Cervical epidural steroid injection (ESI) is primarily used to treat pain arising from cervical herniated discs or spinal stenosis.
After informed consent is obtained, the patient is placed in the prone, lateral decubitus, or sitting position with the neck flexed. The sitting position, with the head resting on the examination table, provides better stabilization of the neck during the procedure but may be a problem if the patient is prone to light-headedness. The patient is prepared in a standard aseptic fashion over an area large enough to allow palpation of landmarks, and sterile technique is used throughout the procedure. Local skin anesthesia is provided with 1% to 2% lidocaine at the C7-T1 interspace. A Tuohy epidural needle is advanced in a midline, horizontal fashion until well seated in the posterior ligaments. A winged needle is preferred because it allows two-handed control of the needle as it is directed toward the epidural space. A midline or paramedian approach may be used, although large epidural veins lie laterally. The stylet is then removed, and a “loss-of-resistance” syringe is attached to the hub of the needle. Two to three mL of air or normal saline should be in the syringe. The needle is slowly advanced 1 to 2 mm at a time, with constant checking for loss of resistance by tapping on the plunger of the syringe. Alternatively, the needle can be advanced slowly and continuously with constant light pressure on the plunger. Once a distinct loss of resistance is obtained, the needle is halted, and an attempt is made to aspirate blood or CSF. After negative aspiration, 6 mg of betamethasone sodium phosphate and acetate or equivalent is injected. Care should be taken to flush the needle with normal saline and to replace the stylet before the needle is removed to avoid depositing steroid in the needle track to the skin.
Cervical epidural injections are similar in technique to lumbar epidural injections in some respects. The cervical spinous processes at C7 and T1 are oriented almost horizontally, as in the lumbar region. Of note, caution must be taken because the cervical ligamentum flavum is thinner in this region than at any other spinal level, and the width of the epidural space is only 3 to 4 mm. A catheter may be placed through a nonshearing needle to achieve the desired level under fluoroscopic guidance.
The most frequent complication of a cervical epidural injection is subarachnoid penetration (wet tap) due to the thinner ligamentum flavum and the reduced width of the cervical epidural space. Cervical epidural injections should only be attempted by those physicians with a great deal of experience with lumbar epidural techniques, because the spinal cord lies in close proximity to the epidural space. These injections are normally completed with fluoroscopic guidance, as noted in Chapter 68. Injection of local anesthetics into the cervical epidural space can result in respiratory depression, particularly if the phrenic nerve roots are blocked (C3 to C5).
Infection or bleeding into the closed epidural space also can result in significant neurologic deficits, including quadriplegia. Any complaint of increasing pain or neurologic changes should be investigated immediately. Early recognition can prevent permanent injury.