Lateral Femoral Cutaneous Nerve Cryoneurolysis for Meralgia Paresthetica: A Case Report.

Meralgia paresthetica (MP) is a disorder of lateral femoral cutaneous nerve mononeuropathy caused by entrapment or compression of the nerve. It is characterized by numbing, tingling, and burning pain in the lateral aspect of the thigh. The current treatments for MP include conventional medical management, peripheral nerve blocks, and surgical interventions. Some patients who suffer from MP can experience intractable pain and medical management of MP is often inadequate to provide satisfactory pain control. Although regional anesthesia provides excellent pain relief, the analgesic effects of peripheral nerve block are short-lived. Emerging evidence suggests that cryoneurolysis has a low-risk safety profile and can provide prolonged pain relief of superficial nerves when administered appropriately. We present a successful case of a patient with intractable neuropathic pain resulting from MP treated with cryoneurolysis therapy. The patient demonstrated immediate pain relief by 100% after the procedure followed by 80% and 60% pain reduction at 1-month and 3-months follow-up, respectively. Cryoneurolysis may be an alternative modality for patients who fail at conventional medical treatments of neuropathic pain.

A Systematic Review of Race, Sex, and Socioeconomic Status Differences in Postoperative Pain and Pain Management.

PURPOSE: Optimal postoperative pain management remains a significant problem despite the availability of multiple preoperative, intraoperative, and postoperative pain management interventions. Recent studies suggest that racialized minorities, female sex, and individuals of lower socioeconomic status (SES) are more likely to experience more severe pain and inadequate pain management postoperatively. Our systematic review aimed to determine race, sex, and SES differences in postoperative pain and postoperative pain management. DESIGN: This study is a systematic review of literature. METHODS: Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology, we systematically searched 5 databases: Cumulative Index to Nursing and Allied Health Literature (CINAHL), PubMed, Embase, Scopus, and Cochrane. We included primary source peer-reviewed articles published after 1990 that measured postoperative pain and race/ethnicity, sex/gender, or SES, which were published in English. Two pairs of reviewers independently screened each title, abstract, and article for inclusion. In cases of disagreement, a third reviewer broke the tie. FINDINGS: A total of 464 articles were screened, of which 32 were included in this study. In most studies, Blacks/African American experience more severe postoperative pain than Whites/Caucasians. Whites were more likely to be prescribed opioids for pain management than Blacks, Hispanics, and Asians. Also, individuals of lower SES and females reported more postoperative pain. One study found no race/ethnic group differences in pain scores and opioid use after the implementation of the enhanced recovery after surgery (ERAS) protocol. CONCLUSIONS: Optimal postoperative pain relief continues to be a challenge for individuals who self-identify as racialized minorities, females, and those of lower SES. Standardization of care may help reduce disparities in postoperative pain management.

The applications of cryoneurolysis for acute and chronic pain management.

BACKGROUND: Cryoneurolysis is a term used to describe the application of extreme cold to targeted nerve tissue. The primary goal of the application of a thermal neurolytic technique is to disrupt the conduction of pain signals from the periphery to the central nervous system and eliminate or diminish the experience of pain. Recent advancements in ultrasound technology coupled with the development and approval of handheld devices specifically designed to deliver cryoneurolysis has expanded the use of this modality in the perioperative setting. APPLICATION: Surgical procedures including total knee arthroplasties, shoulder arthroplasties, thoracotomies, and mastectomies have all demonstrated long-term pain relief benefits when cryoneurolysis has been administered days to weeks prior to the planned procedure. In addition, the newly designed handheld device allows for office-based clinical use and has been utilized for various chronic pain conditions including neuropathic and phantom limb pain. CONCLUSION: The evidence clearly demonstrates that cryoneurolysis has a low risk profile and when administered appropriately, provides prolonged analgesia without promoting motor blockade. This narrative review article describes the unique mechanism of action of cryoneurolysis for prolonged pain relief and provides emerging evidence to support its applications in both acute and chronic pain management.

Rediscovery of Methadone to Improve Outcomes in Pain Management.

Clinically, methadone is most known for its use in the treatment of opioid maintenance therapy. However, methadone's pharmacological profile makes it an excellent analgesic that can enhance acute and chronic pain management. It is a potent µ-receptor agonist with a longer elimination half-life than most clinically used opioids. In addition, methadone inhibits serotonin and norepinephrine uptake, and it is an N-methyl-D-aspartate antagonist. These distinct analgesic pathways mediate hyperalgesic, allodynic, and neuropathic pain. Its unique analgesic properties provide several essential benefits in perioperative use, neuropathic pain, cancer, and noncancer pain. Despite these proven clinical utilities, methadone has not been used widely to treat acute and chronic pain in opioid naïve patients. This article describes the unique pharmacology of methadone and provides emerging evidence to support its application in acute and chronic pain management. Pain management options and guidelines for surgical patients on methadone are discussed as well.

