Percutaneous Neuromodulation of the Brachial Plexus and Sciatic Nerve for the Treatment of Acute Pain Following Surgery: Secondary Outcomes From a Multicenter, Randomized, Controlled Pilot Study.

OBJECTIVES: We recently reported that percutaneous peripheral nerve stimulation (PNS or "neuromodulation") decreased pain and opioid consumption within the first two weeks following ambulatory surgery. However, the anatomic lead locations were combined for the analysis, and benefits for each location remain unknown. We therefore now report the effects of percutaneous PNS for brachial plexus and sciatic nerve leads separately. MATERIALS AND METHODS: Before surgery, leads were implanted percutaneously to target the brachial plexus (N = 21) for rotator cuff repair or sciatic nerve (N = 40) for foot/ankle surgery, followed by a single injection of local anesthetic. Postoperatively, subjects were randomized in a double masked fashion to 14 days of electrical stimulation (N = 30) or sham/placebo (N = 31) using an external pulse generator. The primary outcome of interest was opioid consumption and pain scores evaluated jointly. Thus, stimulation was deemed effective if superior on either outcome and at least noninferior on the other. RESULTS: For brachial plexus leads, during the first seven postoperative days pain measured with the numeric rating scale in participants given active stimulation was a median [interquartile range] of 0.8 [0.5, 1.6] versus 3.2 [2.7, 3.5] in patients given sham (p < 0.001). For this same group, opioid consumption in participants given active stimulation was 10 mg [5, 20] versus 71 mg [35, 125] in patients given sham (p = 0.043). For sciatic nerve leads, pain scores for the active treatment group were 0.7 [0, 1.4] versus 2.8 [1.6, 4.6] in patients given sham (p < 0.001). During this same period, participants given active stimulation consumed 5 mg [0, 30] of opioids versus 40 mg [20, 105] in patients given sham (p = 0.004). Treatment effects did not differ statistically between the two locations. CONCLUSIONS: Ambulatory percutaneous PNS of both the brachial plexus and sciatic nerve is an effective treatment for acute pain free of systemic side effects following painful orthopedic surgery.

Percutaneous Peripheral Nerve Stimulation (Neuromodulation) for Postoperative Pain: A Randomized, Sham-controlled Pilot Study.

BACKGROUND: Percutaneous peripheral nerve stimulation is an analgesic technique involving the percutaneous implantation of a lead followed by the delivery of electric current using an external pulse generator. Percutaneous peripheral nerve stimulation has been used extensively for chronic pain, but only uncontrolled series have been published for acute postoperative pain. The current multicenter study was undertaken to (1) determine the feasibility and optimize the protocol for a subsequent clinical trial and (2) estimate the treatment effect of percutaneous peripheral nerve stimulation on postoperative pain and opioid consumption. METHODS: Preoperatively, an electrical lead was percutaneously implanted to target the sciatic nerve for major foot/ankle surgery (e.g., hallux valgus correction), the femoral nerve for anterior cruciate ligament reconstruction, or the brachial plexus for rotator cuff repair, followed by a single injection of long-acting local anesthetic along the same nerve/plexus. Postoperatively, participants were randomized to 14 days of either electrical stimulation (n = 32) or sham stimulation (n = 34) using an external pulse generator in a double-masked fashion. The dual primary treatment effect outcome measures were (1) cumulative opioid consumption (in oral morphine equivalents) and (2) mean values of the "average" daily pain scores measured on the 0 to 10 Numeric Rating Scale within the first 7 postoperative days. RESULTS: During the first 7 postoperative days, opioid consumption in participants given active stimulation was a median (interquartile range) of 5 mg (0 to 30) versus 48 mg (25 to 90) in patients given sham treatment (ratio of geometric means, 0.20 [97.5% CI, 0.07 to 0.57]; P < 0.001). During this same period, the average pain intensity in patients given active stimulation was a mean ± SD of 1.1 ± 1.1 versus 3.1 ± 1.7 in those given sham (difference, -1.8 [97.5% CI, -2.6 to -0.9]; P < 0.001). CONCLUSIONS: Percutaneous peripheral nerve stimulation reduced pain scores and opioid requirements free of systemic side effects during at least the initial week after ambulatory orthopedic surgery.

