Perioperative Regional Anesthesia on Persistent Opioid Use and Chronic Pain after Noncardiac Surgery: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Whether regional anesthesia impacts the development of chronic postsurgical pain is currently debateable, and few studies have evaluated an effect on prolonged opioid use. We sought to systematically review the effect of regional anesthesia for adults undergoing noncardiac elective surgery on these outcomes. METHODS: A systematic search was conducted in MEDLINE, EMBASE, CENTRAL, and CINHAL for randomized controlled trials (from inception to April 2022) of adult patients undergoing elective noncardiac surgeries that evaluated any regional technique and included one of our primary outcomes: (1) prolonged opioid use after surgery (continued opioid use ≥2 months postsurgery) and (2) chronic postsurgical pain (pain ≥3 months postsurgery). We conducted a random-effects meta-analysis on the specified outcomes and used the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach to rate the quality of evidence. RESULTS: Thirty-seven studies were included in the review. Pooled estimates indicated that regional anesthesia had a significant effect on reducing prolonged opioid use (relative risk [RR] 0.48, 95% CI, 0.24-0.96, P = .04, I 2 0%, 5 trials, n = 348 patients, GRADE low quality). Pooled estimates for chronic pain also indicated a significant effect favoring regional anesthesia at 3 (RR, 0.74, 95% CI, 0.59-0.93, P = .01, I 2 77%, 15 trials, n = 1489 patients, GRADE moderate quality) and 6 months (RR, 0.72, 95% CI, 0.61-0.85, P < .001, I 2 54%, 19 trials, n = 3457 patients, GRADE moderate quality) after surgery. No effect was found in the pooled analysis at 12 months postsurgery (RR, 0.44, 95% CI, 0.16-1.17, P = .10). CONCLUSIONS: The results of this study suggest that regional anesthesia potentially reduces chronic postsurgical pain up to 6 months after surgery. Our findings also suggest a potential decrease in the development of persistent opioid use.

Prevalence and Risk Factors for Chronic Postsurgical Pain After Thoracic Surgery: A Prospective Cohort Study.

OBJECTIVE: Thoracic surgery is associated with one of the highest rates of chronic postsurgical pain (CPSP) among all surgical subtypes. Chronic postsurgical pain carries significant medical, psychological, and economic consequences, and further interventions are needed to prevent its development. This study aimed to determine the prevalence, characteristics, and risk factors associated with CPSP after thoracic surgery. DESIGN: A prospective cohort study. SETTING: Single-center tertiary care hospital. PARTICIPANTS: This study included 285 adult patients who underwent thoracic surgery at Toronto General Hospital in Toronto, Canada, between 2012 and 2020. MEASUREMENTS AND MAIN RESULTS: Demographic, psychological, and clinical data were collected perioperatively, and follow-up evaluations were administered at 3, 6, and 12 months after surgery to assess CPSP. Chronic postsurgical pain was reported in 32.4%, 25.4%, and 18.2% of patients at 3, 6, and 12 months postoperatively, respectively. Average CPSP pain intensity was rated to be 3.37 (SD 1.82) at 3 months. Features of neuropathic pain were present in 48.7% of patients with CPSP at 3 months and 71% at 1 year. Multivariate logistic regression models indicated that independent predictors for CPSP at 3 months were scores on the Hospital Anxiety and Depression Scale (adjusted odds ratio [aOR] of 1.07, 95% CI of 1.02 to 1.14, p = 0.012) and acute postoperative pain (aOR of 2.75, 95% CI of 1.19 to 6.36, p = 0.018). INTERVENTIONS: None. CONCLUSIONS: Approximately 1 in 3 patients will continue to have pain at 3 months after surgery, with a large proportion reporting neuropathic features. Risk factors for pain at 3 months may include preoperative anxiety and depression and acute postoperative pain.

Inferior vena cava ultrasound to predict hypotension after general anesthesia induction: a systematic review and meta-analysis of observational studies.