α2-Adrenergic Receptor Agonist, an Attractive but Underused ERAS Component in Improving Fast-Track Recovery and Surgical Outcomes.

Enhanced Recovery After Surgery (ERAS) protocols have been implemented in many institutions to attenuate the stress of surgery and facilitate early recovery. Careful selection of multimodal analgesic medication plays an essential role in achieving the goals of ERAS protocols. Clonidine and dexmedetomidine are α2-adrenergic receptor (α2-AR) agonists that can greatly enhance various ERAS components owing to their unique pharmacologic properties: antinociception, anxiolysis, anti-inflammation, and renal protection. The α2-AR agonists exert supraspinal and spinal antinociceptive effects by potentiating descending pain modulatory pathways and inhibiting peripheral C fibers. These antinociceptive effects of α2-AR agonists are independent of opioid receptors and result in analgesic synergy with opioid agonists. Several meta-analyses and systematic reviews have reported that α2-AR agonists decrease opioid consumption and side effects in adult and pediatric surgical patients. Given the wide distribution of α2-ARs in the body, α2-AR agonists have been associated with a reduction in anxiety, perioperative stress, inflammation, postoperative nausea and vomiting, shivering, and cognitive dysfunction. This course describes the basic and applied pharmacology of the α2-AR agonists and provides emerging evidence to support their utility in acute pain management and ERAS protocols. Perioperative administration of α2-AR agonists can enhance pain management, decrease adverse effects, and promote surgical recovery.

Measuring comorbidity in cardiovascular research: a systematic review.

Background. Everything known about the roles, relationships, and repercussions of comorbidity in cardiovascular disease is shaped by how comorbidity is currently measured. Objectives. To critically examine how comorbidity is measured in randomized controlled trials or clinical trials and prospective observational studies in acute myocardial infarction (AMI), heart failure (HF), or stroke. Design. Systematic review of studies of hospitalized adults from MEDLINE CINAHL, PsychINFO, and ISI Web of Science Social Science databases. At least two reviewers screened and extracted all data. Results. From 1432 reviewed abstracts, 26 studies were included (AMI n = 8, HF n = 11, stroke n = 7). Five studies used an instrument to measure comorbidity while the remaining used the presence or absence of an unsubstantiated list of individual diseases. Comorbidity data were obtained from 1-4 different sources with 35% of studies not reporting the source. A year-by-year analysis showed no changes in measurement. Conclusions. The measurement of comorbidity remains limited to a list of conditions without stated rationale or standards increasing the likelihood that the true impact is underestimated.

Effect of cyclic stretch on beta1D-integrin expression and activation of FAK and RhoA.

Integrins play a pivotal role in proliferation, differentiation, and survival in skeletal and cardiac myocytes. The beta(1D)-isoform of the beta(1)-integrin is specifically expressed in striated skeletal muscle. However, little is known about the role and the mechanisms by which the splice variant beta(1D)-integrin regulates myogenesis and mechanotransduction. We observed that cyclic mechanical stretch increases beta(1D)-integrin protein levels and activates the downstream cytoskeletal signaling proteins focal adhesion kinase (FAK) and RhoA. Elimination of native beta(1D)-integrin expression by RNA interference in immature developing myoblasts abolished stretch-induced increases in FAK phosphorylation and further downregulated RhoA activity. Blocking of beta(1D)-integrin expression prevented myocellular fusion to form multinucleated mature myotubes. Restoration of human beta(1D)-integrin expression in beta(1D)-integrin-deficient cells partially restored myotube formation. The onset of myofusion also requires the generation of nitric oxide (NO). The release of NO affects cytoskeletal proteins by mediating RhoA activity and protein degradation. Our previous study demonstrated that stretch-induced NO positively modulates mechanical properties of differentiating skeletal myocytes. We found a significant decrease in NO production and apparent elastic modulus in beta(1D)-integrin-deficient cells, suggesting signaling interactions between beta(1D)-integrin and neuronal NO synthase to mediate mechanotransduction and myogenesis in skeletal myocytes. These results suggest that, in addition to regulating differentiation, the beta(1D)-integrin isoform plays a critical role in the response of skeletal myoblasts to cyclic stretch by activating the downstream components of FAK and RhoA activity and affecting NO release.