What Is A Nerve Block?

A nerve block is a procedure involving the injection of an anesthetic or neurolytic agent into or near specific nerves.  Nerve blocks are a method by which pain can be controlled through the use of a local anesthetic, steroids, opioids and under certain conditions, for severe pain, alcohol or phenol which destroys nerve tissue.

What Is The Purpose of A Nerve Block?

The use of neural blockade for diagnostic, therapeutic, prognostic and treatment of chronic pain is a well-established practice.  Regional anesthesia blocks, used for specific surgical procedures, are now used in pain facilities to diagnose and treat pain problems.          

          Diagnostic - to determine the source of pain e.g. is pain central  (within the spinal cord) or peripheral (outside the spinal cord)

           Therapeutic - to treat painful conditions that respond to nerve block

            Prognostic - to predict outcome of permanent interventions such as infusion, neurolysis and rhizotomy

             Preemptive - to prevent painful sequelae of procedures that may cause phantom limb, causalgia or reflex sympathetic dystrophy

How Do Nerve Blocks Work?

Nerve Blocks interrupt the transmission of pain signals to the brain.  An injection is directed into a bundle of nerves to prevent the nerves from sending pain signals to the brain.  If the block is successful, it may help the physician identify which nerves are affected and could lead to better pain treatments.

Who May Benefit From Nerve Blocks?

Patients who suffer from some of the following:

• Arthritis

• Back Pain

• Cancer Pain

• Carpal Tunnel Syndrome

• Complex Regional Pain Syndrome                          Type I (RSD) and Type II (Causalgia)

• Myofascial Pain

• Neck Pain

• Neuropathy

• Pain caused by peripheral vascular disease

• Phantom Limb Pain

• Radiculopathy

• Shingles/Herpes Zoster (Post Herpetic Neuralgia) 

• Spinal Stenosis

• Torticollis

What Agents Are Used In Nerve Blocks?

• Local Anesthetics - help control acute pain

• Steroids - helps reduce nerve and joint inflammation and decrease swelling

• Opioids - helps control pain in specific areas

• Alcohol or Phenol - used to destroy nerve tissue in cases of sever pain for selective nerves.

How Long Does A Patient Have Relief From Pain After A Block?

There is no way of knowing how much or how long a patient will have relief from pain after receiving a nerve block.  You could have relief for several hours, several weeks, several months or in some cases permanently.

How Often Can A Patient Have A Block?

How often you can have a block depends on the type of block and the agent that is injected.  A nerve block can be a single injection or a continuous infusion.  Some types of blocks are given in a series (example:  a lumbar epidural given in a series of 3 injections 2 or 3 weeks apart).  If using a steroid, injections may be spaced 6 months apart.

Are Nerve Blocks Painful?

Most nerve blocks are not painful but the patient may experience some discomfort during the injection.  Many physicians inject a local anesthetic into the injections site to help decrease pain that may be associated with the procedure.  IV sedation may be given to some patients if the physician feels it is indicated.  

What Are The Possible Side Effects or Complications

As with any procedure there is always the possibility of side effects or complications.   Some side effects might include but not limited to:

• Allergic reaction to medications used

• Bleeding

• Bruising, soreness or stiffness

• Swelling or tenderness at injection site

• Infection

• Post dura puncture headache

• Damage to the spinal cord and/or nerves

• Permanent or temporary paralysis

• Total Spinal

• Hematoma

    If steroids are injected they can cause:

• Temporary weight gain

• Water retention

• Increased blood sugar levels

• Insomnia

• Mood changes

    If narcotics are injected they can cause:

• Itching

• Dizziness or drowsiness

• Urinary retention

• Constipation

• Nausea

• Vomiting

Who Should Not Have Blocks

You should not have certain blocks if you:

• Have an on-going infection or temperature

• Have an allergy to any of the medications to be used

• Are taking certain medications such as blood thinners

• Are pregnant or nursing

IMPORTANT TO KNOW

It requires special training for physicians to be able to perform nerve blocks or specific procedures.  Do not hesitate to ask your physician about his/her qualifications.  You should not agree to any nerve block or procedure unless your physician has performed a complete history and physical examination, reviewed your previous medical records, lab work, x-rays, MRI's, etc and/or ordered current lab work and necessary test or x-rays.