PURPOSE: Hypotension after induction of general anesthesia is common and is associated with significant adverse events. Identification of patients at high risk can inform the use of preoperative mitigation strategies. We conducted a systematic review and meta-analysis to assess the diagnostic accuracy of the inferior vena cava collapsibility index (IVC-CI) and maximal diameter (dIVCmax) in predicting postinduction hypotension and to identify their predictive performance across different threshold ranges. METHODS: We searched MEDLINE, PubMed®, and Embase from inception to March 2023 for prospective observational studies exploring the performance of IVC-CI and dIVCmax in predicting postinduction hypotension in adults presenting for elective surgery under general anesthesia. We excluded studies reporting on IVC parameters predicting postinduction hypotension in the obstetric patient population or exclusively in patients with obesity. Trials screening and data extraction were conducted independently. We performed meta-analyses to identify the performance of IVC parameters in predicting postinduction hypotension, followed by subgroup analyses that sought the IVC-CI range with the highest hierarchical summary receiver-operating characteristic area under the curve (HSROC-AUC). We used a bivariate random effects model to calculate summary estimates. We evaluated study quality using Newcastle-Ottawa scores and certainty of evidence using the GRADE framework. RESULTS: We included 14 studies involving 1,166 patients. Pooled sensitivity and specificity of the IVC-CI to predict postinduction hypotension was 0.68 (95% confidence interval [CI], 0.55 to 0.79; coverage probability, 0.91) and 0.78 (95% CI, 0.69 to 0.85; coverage probability, 0.9), respectively, with an HSROC-AUC of 0.80 (95% CI, 0.68 to 0.85, high quality of evidence). An IVC-CI threshold range of 40-45% had an HSROC-AUC of 0.86 (95% CI, 0.69 to 0.93, high quality of evidence). CONCLUSIONS: Preoperative IVC-CI is a strong predictor of postinduction hypotension. We recommend that future studies use an IVC-CI threshold of 40-45% (low certainty of evidence). Future studies are needed to establish whether ultrasound-guided preoperative optimization improves outcomes in high-risk patients. STUDY REGISTRATION: PROSPERO ( CRD42022316140 ); first submitted 10 March 2022.

RéSUMé: OBJECTIF: L'hypotension après l'induction de l'anesthésie générale est fréquente et est associée à des effets indésirables importants. L'identification des patient•es à haut risque peut éclairer l'utilisation de stratégies préopératoires d'atténuation. Nous avons réalisé une revue systématique et une méta-analyse pour évaluer la précision diagnostique de l'indice de collapsibilité de la veine cave inférieure (IC-VCI) et du diamètre maximal (dVCImax) pour prédire l'hypotension post-induction et identifier leurs performances prédictives dans différentes plages de seuils. MéTHODE: Nous avons fait des recherches dans les bases de données MEDLINE, PubMed® et Embase de leur création jusqu'en mars 2023 pour en extraire les études observationnelles prospectives explorant les performances de l'IC-VCI et du dVCImax pour la prédiction de l'hypotension post-induction chez des adultes se présentant pour une chirurgie non urgente sous anesthésie générale. Nous avons exclu les études rapportant des paramètres de VCI prédisant l'hypotension post-induction dans la population obstétricale ou exclusivement chez des personnes obèses. Le tri des études et l'extraction des données ont été menés indépendamment. Nous avons réalisé des méta-analyses pour identifier la performance des paramètres de VCI dans la prédiction de l'hypotension post-induction, suivies d'analyses de sous-groupes qui ont recherché la plage d'IC-VCI avec le plus haut niveau de hiérarchie de l'aire sous la courbe de la courbe ROC (HSROC-AUC). Nous avons utilisé un modèle bivarié à effets aléatoires pour calculer des estimations sommaires. Nous avons évalué la qualité des études à l'aide des scores de Newcastle-Ottawa et la certitude des données probantes à l'aide de l'outil GRADE. RéSULTATS: Quatorze études portant sur 1166 patient·es ont été incluses. La sensibilité et la spécificité combinées de l'IC-VCI pour prédire l'hypotension post-induction étaient de 0,68 (intervalle de confiance [IC] à 95 %, 0,55 à 0,79; probabilité de couverture, 0,91) et 0,78 (IC 95 %, 0,69 à 0,85; probabilité de couverture, 0,9), respectivement, avec une HSROC-AUC de 0,80 (IC 95 %, 0,68 à 0,85, données probantes de haute qualité). Une plage de seuils d'IC-VCI de 40 à 45 % avait une HSROC-AUC de 0,86 (IC 95 %, 0,69 à 0,93, haute qualité des données probantes). CONCLUSION: L'IC-VCI préopératoire est un bon prédicteur de l'hypotension post-induction. Nous recommandons que les études futures utilisent un seuil d'IC-VCI de 40 à 45 % (faible certitude des données probantes). De futures études sont nécessaires pour déterminer si l'optimisation préopératoire échoguidée améliore les devenirs chez la patientèle à risque élevé. ENREGISTREMENT DE L'éTUDE: PROSPERO ( CRD42022316140 ); première soumission le 10 mars 2022.

The Role of Virtual Reality and Artificial Intelligence in Cognitive Pain Therapy: A Narrative Review.

