Char, Steven

Peripheral nerve stimulation (PNS) has been utilized for over 50 years with accumulating evidence of efficacy in a variety of chronic pain conditions. The level and strength of evidence supporting the use of PNS for peripheral neuropathic pain remains unclear. The purpose of this review is to synthesize data from prospective studies on the efficacy of PNS for neuropathic pain as it pertains to pain intensity, neurological deficits/neuropathy (e.g., weakness, sensory deficits, gait/balance), and other secondary outcomes (quality of life, satisfaction, emotional functioning, and adverse events). In compliance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, this review identified articles from MEDLINE(R), EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus. Overall, per the Grading of Recommendations Assessment, Development and Evaluation (GRADE) criteria, pooled results demonstrate very low quality or low quality of evidence supporting modest to substantial improvement in pain and neurological function after PNS implantation for treatment of peripheral neuropathic pain. PNS for phantom limb pain was the only indication that had moderate level evidence. Future prospective and well-powered studies are warranted to assess the efficacy of PNS for peripheral neuropathic pain.

Calciphylaxis is a serious and rare medical condition that leads to substantial clinical manifestations including pain, creating perioperative and treatment challenges. No standard treatment protocol exists nor are comprehensive guidelines available for perioperative management of patients with calciphylaxis. In this review, we evaluate existing literature (January 2000 to May 2021) with the aim to offer guidance for treating patients with this challenging disease through the perioperative period. Although no therapies are currently considered standard for treating calciphylaxis, multiple interventions are available for improving symptoms. Preoperative and intraoperative management involves monitoring and optimizing patient comorbid conditions and any possible electrolyte imbalances. Postoperative management can be challenging when potential calciphylaxis triggers are indicated, such as warfarin and corticosteroids. In addition, poor wound healing and difficult pain control are common. Therefore, a multifactorial approach to controlling postoperative pain is recommended that includes the use of nerve blocks, renal-sparing opioids, benzodiazepines, and/or ketamine. We present preoperative, intraoperative, and postoperative recommendations for treating calciphylaxis with levels of evidence when appropriate.