Essentials of Pain Medicine E-Book

Honorio MD Benzon, Srinivasa N. Raja, Scott M Fishman, Spencer Liu, Steven P Cohen, Robert W Hurley

• Publisher: Elsevier
• Year: 2017
• ISBN:
  9780323445412
• Edition: 4
• Topic: Medicine
• Subtopic: Anesthesiology & Pain Management

Accessible, concise, and clinically focused, Essentials of Pain Medicine, 4th Edition, by Drs. Honorio T. Benzon, Srinivasa N. Raja, Scott M. Fishman, Spencer S. Liu, and Steven P. Cohen, presents a complete, full-color overview of today's theory and practice of pain medicine and regional anesthesia. It provides practical guidance on the full range of today's pharmacologic, interventional, neuromodulative, physiotherapeutic, and psychological management options for the evaluation, treatment, and rehabilitation of persons in pain.

• Covers all you need to know to stay up to date in practice and excel at examinations – everything from basic considerations through local anesthetics, nerve block techniques, acupuncture, cancer pain, and much more.
• Uses a practical, quick-reference format with short, easy-to-read chapters.
• Presents the management of pain for every setting where it is practiced, including the emergency room, the critical care unit, and the pain clinic.

• Features hundreds of diagrams, illustrations, summary charts and tables that clarify key information and injection techniques – now in full color for the first time.
• Includes the latest best management techniques, including joint injections, ultrasound-guided therapies, and new pharmacologic agents (such as topical analgesics).
• Discusses recent global developments regarding opioid induced hyperalgesia, addiction and substance abuse, neuromodulation and pain management, and identification of specific targets for molecular pain.

Section VIII

Interventional Techniques for Pain Management

Outline

Chapter 62. Interlaminar Epidural Steroid Injections

Chapter 63. Transforaminal Epidural Steroid Injections and Selective Nerve Root Blocks

Chapter 64. Antitumor Necrosis Factor-α Drugs and Disease-Modifying Antirheumatic Drugs for Low Back Pain

Chapter 65. Facet Syndrome

Chapter 66. Sacroiliac Joint Pain

Chapter 67. Piriformis Syndrome

Chapter 68. Pulsed Radiofrequency, Water-Cooled Radiofrequency, and Cryoneurolysis

Chapter 69. Discography

Chapter 70. Vertebroplasty and Kyphoplasty

Chapter 71. Neurolytic Sympathetic Blocks

Chapter 72. Central and Peripheral Neurolysis

Chapter 73. Spinal Cord Stimulation

Chapter 74. Peripheral Nerve Stimulation

Chapter 75. Dorsal Root Ganglion Stimulation

Chapter 76. Implanted Drug Delivery Systems for Control of Chronic Pain

Chapter 77. Fluoroscopy and Radiation Safety

Chapter 78. Efficacy of Interventional Procedures for Neuropathic Pain

Chapter 62

Interlaminar Epidural Steroid Injections

Indy Wilkinson, MD, and Steven P. Cohen, MD

Introduction

Back pain is the leading cause of disability worldwide,¹ with an estimated financial burden exceeding $100 billion annually in the United States alone.² Most cases of back pain seen in the primary care setting are acute and axial, attributable to muscular and ligamentous strain and spasm. But patients who are referred to the pain medicine specialist typically suffer from pain that is chronic and more complex in nature. Chronic spine pain arises from an array of often overlapping etiologies and, in many cases, exhibits a radicular component, with epidemiologic studies estimating approximately 40% to be predominantly neuropathic in nature.³ Although randomized, controlled studies have demonstrated that epidural steroid injections (ESIs) may alleviate axial spine pain,^4–8 it is widely acknowledged that it is most effective in the treatment of radicular pain, particularly pain arising from a herniated disc.³