PURPOSE OF REVIEW: This review investigates the roles of artificial intelligence (AI) and virtual reality (VR) in enhancing cognitive pain therapy for chronic pain management. The work assesses current research, outlines benefits and limitations and examines their potential integration into existing pain management methods. RECENT FINDINGS: Advances in VR have shown promise in chronic pain management through immersive cognitive therapy exercises, with evidence supporting VR's effectiveness in symptom reduction. AI's personalization of treatment plans and its support for mental health through AI-driven avatars are emerging trends. The integration of AI in hybrid programs indicates a future with real-time adaptive technology tailored to individual needs in chronic pain management. Incorporating AI and VR into chronic pain cognitive therapy represents a promising approach to enhance management by leveraging VR's immersive experiences and AI's personalized tactics, aiming to improve patient engagement and outcomes. Nonetheless, further empirical studies are needed to standardized methodologies, compare these technologies to traditional therapies and fully realize their clinical potential.

PRECISE trial (Pain RElief Combination Intervention StratEgies): protocol for the clinical trial of a pregabalin-melatonin combination for fibromyalgia.

INTRODUCTION: Fibromyalgia is associated with chronic widespread pain and disturbed sleep. Multidisciplinary, multimodal management often includes pharmacotherapy; however, current drugs used to treat fibromyalgia provide meaningful benefit to only 30-60% of treated individuals. Combining two or more different drugs is common in clinical practice with the expectation of better efficacy, tolerability or both; however, further research is needed to identify which combinations actually provide added benefit. Thus, we are planning a clinical trial to evaluate melatonin (MLT)-pregabalin (PGB) combination in participants with fibromyalgia. METHODS AND ANALYSIS: This will be a single-centre, double-blind, randomised, double-dummy, three-period, crossover trial comparing a MLT-PGB combination to each monotherapy in 54 adult participants satisfying the 2016 American College of Rheumatology criteria for fibromyalgia. Participants will receive maximally tolerated doses of MLT, PGB and MLT-PGB combination for 6 weeks. The primary outcome will be daily pain intensity (0-10); secondary outcomes will include the Fibromyalgia Impact Questionnaire, SF-36 survey, Medical Outcomes Study Sleep Scale, Beck Depression Inventory (BDI-II), adverse events and other measures. Analysis of the primary and secondary outcomes will involve a linear mixed model with sequence, period, treatment, the first-order carryover and baseline pain score as fixed effects and participant as a random effect to test whether there are any treatment differences among three treatments and to estimate the least square mean of the mean daily pain intensity for each treatment, adjusting for carryover as well as period effects (ie, stability of pain levels). ETHICS AND DISSEMINATION: This trial has been registered with the International Standard Randomised Controlled Trial Number Registry, ISRCTN #18278231, has been granted ethical approval by the Queen's University Health Sciences Research Ethics Board (Queen's HSREB Protocol #6040998) and is currently under review for a Clinical Trial Application to Health Canada Natural and Non-prescription Health Products Directorate. All participants will provide written informed consent prior to trial participation. Following trial completion, results will be disseminated in one or more biomedical journal publications and presented at one or more scientific meetings. TRIAL REGISTRATION NUMBER: This trial has been registered with the International Standard Randomised Controlled Trial Number Registry, ISRCTN18278231.

Prevention of persistent pain with lidocaine infusions in breast cancer surgery (PLAN): study protocol for a multicenter randomized controlled trial.

BACKGROUND: Persistent pain is a common yet debilitating complication after breast cancer surgery. Given the pervasive effects of this pain disorder on the patient and healthcare system, post-mastectomy pain syndrome (PMPS) is becoming a larger population health problem, especially as the prognosis and survivorship of breast cancer increases. Interventions that prevent persistent pain after breast surgery are needed to improve the quality of life of breast cancer survivors. An intraoperative intravenous lidocaine infusion has emerged as a potential intervention to decrease the incidence of PMPS. We aim to determine the definitive effects of this intervention in patients undergoing breast cancer surgery. METHODS: PLAN will be a multicenter, parallel-group, blinded, 1:1 randomized, placebo-controlled trial of 1,602 patients undergoing breast cancer surgery. Adult patients scheduled for a lumpectomy or mastectomy will be randomized to receive an intravenous 2% lidocaine bolus of 1.5 mg/kg with induction of anesthesia, followed by a 2.0 mg/kg/h infusion until the end of surgery, or placebo solution (normal saline) at the same volume. The primary outcome will be the incidence of persistent pain at 3 months. Secondary outcomes include the incidence of pain and opioid consumption at 1 h, 1-3 days, and 12 months after surgery, as well as emotional, physical, and functional parameters, and cost-effectiveness. DISCUSSION: This trial aims to provide definitive evidence on an intervention that could potentially prevent persistent pain after breast cancer surgery. If this trial is successful, lidocaine infusion would be integrated as standard of care in breast cancer management. This inexpensive, widely available, and easily administered intervention has the potential to reduce pain and suffering in an already afflicted patient population, decrease the substantial costs of chronic pain management, potentially decrease opioid use, and improve the quality of life in patients. TRIAL REGISTRATION: This trial has been registered on clinicaltrials.gov (NCT04874038, Dr. James Khan. Date of registration: May 5, 2021).

