Interventional Pain Procedures
Procedures: selection, technique, and safety
Interventional care is adjunctive, not a substitute for diagnosis and rehabilitation. Common procedures include trigger-point injections, peripheral nerve blocks, facet joint and medial branch blocks, radiofrequency ablation, epidural steroid injections by interlaminar or transforaminal routes, sympathetic blocks, joint injections, spinal cord stimulation, and intrathecal pumps. Confirm indication, realistic goals, coagulopathy, infection, allergy, pregnancy, and sedation plan. Use sterile technique and image guidance; contrast confirms spread and intravascular placement.
Anticoagulation is a high-yield trap. Follow current ASRA and regional guidelines; for neuraxial procedures, warfarin is generally stopped about 5 days with INR at or below 1.5; DOACs are held according to agent and renal function; aspirin alone is usually not a barrier for many low-risk injections, but guidelines govern. Local anesthetic systemic toxicity presents with perioral numbness, tinnitus, seizures, or arrhythmia; treat with airway support and intravenous lipid emulsion. Steroids can raise glucose, suppress the adrenal axis, and rarely cause neurologic injury.
Traps: not every radiculopathy needs epidural steroid; response to a medial branch block does not prove long-term benefit unless repeated; pain provocation alone is weak evidence. Avoid particulate steroids near cervical foraminal arteries.
Worked example: a 70-kg adult receiving lidocaine 1% without epinephrine has a maximum of 4.5 mg/kg = 315 mg = 31.5 mL. Rule: calculate the milligram dose, not the milliliter volume.