Percutaneous auricular nerve stimulation (neuromodulation) for the treatment of pain: A proof-of-concept case report using total joint arthroplasty as a surrogate for battlefield trauma

Abstract

BACKGROUND:There are few effective pain treatments following trauma on the battlefield other than opioids, which are limited by respiratory depression. Ultrasound-guided percutaneous peripheral nerve stimulation ("neuromodulation") has been proposed as an analgesic, but requires physician-level skills, advanced equipment, and an hour to administer. In contrast, percutaneous auricular neuromodulation may be placed by a medic in the field under nonsterile conditions in a few minutes, theoretically provides analgesia for any anatomic location, has no side effects, and no significant risks. It therefore offers the potential to be applied quickly on the battlefield without any of the limitations of opioids. We propose total joint replacement as a surrogate for battlefield trauma and here present a case report to demonstrate proof of concept. METHODS:Following open total knee or hip arthroplasty under spinal anesthesia, two patients had an auricular neuromodulation device applied within the recovery room. Patients were discharged with the unit and contacted daily for 7 days. RESULTS:The devices were each applied in under 3 minutes without difficulty, were well tolerated during use, and removed without complication at home on Day 5. During use, neither patient experienced pain while lying, sitting, or ambulating. Neither required analgesics other than scheduled celecoxib; and a single tablet (50 mg) of tramadol for one patient on postoperative Days 3 and 4 for pain while lowering herself to a seated position. On Days 6 and 7, both patients experienced an increase in pain, one of whom required around-the-clock tramadol. CONCLUSION:Ambulatory postoperative percutaneous auricular neuromodulation is feasible. In these two cases, it appears to have markedly reduced pain scores and opioid requirements free of systemic side effects during the week following major orthopedic surgery. Considering the potential of this modality to treat trauma on the battlefield without systemic side effects, additional investigation appears warranted.

Percutaneous auricular nerve stimulation (neuromodulation) for the treatment of pain following outpatient surgery: a proof-of-concept case series

“…Furthermore, the number of prescribed opioid tablets is directly correlated with the probability of continuing their use,20 and therefore, a modality allowing the prescription of just a few opioid tablets could prove greatly beneficial to individuals and their communities. Neuromodulation avoids the systemic side effects related to opioid use such as nausea, sedation, and respiratory depression; and it has no potential for misuse, dependence, and diversion 16. Moreover, the device used in this report is FDA cleared to reduce symptoms associated with opioid withdrawal, which includes anxiety, insomnia, muscle aches, nausea, and vomiting, all of which are frequent following surgery 10–12 16…”

“…This is an inconvenient reality which dramatically decreases generalizability of the results from any one clinical trial to other devices, requiring investigation of each device independent of the others. The pulse generator of the current report uses an integrated 3 V battery, has a load impedance range of 1k–10k Ω with 3.2 V maximum, and provides symmetrical, biphasic stimulation cycles occurring at a frequency of 0.125 Hz with periodic rest 16…”

“…The first lead was placed at the most cephalad portion of the antihelix by simply pressing the electrode directly into the skin and affixed with an overlying dressing (figure 2). 16 The second electrode was inserted immediately cephalo-anterior to the incisura and posterior to the superficial temporal arterial pulse 16. The third electrode was inserted on the posterior ear opposite the antihelix at the level of the incisura 16.…”

“…16 The second electrode was inserted immediately cephalo-anterior to the incisura and posterior to the superficial temporal arterial pulse 16. The third electrode was inserted on the posterior ear opposite the antihelix at the level of the incisura 16. The ground electrode with four 2 mm long integrated needles was inserted on the anterior side of the lobule (figure 2, inset), completing the circuit, and beginning the 5-day period of stimulation 16.…”

“…The pulse generators automatically ceased functioning after 120 hours (5 days) and patients or their caretakers then detached the device by first removing the round bandage of the grounding electrode, which extracted the electrode from the patient along with the bandage 16. The remaining three electrodes were subsequently removed in the same manner, followed by the pulse generator, after which the single-use, disposable device was discarded 16. No device-related localized irritation, systemic side effects, or complications were identified 16…”