Improving access to chronic pain care with central referral and triage: The 6-year findings from a single-entry model.

Background: Despite the established efficacy of multidisciplinary chronic pain care, barriers such as inflated referral wait times and uncoordinated care further hinder patient health care access. Aims: Here we describe the evolution of a single-entry model (SEM) for coordinating access to chronic pain care across seven hospitals in Toronto and explore the impact on patient care 6 years after implementation. Methods: In 2017, an innovative SEM was implemented for chronic pain referrals in Toronto and surrounding areas. Referrals are received centrally, triaged by a clinical team, and assigned an appointment according to the level of urgency and the most appropriate care setting/provider. To evaluate the impact of the SEM, a retrospective analysis was undertaken to determine referral patterns, patient characteristics, and referral wait times over the past 6 years. Results: Implementation of an SEM streamlined the number of steps in the referral process and led to a standardized referral form with common inclusion and exclusion criteria across sites. Over the 6-year period, referrals increased by 93% and the number of unique providers increased by 91%. Chronic pain service wait times were reduced from 299 (±158) days to 176 (±103) days. However, certain pain diagnoses such as chronic pelvic pain and fibromyalgia far exceed the average. Conclusions: The results indicate that the SEM helped reduce wait times for pain conditions and standardized the referral pathway. Continued data capture efforts can help identify gaps in care to enable further health care refinement and improvement.

Contexte: Malgré l'efficacité établie des soins multidisciplinaires dans le traitement de la douleur chronique, des obstacles tels que des délais d'attente prolongés et l'absence de coordination des soins entravent davantage l'accès des patients aux services de santé.Objectifs: Nous décrivons ici l'évolution d'un modèle à entrée unique visant à coordonner l'accès aux soins pour la douleur chronique dans sept hôpitaux de Toronto. Nous examinons également l'effet de ce modèle sur les soins aux patients six ans après sa mise en œuvre.Méthodes: En 2017, un modèle à entrée unique novateur a été mis en place pour orienter les patients souffrant de douleur chronique à Toronto et dans les régions avoisinantes. Les patients sont reçus de manière centralisée, triés par une équipe clinique et un rendez-vous leur est attribué en fonction du degré d'urgence et de l'établissement de soins ou du prestataire le plus approprié.Pour évaluer l'impact du modèle à entrée unique, une analyse rétrospective a été entreprise afin de déterminer les schémas de consultation, les caractéristiques des patients et les temps d'attente pour les demandes de consultation au cours des six dernières années.Résultats: La mise en œuvre d'un modèle à entrée unique a permis de rationaliser le nombre d'étapes du processus de demande de consultation et a conduit à l'élaboration d'un formulaire de demande de consultation normalisé comprenant des critères d'inclusion et d'exclusion communs à tous les sites. Au cours de la période de six ans, le nombre de demandes de consultation a augmenté et le nombre de prestataires uniques a augmenté de 91 %.Les temps d'attente pour les services de traitement de la douleur chronique ont diminué de 299 (±158) jours à 176 (±103) jours. Cependant, certains diagnostics de douleur, comme la douleur pelvienne chronique et la fibromyalgie, dépassent de loin la moyenne.Conclusions: Les résultats indiquent que le modèle à entrée unique a contribué à réduire les temps d'attente pour les affections douloureuses et à normaliser le parcours de consultation. La poursuite des efforts de collecte des données peut aider à recenser les lacunes dans les soins, permettant ainsi une amélioration continue des soins de santé.

Comparative benefits and harms of perioperative interventions to prevent chronic pain after orthopedic surgery: a systematic review and network meta-analysis of randomized trials.

