Combined Local Anesthetic Blockade and Neuromodulation vs Local Anesthetic Blockade Only for Analgesia After Below-knee Amputation: RCT

A Randomized Clinical Trial Comparing the Analgesic Efficacy of Combined Local Anesthetic Blockade and Neuromodulation (Hybrid Technique) Versus Local Anesthetic Blockade Only for Analgesia After Below-knee Amputation

This multi-site clinical trial aims to assess the efficacy and safety of combining peripheral nerve stimulation with local anesthetic nerve blockade compared to the standard of care, i.e., local anesthetic blockade only using safe stimulation parameters in a condition associated with high postoperative pain state, i.e. a patient undergoing lower limb amputation.

The primary aim of this pilot trial is to evaluate the feasibility, safety, and analgesic efficacy of the hybrid technique (combined PNS and LA-based PNB) compared to that of PNB during the hospital course in patients undergoing below-knee amputations. The secondary aims are to estimate analgesia and opioid-sparing effects at later timepoints of 3, 6, and 12 months following the surgery.

Inclusion Criteria:

• Patients at least 18 years of age
• Undergoing below-knee amputation

Exclusion Criteria:

• Chronic opioid use (daily use within the two weeks before surgery and duration of use of more than four weeks of > 30 mg of oxycodone per day or > 50 of morphine milligrams per day)
• Neuromuscular deficit of the target nerve(s)
• Compromised immune system or concurrent risk of infection based on medical history (e.g., immunosuppressive therapies such as chemotherapy, radiation, sepsis, infection).
• Implanted spinal cord stimulator, cardiac pacemaker/defibrillator, deep brain stimulator, or another implantable neurostimulator whose stimulus current pathway may overlap
• History of bleeding disorder or chronic antiplatelet or anticoagulation therapies (other than aspirin) that require to be restarted within the first three postoperative days
• Allergy to study medications or devices (including occlusive dressings, bandages, tape, etc.)
• Incarceration
• Pregnancy
• Chronic pain for more than three months of any severity in an anatomic location other than the surgical site
• Anxiety disorder
• History of substance abuse
• Inability to consent