Peripheral Nerve Stimulation of the Shoulder: A Technical Primer.

Scapulalgia or shoulder pain accounts for 16% of all musculoskeletal complaints in the healthy adult population and becomes more common as we age. When this pain exceeds 3 months in duration, it is deemed to be chronic, and typically treated in an escalating manner. Spanning a continuum of conservative and non-conservative measures, chronic shoulder pain treatments range from rest and physical therapy to surgery. Since each patient presents with a unique spectrum of symptoms a customized treatment plan is often required. Over the lifetime of many of these patients, a variety of treatment options are required. One of these treatment options, peripheral nerve stimulation (PNS), is a minimally invasive procedure in which an electrical impulse is delivered through a percutaneously implanted, small caliber electrode to a peripheral nerve proximal to the lesion which interferes with the pain signals. Over the past several years, significant growth of PNS in the treatment of chronic neuropathic pain has been observed. However, the procedural techniques have not been well described. The foundation of long-term, minimally invasive percutaneous PNS in patients with chronic shoulder pain, and procedural techniques for stimulating the suprascapular and axillary nerves using fluoroscopy or ultrasonography will be described in this report.

Results From a Prospective, Clinical Study (US-nPower) Evaluating a Miniature Spinal Cord Stimulator for the Management of Chronic, Intractable Pain.

BACKGROUND: Chronic, intractable, neuropathic pain is readily treatable with spinal cord stimulation (SCS). Technological advancements, including device miniaturization, are advancing the field of neuromodulation. OBJECTIVES: We report here the results of an SCS clinical trial to treat chronic, low back and leg pain, with a micro-implantable pulse generator (micro-IPG). STUDY DESIGN: This was a single-arm, prospective, multicenter, postmarket, observational study. SETTING: Patients were recruited from 15 US-based comprehensive pain centers. METHODS: This open-label clinical trial was designed to evaluate the performance of the Nalu™ Neurostimulation System (Nalu Medical, Inc., Carlsbad, CA) in the treatment of low back and leg pain. Patients, who provided informed consent and were successfully screened for study entry, were implanted with temporary trial leads. Patients went on to receive a permanent implant of the leads and micro-IPG if they demonstrated a >= 50% reduction in pain during the temporary trial period. Patient-reported outcomes (PROs), such as pain scores, functional disability, mood, patient impression of change, comfort, therapy use profile, and device ease of use, were captured. RESULTS: At baseline, the average pain Visual Analog Scale (VAS) score was 72.1 ± 17.9 in the leg and 78.0 ± 15.4 in the low back. At 90 days following permanent implant (end of study), pain scores improved by 76% (VAS 18.5 ± 18.8) in the leg and 75% (VAS 19.7 ± 20.8) in the low back. Eighty-six percent  of both leg pain and low back pain patients demonstrated a >= 50% reduction in pain at 90 days following implant. The comfort of the external wearable (Therapy Disc and Adhesive Clip) was rated 1.16 ± 1.53, on average, at 90 days on an 11-point rating scale (0 = very comfortable, 10 = very uncomfortable). All PROs demonstrated statistically significant symptomatic improvement at 90 days following implant of the micro-IPG. LIMITATIONS:   Limitations of this study include the lack of long-term results (beyond 90 days) and a relatively small sample size of 35 patients who were part of the analysis; additionally, there was no control arm or randomization as this was a single-arm study, without a comparator, designed to document the efficacy and safety of the device. Therefore, no direct comparisons to other SCS systems were possible. CONCLUSIONS: This clinical study demonstrated profound leg and low back pain relief in terms of overall pain reduction, as well as the proportion of therapy responders. The study patients reported the wearable aspects of the system to be very comfortable.

HTX-011 (bupivacaine and meloxicam) for the prevention of postoperative pain - clinical considerations.