BACKGROUND: Chronic postsurgical pain (CPSP) is common following musculoskeletal and orthopedic surgeries and is associated with impairment and reduced quality of life. Several interventions have been proposed to reduce CPSP; however, there remains uncertainty regarding which, if any, are most effective. We will perform a systematic review and network meta-analysis of randomised trials to assess the comparative benefits and harms of perioperative pharmacological and psychological interventions directed at preventing chronic pain after musculoskeletal and orthopedic surgeries. METHODS: We will search MEDLINE, Embase, PsycINFO, CINAHL, and the Cochrane Central Register of Controlled Trials from inception to present, without language restrictions. We will include randomised controlled trials that as follows: (1) enrolled adult patients undergoing musculoskeletal or orthopedic surgeries; (2) randomized them to any pharmacological or psychological interventions, or their combination directed at reducing CPSP, placebo, or usual care; and (3) assessed pain at 3 months or more after surgery. Screening for eligible trials, data extraction, and risk-of-bias assessment using revised Cochrane risk-of-bias tool (RoB 2.0) will be performed in duplicate and independently. Our main outcome of interest will be the proportion of surgical patients reporting any pain at ≥ 3 months after surgery. We will also collect data on other patient important outcomes, including pain severity, physical functioning, emotional functioning, dropout rate due to treatment-related adverse event, and overall dropout rate. We will perform a frequentist random-effects network meta-analysis to determine the relative treatment effects. When possible, the modifying effect of sex, surgery type and duration, anesthesia type, and veteran status on the effectiveness of interventions will be investigated using network meta-regression. We will use the GRADE approach to assess the certainty evidence and categorize interventions from most to least beneficial using GRADE minimally contextualised approach. DISCUSSION: This network meta-analysis will assess the comparative effectiveness of pharmacological and psychological interventions directed at preventing CPSP after orthopedic surgery. Our findings will inform clinical decision-making and identify promising interventions for future research. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42023432503.

Prevention of hypotension after induction of general anesthesia using point-of-care ultrasound to guide fluid management: a randomized controlled trial.

PURPOSE: Hypotension after induction of general anesthesia (GAIH) is common and is associated with postoperative complications including increased mortality. Collapsibility of the inferior vena cava (IVC) has good performance in predicting GAIH; however, there is limited evidence whether a preoperative fluid bolus in patients with a collapsible IVC can prevent this drop in blood pressure. METHODS: We conducted a single-centre randomized controlled trial with adult patients scheduled to undergo elective noncardiac surgery under general anesthesia (GA). Patients underwent a preoperative point-of-care ultrasound scan (POCUS) to identify those with a collapsible IVC (IVC collapsibility index ≥ 43%). Individuals with a collapsible IVC were randomized to receive a preoperative 500 mL fluid bolus or routine care (control group). Surgical and anesthesia teams were blinded to the results of the scan and group allocation. Hypotension after induction of GA was defined as the use of vasopressors/inotropes or a decrease in mean arterial pressure < 65 mm Hg or > 25% from baseline within 20 min of induction of GA. RESULTS: Forty patients (20 in each group) were included. The rate of hypotension after induction of GA was significantly reduced in those receiving preoperative fluids (9/20, 45% vs 17/20, 85%; relative risk, 0.53; 95% confidence interval, 0.32 to 0.89; P = 0.02). The mean (standard deviation) time to complete POCUS was 4 (2) min, and the duration of fluid bolus administration was 14 (5) min. Neither surgical delays nor adverse events occurred as a result of the study intervention. CONCLUSION: A preoperative fluid bolus in patients with a collapsible IVC reduced the incidence of GAIH without associated adverse effects. STUDY REGISTRATION: ClinicalTrials.gov (NCT05424510); first submitted 15 June 2022.

RéSUMé: OBJECTIF: L'hypotension après induction de l'anesthésie générale (AG) est fréquente et est associée à des complications postopératoires, notamment à une augmentation de la mortalité. La collapsibilité de la veine cave inférieure (VCI) a été utilisée avec succès pour prédire la l'hypotension post-induction de l'AG; cependant, il existe peu de données probantes qu'un bolus liquidien préopératoire chez les patient·es présentant une collapsibilité de la VCI puisse prévenir cette baisse de la tension artérielle. MéTHODE: Nous avons réalisé une étude randomisée contrôlée monocentrique auprès de patient·es adultes devant bénéficier d'une chirurgie non cardiaque non urgente sous anesthésie générale. Les patient·es ont passé une échographie préopératoire ciblée (POCUS) pour identifier les personnes présentant une collapsibilité de la VCI (indice de collapsibilité de la VCI ≥ 43 %). Les personnes présentant une collapsibilité de la VCI ont été randomisées à recevoir un bolus de liquide préopératoire de 500 mL ou des soins de routine (groupe témoin). Les équipes chirurgicales et d'anesthésie ne connaissaient pas les résultats de l'examen ni l'attribution des groupes. L'hypotension après induction de l'AG a été définie comme l'utilisation de vasopresseurs/inotropes ou une diminution de la tension artérielle moyenne < 65 mm Hg ou > 25 % par rapport aux valeurs de base dans les 20 minutes suivant l'induction de l'AG. RéSULTATS: Quarante patient·es (20 dans chaque groupe) ont été inclus·es. Le taux d'hypotension après induction de l'AG était significativement réduit chez les personnes recevant des liquides préopératoires (9/20, 45 % vs 17/20, 85 %; risque relatif, 0,53; intervalle de confiance à 95 %, 0,32 à 0,89; P = 0,02). Le temps moyen (écart type) pour compléter l'échographie ciblée était de 4 (2) min, et la durée de l'administration du bolus liquidien était de 14 (5) min. Ni retards chirurgicaux ni effets indésirables ne sont survenus à la suite de l'intervention à l'étude. CONCLUSION: Un bolus liquidien préopératoire chez les patient·es présentant une collapsibilité de la VCI a réduit l'incidence d'hypotension après l'induction de l'anesthésie générale sans effets indésirables associés. ENREGISTREMENT DE L'éTUDE: ClinicalTrials.gov (NCT05424510); première soumission le 15 juin 2022.

