The analgesic effectiveness of perioperative lidocaine infusions for acute and chronic persistent postsurgical pain in patients undergoing breast cancer surgery: a systematic review and meta-analysis.

BACKGROUND: Breast cancer is the most common cancer among women and tumour resection carries a high prevalence of chronic persistent postsurgical pain (CPSP). Perioperative i.v. lidocaine infusion has been proposed as protective against CPSP; however, evidence of its benefits is conflicting. This review evaluates the effectiveness of perioperative lidocaine infusions for breast cancer surgery. METHODS: Randomised trials comparing perioperative lidocaine infusions with parenteral analgesia in breast cancer surgery patients were sought. The two co-primary outcomes were the odds of CPSP at 3 and 6 months after operation. Secondary outcomes included rest pain at 1, 6, 12, and 24 h; analgesic consumption at 0-24 and 25-48 h; quality of recovery; opioid-related side-effects; and lidocaine infusion side-effects. Hartung-Knapp-Sidik-Jonkman (HKSJ) random effects modelling was used. RESULTS: Thirteen trials (1039 patients; lidocaine: 518, control: 521) were included. Compared with control, perioperative lidocaine infusion did not decrease the odds of developing CPSP at 3 and 6 months. Lidocaine infusion improved postoperative pain at 1 h by a mean difference (95% confidence interval) of -0.65 cm (-0.73 to -0.57 cm) (P<0.0001); however, this difference was not clinically important (1.1 cm threshold). Similarly, lidocaine infusion reduced oral morphine consumption by 7.06 mg (-13.19 to -0.93) (P=0.029) over the first 24 h only; however, this difference was not clinically important (30 mg threshold). The groups were not different for any of the remaining outcomes. CONCLUSIONS: Our results provide moderate-quality evidence that perioperative lidocaine infusion does not reduce CPSP in patients undergoing breast cancer surgery. Routine use of lidocaine infusions for perioperative analgesia and CPSP prevention is not supported in this population. SYSTEMATIC REVIEW PROTOCOL: PROSPERO CRD42023420888.

Incidence of subsequent surgical decompression following minimally invasive approaches to treat lumbar spinal stenosis: A retrospective review.

BACKGROUND CONTEXT: Surgical decompression is the definitive treatment for managing symptomatic lumbar spinal stenosis; however, select patients are poor surgical candidates. Consequently, minimally invasive procedures have gained popularity, but there exists the potential for failure of therapy necessitating eventual surgical decompression. PURPOSE: To evaluate the incidence and characteristics of patients who require surgical decompression following minimally invasive procedures to treat lumbar spinal stenosis. STUDY DESIGN/SETTING: Retrospective review. PATIENT SAMPLE: Patients who underwent minimally invasive procedures for lumbar spinal stenosis (Percutaneous Image-guided Lumbar Decompression [PILD] or interspinous spacer device [ISD]) and progressed to subsequent surgical decompression within 5 years. OUTCOME MEASURES: The primary outcome was the rate of surgical decompression within 5 years following the minimally invasive approach. Secondary outcomes included demographic and comorbid factors associated with increased odds of requiring subsequent surgery. METHODS: Patient data were collected using the PearlDiver-Mariner database. The rate of subsequent decompression was described as a percentage while univariable and multivariable regression analysis was used for the analysis of predictors. RESULTS: A total of 5278 patients were included, of which 3222 (61.04%) underwent PILD, 1959 (37.12%) underwent ISD placement, and 97 (1.84%) had claims for both procedures. Overall, the incidence of subsequent surgical decompression within 5 years was 6.56% (346 of 5278 patients). Variables associated with a significantly greater odds ratio (OR) [95% confidence interval (CI)] of requiring subsequent surgical decompression included male gender and a prior history of surgical decompression by 1.42 ([1.14, 1.77], p = 0.002) and 2.10 times ([1.39, 3.17], p < 0.001), respectively. In contrast, age 65 years and above, a diagnosis of obesity, and a Charlson Comorbidity Index score of three or greater were associated with a significantly reduced OR [95% CI] by 0.64 ([0.50, 0.81], p < 0.001), 0.62 ([0.48, 0.81], p < 0.001), and 0.71 times ([0.56, 0.91], p = 0.007), respectively. CONCLUSIONS: Minimally invasive procedures may provide an additional option to treat symptomatic lumbar spinal stenosis in patients who are poor surgical candidates or who do not desire open decompression; however, there still exists a subset of patients who will require subsequent surgical decompression. Factors such as gender and prior surgical decompression increase the likelihood of subsequent surgery, while older age, obesity, and a higher Charlson Comorbidity Index score reduce it. These findings aid in selecting suitable surgical candidates for better outcomes in the elderly population with lumbar spinal stenosis.