Ultrasound-Guided Percutaneous Peripheral Nerve Stimulation: A Pragmatic Effectiveness Trial of a Nonpharmacologic Alternative for the Treatment of Postoperative Pain.

BACKGROUND: Percutaneous peripheral nerve stimulation (PNS) is an analgesic modality involving the insertion of a lead through an introducer needle followed by the delivery of electric current after needle withdrawal. This modality has been used extensively to treat chronic pain, but only small series have been published involving postoperative pain. The ultimate objective of this study is to determine the postoperative effects of percutaneous PNS following moderately to severely painful ambulatory surgery within a real-world clinical practice setting. The primary hypothesis is that surgical pain and opioid consumption during the initial 7 days after surgery will be reduced by percutaneous PNS compared with usual and customary analgesia (dual primary outcome measures). DESIGN: A multicenter pragmatic effectiveness trial. We are randomizing participants having painful orthopedic surgical procedures of the upper and lower extremity to receive 14 days of either 1) electrical stimulation or 2) sham in a double-masked fashion. End points are being assessed at various time points over 12 postoperative months. SUMMARY: The postoperative experience will be much improved if percutaneous PNS provides potent analgesia while concurrently decreasing opioid requirements following painful surgery. Because this modality can be administered for up to 60 days at home, it may provide postoperative analgesia that outlasts surgical pain yet has relatively few risks and, unlike opioids, has no systemic side effects or potential for abuse, addiction, and overdose. Percutaneous PNS has the potential to revolutionize postoperative analgesia as it has been practiced for the past century. This study will inform key stakeholders regarding an evidence-based nonpharmacologic approach to the management of postoperative pain.

Percutaneous Peripheral Nerve Stimulation for Pain Reduction and Improvements in Functional Outcomes in Chronic Low Back Pain.

Chronic low back pain represents one of the most common sources of disability and a significant healthcare burden for the U.S. military. Present treatments for chronic back pain are often ineffective, poorly tolerated, invasive, destructive, and/or associated with complications and lead to the progression to invasive surgical procedures. There have been multiple calls for the development of a minimally invasive system that is effective without the risks or complications of existing surgical therapies, which could prevent the need for surgery and the recurrence of pain. The goal of this study was to evaluate a novel, minimally invasive approach using a percutaneous peripheral nerve stimulation (PNS) system designed to provide pain relief without surgery, to reduce complications, and provide a less-invasive treatment option. In nine subjects, percutaneous PNS improved participants' function, as evidenced by clinically and statistically significant reductions in pain, disability, and pain interference. Subjects also experienced reductions in opioid and non-opioid analgesic medication usage and reported improvements in quality of life with treatment. There were no serious or unanticipated adverse events. These results demonstrate the potential of percutaneous PNS as a non-surgical therapy to treat chronic back pain without opioids.

A randomized, single-blind, prospective trial of auricular 'battlefield' acupuncture for the reduction of postoperative tonsillectomy pain in adults.

AIM: The purpose of this randomized, single-blind trial was to evaluate the efficacy of battlefield acupuncture in reducing postoperative pain and opioid consumption after adult tonsillectomy. METHODS: Adult participants undergoing a tonsillectomy were randomized to either receive auricular 'battlefield' acupuncture or not. Groups were compared using the Wilcox rank sum test, Fisher's exact test and a generalized estimating equations model for post-discharge pain scores. RESULTS: Statistically significant difference was not noted for morphine equivalent opioid use, nor was there any difference noted in the pain scores between the control group and treatment group. CONCLUSION: Acupuncture is cheap, safe and effective in many settings. Peri-operative battlefield auricular acupuncture did not reduce postoperative pain or opioid consumption in this study.

Acupuncture for the Treatment of Chronic Pain in the Military Population: Factors Associated With Treatment Outcomes.

