’s important to note that not everyone experiences pain relief from nerve blocks, and if you do undergo this procedure, it’s crucial to promptly inform your healthcare provider of any new symptoms or complications, including infections or nerve-related problems like burning pain, weakness, or tingling.