Transition from acute to chronic postsurgical pain: risk factors and protective factors

Predictors of Persistent Pain after Total Knee Arthroplasty

BACKGROUND

Total knee arthroplasty (TKA) is an orthopedic procedure performed on patients with severe knee pain and advanced knee conditions, such as osteoarthritis and rheumatoid arthritis, in order to restore joint function. Despite the procedure's high success rates, persistent postoperative pain (PPP) remains a significant complication, affecting a substantial proportion of patients. Identifying predictors of PPP is crucial for improving patient outcomes and satisfaction.

METHODS

A retrospective analytic study was conducted, reviewing the medical records of patients who underwent unilateral or bilateral TKA at King Abdulaziz Medical City. The data collection focused on demographics, comorbidities, clinical presentations, surgical details, and postoperative outcomes. Data were analyzed using JMP software. A p-value of less than 0.05 was considered statistically significant.

RESULTS

This study included 838 patients, predominantly female (71.5%), with an average age of 65.4 years. Osteoarthritis was the primary reason for surgery (98.3%). The mean preoperative pain score was 3.4, and the average pain duration prior to surgery was 6.2 years. We identified dyslipidemia as a significant predictor of PPP (OR 1.40, p = 0.042), while we found younger age to be a significant predictor (OR 0.979, 95% CI 0.967-0.991, p = 0.001). Other factors such as gender, diabetes, hypertension, cardiovascular disease, anxiety disorder, mood disorder, tobacco use, chronic kidney disease, chronic lung disease, and BMI were not significant predictors of PPP.

CONCLUSION

This study identifies younger age and dyslipidemia as significant predictors of persistent postoperative pain and improved outcomes following total knee arthroplasty Further research is needed to validate these results in diverse populations and settings, with the objective should be to refine preoperative counseling and postoperative pain management protocols.

Nerve Blocks for Post-Surgical Pain Management: A Narrative Review of Current Research

Opioids remain the mainstay of post-surgical pain management; however, concerns regarding addiction and side effects necessitate the exploration of alternatives. This narrative review highlights the potential of nerve blocks as a safe and effective strategy for post-surgical pain control. This review explores the use of various nerve block techniques tailored to specific surgical procedures. These include nerve blocks for abdominal surgeries; fascial plane blocks for chest surgeries; nerve blocks for arm surgeries; and nerve blocks for lower limb surgery including; femoral, hip, and knee surgeries. By targeting specific nerves, these blocks can provide targeted pain relief without the negative side effects associated with opioids. Emerging evidence suggests that nerve blocks can be as effective as opioids in managing pain, while potentially offering additional benefits such as faster recovery, improved patient satisfaction, and reduced reliance on opioids. However, the effectiveness of nerve blocks varies depending on type of surgery, and in individual patients. Rebound pain, which temporary increase in pain after a block wears off, can occur. In addition, some techniques require specialized guidance for accurate placement. In conclusion, nerve blocks show great promise as effective alternatives for managing post-surgical pain. They can reduce the need for opioids and their side effects, leading to better patient outcomes and satisfaction. Future studies should assess the long-term impacts of specific nerve blocks on mortality rates, cost-effectiveness, and their incorporation into multimodal pain management approaches to further enhance post-surgical care.

Transitional pain services updates and a novel service for the obstetric population

PURPOSE OF REVIEW

This paper is an update of the publications on Transitional Pain Services and explores the viability of a dedicated transitional pain service for women.

RECENT FINDINGS

We address common pain pathologies establishing referral criteria, pathways, and effective strategies to decrease chronification of pain during pregnancy.

SUMMARY

This review highlights the importance establishing transitional pain service models at every institution and in particular in obstetric population as pain is normalized by Society during pregnancy.

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.

Genetics Affecting the Prognosis of Dental Treatments

Genetics plays a significant role in determining an individual's susceptibility to dental diseases, the response to dental treatments, and the overall prognosis of dental interventions. Here, the authors explore the various genetic factors affecting the prognosis of dental treatments focusing on dental caries, orthodontic treatment, oral cancer, prosthodontic treatment, periodontal disease, developmental disorders, pharmacogenetics, and genetic predisposition to faster wound healing. Understanding the genetic underpinnings of dental health can help personalize treatment plans, predict outcomes, and improve the overall quality of dental care.

