Cryoneurolysis in Patients with Refractory Chronic Peripheral Neuropathic Pain.

PURPOSE: To evaluate the safety and efficacy of cryoneurolysis in patients with refractory peripheral neuropathic pain. MATERIALS AND METHODS: Twenty-two patients referred for cryoneurolysis of refractory peripheral neuropathy were recruited prospectively from July 2011 to July 2013. The mean patient age was 49.5 years, and 41% of patients were female. Ultrasound imaging of the involved nerves was used for guidance. Percutaneous ablations were performed with a PerCryo 17R device. Pain levels were recorded on a visual analog scale (scores 0-10) before and at 1, 3, 6, 9, and 12 months after the procedure, and complications were documented. RESULTS: Mean pain levels were 8.3 ± 1.9 before intervention and 2.3 ± 2.5 at 1 month, 3.2 ± 2.5 at 3 months, 4.7 ± 2.7 at 6 months, and 5.1 ± 3.7 at 12 months afterward. A Wilcoxon rank-sum test was performed and showed a statically significant decrease between pre- and postprocedural pain scores. There were no complications from the procedures. DISCUSSION: Cryoneurolysis caused a significant decrease in self-reported pain scores in patients with chronic refractory neuropathic pain, with moderately long-term relief. Cryoneurolysis is an additional therapy that can alleviate severe chronic neuropathic pain.

Analgesic management of acute pain in the opioid-tolerant patient.

PURPOSE OF REVIEW: The management of acute pain in the opioid-tolerant patient is an area in perioperative medicine that is growing, as the use of opioids for chronic noncancer pain has been tolerated in the USA. Adding to this population is an increase in opioid abusers, addicts and those in recovery and maintenance programmes. These patients will continue to present for surgery and with acute pain that anaesthesiologists and other members of the healthcare team must become more adept at managing. RECENT FINDINGS: This review covers some of the strategies that may be used by practitioners in the management of acute pain in the opioid-tolerant patient. It is important to collect a detailed history of opioid and drugs of abuse, including the timing of the last dose in order to avoid precipitation of withdrawal. The use of multimodal anaesthetic and analgesic strategies is important for both patient safety and satisfaction and can enhance recovery and discharge home. SUMMARY: There is a need for more high-level evidence-based guidelines to help practitioners achieve the best care of this growing high-risk population of patients.

Report from a quality assurance program on patients undergoing the MILD procedure.

OBJECTIVES: To characterize trends in pain and functional outcomes and identify risk factors in patients with lumbar spinal stenosis (LSS) and neurogenic claudication undergoing the "Minimally Invasive Lumbar Decompression" (MILD) procedure. DESIGN: Retrospective observational cohort study. SETTING: Academic multidisciplinary pain center at Stony Brook Medicine. SUBJECTS: Patients undergoing the MILD procedure from October 2010 to November 2012. METHODS: De-identified perioperative, pain and function related data for 50 patients undergoing MILD were extracted from the Center for Pain Management's quality assessment database. Data included numerical rating scale (NRS), symptom severity and physical function (Zurich Claudication Questionnaire), functional status (Oswestry Disability Index [ODI]), pain interference scores (National Institutes of Health Patient-Reported Outcomes Measurement Information System [PROMIS]), and patients' self-reported low back and lower extremity pain distribution. RESULTS: No MILD patient incurred procedure-related complications. Average NRS scores decreased postoperatively and 64.3% of patients reported less pain at 3 months. Clinically meaningful functional ODI improvements of at least 20% from baseline were present in 25% of the patients at 6 months. Preliminary analysis of changes in PROMIS scores at 3 months revealed that pre-MILD "severe" lumbar canal stenosis may be associated with high risk of "no improvement." No such impact was observed for NRS or ODI outcomes. CONCLUSION: Overall, pain is reduced and functional status improved in LSS patients following the MILD procedure at 3 and 6 months. Given the small sample size, it is not yet possible to identify patient subgroups at risk for "no improvement." Continued follow-up of longer-term outcomes appears warranted to develop evidence-based patient selection criteria.

Best Practice Guidelines on the Diagnosis and Treatment of Vertebrogenic Pain with Basivertebral Nerve Ablation from the American Society of Pain and Neuroscience.

Chronic low back pain is a worldwide leading cause of pain and disability. Degenerative disc disease has been the presumptive etiology in the majority of cases of chronic low back pain (CLBP). More recent study and treatments have discovered that the vertebral endplates play a large role in CLBP in a term defined as vertebrogenic back pain. As the vertebral endplates are highly innervated via the basivertebral nerve (BVN), this has resulted in a reliable target in treating patients suffering from vertebrogenic low back pain (VLBP). The application of BVN ablation for patients suffering from VLBP is still in its early stages of adoption and integration into spine care pathways. BVN ablation is grounded in a solid foundation of both pre-clinical and clinical evidence. With the emergence of this therapeutic option, the American Society of Pain and Neuroscience (ASPN) identified the need for formal evidence-based guidelines for the proper identification and selection of patients for BVN ablation in patients with VLBP. ASPN formed a multidisciplinary work group tasked to examine the available literature and form best practice guidelines on this subject. Based on the United States Preventative Task Force (USPSTF) criteria for grading evidence, gives BVN ablation Level A grade evidence with high certainty that the net benefit is substantial in appropriately selected individuals.

