Ultrasound-guided lumbar epidural block is utilized in a variety of clinical scenarios as a diagnostic, prognostic, and therapeutic maneuver as well as to provide surgical anesthesia for pelvic and lower extremity surgeries. As a diagnostic tool, ultrasound-guided lumbar epidural block allows accurate placement of the epidural needle tip within a specific area of the epidural space when performing differential neural blockade on an anatomic basis in the evaluation of lower abdominal, back, groin, pelvic, bladder, perineal, genital, rectal, anal, and lower extremity pain. As a prognostic tool, ultrasoundguided lumbar epidural block can be utilized as a prognostic indicator of the degree of motor and sensory impairment that the patient may experience if lumbar nerve roots are going to be destroyed in an effort to palliate intractable pain in patients too sick to undergo neurosurgical destructive procedures. In the acute pain setting, ultrasound-guided lumbar epidural block with local anesthetics and/or opioids may be used to palliate acute pain emergencies while waiting for pharmacologic, surgical, and/or antiblastic methods to become effective. This technique has great clinical utility in both children and adults when managing acute postoperative and posttrauma pain. Sympathetically mediated pain syndromes including the pain of acute herpes zoster of the lumbar dermatomes and the pain of ureteral calculi can also be effectively managed with epidurally administered local anesthetics, steroids, and/or opioids. Additionally, this technique is of value in patients suffering from acute vascular insufficiency of the lower extremities secondary to vasospastic and vasoocclusive disease, including frostbite and ergotamine toxicity. There is increasing evidence that the prophylactic or preemptive use of lumbar epidural nerve blocks in patients scheduled to undergo lower extremity amputations for ischemia will result in a decreased incidence of phantom limb pain. The administration of local anesthetic and/or steroids via the ultrasound-guided lumbar approach to the epidural space is useful in the treatment of a variety of chronic benign pain syndromes, including lumbar radiculopathy, low back syndrome, spinal stenosis, postlaminectomy syndrome, phantom limb pain, vertebral compression fractures, diabetic polyneuropathy, chemotherapy-related peripheral neuropathy, postherpetic neuralgia, reflex sympathetic dystrophy, orchalgia, proctalgia, and pelvic pain syndromes (Fig. 107.1).

Pain of malignant origin involving the lower abdomen, groin, back, pelvis, perineum, rectum, and lower extremities as well as spinal metastatic disease (especially from breast and prostate primary cancers) is also amenable to treatment with epidurally administered local anesthetics, steroids, and/or opioids.

The cephalad boundary of the epidural space is the fused periosteal and spinal layers of dura at the level of the foramen magnum. The caudad border of the epidural space is the fused layers of connective tissue that make up the sacrococcygeal membrane. Anteriorly, the lumbar epidural space is bounded by the posterior longitudinal ligament. Posteriorly, the lumbar epidural space is bounded by the vertebral laminae and the ligamentum flavum (Fig. 107.2). The vertebral pedicles and intervertebral foramina form the lateral limits of the epidural space (Fig. 107.3). The lumbar epidural space is 5 to 6 mm at the L2-L3 interspace with the lumbar spine flexed. The lumbar epidural space contains fat, veins, arteries, lymphatics, and connective tissue.

Ultrasound-guided lumbar epidural block can be carried out by placing the patient in the prone position with the patient’s abdomen resting on a thin pillow (Fig. 107.4). A total of 10 mL of local anesthetic suitable for epidural administration is drawn up in a 12-mL sterile syringe. If the painful condition being treated is thought to have an inflammatory component, 40 to 80 mg of depot steroid is added to the local anesthetic. To perform ultrasound-guided lumbar epidural block, a threestep process is used. Although this may seem cumbersome, the


three-step process allows the clinician to quickly identify critical anatomic structures while at the same time maintaining a transducer position that allows a safe and easy placement of needles into the lumbar epidural space.