Percutaneous Peripheral Nerve Stimulation (Neuromodulation) for Postoperative Analgesia

The moderate-to-severe pain many patients experience following orthopedic surgery is often treated with opioids, which are associated with side effects such as nausea/vomiting, sedation, and respiratory depression (and a risk of abuse). Potent site-specific analgesia with fewer side effects may be provided with a "continuous peripheral nerve block," which involves the percutaneous insertion of a catheter adjacent to the peripheral nerve(s) supplying a surgical site. Local anesthetic is introduced via the catheter. However, there are major problems with continuous nerve blocks that have dramatically limited their use outside academic centers. Percutaneous peripheral nerve stimulation (PNS) or "nerve modulation" is an alternative method of pain control involving the insertion of an electrical lead through an introducing needle-obviating an open surgical incision for placement-followed by the introduction of electric current to produce analgesia. This modality has been used to treat chronic pain, but it has not been evaluated with a randomized, controlled study when applied to acute pain management (post-surgical analgesia). This temporary therapy has multiple theoretical benefits over existing analgesics, such as a lack of systemic side effects (e.g., nausea, respiratory depression), an absence of induced muscle weakness, and a reduced risk of adverse events (e.g. infection). The purpose of the proposed randomized, double-masked, placebo-controlled, crossover, feasibility study is to explore the possibility of treating postoperative pain with ultrasound-guided percutaneous PNS and, if so, to help power a subsequent definitive randomized, controlled trial.