Neuromodulation for the Sphenopalatine Ganglion-a Narrative Review.

PURPOSE OF REVIEW: To provide an integrated overview of the current state of knowledge of neuromodulation for the sphenopalatine ganglion (SPG) by reviewing relevant and significant literature. RECENT FINDINGS: There are several case reports and clinical trials evaluating neuromodulation for the SPG. We identified two blinded, randomized clinical trials for patients with chronic cluster headache. The randomized trials and additional studies demonstrated the long-term safety, efficacy, and cost-effectiveness of neuromodulation for the SPG. Recent studies in Europe and the USA suggest that SPG neuromodulation is a novel modality with clinical importance for treating acute cluster headaches and reducing the frequency of attacks.

Identifying Predictors for Early Percutaneous Spinal Cord Stimulator Explant at One and Two Years: A Retrospective Database Analysis.

OBJECTIVES: Placement of percutaneous spinal cord stimulator (SCS) implant has become a therapeutic option for various chronic pain conditions; however, early surgical explant still occurs. Unfortunately, evidence regarding the incidence of early surgical explant, and patient-specific factors and comorbidities associated with such, is limited and mixed. The objective of this retrospective analysis was to elucidate the incidence and predictors of percutaneous SCS explant within the first two years of device placement. MATERIALS AND METHODS: The PearlDiver-Mariner Patient Record Database of all payer claims was used to identify patients who underwent percutaneous lead SCS implant (leads and generator) with subsequent explant within two years of initial device implant. The primary outcome was to determine the incidence of SCS explant within the first two years of device placement. Secondary outcomes included evaluating the effects of several patient-specific comorbidities on explant rates using univariate regression analysis. RESULTS: Across the database, a total of 52,070 patients who underwent percutaneous lead SCS implant were included, of whom 3104 (5.96%) had SCS explant within the first two years. Most explants occurred within the first-year time interval at 72.8% (2260 patients), whereas only 27.2% (844 patients) had SCS explant between years one and two. At the one-year time interval, covariates associated with an increased odds ratio (OR) (95% CI) of SCS explant were 1) depression (1.39 [1.26, 1.52]), 2) chronic preoperative (1.27 [1.16, 1.39]) or postoperative (1.23 [1,13, 1.36]) opioid use, 3) cannabis abuse (1.58 [1.20, 2.02]), 4) tobacco use (1.13 [1.04, 1.23]), and 5) coagulopathy (1.22 [1.07, 1.38]). In contrast, the OR of explant was lower in patients who were older, men, or had diabetes (complicated or uncomplicated). All associated covariates became nonsignificant after the first year of SCS implant (ie, between the first and second years), and only depression and tobacco use remained as associated factors for device explant. CONCLUSIONS: Our retrospective analysis highlights that the rate of percutaneous SCS explant appears to considerably decrease after the first year of device implant. Furthermore, this analysis sheds additional insights into patients who may be at risk of early percutaneous SCS explant, especially within the first year of device placement, and underscores the importance of a continued multidimensional/biopsychologic assessment in patients with chronic pain.

