Abstract:

Acute pain is elicited by the injury of body tissues and activation of nociceptive transducers at the site of local tissue damage. This type of pain is often a reason to seek health care, and it occurs after trauma, surgical interventions, and some disease processes.

Chronic pain has been defined as "persistent or episodic pain of duration or intensity that adversely affects the function or well-being of the patient, attributable to any nonmalignant etiology" ("Practice Guidelines for Chronic Pain Management: A Report by the American Society of Anesthesiologists Task Force on Pain Management, Chronic Pain Section"). In addition, the pain has been refractory to repeated attempts at medical management and usually has been present for at least three to six months.

Pain associated with cancer includes pain associated with disease progression as well as treatments. Pain associated with cancer can have multiple causes—namely, disease progression, treatment (e.g., neuropathic pain resulting from radiation therapy), and co-occurring diseases (e.g., arthritis). Regardless of whether the pain associated with cancer stems from disease progression, treatment, or a co-occurring disease, it may be either acute or chronic.

Spinal pain generates from multiple structures in the spine. Certain conditions may not be detectable using currently available technology or biochemical studies. However, for a structure to be implicated, it should have been shown to be a source of pain in patients, using diagnostic techniques of known reliability and validity. The structures responsible for pain in the spine, include but are not limited to, the vertebral bodies, intervertebral discs, spinal cord, nerve roots, facet joints, ligaments, muscles, atlanto-occipital joints, atlanto-axial joints, and sacroiliac joints.

Postlaminectomy syndrome/failed back syndrome or pain following operative procedures of the spine, sometimes known as failed management syndrome, is becoming an increasingly common entity in modern medicine. Other spinal conditions causing pain include various degenerative disorders such as spinal stenosis, spondylolysis, spondylolisthesis, degenerative scoliosis, idiopathic vertebrogenic sclerosis, diffuse idiopathic spinal hyperostosis, and segmental instability. Degenerative conditions other than disc disruption and facet arthritis may contribute to approximately 5% to 10% of spinal pain.

Neural blockade is one technique used in chronic pain management. Neural blockade is the interruption of neural transmission by the injection of a local anesthetic agent or other drug. Nerve block therapy can be used to answer specific questions resulting from a careful evaluation of the patient's pain problem and to gain insight into the underlying problem causing the pain. Success of the nerve block is determined by the adequacy of interruption of nerve function, and the effect of that blockade on the patient's pain. The goal of chronic pain management is to achieve optimal pain control, recognizing that a pain-free state may not be achievable; minimize adverse outcomes; enhance functional abilities and physical and psychological well-being; and enhance the quality of life for patients with chronic pain.

The decision to treat chronic pain by invasive or destructive procedures must be based on a thorough evaluation of the patient and include a systematic assessment of the location, intensity, and pathophysiology of the pain. A detailed pain history that includes prior treatment and response to treatment is essential. A detailed physical examination and review of all pertinent diagnostic tests is also needed. This local coverage determination documents National Government Services indications and limitations for pain management treatment.

For complete coverage detail, please review each of the following sections: Indications and Limitations for Specific Types of Injections, Limitations for All Diagnostic and Therapeutic Pain Management Services, Documentation Requirements and Utilization Guidelines.

Indications and Limitations for Specific Types of Injections

TRIGGER POINT INJECTIONS

Trigger point injection is one of the many modalities utilized in the management of chronic pain. Myofascial trigger points are self-sustaining hyperirritative foci that may occur in any skeletal muscle in response to strain produced by acute or chronic overload. These trigger points produce a referred pain pattern characteristic for that individual muscle. Production of a referred pain pattern differentiates myofascial pain syndrome from tender points and fibromyalgia. Each pattern becomes part of a single muscle myofascial pain syndrome (MPS); and each of these single muscle syndromes is responsive to appropriate treatment, which includes injection therapy. Injection is achieved with needle insertion and the administration of agents such as local anesthetics.

Indications:

The diagnosis of trigger points requires a detailed history and thorough physical examination. The following clinical features are present most consistently, and are helpful in making the diagnosis:

• History of onset of the painful condition, and its presumed cause (injury, sprain, etc.);
• Distribution pattern of pain consistent with the referral pattern of the trigger points;
• Restriction of range of motion with increased sensitivity to stretch;
• Muscular deconditioning in the affected area;
• Focal tenderness of a trigger point;
• Palpable taut band of muscle in which trigger point is located;
• Local taut response to snapping palpation or needle insertion; and
• Reproduction of referred pain pattern upon stimulation of the trigger point.

The goal is to treat the cause of the pain and not just the symptom of pain. Other treatment modalities include:

• Pharmacologic treatment including analgesics and medications to induce sleep and relax muscles (i.e. antidepressants, neuroleptics, or non steroidal anti-inflammatory drugs); and
• Nonpharmacologic treatment modalities (i.e., osteopathic manual medicine techniques, massage, ultrasonography, application of heat or ice, transcutaneous electrical nerve stimulation, Spray and Stretch technique); and
• For trigger points in the acute state of formation (before additional pathologic changes develop), effective treatment may be delivered through physical therapy.

After myofascial pain syndrome is established as described above, trigger point injection may be indicated when noninvasive medical management is not successful or as first line treatment. Additionally, trigger point injection is indicated when the movement of a joint is mechanically blocked as is the case of the coccygeus muscle.

Limitations:

Only one trigger point injection procedure (CPT codes 20552 or 20553) should be reported on any particular day, no matter how many sites or regions are injected.

The local anesthetic administered in conjunction with trigger point injections is included in the practice expense for these procedures.

Trigger point injections used on a routine basis, e.g., on a regular periodic and continuous basis, for patients with chronic non-malignant pain syndromes are not considered medically necessary.