Peripheral Nerve Injections for Complex Regional Pain Syndrome

Recruiting at 1 trial location

Overseen By Mark Campbell, MD

Age: 18+

Sex: Any

Trial Phase: Phase 2

Sponsor: Ottawa Hospital Research Institute

Disqualifiers: Uncontrolled hypertension, Sepsis, Active cancer, others

Prior Safety Data This treatment has passed at least one previous human trial

Compensation: Varies

Number of Visits: Unknown

Duration: 12 weeks

50 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

Background Complex regional pain syndrome (CRPS) is characterized by intense pain, loss of function, and associated with motor, trophic, sudomotor, and/or vasomotor changes of the affected extremity. Upper extremity CRPS is seen frequently in electrodiagnostic, neurology, and musculoskeletal clinics and occurs in up to one-third of patients who have undergone common surgical procedures (i.e. carpal tunnel surgery). To date, there is a limited understanding of the underlying pathophysiology of CRPS. As a consequence, few effective treatment options are available. Peripheral nerve blocks have proven to be successful in reducing pain for several musculoskeletal and neurologic conditions. Similarly, this procedure could be used to block somatic and autonomic sensory fibers which are thought to contribute to CRPS. In a small exploratory study, investigators found peripheral nerve blocks in the upper extremity (suprascapular and median nerves) were well-tolerated in patients with CRPS and resulted in a 56% and 37% pain reduction in the shoulder and hand 2 weeks after injection, respectively. While this is highly encouraging, large randomized placebo-controlled trials (RCTs) are necessary to demonstrate effectiveness and safety of nerve blocks for this population before it is accepted into clinical practice. This proposal is a phase II feasibility study that will test the critical elements necessary for performing such a RCT. Methods The investigators will recruit participants (≥18 years old) from The Ottawa Hospital, Bruyère Continuing Care (Elisabeth Bruyère Hospital, St-Vincent Hospital), and Providence Care Hospital (Kingston, ON), meeting the well-established clinical Budapest criteria for upper extremity CRPS and having a visual analog scale (VAS) pain score of at least 40 mm (to avoid flooring effect). Participants will be block-randomized by the Ottawa Methods Centre to receive injections of either A) intervention (suprascapular, median, and ulnar nerves) with bupivacaine and triamcinolone acetonide, or B) placebo (saline). All participants will receive standard care for CRPS. Primary outcomes will focus on crucial methodologic aspects for the future RCT, including: (1) level of recruitment, (2) rate of acceptance from eligible patients to the randomization procedure, (3) blinding efficacy, (4) degree of patient retention, (5) rate of data completion, and (6) rate of adverse events for both the placebo and intervention groups.

Do I need to stop my current medications for the trial?

The trial information does not specify whether you need to stop taking your current medications. It's best to discuss this with the trial coordinators or your doctor.

Is it safe to receive peripheral nerve injections?

Peripheral nerve injections are generally safe, but there is a small risk of nerve injury, especially if high pressure is used during the injection. Careful monitoring and technique can help minimize these risks. ^{1 2 3 4 5}

How do peripheral nerve injections differ from other treatments for complex regional pain syndrome?

Peripheral nerve injections are unique because they involve directly targeting the affected nerves with injections, which can provide localized pain relief. This approach is different from other treatments like peripheral nerve stimulation, which uses electrical impulses, or continuous nerve blocks, which involve continuous infusion of anesthetic medication. ^{6 7 8 9 10}

What data supports the effectiveness of the treatment Peripheral Nerve Injections for Complex Regional Pain Syndrome?

Research shows that techniques similar to peripheral nerve injections, like peripheral nerve stimulation and continuous peripheral nerve blocks, have been effective in reducing pain and improving function in patients with complex regional pain syndrome and other chronic pain conditions. ^{6 7 11 12 13}

Who Is on the Research Team?

Mark Campbell, MD

Principal Investigator

Elisabeth Bruyere Hospital and The Ottawa Hospital

Are You a Good Fit for This Trial?

