A lumbar epidural injection is a safe and effective minimally invasive treatment for the treatment of certain types of low back pain. This type of spinal injection reduces nerve inflammation, calms symptoms, aids healing and, provides the physician with important diagnostic information.
The procedure involves injecting a corticosteroid into the epidural space. A corticosteroid is a powerful, slow-releasing, and long-lasting anti-inflammatory medication effective at reducing inflammation. Sometimes a narcotic is injected to increase pain relief. The epidural space is between the protective membrane (dura mater) that covers the spinal cord and the bony spinal canal. After medication is injected, it flows and coats the nerve roots.
Diagnostically, when the patient’s symptoms are relieved, the injection provides evidence that a particular nerve root is a pain generator.
Many spinal problems cause low back and leg pain (sciatica).
Basics about Lumbar Spinal Nerves
There are 5 pair of spinal nerves In the lumbar spine. Each pair of nerves provides sensation and function to specific parts of the body. The spinal nerve pairs are numbered to correspond with the adjacent vertebral level. The nerve roots at L1 exit at the left and right between the first and second lumbar vertebrae (L1-L2). L5 exits between the last lumbar vertebra and the sacrum (L5-S1).
Each pair of nerve roots exit the spinal column and branch out into the body forming the peripheral (outer) nervous system. These nerves innervate the lower part (below the waist) of the body and enable movement (motor function) and feeling (sensory function). Dermatones are skin areas innervated by spinal nerve roots. Physicians use dermatomal patterns to help diagnose the location of certain spinal problems based on where the patient reports pain or weakness.
Based on symptoms, medical history, physical and neurological examination, and imaging study findings (x-ray, MRI), the physician can determine the spinal nerve root(s) associated with pain and other symptoms.
Patient Procedure Preparation
Some types of medications have to be stopped several days before the procedure. Certain medications increase the risk for bleeding. The physician may ask the patient to stop pain medication, including anti-inflammatory drugs to determine the full effectiveness of the lumbar epidural injection.
Possible Risks and Complications
Any medical procedure poses risks or possible complications. Although rare, possible risks or complications include bleeding, infection, nerve injury, and allergic reaction to medication. Furthermore, the injection may increase pain and cause tenderness at the injection site. The physician discusses all potential risks and complications with the patient well in advance of the procedure date.
What to Expect: The Procedure and After
The procedure is performed in a sterile setting. After checking into the facility, the patient changes into a hospital gown and lies on the treatment bed, and an intravenous line is started through which medications are administered. Relaxing medication is given; complete sedation is not necessary.
In the procedure room, the patient is positioned face down with a cushion placed under the abdomen. This keeps the spine in a flexed position and the patient comfortable. The skin area is cleansed using a sterile solution. Local anesthetic is injected to numb the injection site.
Fluoroscopic imaging equipment called a C-arm is positioned over the patient. During the procedure fluoroscopy captures x-rays in real time and displays the images on a monitor. Under fluoroscopic guidance, the physician inserts the needle and injects a small amount of contrast (dye) to verify needle placement. Next, an anesthetic and corticosteroid is injected into the epidural space. Pain may temporarily increase during the injection. The physician asks the patient for feedback during the procedure and makes the patient as comfortable as possible. When the injection is over, the injection site is covered with a small bandage.
A lumbar epidural injection treatment may involve one or more injections. The procedure takes about 15-minutes. After the procedure, the patient is moved into the recovery area where the nurse monitors vital signs. Soon, the patient is discharged with written home care instructions.
Some patients experience discomfort after the procedure for two or three days. This is normal and does not necessarily mean the corticosteroid is not taking effect. Typically, the physician’s office will call the next day to follow up. Some physicians recommend that patients keep a daily record of pain levels and symptoms following a lumbar injection to provide the medical team with information that could guide further treatment.
Lumbar spinal injections have provided significant pain relief to many people with moderate to severe low back pain. Not everyone is an appropriate candidate for this procedure, and prospective patients should discuss risks and benefits with their physicians.