Pain management specialists are physicians who have completed a residency in anesthesiology, physical medicine and rehabilitation, neurology, internal medicine, emergency medicine, or psychiatry and usually also a fellowship in pain management to learn medication management and interventional techniques for acute, chronic, and cancer pain. Interventional pain management modalities performed by pain management specialists involve neuromodulation of specific targets to alleviate pain. The procedures they perform include percutaneous needle injection of local anesthetics and/or corticosteroids, radiofrequency (thermal) lesioning, cryotherapy, chemical neurolysis, or surgical implantation of intrathecal medication delivery pump systems or neurostimulation devices. While invasive procedures carry their own inherent risks such as bleeding or infection, they can drastically reduce or even obviate the need for conventional pharmacological therapies that may have side effects or be burdensome to the individual.
For some patients, a nerve block, such as a celiac plexus block for pain from pancreatic cancer, can provide substantial relief. Intrathecal pumps may be most useful for patients with severe pain responsive to opioids but who require such large doses that systemic side effects (eg, sedation, urinary retention, and constipation) become limiting. In the palliative care setting, these pumps are appropriate when life expectancy is long enough to justify the discomfort and cost of surgical implantation.
Clinicians do not need to know all the details of interventional pain procedures but should consider referring their patients to pain management specialists if such procedures may be beneficial. For example, a common question is whether prolonged opioid therapy with its inherent risks is better than an injection or an implanted device. Beyond knowing the benefits and risks, fiscal considerations may be key. The S.A.F.E. principles stand for Safety, Appropriateness, Fiscal Neutrality, and Efficacy of a therapy. These principles create a framework for decision-making about interventional modalities.
Tables 5–10 and 5–11 list the procedures and the agents typically used in interventional pain modalities.
Table 5–10.Interventional techniques for chronic pain by anatomic location. |Favorite Table|Download (.pdf) Table 5–10. Interventional techniques for chronic pain by anatomic location.
| Intrathecal |
| Epidural (caudal, lumbar, thoracic, cervical; interlaminar vs. transforaminal) |
|Paraneuraxial (planar blockade) |
| Paravertebral (intercostal) |
| Transversus abdominis plane/quadratus lumborum |
| Pectoralis and serratus anterior |
|Peripheral nerve (perineural blockade) |
| Brachial plexus and branches |
| Lumbar plexus and branches |
| Intra-articular injections |
| Joint denervation procedures |
|Sympathetic ganglion |
| Gasserian ganglion |
| Sphenopalatine ganglion |
| Cervical sympathetic blockade (stellate ganglion) |
| Lumbar sympathetic blockade |
| Celiac plexus |
| Superior hypogastric plexus |
| Ganglion impar |
|Continuous neuraxial drug delivery |
| Epidural (tunneled catheter, port) |
| Intrathecal (implanted intrathecal pump) |
| Dorsal column stimulation (spinal cord stimulation) |
| Dorsal root ganglion stimulation |
| Peripheral nerve or field stimulation |
Table 5–11.Agents used1 in neuromodulatory therapies. |Favorite Table|Download (.pdf) Table 5–11. Agents used1 in neuromodulatory therapies.
|Voltage-gated sodium channel blockade—local anesthetics |
| Lidocaine |
| Mepivacaine |
| Bupivacaine |
| Ropivacaine |
| Triamcinolone |
| Methylprednisolone |
| Dexamethasone |
| Morphine |
| Hydromorphone |
| Fentanyl |
| Clonidine |
| Dexmedetomidine |
| Others |
|Chemical neurolysis |
| Alcohol |