Nerves are like wires, carrying messages about touch heat, pain and other sensations to the brain. By injecting a substance, such as a local anesthetic (freezing) or cortisone-like drug (steroid), into or around a nerve, or beside the spine, the nerve is temporarily "numbed" and stops sending messages to the brain. The length of time that the signals are blocked depends on the individual patient, the type of nerves blocked, and the amount and type of local anesthetic used.
Nerve blocks are commonly used for acute pain for short-term pain relief after some surgeries and for anesthesia during procedures such as suturing a wound or filling a tooth.
Nerve blocks can also be used, as a treatment for some chronic pains. With chronic pain, the continual "bombardment" of the pain centers in the spinal cord and brain cause a number of physical and chemical changes that sensitize the brain to pain signals. This process of "central sensitization" is what we are attempting to treat with injection treatments.
Preparation for Injections
- Bring a driver.
- Eat and drink a modest amount at least 1-2 hours before the procedure.
- Plan to remain in the clinic for about 30 minutes after your treatment
Every medical treatment can have side effects. You will be asked to read and provide an informed consent (a regulatory requirement) which lists the common, mild side effects, as well as the uncommon, severe ones. If you have any questions, please ask your doctor.
Nerve blocks are not recommended if you have a blood – clotting disorder, are on blood thinning drugs (such as Heparin, Warfarin, Plavix or others), or have any type of uncontrolled infection. Always consult with your physician first if you have other chronic medical conditions.
Risks and Possible Side Effects
Getting an injection is mildly painful for most people. Muscle soreness may occur at the site of injection for 1-2 days, which improves with ice packs. Although the skin is always cleansed with antiseptic before giving an injection, there is always a small chance that an infection can occur at the site of injection.
Advise our clinic immediately or go to the ER after hours if:
- The injection site becomes red, warm and/ or swollen.
- You develop a fever.
- You experience severe weakness or dizziness.
- You develop shortness of breath
- You have a seizure.
Other possible risks are accidental injections into a blood vessel causing a seizure, injecting into a nerve, causing damage, or puncture of a lung causing a lung collapse. Very rarely, nerve blocks near the spine can cause damage to the arteries that supply blood to the spinal cord, possibly resulting in paralysis.
The pain-relieving benefits of injections are different for each person, thus it is difficult to predict how long injections may help. Some people only get a few hours of relief while others may experience pain relief lasting for many weeks. Unfortunately, some patients obtain no benefit at all from these injections. We believe injections work by decreasing or reversing some of the sensitization in the central nervous system. With less pain, we hope that this can improve your ability to function. Most doctors who use injections will try an initial series of weekly blocks (4-6) to see if there is a benefit lasting longer than the few hours normally seen from the local anesthetic. It is important that you keep track of your pain and other symptoms to help your doctor decide if continuing with blocks is worthwhile for you. If there is no long- term benefit after the initial series of blocks, then the doctor may suggest other treatment options.
Please notify our clinic immediately if you have been seen at the hospital within 10 days of a receiving an injection.