Cognitive dissonance increases spine loading in the neck and low back.

Cognitive dissonance refers to a state where two psychologically inconsistent thoughts, behaviours, or attitudes are held at the same time. The objective of this study was to explore the potential role of cognitive dissonance in biomechanical loading in the low back and neck. Seventeen participants underwent a laboratory experiment involving a precision lowering task. To establish a cognitive dissonance state (CDS), study participants were provided negative feedback on their performance running counter to a pre-established expectation that their performance was excellent. Dependent measures of interest were spinal loads in the cervical and lumbar spines, calculated via two electromyography-driven models. The CDS was associated with increases to peak spinal loads in the neck (11.1%, p < .05) and low back (2.2%, p < .05). A greater CDS magnitude was also associated with a greater spinal loading increase. Therefore, cognitive dissonance may represent a risk factor for low back/neck pain that has not been previously identified.Practitioner summary: Upon establishing a cognitive dissonance state in a group of participants, spinal loading in the cervical and lumbar spines were increased proportional to the magnitude of the cognitive dissonance reported. Therefore, cognitive dissonance may represent a risk factor for low back and neck pain that has not been previously identified.

The Potential Relationship Between a Cognitive Dissonance State and Musculoskeletal Injury: A Systematic Review.

OBJECTIVE: The objective of this systematic review was to investigate the potential link between cognitive dissonance or its related constructs (emotional dissonance, emotional labor) and musculoskeletal disorders. BACKGROUND: The etiology of musculoskeletal disorders is complex, as pain arises from complex interactions among physical, social, and psychological stressors. It is possible that the psychological factor of cognitive dissonance may contribute to the etiology and/or maintenance of musculoskeletal disorders. METHOD: MEDLINE, APA PsycInfo, and CINAHL Plus databases were searched for studies investigating cognitive dissonance or its related constructs as exposure(s) of interest and outcomes related to physical health (including, but not limited to, musculoskeletal pain). Risk of bias was assessed using the Appraisal tool for Cross-Sectional Studies (AXIS) tool. RESULTS: The literature search yielded 7 studies eligible for inclusion. None of the included studies investigated cognitive dissonance directly but instead investigated dissonance-related constructs of emotional dissonance and emotional labor, in which a mismatch between required and felt emotions might elicit a psychological response consistent with the cognitive dissonance state. Moderate effect sizes between dissonance-related constructs and musculoskeletal disorders were noted (OR 1.25-2.22). CONCLUSION: There is likely a relationship between the two factors studied. However, as the included studies were cross-sectional in nature, a causal relationship between cognitive dissonance-related constructs and musculoskeletal disorders cannot be inferred. Therefore, future study proposing and validating a causal pathway between these variables is warranted. APPLICATION: Cognitive dissonance and its related constructs may serve as risk factors for musculoskeletal disorders that have not been considered previously.

Incidence and Predictors of Inadvertent Dural Puncture After Percutaneous Spinal Cord Stimulation: A Retrospective Database Analysis.

OBJECTIVES: Inadvertent dural puncture (IDP) is a known complication associated with traditional neuraxial procedures; however, its characterization after percutaneous spinal cord stimulation (SCS) lead placement has yet to be clearly established in large population studies. This retrospective analysis aims to understand the incidence and associated characteristics of patients with IDP after percutaneous SCS lead placement. MATERIALS AND METHODS: The PearlDiver Mariner database of national all-payer claims was used to identify patients who received percutaneous SCS leads and had a claim for IDP (intraoperative IDP or postdural puncture headache [PDPH] claim) within 45 days. The primary outcome was to determine the overall incidence of IDP. Secondary outcomes included an evaluation of associated risk factors for IDP and treatments used in symptomatic management. RESULTS: A total of 90,952 patients who underwent percutaneous lead SCS placement were included. The incidence of IDP was 0.48% (436/90,952 patients). Older age (odds ratio [OR]: 0.96; 95% CI: 0.95-0.97; p < 0.0001) and male sex (OR: 0.66; 95% CI: 0.53-0.81; p < 0.001) had a lower odds of having a claim for IDP, whereas a history of IDP was associated with a higher OR (95% CI) by 13.72 times (10.72-17.58) (p < 0.0001). Of the IDP patients, 64% (277/436 patients) had a claim for a therapeutic blood patch. Discrepancy in type of claim for IDP was observed, with most being for PDPH. CONCLUSIONS: Our findings suggest that IDP after percutaneous SCS lead placement is an uncommon event; however, certain factors are associated with its development. Overall, early recognition of IDP after percutaneous SCS lead placement is imperative to facilitate the delivery of targeted treatments and prevent further harmful consequences to the patient.