OBJECTIVES: Acupuncture is characterized as an alternative or complementary medicine with a low complication rate and minimal side effects. There is a lack of robust evidence that shows acupuncture is an effective treatment for chronic pain. The purpose of this study was to determine which (if any) characteristics can predict successful response to acupuncture in chronic pain patients treated at military treatment facilities. METHODS: Data from 222 patients who received treatment for a chronic pain condition were collected from 2 medical centers. The patients underwent at least 4 acupuncture treatments and had an average pain score of 4 or higher on a 0- to 10-point numerical rating scale or visual analog scale in the week before treatment initiation. A successful outcome was defined to be a 2-point or greater reduction on the numerical rating scale or visual analog scale 12 weeks postinitial treatment. RESULTS: The overall treatment success rate was 42.3%. Multivariate logistic regression found a higher baseline pain rating and the use of stimulation needles to be associated with a positive outcome (odds ratio [OR]=1.26; 95% confidence interval [CI], 1.03-1.55; P=0.02 and OR=2.73; 95% CI, 1.39-5.32; P=0.03, respectively). Only the presence of one or more psychological comorbidities was found to be associated with treatment failure (OR=0.67; 95% CI, 0.49-0.92; P=0.01). DISCUSSION: The use of electrical stimulation and higher baseline pain score were associated with a positive treatment outcome, while the presence of a psychological comorbidity diminished the likelihood of treatment success. Practitioners should consider using electrical stimulation more frequently, and addressing psychopathology before or concurrent to treatment, when initiating acupuncture.

A multi-center analysis evaluating factors associated with spinal cord stimulation outcome in chronic pain patients.

BACKGROUND: In addition to its conventional use as a treatment for refractory neuropathic extremity pain, spinal cord stimulation (SCS) has recently emerged as a possible treatment for visceral and arthritic pain. But concurrent with the expansion of possible conditions amenable to SCS, other studies have questioned the long-term efficacy of SCS for traditional indications. These disparate findings argue strongly for the refinement of selection criteria. The purpose of this study is to identify correlates of outcome for SCS. METHODS: Data were retrospectively collected on 244 patients who underwent a SCS trial at two academic medical centers. Success was predefined as ≥50% pain relief sustained for ≥6 months. Variables analyzed for their association with outcome included demographics, location of pain, diagnosis, presence of coexisting diseases, pain descriptors, opioid and adjuvant medication use, duration and pain relief during trial, and complications. RESULTS: The presence of allodynia and/or hyperalgesia correlated with both a positive SCS trial (P = 0.01) and long-term implantation outcome (P = 0.05). History of substance abuse was associated with a negative permanent SCS outcome (P = 0.05) but bore no relationship to trial results. The variable most strongly associated with an SCS outcome was experiencing <50% pain relief during the trial, which strongly presaged a negative result (P < 0.001). CONCLUSIONS: Although weak associations with outcome were noted for several clinical variables, none was strongly associated with trial and permanent implantation results. The strongest predictor of a negative SCS outcome was obtaining <50% pain relief during the trial period.

Awake thyroidectomy under local anesthesia and dexmedetomidine infusion.

UNLABELLED: Dexmedetomidine (DEX) is an alpha-2 receptor agonist with sedative and analgesic properties. It has been reported to preserve the patient's ability to cooperate and provide opioid sparing properties. Patients with obstructive sleep apnea (OSA) have demonstrated an increased risk for oxygen desaturation following general anesthesia. We report a case of a 64-year-old male, ASA IV with severe chronic obstructive pulmonary disease, OSA, unilateral vocal cord dysfunction, gastro-esophageal reflux disease, and congestive heart failure undergoing an awake thyroidectomy under local anesthesia and a DEX infusion. The patient was given a loading dose of DEX of 1 mcg/kg and an infusion ranging from 0.2 to 1.0 g/kg/hr. He received a total of 250 mcg of fentanyl and 7.5 mg of ketorolac throughout the case. RESULTS: The patient tolerated the procedure well. He was able to cooperate with simple commands. His vital signs remained stable. He reported a pain score of 2 out of 10 in the recovery unit. CONCLUSIONS: This case demonstrates the successful use of a DEX infusion along with local anesthesia administered by the surgeon for an awake thyroidectomy.