Peripheral nerve blocks can either consist of a single injection at a time, or a continuous nerve block. Read below to learn more about peripheral nerve blocks.
For patients with long-term or chronic pain, relief is most treasured yet rarely acquired. Finding the right pain management option is key. Pain management options differ in effectiveness from case to case, depending on the nature and origin of the pain.
While pain is purely subjective, it usually has an objective cause: an infection, nerve damage, inflammation, or other reasons. For pain originating in the nervous system, pain management options can range from short-term analgesics to non-invasive interventions, such as a nerve block.
Peripheral nerve blocks are especially helpful in addressing post-operative pain in many regions of the body and help diagnose the cause of a patient’s pain by blocking signals from specific parts of the nervous system.
In addition to being a surgical and diagnostic tool, nerve blocks can provide long-term relief for chronic pain patients and help treat extreme and intractable pain via neurolysis (through permanent neural blockade or chemical ablation). Their versatility makes them an important medical tool in clinics and hospitals throughout the country. But how do they work? Let’s take a look.
What is a Peripheral Nerve Block?
Let’s take these terms apart. A nerve block is a non-invasive procedure involving a chemical agent, anesthetic, or analgesic solution to numb or “block” a nerve or cluster of nerves via injection. A doctor will guide the needle to the nerve’s location and inject the solution to provide pain relief using imaging technology.
Nerve blocks may also be used as a form of local anesthesia. For example, someone about to undergo surgery in their hand may have the nerve responsible for relaying pain signals from the hand to the brain blocked for a few hours just before surgery. This way, they can remain awake and avoid the drawbacks of general anesthesia, which may not be necessary for a minor procedure.
A peripheral nerve block is applied to a nerve within the peripheral nervous system. Because nerve blocks aren’t applied to the central nervous system (i.e., the brain and spinal cord), all nerve blocks are, by extension, peripheral nerve blocks.
The most common areas a nerve block is applied to are the legs and arms. However, they can also be applied to the neck, back, abdomen, hip, and even head. For example, a nerve block can serve as an effective short-term treatment method when treating severe facial pain caused by a shingles infection of the trigeminal nerve.
Nerve blocks are not the end-all-be-all pain management solution for all cases of neuralgia (nerve pain), but they are an important tool in a pain specialist’s repertoire, both for treatment and diagnostics. But when do doctors decide to use a nerve block to begin with?
When is a Peripheral Nerve Block Used?
Although a peripheral nerve block is still a non-invasive treatment method, it is rarely considered a first-line treatment. Most doctors and pain specialists would recommend other conservative pain management options first, including over-the-counter medication and different pain management strategies depending on the cause and type of pain being discussed.
Some indications for nerve blocks over general anesthesia, for example, include a history of respiratory depression, sleep apnea, obesity, or advanced age. In other words, nerve blocks become a considered option when there is cause to avoid general anesthesia (for surgery) or opioid painkillers. Other indications for a nerve block include a history of allergic reactions to opioid medication or intractable pain.
Nerve blocks can either consist of a single injection at a time or a continuous nerve block. With the latter, the nerve block is constantly reapplied via a catheter inserted via ultrasound near the affected nerve. Continuous nerve blocks may play a more significant role in long-term chronic pain management.
In contrast to acute pain, chronic pain is any pain lasting longer than three to six months, either constantly or episodically. Common causes of chronic pain include repeated injury, post-operative complications, infections, autoimmune diseases, and more.
How are Peripheral Nerve Blocks Applied?
The application of a nerve block is quick and nearly painless. It’s nothing more than a guided injection, utilizing imaging technology (ultrasound or x-rays with contrast dye) and an anesthetic or painkiller.
Depending on the circumstances under which the nerve block is applied, a doctor may apply a local anesthetic or give you medicine to relax and help you feel calm via an IV (if used for an operation).
Then, they will lead a needle to a point near your nerve and begin the injection via imaging. There may be some tingling and numbness, followed by relief. The nerve block itself can last a few hours or much longer, depending on how it was applied and for what purpose.
Recovery Time and Potential Complications
If a peripheral nerve block was applied for an operation, the patient would usually be asked to stay until the numbness goes away and be monitored until then. Depending on age, size, sex, and genes, the pain relief of a temporary nerve block can last anywhere from 4 to 18 hours.
Because nerve blocks interfere with the nervous system, it isn’t recommended to operate any machinery or drive until the effects of the nerve block have weaned. Patients can go home as soon as the numbness wears off or a day after the nerve block was applied at the latest.
Complications are rare but can occur. The most common, as with any injection, is unexpected bleeding and infection at the injection site. Bruising may also occur, and monitoring a patient after a nerve block can help mitigate these complications.
It’s important to fully communicate with your doctor before and after the nerve block and ensure that they know exactly what medication and drugs you take, medically or otherwise.
If you have any history of allergies to all forms of anesthesia or reservations about nerve blocks, be sure to communicate these with your doctor and review your options thoroughly. The information above is not meant to replace the medical advice a professional can give you face-to-face. Pain management is a multifaceted field of medicine with many different options and modalities.