Postoperative Analgesic Effectiveness of Quadratus Lumborum Block for Cesarean Delivery under Spinal Anesthesia.

BACKGROUND: Spinal morphine is the mainstay of postcesarean analgesia. Quadratus lumborum block has recently been proposed as an adjunct or alternative to spinal morphine. The authors evaluated the analgesic effectiveness of quadratus lumborum block in cesarean delivery with and without spinal morphine. METHODS: Randomized trials evaluating quadratus lumborum block benefits in elective cesarean delivery under spinal anesthesia were sought. Three comparisons were considered: spinal morphine versus spinal morphine and quadratus lumborum block; spinal morphine versus quadratus lumborum block; and no block or spinal morphine versus quadratus lumborum block. The two coprimary outcomes were postoperative (1) 24-h cumulative oral morphine equivalent consumption and (2) pain at 4 to 6 h. Secondary outcomes included area under the curve pain, time to analgesic request, block complications, and opioid-related side effects. RESULTS: Twelve trials (924 patients) were analyzed. The mean differences (95% CIs) in 24-h morphine consumption and pain at 4 to 6 h for spinal morphine versus spinal morphine and quadratus lumborum block comparison were 0 mg (-2 to 1) and -0.1 cm (-0.7 to 0.4), respectively, indicating no benefit. For spinal morphine versus quadratus lumborum block, these differences were 7 mg (-2 to 15) and 0.6 cm (-0.7 to 1.8), respectively, also indicating no benefit. In contrast, for no block or spinal morphine versus quadratus lumborum block, improvements of -18 mg (-28 to -7) and -1.5 cm (-2.4 to -0.6) were observed, respectively, with quadratus lumborum block. Finally, for no block or spinal morphine versus quadratus lumborum block, quadratus lumborum block improved area under the 48-h pain curve by -4.4 cm · h (-5.0 to -3.8), exceeding the clinically important threshold (3.96 cm · h), but no differences were observed in the other comparisons. CONCLUSIONS: Moderate quality evidence suggests that quadratus lumborum block does not enhance analgesic outcomes when combined with or compared with spinal morphine. However, the block improves postcesarean analgesia in the absence of spinal morphine. The clinical utility of this block seems limited to situations in which spinal morphine is not used.

Perineural Liposomal Bupivacaine Is Not Superior to Nonliposomal Bupivacaine for Peripheral Nerve Block Analgesia.

