Ketamine Infusion for Neuropathic Pain in Brachial Plexus Injuries

Ketamine Infusion for Treatment of Chronic Neuropathic Pain in Traumatic Brachial Plexus Injuries, a Prospective Randomized Control Study

The purpose of this study is to assess pre- and postoperative neuropathic pain in patients with traumatic brachial plexus injuries to determine if intraoperative ketamine infusion affect neuropathic pain associated with avulsion injuries of the brachial plexus.

Study Overview

• Status: Enrolling by invitation
• Conditions: Brachial Plexus Injury
• Intervention / Treatment: Drug: Ketamine Infustion

Detailed Description

Neuropathic pain following traumatic brachial plexus injuries is a common and debilitating problem that has been reported in up to 64-75% of patients. Neuropathic pain is difficult to treat, particularly when secondary to avulsion injuries of the brachial plexus. Current treatment options include neuromodulating pharmacologic agents including gabapentin, pregabalin, tricyclic antidepressants, and duloxetine among others. Other analgesic modalities include TENS unit application, massage, acupuncture, and topical medications. Despite these treatment options, patients frequently continue to experience significant, debilitating neuropathic pain.

The use of ketamine has recently been studied in complex regional pain syndrome (CRPS), spinal cord injuries, and chronic neuropathic pain with encouraging results. Ketamine is thought to exert its analgesic properties via noncompetitive central nervous system N-methyl-D-aspartate (NMDA) antagonism among other primarily central mechanisms including sodium channel blockade, activation of D2 dopamine receptors and facilitation of γ-aminobutyric acid A (GABA-A) signaling. It is utilized clinically in acute and chronic pain management primarily in hospitalized settings to treat a variety of pain states as well as medically refractory depression and headache disorders. The dosing and administration of ketamine infusion varies widely across studies and includes oral ketamine, low dose infusions, and infusions producing an anesthetic effect. To our knowledge, ketamine's use in subanesthetic doses has not been adequately evaluated in patients with neuropathic pain following traumatic brachial plexus injuries. Our study aims to determine how intraoperative ketamine infusion alters neuropathic pain severity associated with brachial plexus avulsion injury in the post-operative period. In addition, we hypothesize that patients receiving intraoperative ketamine infusion will require less narcotic pain medication through the follow-up period of 6 months following surgery.

Patients who are undergoing planned surgery for brachial plexus reconstruction at Mayo Clinic will be enrolled into this study to be randomized into getting ketamine infusions or a placebo medication during surgery and in the 24 hour postoperative period after surgery. Pain will be measured before surgery and at various time points to up to 6 months after surgery through online pain measurement scores.

• Study Type: Interventional
• Enrollment (Estimated): 100
• Phase: Phase 4

Contacts and Locations

Study Locations

• United States
  • Minnesota
    • Rochester, Minnesota, United States, 55905
      • Mayo Clinic in Rochester

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patients with neuropathic pain associated with avulsion injuries following traumatic brachial plexus injuries scheduled for brachial plexus exploration and reconstruction by three senior surgeons at Mayo Clinic (AYS, ATB, RJS):
• Neuropathic pain defined as pain directly related to injury to the somatosensory system, and score >4/10 on the Douleur Neuropathique en 4 Questions (DN4) neuropathic pain questionnaire. Symptoms of neuropathic pain include allodynia, hyperalgesia, burning, needle-like, throbbing, shooting, or electrical-type sensation.
• Nerve root avulsion on CT myelogram.
• Traumatic brachial plexus injuries defined as blunt or penetrating trauma resulting in injury and dysfunction along the course of the brachial plexus defined as nerve roots C5-T1, trunks, divisions, cords, and terminal branches.

Exclusion Criteria:

• Patients without pain following traumatic brachial plexus injuries.
• Patients with brachial plexus injuries due to non-traumatic causes such as tumors, infection, radiation, or inflammatory disorders such as Parsonage Turner Syndrome.
• Patients who do not require surgery for exploration/reconstruction at the brachial plexus.
• Patients under 18 years of age.
• Contraindication to ketamine use (severe hepatic dysfunction -cirrhosis, high-risk coronary artery disease, poorly controlled psychiatric condition- schizophrenia.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Ketamine Infusion Group; Subjects will receive ketamine infusion during their planned surgery and postoperatively.	Drug: Ketamine Infustion; Intravenous infusion at 0.5 mg/kg/hr from induction to emergence from anesthesia during the subject's brachial plexus reconstruction surgery. In addition, subjects will receive postoperative ketamine infusion of 0.1-0.3 mg/kg/hr for 24 hours titrated to side effects while patients are admitted to the hospital following surgery.; Other Names: Ketamine
No Intervention: Standard of Care Group; Subjects will receive general anesthesia as standard of care during their planned surgery

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in PROMIS Pain Quality - Neuropathic Pain (PQ-Neuro) score	Measured by the PROMIS Pain Quality - Neuropathic Pain (PQ-Neuro) self-reported questionnaire asking about pain in the past 7 days using a scale of 1=not at all and 5=very much. Higher scores indicate a worse outcome.	Baseline, 1 week

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Opioid medication use	Change in opioid medication use measured by oral morphine equivalents (OMEs) at postoperative week 1 from baseline	Baseline, 1 week postoperatively
Pain Score	Measured using the Visual Analogue Scale for pain rated from 0-10, where 0 is no pain and 10 is the worst pain imaginable.	1 day postoperatively
Adverse Events	Number of participants to experience sepsis, embolism, wound healing failure, hematomas, or nightmares/hallucinations following surgery	6 weeks

Collaborators and Investigators

• Sponsor: Mayo Clinic
• Investigators: Principal Investigator: Alexander Shin, MD, Mayo Clinic

Publications and helpful links

Helpful Links

• Mayo Clinic Clinical Trials

Study record dates

Study Major Dates

• Study Start (Actual): December 15, 2021
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): December 1, 2026

Study Registration Dates

• First Submitted: June 15, 2021
• First Submitted That Met QC Criteria: June 15, 2021
• First Posted (Actual): June 21, 2021

Study Record Updates

• Last Update Posted (Actual): April 24, 2026
• Last Update Submitted That Met QC Criteria: April 21, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Nervous System Diseases; Neuromuscular Diseases; Peripheral Nervous System Diseases; Wounds and Injuries; Neuralgia; Organic Chemicals; Hydrocarbons; Cyclohexanes; Cycloparaffins; Hydrocarbons, Alicyclic; Hydrocarbons, Cyclic; Ketamine
• Other Study ID Numbers: 20-011213

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No