LCD L37641: Continuous Peripheral Nerve Blocks (CPNB)

This Local Coverage Determination (LCD) specifically addresses continuous paravertebral, interscalene, supraclavicular, infraclavicular, interscalene brachial plexus, axillary, femoral, lumbar plexus, sciatic, and popliteal (sciatic) nerve blocks.

Background

Out of necessity, multiple continuous peripheral nerve blocks (CPNB) were administered in Operation Iraqi Freedom in 2003. Real-time imaging (portable ultrasound) and peripheral nerve stimulation (PNS) have revolutionized the practice of CPNB anesthesia by providing objective evidence of needle proximity to targeted nerves. In the majority of peripheral nerve blocks (PNB), stimulation of nerves at a current of 0.5 mA or less suggests accurate needle placement for injection of local anesthetic. Differential blockade to achieve pain and temperature block while minimizing motor block can be achieved by using levorotatory enantiomers of local anesthetics and delivering specific concentrations to the nerve. A variety of anesthesia textbooks publish maximum recommended dosages for local anesthetics in an attempt to prevent high dose injections leading to toxicity. Because local anesthetic toxicity is related more to intravascular injection than to total dose, some physicians have suggested maximum dose recommendations are irrelevant. It is reasonable to assume that intravascular injections will occur, and practitioners of regional anesthesia should select techniques designed to minimize their occurrence.

This LCD addresses the use of these blocks in the definition and treatment of pain and conditions primarily treated with nerve blockade, such as complex regional pain syndrome (CRPS) and certain hyperhidroses. Pain is defined as an unpleasant sensory and emotional experience associated with actual or potential tissue damage. Pain is chronic when it has been present, continuously or intermittently, despite therapy for 3 months or more. CPNB involves the percutaneous insertion of a catheter directly adjacent to a peripheral nerve. The catheter is then infused with local anesthetic resulting in potent, site-specific analgesia that lasts well beyond the normal duration of a single injection nerve block. Longer-lasting or permanent blockade may be induced with the injection of neurolytic agents and/or application of thermal (not pulsed) radiofrequency.

Prior to blockade, all patients with pain complaints require an evaluation that includes an assessment of the source of the pain and treatment of any underlying pathology. Evaluation must be documented in the patient’s records. In addition, those patients who do not respond to injections or otherwise continue with persistent or poorly responsive pain should be referred for a multi-disciplinary comprehensive evaluation.

Indications

CPNB may be performed for several reasons and may be covered for the following purposes:

• Therapeutic - to treat painful conditions or hyperhidroses that respond to nerve blocks

• Prognostic - to predict the outcome of long-lasting interventions (e.g., neurolysis, rhizotomy)

Limitations

• CPNB is a physician (or other qualified practitioner) service.

• There is no coverage of CPNB services and supplies ‘incident to’ the professional services of a physician (or other qualified practitioner) in private practice.

• CPNB should be performed with real-time ultrasound imaging and/or PNS to help prevent undesirable side effects such as muscle weakness.

• In general, different types of nerve blocks should not be performed at the same setting as other blocks in the same body region.

• When not used as the primary mode of anesthesia, the medically reasonable and necessary placement of CPNB may be reimbursable. Examples:

• A continuous femoral nerve block placed to provide postoperative analgesia for an anterior cruciate ligament repair or a total knee replacement could be reported separately from the surgical anesthesia.

• For shoulder surgery performed under continuous interscalene brachial plexus block along with a general anesthetic as the primary anesthesia, the block would be separately reportable as long as it will be used for postoperative pain control.

• A continuous brachial plexus block might also provide both the anesthesia and the postoperative pain control for an open reduction of a wrist fracture. Only the anesthesia code would be reported.

N/A