HTX-011 is an extended-release, dual-acting local anesthetic consisting of bupivacaine (sodium-channel blocker) and low-dose meloxicam (non-steroidal anti-inflammatory drug [NSAID]) applied needle-free during surgery. Introducing low-dose meloxicam addresses the limited efficacy of liposomal bupivacaine in acidic inflamed tissues and allows enhanced analgesic effects over three days. It has great promise to be an extremely effective postoperative pain regimen and produce an opioid-free surgical recovery, as it has consistently significantly reduced pain scores and opioid consumption through 72 h. This manuscript provides an updated, concise narrative review of the pharmacology, clinical efficacy, safety and tolerability of this drug and its applications to prevent postoperative pain.

Lay abstract HTX-011 is a local anesthetic (a drug to induce temporary loss of sensation or awareness, usually during a medical procedure), which is made up of a combination of two drugs and applied needle-free during surgery. It has great promise to provide effective treatment for postoperative pain (pain after an operation), allowing patients to have an opioid-free option for their pain relief. This paper reviews how this drug works and the clinical trials that have taken place so far to investigate its safety and effectiveness in reducing pain after an operation.

New Pain Management Options for the Surgical Patient on Methadone and Buprenorphine.

Perioperative management of patients receiving opioid addiction therapy presents a unique challenge for the anesthesiologist. The goal of pain management in this patient population is to effectively manage postoperative pain, to improve patient satisfaction and outcomes, and to reduce the cost of health care. Multimodal analgesics, including nonsteroid anti-inflammatory drugs, intravenous acetaminophen, gabapentanoid agents, and low-dose ketamine infusions, have been used to improve postoperative pain and to reduce postoperative opioid use. Patients on long-term opioid management therapy with methadone and buprenorphine require special considerations. Recommendations and options for treating postoperative pain in patients on methadone and buprenorphine are outlined below. Other postoperative pain management options include patient-controlled analgesia, intravenous, and transdermal, in addition to neuraxial and regional anesthesia techniques. Special patient populations include the parturient on long-term opioid therapy. Recommendations for use of opioids in these patients during labor and delivery and in the postpartum period are discussed.

Supraclavicular and paravertebral blocks: Are we underutilizing these regional techniques in perioperative analgesia?

There has been a renewed interest in supraclavicular and paravertebral blocks for regional anesthesia. Studies have shown a high block success rate with the supraclavicular approach to the brachial plexus. Despite the use of ultrasound, pleural puncture and pneumothorax may still occur. The supraclavicular block is associated with a higher incidence of phrenic nerve paralysis and caution should be exercised in patients with respiratory difficulties. Paravertebral blocks have been used successfully to provide analgesia and anesthesia for a variety of surgical procedures. When compared to thoracic epidural blockade for thoracic surgery, paravertebral blockade provides comparable analgesia with a better preservation of pulmonary function and a lower incidence of hypotension. This brings forth the question as to whether paravertebral blocks have replaced epidural blockade as the gold standard in perioperative pain management for thoracoabdominal procedures.

Intraoperative and Postoperative Blood Glucose Concentrations in Diabetic Surgical Patients Receiving Lactated Ringer's Versus Normal Saline: A Retrospective Review of Medical Records.

BACKGROUND: Hyperglycemia is associated with poor postoperative outcomes after carotid endarterectomy. This retrospective study examined the effect of lactated Ringer's and normal saline solutions on intraoperative blood glucose control in diabetic patients undergoing carotid endarterectomy. METHODS: The anesthetic and surgical records of type 2 diabetic patients who underwent carotid endarterectomy and received either lactated Ringer's solution or normal saline exclusively during the case were reviewed, and 20 patients were randomly selected from each group for further analysis. The outcome of interest was preoperative to postoperative change in blood glucose. RESULTS: The preoperative to postoperative mean changes in glucose for the normal saline and lactated Ringer's groups were 34.4 ± 70.32 mg/dL and 64.5 ± 61.38 mg/dL, respectively. This slight difference in the mean change in glucose between the 2 groups was not statistically significant (P=0.157). CONCLUSION: Lactated Ringer's solution does not appear to cause a significant change in the mean blood glucose levels in diabetic patients undergoing carotid endarterectomy compared to patients receiving normal saline. Randomized controlled trials are needed to further determine whether lactated Ringer's solution adversely affects glucose control in diabetic surgical patients.