If you are planning to have surgery and you’ve never had (or heard of) a nerve block, a type of regional anesthesia, you might be surprised to learn how easy and effective it is. 

The anesthesiologist inserts a fine needle into the surgery site and injects pain medication in an effort to bathe (but not touch) the nerves. Then, when the surgeon makes the incision, the nerves will be too numb to do their usual work of alerting the brain about the pain, which means you won’t feel it.

“Nerve blocks are a way to better control the acute pain at the time of surgery, and it can help us ease the transition to controlling pain when you’re home,” says Jinlei Li, MD, who is Yale Medicine’s director of regional anesthesia for Yale New Haven Hospital’s Saint Raphael Campus. While nerve blocks have been around for decades, improved ultrasound guidance in the 1990s increased the precision of the injections, making them a safer and more effective choice, Dr. Li says.

Unlike with general anesthesia, Dr. Li says patients using nerve blocks receive multiple benefits, including better pain control, less time in the hospital, quicker recovery, and less need for medication when they go home. She has been working to make nerve blocks available to more Yale Medicine patients having musculoskeletal and other types of surgeries, and pursuing research on their effectiveness.

An anesthesiologist will choose a type of the nerve block based on several factors, including your general health and the surgical procedure you are about to undergo. In many cases, your doctor may administer a single shot of medication that will provide pain relief throughout the surgery and often for a few hours afterwards.  

Depending on the site of the surgery, there are also epidural blocks, that are often used to control pain during labor, and spinal blocks, which involve injecting anesthetic medication near the spinal canal. For some patients, the anesthesiologist may recommend using a combination of drugs and techniques that can include a nerve block, general anesthesia—and, in some cases, a small amount of opioid medication—to provide the most effective relief in a particular situation.

If you are going to have surgery, talk to your surgeon or anesthesiologist beforehand to ask if you are eligible for a nerve block. 

You may not be eligible for one if you have an infection at the site where the injection would be made, if you have a bleeding disorder, if you are taking an anticoagulant (a drug such as warfarin that prevents blood clots) that you have not stopped ahead of time, or if you have had problems with the nerve in the area that would be targeted by the injection.

The anesthesiologist will perform a nerve block before you go into the operating room. Often, she will give you a mild sedative first to relieve any anxiety and help you relax. Next, she will insert a hair-thin needle—the size of an acupuncture needle—and inject medication into the surgical site in an area around the nerve. The anesthesiologist will watch the progress of the needle on a monitor, using “real-time” ultrasound guidance to make sure the pain relief medication is delivered with precision.

With a nerve block, the idea is to only send medication around the nerve so that the nerve can absorb it. It’s important to avoid making an injection directly into it, which can cause serious side effects including limb numbness or weakness. The anesthesiologist may choose from a variety of numbing medications, including lidocaine, which is also used as a numbing agent for dental procedures.

A nerve block typically takes less than 10 minutes to administer and up to 30 minutes to take full effect. 

If your anesthesiologist gives you mild sedation, it may make you drowsy and relaxed. The nerve block injection itself should cause minimal pain, if any. Otherwise, for certain procedures such as hand surgery, you should be able to remain awake and aware of your surroundings and free to communicate with your caregivers during surgery, if desired. This is different from general anesthesia, which would make you unconscious, and could lead to some lingering confusion and cognitive dysfunction when you wake up, especially if you are an older adult.

Once your surgery is over, you may feel some heaviness or numbness from the nerve block. It’s important to talk to your caregivers before you stand up and move around—or put any pressure at all on your body—because the nerve block may continue to affect your muscle control and balance for a while. 

If you have a single-shot nerve block, it may continue to provide pain relief for a few hours after surgery—up to 24 hours in some cases. 

How well the nerve block controls pain also depends on the type of operation you have—for instance, total knee replacement surgeries can cause significant pain, bruising and swelling during physical therapy, and are more difficult to recover from than, say, finger surgeries. If there is still pain once the nerve block wears off—and you are worried about feeling pain once you go home—you can talk to your doctor about additional medication.

In most cases, the doctor will prescribe pain control medication in the form of pills to take at home. There are non-opioid options available, and talk to your doctor about your preferences.

Like anything else, there are risks—although rare—associated with nerve blocks. They might include bleeding, soreness or infection at the site of the injection.

Nerve injury is rare. If it happens, it is temporary in most cases, and very rarely becomes permanent. In general, the rate of nerve injury is low, varying with the type of nerve blockade and surgery. As with any type of anesthesia or surgery, if you experience any feelings that seem unusual, you should tell your anesthesiologist right away.   

Nerve blocks have proven to be more effective at controlling pain than medications delivered through an intravenous (IV) or intramuscular (IM), which involves injecting medication into a vein or muscle. Because a nerve block controls acute pain so well, patients tend to need less pain medication in the hospital and at home after surgery.

Another advantage of a nerve block is that, for selected procedures, it can help you avoid general anesthesia, which has side effects that can range from nausea and vomiting to temporary confusion. 

Since there is no need to recover from a nerve block—and there typically will be less pain later—you can begin to eat and drink earlier, and participate in physical therapy faster after surgery, which is associated with faster healing and better health outcomes. You can go home from the hospital sooner and start any physical therapy to heal fully.

A nerve block is a strategy to help limit the use of prescription opioids, which are a type of narcotic medication that was once thought of as the most effective treatment for pain. Opioids control pain by reducing the intensity of pain signals that affect the areas of the brain that control sensation and emotion. They pose serious health risks if they are misused.

Until fairly recently, opioid medications such as the powerful narcotic oxycodone, or its long-acting formula sold under such well-known brand names as OxyContin, were prescribed routinely to help surgery patients control pain once they go home. Now, many people want to avoid opioids because the drugs are highly addictive or they’ve experienced unpleasant side effects from them, including constipation, confusion, drowsiness, sluggishness, and nausea.

Non-opioid alternatives include acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) such as Celebrex. Other medications commonly used to help with pain control include gabapentin, also known as Neurontin; pregabalin, also as known as Lyrica; and ketamine. In some cases, the anesthesiologist will use these pain control drugs in combination with opioid pain medication—but with less opioid medication and for a shorter period of time.

Opioids may still be an important part of pain control for some people, including those who have active bleeding disorders or other contraindications for nerve blocks. If you have any questions about opioids, talk to your doctor.

Yale Medicine Anesthesiology specialists offer a wide variety of medicines, equipment and techniques that many not be as easy to find in other medical centers. They provide many regional approaches to pain management and have extensive experience delivering them.

Patients anticipating surgery should know that Yale Medicine provides nerve blocks for the vast majority of musculoskeletal surgeries, as well as for many other operations, tailoring their recommendations to each person.  “It’s our job to provide each patient with precise, individualized care,” says Dr. Li.