BACKGROUND: Liposomal bupivacaine is purported to extend analgesia of peripheral nerve blocks when administered perineurally. However, evidence of the clinical effectiveness of perineural liposomal bupivacaine is mixed. This meta-analysis seeks to evaluate the effectiveness of perineural liposomal bupivacaine in improving peripheral nerve block analgesia as compared with nonliposomal local anesthetics. METHODS: The authors identified randomized trials evaluating the effectiveness of peripheral nerve block analgesic that compared liposomal bupivacaine with nonliposomal local anesthetics. The primary outcome was the difference in area under the receiver operating characteristics curve (AUC) of the pooled 24- to 72-h rest pain severity scores. Secondary outcomes included postoperative analgesic consumption, time to first analgesic request, incidence of opioid-related side effects, patient satisfaction, length of hospital stay, liposomal bupivacaine side effects, and functional recovery. AUC pain scores were interpreted in light of a minimal clinically important difference of 2.0 cm · h. RESULTS: Nine trials (619 patients) were analyzed. When all trials were pooled, AUC pain scores ± SD at 24 to 72 h were 7.6 ± 4.9 cm · h and 6.6 ± 4.6 cm · h for nonliposomal and liposomal bupivacaine, respectively. As such, perineural liposomal bupivacaine provided a clinically unimportant benefit by improving the AUC (95% CI) of 24- to 72-h pain scores by 1.0 cm · h (0.5 to 1.6; P = 0.003) compared with nonliposomal bupivacaine. Excluding an industry-sponsored trial rendered the difference between the groups nonsignificant (0.7 cm · h [-0.1 to 1.5]; P = 0.100). Secondary outcome analysis did not uncover any additional benefits to liposomal bupivacaine in pain severity at individual timepoints up to 72 h, analgesic consumption, time to first analgesic request, opioid-related side effects, patient satisfaction, length of hospital stay, and functional recovery. No liposomal bupivacaine side effects were reported. CONCLUSIONS: Perineural liposomal bupivacaine provided a statistically significant but clinically unimportant improvement in the AUC of postoperative pain scores compared with plain local anesthetic. Furthermore, this benefit was rendered nonsignificant after excluding an industry-sponsored trial, and liposomal bupivacaine was found to be not different from plain local anesthetics for postoperative pain and all other analgesic and functional outcomes. High-quality evidence does not support the use of perineural liposomal bupivacaine over nonliposomal bupivacaine for peripheral nerve blocks.

Long-Term Efficacy of a Novel Spinal Cord Stimulation Clinical Workflow Using Kilohertz Stimulation: Twelve-Month Results From the Vectors Study.

BACKGROUND AND OBJECTIVES: Multiple variables play a role in spinal cord stimulation (SCS) treatment outcomes, including patient anatomy, pain pattern, lead location, stimulation parameters, and so on. A wide range of stimulation parameters are considered safe and on-label, and as a result a growing number of new frequencies and frequency-combinations are being incorporated into standard practice. A standardized approach to therapy delivery may provide more consistent outcomes for more patients. The Vectors study evaluated whether there is significant sustained improvement in pain and functional outcomes when therapy is delivered using a standardized approach. MATERIALS AND METHODS: Vectors, a post-market, single-arm study evaluated the safety and efficacy of SCS with an implantable neurostimulator starting with 1 kHz stimulation, targeting the T9-T10 disc space following paresthesia mapping. Subjects with chronic intractable low back and leg pain (visual analogue scale [VAS] ≥ 50 mm) were enrolled. The primary endpoint was change in overall pain (VAS) at the three-month visit compared to baseline. Subjects were followed through 12 months. Secondary endpoints included changes in low back and leg pain, quality of life (European Quality of Life - Five Dimensions, EQ-5D-5L), disability (Oswestry Disability Index, ODI), individual subject goals, and subject satisfaction. RESULTS: There was a significant reduction in overall pain (VAS; 45.4 mm) through the three-month visit, which was sustained through 12 months. At 12 months, 79% of subjects had ≥50% improvement in at least one pain domain (overall, lowback or leg) with 85% of subjects reporting therapy satisfaction. There was a decrease in disability and an improvement in quality of life with 70% of subjects achieving a personal activity goal by the three-month visit. CONCLUSIONS: Long-term pain relief and improvement in quality of life and function were achieved when following a standardized workflow. CLINICAL TRIAL REGISTRATION: The Clinicaltrials.gov registration number for the study is NCT03345472.

Comparative analgesic efficacy and safety of intermittent local anaesthetic epidural bolus for labour: a systematic review and meta-analysis.