Radicular pain, also known by the ambiguous and misleading term sciatica, can be caused by several distinct conditions, but by far its most common causes are herniated disc and spinal stenosis. Disc herniation, or the extrusion of disc material from the nucleus pulposus beyond the limits of the intervertebral disc space, results in the liberation of inflammatory mediators near spinal nerve roots.⁹ A combination of chemical and mechanical factors may serve to irritate adjacent exposed nerve root(s), causing radiating pain that is often described as tingling, burning, or electrical in nature. The prevalence of disc disruption in patients with chronic low back pain is high and has been reported to be near 40%.^10–12 Whereas 95% of all disc herniation occurs in the lumbar spine at L4-5 or L5-S1, the cervical spine can also be affected, most commonly at C6-7.¹³

Spinal stenosis, or the progressive narrowing of the spinal canal, may occur alone or in conjunction with disc herniation. Spinal stenosis can be congenital (i.e., short pedicles) but is most frequently caused by degenerative changes of the spinal anatomy, which may include thickening and buckling of the ligamentum flavum, facet hypertrophy, osteophyte formation, or a combination of these conditions.¹⁴ A narrowed central spinal canal results in compression-induced ischemia of the spinal cord (in the neck) and/or cauda equina.¹⁵ The incidence of spinal stenosis increases with age, with the prevalence among patients aged 60–69 years documented to be as high as 47% for mild to moderate stenosis and 19% for severe stenosis (defined as a spinal canal anteroposterior diameter of less than 12 mm).¹⁶ The most common vertebral levels affected by spinal stenosis are L4-5 in the lumbar spine¹⁷ and C5-6 in the neck.¹⁸

Physicians have performed therapeutic epidural injections for well over 100 years in an effort to treat a wide scope of conditions.¹⁹ Until the first epidural injection of corticosteroids was performed in 1952, these procedures utilized an injectate of plain local anesthetic (LA) solution.²⁰ In this case study published by Robecchi and Capra,²⁰ hydrocortisone was injected through the S1 posterior sacral foramen in an effort to treat lumbar radicular pain. Since that time, the procedure has evolved, and the sacral route, though still utilized,²¹ has largely been supplanted in favor of the more targeted and accessible caudal, lumbar, and cervical techniques.^22,23 Today, ESIs are the most frequently performed procedures by interventional pain physicians worldwide and have been the subject of dozens of reviews and guidelines.³ Despite its extensive study, the resulting body of data has been largely conflicting in terms of procedural efficacy, polarizing health care professionals on its utility and casting a shadow on the future of the procedure.

Technique

The performance of interlaminar ESI (ILESI) requires directing a needle at the midline or paramedian interlaminar space closest to the site of pathology. The needle must pass through the skin, subcutaneous fat, supraspinous ligament, interspinous ligament, and ligamentum flavum to enter the epidural space. The loss-of-resistance (LOR) technique, where manual pressure is applied to the plunger as the needle is advanced through the spinous ligaments, exploits the palpable difference in resistance between the thick fibrous ligamentum flavum and the vacuous potential epidural space. Typically, a 17- or 18-gauge Tuohy needle is used. Smaller 20-gauge needles have been advocated to optimize patient comfort and decrease the risk of spinal headache, but they have been found to be more technically difficult to use and less accurate than their larger counterparts.²⁴

Studies analyzing the accuracy of epidural needle positioning have found that extradural injection occurs in up to 30% of patients in whom blind placement is attempted, even in the hands of experienced proceduralists,^25,26 compared with very accurate and precise placement using confirmatory fluoroscopy.²⁷ A multicenter, retrospective analysis of cervical epidurograms by Stojanovic et al. observed a 53% rate of false LOR during the first attempt to enter the epidural space and determined that the use of epidurography can improve the accuracy of needle placement and medication delivery.²⁸ Whereas blind ESI is still performed in some places, the use of fluoroscopic guidance has been found to provide superior accuracy and safety and has become the standard of care.^29,30

Even without the use of real-time fluoroscopic guidance, the inherent margin of safety of lumbar ILESI is relatively high due in part to the diameter of the lumbar epidural space (4–7 mm)³¹ and the free mobility of the...