What is the procedure for administering perineural injections for pain relief?

Perineural Injection Technique for Pain Relief

Critical Clarification

The question references a specific provider's technique, but perineural injections are a standardized medical procedure with established protocols, not proprietary methods developed by individual providers. The technique varies based on anatomical target and clinical indication.

General Perineural Injection Procedure

Pre-Procedure Requirements

Ultrasound guidance must be used to reduce the risk of local anesthetic systemic toxicity and ensure accurate needle placement 1. This is considered standard of care for peripheral nerve blocks 1.

• Patient preparation and asepsis should follow the same sterile protocols used for neuraxial procedures 1
• Calculate and document safe doses of local anesthetics before beginning 1
• Obtain informed consent with discussion of potential complications including infection, nerve injury, and systemic toxicity 1

Injection Technique Components

The procedure involves infiltration of medication (typically local anesthetic with or without corticosteroid) around the target nerve under image guidance 2, 3:

• Position the ultrasound probe to visualize the target nerve in cross-section 4
• Insert the needle under real-time ultrasound visualization, advancing incrementally with frequent confirmation of position 1
• Aspirate before injection to confirm non-intravascular placement 1
• Inject the therapeutic solution adjacent to (perineural) the target nerve 3, 4
• Observe spread of injectate around the nerve on ultrasound 4

Medication Selection

Local anesthetic (typically bupivacaine) provides immediate pain relief for several hours, while corticosteroid provides delayed pain control lasting 3-5 weeks 2:

• Common combinations include methylprednisolone (40 mg) with 1% trimecaine or lidocaine 4
• For chronic pain conditions, 5% dextrose water has been used as an alternative to steroids 5
• The benefit of perineural adjuvants must be balanced against risks of immunosuppression (dexamethasone), sedation, bradycardia and hypotension (clonidine/dexmedetomidine) 1

Post-Injection Assessment

Test the quality of the block 2 hours after injection using pinprick sensory examination of the nerve's receptive field 2:

• Reduced pinprick sensation indicates successful perineural anesthesia 2
• The number of nerve branches successfully anesthetized correlates with pain reduction (approximately 0.66 point decrease in pain score per additional branch) 2
• Normal pinprick response suggests the nerve was not adequately penetrated by local anesthetic 2

Site-Specific Considerations

For Spinal/Radicular Pain

Epidural perineural injections require fluoroscopic guidance to confirm correct needle position and contrast spread before injecting therapeutic substances 1:

• Transforaminal approach requires specific C-arm angle settings that vary by spinal level 6
• Obtain AP and lateral fluoroscopic views to confirm needle tip position 6
• Document final needle position and contrast pattern 6

For Peripheral Nerves

Choose blocks least likely to interfere with respiratory function 1:

• Prefer axillary or infraclavicular brachial plexus block over supraclavicular approach 1
• Prefer superior trunk block over interscalene block when possible 1
• Allow adequate onset time (typically longer than anticipated) to reduce risk of conversion to general anesthesia 1

Common Pitfalls to Avoid

• Do not perform perineural injections without image guidance - this significantly increases risk of complications and reduces efficacy 1
• Do not use excessive sedation - this may compromise respiratory function and require airway intervention 1
• Do not assume complete anesthesia of all nerve branches - only 13.2% of patients achieve complete block of all targeted branches 2
• Do not use perineural blockade as a definitive diagnostic test - incomplete blocks are common and do not rule out nerve involvement 2

Evidence Quality Note

The evidence for specific perineural injection techniques comes primarily from observational studies and case series 2, 3, 4. Ultrasound guidance represents current best practice based on safety considerations rather than high-quality comparative trials 1.