BACKGROUND: Continuous epidural infusion (CEI) is commonly used for labour analgesia, but concerns over potential motor block, second-stage labour complications, and ineffective analgesia in late labour have prompted examining intermittent epidural bolus (IEB) as an alternative. However, evidence comparing these modalities is conflicting. The meta-analysis evaluates the analgesic efficacy of CEI vs IEB. METHODS: Databases were searched for trials comparing CEI to IEB for labour analgesia. The two co-primary outcomes were risk of breakthrough pain and difference in area under the curve (AUC) for pain scores during the first 4 h post-epidural initiation. Local anaesthetic consumption, maternal outcomes (i.e. delivery mode, labour duration, and maternal satisfaction), and side-effects of epidural analgesia were also evaluated. Results were pooled using random-effects modelling. Trial sequential analysis (TSA) was used to evaluate evidence reliability. RESULTS: Twenty-seven studies (3133 patients) were analysed. Compared with CEI, IEB decreased risk of breakthrough pain by 38% (risk ratio [95% confidence interval {CI}] of 0.62 [0.48, 0.81]; P=0.0004; I2=47%; 1164 patients) and reduced AUC of pain during the 4 h interval by 32.9% (mean difference [95% CI] of -16.7 mm h-1 [-18.9, -14.4]; P<0.0001; 1638 patients). Intermittent epidural bolus enhanced maternal satisfaction, shortened labour duration, decreased motor block, and reduced local anaesthetic consumption. The difference between the two groups was not statistically significant for epidural side-effects or mode of delivery. The TSA indicated adequate power for reliable inferences. CONCLUSIONS: Intermittent epidural bolus provides improved labour pain control during the first 4 h after epidural initiation with less breakthrough pain. Moderate- to high-quality evidence of intermittent epidural bolus superiority support its use as a safe and effective continuous epidural infusion alternative for labour analgesia.

Is Supraclavicular Block as Good as Interscalene Block for Acute Pain Control Following Shoulder Surgery? A Systematic Review and Meta-analysis.

BACKGROUND: Interscalene block (ISB) is the acute pain management technique of choice for shoulder surgery, but its undesirable respiratory side effects have prompted seeking alternatives. Supraclavicular block (SCB) is proposed as an ISB alternative, but evidence of comparative analgesic and respiratory-sparing effects is inconsistent. We compared the analgesic and respiratory effects of SCB and ISB for shoulder surgery. METHODS: Trials comparing ISB to SCB for shoulder surgery were sought. We decided a priori that SCB would be an acceptable alternative if it were noninferior for (1) postoperative 24-hour cumulative oral morphine equivalent consumption (primary outcome, noninferiority margin Δ = -25 mg) and (2) postoperative pain (secondary outcome, noninferiority margin Δ = 4.0 cm·hour); and superior for (3) postblock respiratory dysfunction (primary outcome). Opioid-related side effects and block-related complications were also evaluated. RESULTS: Fifteen studies (1065 patients) were analyzed. In single-injection blocks, SCB was noninferior to ISB for 24-hour morphine consumption (mean difference for SCB-ISB, MD [95% confidence interval {CI}] = -3.11 mg [-9.42 to 3.19], Δ = -25 mg); it was also noninferior for 24-hour pain scores (MD = 0.78 cm·hour [0.07-1.49], Δ = 4.0 cm·hour); and decreased the odds of respiratory dysfunction (odds ratio [OR] [95% CI] = 0.08 [0.01-0.68]). Similarly, in continuous blocks, SCB was noninferior to ISB for 24-hour morphine consumption (MD = 0.46 mg [-6.08 to 5.15], Δ = -25 mg), and decreased the odds of respiratory dysfunction (OR = 0.22 [0.08-0.57]). SCB also decreased odds of minor block-related complications (OR = 0.36 [0.20-0.68] and OR = 0.25 [0.15-0.41] for single-injection and continuous blocks, respectively). Consequently, the null joint-hypothesis was rejected, and SCB can be considered an acceptable alternative to ISB. CONCLUSIONS: For acute pain control following shoulder surgery, high-quality evidence indicates that SCB can be used as an effective ISB alternative. SCB is noninferior for postoperative opioid consumption and acute pain, and it reduces the odds of postblock respiratory dysfunction.