TRPV1 corneal neuralgia mutation: Enhanced pH response, bradykinin sensitization, and capsaicin desensitization

The factors that contribute to pain after nerve injury remain incompletely understood. Laser-assisted in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) are common surgical techniques to correct refractive errors. After LASIK or PRK, a subset of patients suffers intense and persistent pain, of unknown origin, described by patients as feeling like shards of glass in their eye. Here, we evaluated a TRPV1 variant, p.V527M, found in a 49-y-old woman who developed corneal pain after LASIK and subsequent PRK enhancement, reporting an Ocular Surface Disease Index score of 100. Using patch-clamp and Ca2+ imaging, we found that the V527M mutation enhances the response to acidic pH. Increasing proton concentration induced a stronger leftward shift in the activation curve of V527M compared to WT, resulting in channel activity of the mutant in acidic pH at more physiological membrane potentials. Finally, comparing the responses to consecutive applications of different agonists, we found in V527M channels a reduced capsaicin-induced desensitization and increased sensitization by the arachidonic acid metabolite 12-hydroxyeicosatetraenoic acid (12-HETE). We hypothesize that the increased response in V527M channels to protons and enhanced sensitization by 12-HETE, two inflammatory mediators released in the cornea after tissue damage, may contribute to the pathogenesis of corneal neuralgia after refractive surgery.

Perioperative N-acetylcysteine: evidence and indications

Nonopioid analgesics serve to improve analgesia and limit side effects and risks of perioperative opioids. N-acetylcysteine (NAC), the primary treatment of acetaminophen toxicity, may have perioperative indications, including analgesia. NAC impacts glutathione synthesis, oxidant scavenging, glutamate receptor modulation and neuroinflammation. Potential perioperative benefits include arrhythmia prevention after cardiac surgery, decreased contrast-induced nephropathy, improved post-transplant liver function and superior pulmonary outcomes with general anesthesia. NAC may improve perioperative analgesia, with some studies displaying a reduction in postoperative opioid use. NAC is generally well tolerated with an established safety profile. NAC administration may predispose to gastrointestinal effects, while parenteral administration may carry a risk of anaphylactoid reactions, including bronchospasm. Larger randomized trials may clarify the impact of NAC on perioperative analgesic outcomes.

The prevalence and predictors of discharge opioid overprescribing in opioid-naïve patients after breast, gynecologic, and head and neck cancer surgery: a prospective cohort study

PURPOSE

The management of pain following cancer-related surgeries involves the use of opioid analgesics. Nevertheless, there is little evidence characterizing the utility and prescription patterns of opioids after these procedures. Our primary aim was to identify patients from three types of cancer surgery who were overprescribed with opioids. The secondary aim was to determine the potential predictors of overprescribing in the same period.

METHODS

We conducted the study at a single cancer referral hospital. Opioid-naïve patients with breast, gynecologic, or head and neck cancer were studied. Patients were considered opioid-naïve if they had a history of opioid use ≤ 30 mg oral morphine equivalent daily dose for less than seven days in the preceding three months before surgery. We recruited eligible participants by convenience sampling on the wards until at least 102 patients were included in the final analysis. After discharge, we followed up on the participants on day 7 via telephone using a structured proforma including questions to identify the last date and amount of opioid dose taken. The equivalent days of opioid use were calculated by their 24-hr use before discharge and the number of doses prescribed for discharge. Our primary outcome was the prevalence of overprescribing in the three surgical specialties defined as the number of patients taking less than 50% of discharge opioids within the first seven days after discharge. We examined the predictors on incidents of overprescribing using multivariable Poisson regression as the secondary outcome.

RESULTS

We recruited 119 patients, and 107 patients were included in the final analysis. There were 59/107 (55%) patients found to be overprescribed with opioids. At discharge, they exhibited lower mean numerical rating scale pain scores, lower mean pain severity scores, higher equivalent days of opioids prescribed, and not used opioids in the last 24 hr before discharge. The incidence of overprescribing was 2.4 times greater for patients prescribed with opioids without 24-hr opioid use (relative risk [RR], 2.38; 95% confidence interval [CI], 1.30 to 4.35; P = 0.005). Similarly, the incidence of overprescribing was 1.7 times greater for patients who had opioids 24 hr before discharge and were supplied with opioids for five equivalent days or more at the time of discharge (RR, 1.67; 95% CI, 1.09 to 2.56; P = 0.02).