A Prospective Cohort Study of Acute Pain and In-Hospital Opioid Consumption After Cardiac Surgery: Associations With Psychological and Medical Factors and Chronic Postsurgical Pain.

BACKGROUND: Understanding the association of acute pain intensity and opioid consumption after cardiac surgery with chronic postsurgical pain (CPSP) can facilitate implementation of personalized prevention measures to improve outcomes. The objectives were to (1) examine acute pain intensity and daily mg morphine equivalent dose (MME/day) trajectories after cardiac surgery, (2) identify factors associated with pain intensity and opioid consumption trajectories, and (3) assess whether pain intensity and opioid consumption trajectories are risk factors for CPSP. METHODS: Prospective observational cohort study design conducted between August 2012 and June 2020 with 1-year follow-up. A total of 1115 adults undergoing cardiac surgery were recruited from the preoperative clinic. Of the 959 participants included in the analyses, 573 completed the 1-year follow-up. Main outcomes were pain intensity scores and MME/day consumption over the first 6 postoperative days (PODs) analyzed using latent growth mixture modeling (GMM). Secondary outcome was 12-month CPSP status. RESULTS: Participants were mostly male (76%), with a mean age of 61 ± 13 years. Three distinct linear acute postoperative pain intensity trajectories were identified: "initially moderate pain intensity remaining moderate" (n = 62), "initially mild pain intensity remaining mild" (n = 221), and "initially moderate pain intensity decreasing to mild" (n = 251). Age, sex, emotional distress in response to bodily sensations, and sensitivity to pain traumatization were significantly associated with pain intensity trajectories. Three distinct opioid consumption trajectories were identified on the log MME/day: "initially high level of MME/day gradually decreasing" (n = 89), "initially low level of MME/day remaining low" (n = 108), and "initially moderate level of MME/day decreasing to low" (n = 329). Age and emotional distress in response to bodily sensations were associated with trajectory membership. Individuals in the "initially mild pain intensity remaining mild" trajectory were less likely than those in the "initially moderate pain intensity remaining moderate" trajectory to report CPSP (odds ratio [95% confidence interval, CI], 0.23 [0.06-0.88]). No significant associations were observed between opioid consumption trajectory membership and CPSP status (odds ratio [95% CI], 0.84 [0.28-2.54] and 0.95 [0.22-4.13]). CONCLUSIONS: Those with moderate pain intensity right after surgery are more likely to develop CPSP suggesting that those patients should be flagged early on in their postoperative recovery to attempt to alter their trajectory and prevent CPSP. Emotional distress in response to bodily sensations is the only consistent modifiable factor associated with both pain and opioid trajectories.

Peripheral magnetic stimulation for chronic peripheral neuropathic pain: A systematic review and meta-analysis.

OBJECTIVES: To provide a systematic review of the literature on the effects of peripheral magnetic stimulation (PMS) in the treatment of chronic peripheral neuropathic pain. METHODS: A systematic search of MEDLINE, EMBASE, CENTRAL, CINHAL, Web of Science, and ProQuest was conducted from inception to July 2023 to identify studies of any design published in English language that enrolled adult patients (≥18 years) that received PMS for treatment of a chronic peripheral neuropathic pain disorder (pain > 3 months). RESULTS: Twenty-three studies were identified which included 15 randomized controlled trials (RCTs), five case series, two case reports, and one non-randomized trial. PMS regimens varied across studies and ranged from 5 to 240 min per session over 1 day to 1 year of treatment. Results across included studies were mixed, with some studies suggesting benefits while others showing no significant differences. Of nine placebo-controlled RCTs, four reported statistically significant findings in favor of PMS use. In the meta-analysis, PMS significantly reduced pain scores compared to control within 0-1 month of use (mean difference -1.64 on a 0-10 numeric rating scale, 95% confidence interval -2.73 to -0.56, p = 0.003, I2 = 94%, 7 studies [264 participants], very low quality of evidence), but not at the 1-3 months and >3 months of PMS use (very low and low quality of evidence, respectively). Minimal to no adverse effects were reported with PMS use. DISCUSSION: There is limited and low-quality evidence to make definitive recommendations on PMS usage, however, the available data is encouraging, especially for short-term applications of this novel modality. Large high-quality randomized controlled trials are required to establish definitive efficacy and safety effects of PMS.