Potential perioperative cardiovascular outcomes in cannabis/cannabinoid users. A call for caution.

Background: Cannabis is one of the most widely used psychoactive substances. Its components act through several pathways, producing a myriad of side effects, of which cardiovascular events are the most life-threatening. However, only a limited number of studies address cannabis's perioperative impact on patients during noncardiac surgery. Methods: Studies were identified by searching the PubMed, Medline, EMBASE, and Google Scholar databases using relevant keyword combinations pertinent to the topic. Results: Current evidence shows that cannabis use may cause several cardiovascular events, including abnormalities in cardiac rhythm, myocardial infarction, heart failure, and cerebrovascular events. Additionally, cannabis interacts with anticoagulants and antiplatelet agents, decreasing their efficacy. Finally, the interplay of cannabis with inhalational and intravenous anesthetic agents may lead to adverse perioperative cardiovascular outcomes. Conclusions: The use of cannabis can trigger cardiovascular events that may depend on factors such as the duration of consumption, the route of administration of the drug, and the dose consumed, which places these patients at risk of drug-drug interactions with anesthetic agents. However, large prospective randomized clinical trials are needed to further elucidate gaps in the body of knowledge regarding which patient population has a greater risk of perioperative complications after cannabis consumption.

American Society of Pain and Neuroscience Best Practice (ASPN) Guideline for the Treatment of Sacroiliac Disorders.

Clinical management of sacroiliac disease has proven challenging from both diagnostic and therapeutic perspectives. Although it is widely regarded as a common source of low back pain, little consensus exists on the appropriate clinical management of sacroiliac joint pain and dysfunction. Understanding the biomechanics, innervation, and function of this complex load bearing joint is critical to formulating appropriate treatment algorithms for SI joint disorders. ASPN has developed this comprehensive practice guideline to serve as a foundational reference on the appropriate management of SI joint disorders utilizing the best available evidence and serve as a foundational guide for the treatment of adult patients in the United States and globally.

Neuromodulation for Peripheral Nerve Regeneration: Systematic Review of Mechanisms and In Vivo Highlights.

While denervation can occur with aging, peripheral nerve injuries are debilitating and often leads to a loss of function and neuropathic pain. Although injured peripheral nerves can regenerate and reinnervate their targets, this process is slow and directionless. There is some evidence supporting the use of neuromodulation to enhance the regeneration of peripheral nerves. This systematic review reported on the underlying mechanisms that allow neuromodulation to aid peripheral nerve regeneration and highlighted important in vivo studies that demonstrate its efficacy. Studies were identified from PubMed (inception through September 2022) and the results were synthesized qualitatively. Included studies were required to contain content related to peripheral nerve regeneration and some form of neuromodulation. Studies reporting in vivo highlights were subject to a risk of bias assessment using the Cochrane Risk of Bias tool. The results of 52 studies indicate that neuromodulation enhances natural peripheral nerve regeneration processes, but still requires other interventions (e.g., conduits) to control the direction of reinnervation. Additional human studies are warranted to verify the applicability of animal studies and to determine how neuromodulation can be optimized for the greatest functional restoration.

The role of neuroinflammation in the transition of acute to chronic pain and the opioid-induced hyperalgesia and tolerance.