A survey on teaching ultrasound-guided chronic pain procedures in pain medicine fellowship programs.

BACKGROUND: Over the last decade ultrasound guidance (USG) has been utilized very successfully in acute pain procedures to confirm nerves' anatomic location and obtain live images. Not only the utilization, but the teaching, of USG has become an essential part of anesthesiology residency training. Prior to the introduction of USG, chronic pain procedures were always done either under fluoroscopy or blindly. USG offers advantages over fluoroscopy for completion of chronic pain procedures. USG decreases radiation exposure and the expenses associated with operating a fluoroscopy machine and allows live visualization of soft tissues and blood flow, a feature that fluoroscopy does not directly offer. Even today, the utilization and teaching of the technique for chronic pain procedures has not been as widely accepted as in acute pain management. OBJECTIVES: To understand the current practices and the factors affecting the teaching of ultrasound guided chronic pain procedures in chronic pain fellowship programs throughout the United States. STUDY DESIGN: Survey conducted by internet and mail. The survey was distributed to program directors of ACGME-accredited pain medicine fellowships. When the survey was distributed there were 92 accredited pain medicine fellowships. METHODS: REDCap survey software was used for designing the questionnaire and sending email invitations. Also, paper questionnaires were sent to those who did not respond electronically. Additional copies of the survey were mailed or faxed upon request. We received 43 responses (a response rate of 46.7%). Statistical analyses included frequencies, crosstabs, and nonparametric Spearman rank-order correlations. RESULTS: The majority of stellate ganglion blocks, occipital nerve blocks, and peripheral nerve blocks are currently being done under ultrasound guidance. Although interest among trainees is very high, only 48.8% of the fellowship programs require fellows to learn the technique before graduation and 32.6% of the program directors agree that teaching of USG should be an ACGME requirement for pain medicine fellowship training. Faculty training is considered to be the most important factor for teaching the technique by 62.8% of directors. In the opinion of the majority of program directors, the greatest factor that stands against teaching the technique is the fact that it is time consuming. Nearly half (44.2%) of program directors believe that the technique will never replace fluoroscopy; but one quarter (25.6%) think that the new 3D ultrasound technology, when available, will replace fluoroscopy. LIMITATIONS: A moderate response rate (46.7%) may limit the generalizability of the findings. However, our survey respondents seem to represent the study population quite well, although there was a bias towards the university-based programs. Training programs located at community-based hospitals and U.S. government installations were not as well represented. CONCLUSION: The teaching of ultrasound guided chronic pain procedures varies significantly between individual programs. Though many program directors do require that fellows demonstrate competency in the technique before graduation, as of today there is no ACGME guideline regarding this. The advancement in ultrasound technology and the increase in number of trained faculty may significantly impact the use of USG in training fellows to perform chronic pain procedures.

Pregabalin for the treatment of postsurgical pain.

IMPORTANCE OF THE FIELD: Multimodal postoperative pain management targeted at diminishing harmful outcomes should include pregabalin in cases that need opioid reduction and when the risk of developing chronic neuropathic postsurgical pain is present. Gabapentanoids have grown in importance due to their opioid-sparing effects. They may also contribute to the prevention of chronic postsurgical pain. AREAS COVERED IN THIS REVIEW: We reviewed the literature regarding the use of gabapentanoids and their role in treatment modalities in acute postsurgical pain. Dosing, therapeutic efficacy, side effects, and their role within a multimodal regimen are discussed. Particular emphasis is placed on their ability to provide an opioid-sparing effect, as well as on their potential for inhibiting chronic neuropathic pain. A Pubmed search of pregabalin, gabapentin, acute pain, multimodal analgesia, chronic postsurgical pain, and neuropathic pain between 2000 and 2010 was done. Relevant articles - including randomized controlled trials, retrospective trials, case series, case reports, and review articles - were filtered to include those that relate to postsurgical pain. WHAT THE READER WILL GAIN: Readers will gain an increased appreciation of the role of pregabalin in postsurgical pain in patients at risk of developing chronic pain. TAKE HOME MESSAGE: Pregabalin is a safe and effective medication that may decrease perioperative opioid use in patients with more acute neuropathic pain than acute inflammatory pain. When surgery involves more neuropathic-type acute pain there is growing evidence that pregabalin may decrease the incidence of chronic pain.