End-on versus parallel radiofrequency lesioning for neurotomy of the cervical medial branch nerves: a study protocol of a prospective, randomized, double-blind clinical trial: the "EndPaRL" study.

BACKGROUND: Cervical facet joint disease is a common source of neck pain and its prevalence increases with aging. Conservative multimodal management options (e.g., strengthening of neck muscles, non-steroidal anti-inflammatory medications, massage, and thermal modalities) often fail to relieve pain. Cervical medial branch nerve (CMBN) radiofrequency neurotomy (RFN) is an effective minimally invasive technique for treating chronic neck pain secondary to facet joint disease. An end-on approach for this procedure has been proposed that may be technically easier and require less time while reducing post-procedural discomfort. The protocol presented here is for a study that aims to compare the efficacy of a new end-on approach using multi-tined cannulae, against the conventional parallel technique that employs straight cannulae for RFN of the CMBN in patients with chronic neck pain due to cervical facet joint disease. METHODS: A multicentre randomized, non-inferior, active comparator-controlled trial will be conducted with two parallel groups and blinding of participants and outcome assessor. The study will include 72 adults with chronic neck pain secondary to facet joint disease who are candidates for RFA of the CMBN. Participants will be randomized to either the conventional parallel or the end-on approach in a 1:1 ratio. The intensity of pain and pain-related domains (function, quality of life, sleep, adverse effects of the interventions, analgesic intake) will be measured at 1, 3, 6, and 12 months after the procedure. DISCUSSION: Neck pain secondary to cervical facet joint disease is prevalent and RFA of the CMBN is a validated treatment for relieving it. The conventional parallel technique can be technically challenging, and it can be associated with adverse effects while the newer end-on approach has the potential of being a simpler technique with less adverse effects. This trial will be the first non-inferiority study to compare the clinical efficacy of the end-on approach against the conventional parallel approach for RFN of CMBN in patients with chronic neck pain due to cervical facet joint disease. TRIAL REGISTRATION: ClinicalTrials.gov NCT05818774. Registered on April 20, 2023.

Point-of-Care Ultrasound (PoCUS) and Its Potential to Advance Patient Care in Low-Resource Settings and Conflict Zones.

Point-of-care ultrasound (PoCUS) is used by health care professionals of various specialties worldwide, with excellent results demonstrating significant potential to advance patient care. However, in low resource areas of the world, where other imaging modalities are scarce and the potential of handheld pocket-sized PoCUS devices with great versatility and increasing affordability seems most significant, its use is far from being widespread. In this report, our group of Chadian, Israeli, and Canadian physicians with experience in rural, military, and conflict zone medical aid, discusses the barriers to the implementation of PoCUS in low resource areas and offers potential solutions.

Disparities in Pain Management.

Health disparities in pain management remain a pervasive public health crisis. Racial and ethnic disparities have been identified in all aspects of pain management from acute, chronic, pediatric, obstetric, and advanced pain procedures. Disparities in pain management are not limited to race and ethnicity, and have been identified in multiple other vulnerable populations. This review targets health care disparities in the management of pain, focusing on steps health care providers and organizations can take to promote health care equity. A multifaceted plan of action with a focus on research, advocacy, policy changes, structural changes, and targeted interventions is recommended.

Prevalence and Risk Factors for Chronic Postsurgical Pain after Cardiac Surgery: A Single-center Prospective Cohort Study.