Current evidence suggests that activation of glial and immune cells leads to increased production of proinflammatory mediators, creating a neuroinflammatory state. Neuroinflammation has been proven to be a fundamental mechanism in the genesis of acute pain and its transition to neuropathic and chronic pain. A noxious event that stimulates peripheral afferent nerve fibers may also activate pronociceptive receptors situated at the dorsal root ganglion and dorsal horn of the spinal cord, as well as peripheral glial cells, setting off the so-called peripheral sensitization and spreading neuroinflammation to the brain. Once activated, microglia produce cytokines, chemokines, and neuropeptides that can increase the sensitivity and firing properties of second-order neurons, upregulating the signaling of nociceptive information to the cerebral cortex. This process, known as central sensitization, is crucial for chronification of acute pain. Immune-neuronal interactions are also implicated in the lesser-known complex regulatory relationship between pain and opioids. Current evidence suggests that activated immune and glial cells can alter neuronal function, induce, and maintain pathological pain, and disrupt the analgesic effects of opioid drugs by contributing to the development of tolerance and dependence, even causing paradoxical hyperalgesia. Such alterations may occur when the neuronal environment is impacted by trauma, inflammation, and immune-derived molecules, or when opioids induce proinflammatory glial activation. Hence, understanding these intricate interactions may help in managing pain signaling and opioid efficacy beyond the classical pharmacological approach.

Wearable motion-based platform for functional spine health assessment.

INTRODUCTION: Low back pain is a significant burden to society and the lack of reliable outcome measures, combined with a prevailing inability to quantify the biopsychosocial elements implicated in the disease, impedes clinical decision-making and distorts treatment efficacy. This paper aims to validate the utility of a biopsychosocial spine platform to provide standardized wearable sensor-derived functional motion assessments to assess spine function and differentiate between healthy controls and patients. Secondarily, we explored the correlation between these motion features and subjective biopsychosocial measures. METHODS: An observational study was conducted on healthy controls (n=50) and patients with low back pain (n=50) to validate platform utility. The platform was used to conduct functional assessments along with patient-reported outcome assessments to holistically document cohort differences. Our primary outcomes were motion features; and our secondary outcomes were biopsychosocial measures (pain, function, etc). RESULTS: Our results demonstrated statistically significant differences in motion features between healthy and patient cohorts across anatomical planes. Importantly, we found velocity and acceleration in the axial plane showed the largest difference, with healthy controls having 49.7% and 55.7% higher values, respectively, than patients. In addition, we found significant correlations between motion features and biopsychosocial measures for pain, physical function and social role only. CONCLUSIONS: Our study validated the use of wearable sensor-derived functional motion metrics in differentiating healthy controls and patients. Collectively, this technology has the potential to facilitate holistic biopsychosocial evaluations to enhance spine care and improve patient outcomes. TRIAL REGISTRATION NUMBER: NCT05776771.

Postoperative nausea and vomiting prophylaxis from an economic point of view.

Patients rank postoperative nausea and vomiting (PONV) in the top five most undesirable outcomes of surgery. Thirty percent of all surgical patients experience PONV. We conducted an economic study to determine the financial implications of providing surgical patients with PONV prophylaxis to increase patient satisfaction and minimize postoperative complications. Our main objective was to develop an economic model of PONV prophylaxis. We retrospectively reviewed all surgical cases who received care at our institution from June 2005 to June 2007 in which the surgical patient was billed for treatment of nausea and vomiting while in the hospital. The PONV risk factors for these patients were assessed as well as the revenue stream associated with those patients who returned to the hospital within 5 days with nausea and vomiting as their chief complaint. Of the total number of medical charts reviewed (56,532), 28 (1.57%) of 1783 patients who were billed for PONV while in the hospital returned to the hospital with PONV. The total billable charges for PONV for these returning patients were $83,674; the total reimbursements were $25,816 yielding a 31% reimbursement rate. The total hospital expenses were $24,123 yielding a net hospital profit of $1693 for treating these 28 patients. The average hospital cost and charge per antiemetic drug dose was $0.304 and $3.66, respectively. Using these figures, we determined that our hospital's net profit increases linearly with increased PONV prophylaxis administration. Our economic analysis shows that PONV prophylaxis is economically beneficial for the hospital when weighed against the expenses generated by treating patients returning to the hospital with PONV.