This trial is for adults over 18 with upper extremity Complex Regional Pain Syndrome (CRPS) who meet the Budapest Criteria and have significant pain, indicated by a score of at least 40 mm on the visual analog scale. Participants must be able to consent to treatment.

Inclusion Criteria

Satisfy the Budapest Criteria for upper extremity CRPS

Able to provide signed and dated informed consent form

I experience significant pain in my upper extremity, scoring at least 40 on the VAS.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2 weeks

Treatment

Participants receive peripheral nerve injections with either bupivacaine and triamcinolone acetonide or placebo (saline) for CRPS

12 weeks

Multiple visits for injections and assessments

Follow-up

Participants are monitored for safety and effectiveness after treatment

12 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Peripheral Nerve Injections

Trial Overview The study tests nerve blocks as a CRPS treatment in the arms. Patients are randomly assigned to receive either bupivacaine and triamcinolone injections or placebo saline injections, alongside standard CRPS care.

How Is the Trial Designed?

Group I: Treatment Experimental Treatment 2 Interventions

The intervention group will receive: 1. Suprascapular nerve block - 3 mL of 0.5% Bupivacaine and 1 mL of 40 mg/mL Kenalog 2. Median nerve block - 3.5 mL of 0.5% Bupivacaine and 0.5 mL of 40 mg/mL Kenalog 3. Ulnar nerve block - 3.5 mL of 0.5% Bupivacaine and 0.5 mL of 40 mg/mL Kenalog

Group II: Placebo Placebo Group 1 Intervention

Placebo The placebo group will receive: 1. Suprascapular nerve injection - 4 mL of normal saline 2. Median nerve injection - 4 mL of normal saline 3. Ulnar nerve injection - 4 mL of normal saline

Who Is Running the Clinical Trial?

Ottawa Hospital Research Institute

Lead Sponsor

Trials

585

Recruited

3,283,000+

Citations

1. England pubmed.ncbi.nlm.nih.gov

Ultrasound-Guided Continuous Superficial Radial Nerve Block for Complex Regional Pain Syndrome. [2022]

2. United States pubmed.ncbi.nlm.nih.gov

Long-term results of peripheral nerve stimulation for reflex sympathetic dystrophy. [2011]

3. United States pubmed.ncbi.nlm.nih.gov

Continuous peripheral nerve blocks: a review of the published evidence. [2022]

4. England pubmed.ncbi.nlm.nih.gov

Ultrasound-guided percutaneous peripheral nerve stimulation for chronic refractory neuropathic pain: a unique series. [2023]

5. Scotland pubmed.ncbi.nlm.nih.gov

Peripheral median nerve stimulation for the treatment of iatrogenic complex regional pain syndrome (CRPS) type II after carpal tunnel surgery. [2009]

6. India pubmed.ncbi.nlm.nih.gov

Injection-related iatrogenic peripheral nerve injuries: Surgical experience of 354 operated cases. [2022]

7. England pubmed.ncbi.nlm.nih.gov

Current devices used for the monitoring of injection pressure during peripheral nerve blocks. [2019]

8. Japan pubmed.ncbi.nlm.nih.gov

[Iatrogenic injury of peripheral nerves]. [2014]

9. United States pubmed.ncbi.nlm.nih.gov

Peripheral nerve injury after local anesthetic injection. [2021]

10. United States pubmed.ncbi.nlm.nih.gov

Debilitating chronic pain syndromes after presumed intraneural injections. [2019]

11. United States pubmed.ncbi.nlm.nih.gov

Continuous peripheral nerve blocks at home for treatment of recurrent complex regional pain syndrome I in children. [2022]

12. England pubmed.ncbi.nlm.nih.gov

Botulinum toxin A for treatment of allodynia of complex regional pain syndrome: a pilot study. [2010]

13. New Zealand pubmed.ncbi.nlm.nih.gov

Treatment of complex regional pain syndrome using free-flap surgery: a case report. [2020]