BACKGROUND: Chronic postsurgical pain is a common complication of surgery. The role of psychologic risk factors like depression and anxiety is substantially understudied in cardiac surgery. This study sought to identify perioperative factors associated with chronic pain at 3, 6, and 12 months after cardiac surgery. The authors hypothesize that baseline psychologic vulnerabilities have a negative influence on chronic postsurgical pain. METHODS: The authors prospectively collected demographic, psychologic, and perioperative factors in a cohort of 1,059 patients undergoing cardiac surgery at the Toronto General Hospital between 2012 and 2020. Patients were followed and completed chronic pain questionnaires at 3, 6, and 12 months after surgery. RESULTS: The study included 767 patients who completed at least one follow-up questionnaire. The incidence of postsurgical pain (more than 0 out of 10) at 3, 6, and 12 months after surgery was 191 of 663 (29%), 118 of 625 (19%), and 89 of 605 (15%), respectively. Notably, among patients reporting any pain, the incidence of pain compatible with a neuropathic phenotype increased from 56 of 166 (34%) at 3 months to 38 of 97 (39%) at 6 months and 43 of 67 (64%) at 12 months. Factors associated with postsurgical pain scores at 3 months include female sex, pre-existing chronic pain, previous cardiac surgery, preoperative depression, baseline pain catastrophizing scores, and moderate-to-severe acute pain (4 or more out of 10) within 5 postoperative days. CONCLUSIONS: Nearly one in three patients undergoing cardiac surgery reported pain at 3 months of follow-up, with approximately 15% reporting persistent pain at 1 yr. Female sex, pre-existing chronic pain, and baseline depression were associated with postsurgical pain scores across all three time periods.

Effect of Peripheral Magnetic Stimulation on Acute and Chronic Pain After Surgery: A Systematic Review and Meta-Analysis.

Peripheral magnetic stimulation (PMS) is a potentially promising modality to help manage postoperative pain. We systematically reviewed the effect of PMS on acute and chronic postoperative pain. MEDLINE, Cochrane CENTRAL, EMBASE, ProQuest Dissertations, and clinical trials.gov were searched from inception until May 2021. We included studies of any study design that included patients ≥18 years of age undergoing any type of surgery that administered PMS within the perioperative period and evaluated postoperative pain. Seventeen randomized controlled trials and 1 nonrandomized clinical trial were included into the review. Thirteen out of the 18 studies found a positive effect with PMS on postoperative pain scores. In our meta-analysis, peripheral magnetic stimulation was more efficacious than sham or no intervention within the first 7 postoperative days (mean difference [MD] -1.64 on a 0 to 10 numerical rating score, 95% confidence interval [CI] -2.08 to -1.20, I2 = 77%, 6 studies, 231 patients). This was also true at 1 and 2 months after surgery (MD -1.82, 95% CI -2.48 to -1.17, I2 = 0%, 3 studies, 104 patients; and MD -1.96, 95% CI -3.67 to -.26, I2 = 84%, 3 studies, 104 patients, respectively). A difference was not seen with persistent pain at 6 and 12-months after surgery, acute postoperative opioid consumption, or adverse events between groups. Results are limited by heterogeneity and generally low-quality studies, as well as low or very low quality of evidence. High-quality and adequately blinded trials are needed to definitively confirm the benefits of peripheral magnetic stimulation administered in the perioperative period. PERSPECTIVE: This review evaluates the efficacy and safety of PMS on postoperative pain. The results help elucidate PMS' role in postoperative pain management and identify gaps where more research is required.

Trial protocol for a multicenter randomized controlled trial to assess the efficacy and safety of intravenous ketamine for chronic daily headaches: the "KetHead" trial.

BACKGROUND: Chronic daily headaches (CDH) are common and associated with significant morbidity, poor quality of life, and substantial burden on the healthcare system. CDH tends to be refractory to conventional medical management and/or patients cannot afford expensive treatments. It is stipulated that CDH share a mechanism of central sensitization in the trigeminocervical complex, mediated by activation of the N-methyl-D-aspartate (NMDA) receptors. Ketamine, a non-competitive NMDA antagonist, has been used in the treatment of chronic pain, but its role in CDH has not been completely established. This trial aims to evaluate the effect of high-dose IV ketamine infusions (compared to placebo) on the number of headache days at 28 days post-infusion. METHODS: A multicenter, placebo-controlled, randomized controlled trial will be conducted with two parallel groups and blinding of participants and outcome assessors. The study will include 56 adults with a CDH diagnosis as per ICHD-3 criteria. Participants will be randomized (1:1) to either ketamine (1 mg. kg-1 bolus followed by infusion of 1 mg. kg-1. h-1 for 6 h) or placebo (0.9% saline in the same volume and infusion rate as the trial medication) bolus and infusion for 6 h. The impact on the number of monthly headache days, headache intensity, physical activity, mood, sleep, quality of life, analgesic consumption, and adverse effects will be recorded at baseline, immediately post-infusion, and from 1 to 28 days, 29 to 56 days, and 57 to 84 days after the infusion DISCUSSION: Despite advancements in treatment, many patients continue to suffer from CDH. This trial investigates whether high-dose IV ketamine infusions can effectively and safely improve the CDH burden as compared to a placebo infusion. This treatment could become a safe, affordable, and widely available option for patients living with refractory headache. TRIAL REGISTRATION: ClinicalTrials.gov NCT05306899. Registered on April 1, 2022.