CONCLUSION

Our study shows that the majority of recruited patients undergoing breast, gynecologic, or head and neck cancer surgery were overprescribed opioids. Individualized assessments on patients' 24-hr opioid requirements before discharge and supplying for less than five days are important considerations to reduce overprescribing in opioid-naïve patients after cancer surgery.

Perioperatives Schmerzempfinden von Patienten bei dermatochirurgischen Eingriffen in Lokalanästhesie – Eine prospektive Beobachtungsstudie

Hintergrund

Dermatochirurgische Eingriffe finden überwiegend in Lokalanästhesie statt, jedoch gibt es nur wenig Studien zum perioperativen Schmerzmanagement ausgedehnter oder mehrzeitiger Operationen. Das Ziel dieser Erhebung ist die Erfassung von Schmerzen im Rahmen dermatochirurgischer Eingriffe, der Darstellung der perioperativen Schmerztherapie sowie der Identifizierung von Einflussfaktoren auf das Schmerzempfinden.

Patienten und Methodik

In diese prospektive, monozentrische Studie wurden stationäre Patienten von April bis Dezember 2021 eingeschlossen, die einen dermatochirurgischen Eingriff in Lokalanästhesie erhielten. Präoperativ wurden demographische Fragen, ein Schmerzfragebogen und vier psychometrische Fragebögen (PCS, LOT‐R, SFQ, PHQ‐9) erhoben. Postoperativ empfundene Schmerzen und benötigte Schmerzmedikamente der ersten 24 Stunden wurden erhoben.

Ergebnisse

120 Patienten (mit insgesamt 191 Eingriffen) wurden eingeschlossen. Durchschnittliche postoperative Schmerzen wurden sehr niedrig (NRS < 2) angegeben. Präoperativ bestehende Schmerzen und postoperativ erwartete Schmerzen zeigten sich als prädiktive Merkmale für postoperativen Schmerz. Ein starker Zusammenhang zwischen Katastrophisieren und Angst vor der Operation (r = 0,65) sowie ein mittlerer Zusammenhang für Depression und Angst vor der Operation (r = 0,46) konnten dargestellt werden.

Schlussfolgerungen

Dermatochirurgische Eingriffe in Lokalanästhesie werden insgesamt als schmerzarm empfunden. Bei der präoperativen Aufklärung und Untersuchung sollte auf Patienten geachtet werden, die bereits Schmerzen angeben oder postoperativ Schmerzen erwarten, da sie ein erhöhtes Risiko für die Entwicklung postoperativer Schmerzen zeigten.

Tailored Yoga Intervention for Postlumbar Spine Surgical Pain Management: A Feasibility Study

Introduction: Severe pain, anxiety, and high opioid use are common following lumbar spine surgery (LSS). Yoga helps to reduce pain and anxiety, but it has not been considered for postsurgical care. The authors developed and tested the feasibility of a tailored yoga program designed for individuals undergoing LSS and explored clinical feasibility of yoga intervention on measures of pain, function, psychological status, and opioid use. Methods: Individuals scheduled for LSS were randomized into yoga versus control groups presurgery. Participants in the yoga group received tailored yoga sessions plus usual care, whereas participants in the control group received usual care only during the hospital stay post-LSS. In-person daily yoga sessions were individually presented and performed in the participant's hospital room. Feasibility was assessed by recruitment and retention rates, rate of yoga session completion, tolerance to yoga intervention, and ability to carry out planned assessment. Exploratory clinical outcomes included pain, psychological measures, Timed-Up-and-Go test, gait distance, and opioid use, during the hospital stay post-LSS. Results: Forty-one participants were enrolled, of which 30 completed. There were no dropouts. Planned assessments were completed within 45 min, suggesting no excessive burden on participants. Baseline variables were similar across both groups. The majority of participants participated in yoga intervention on the day of surgery or one day after surgery with acceptance rate of 100%. Participants showed good tolerance to yoga intervention on 0-4 tolerance scale and by their reports of exploratory clinical outcomes. Conclusion: This study indicates feasibility for a modified yoga program for postoperative care following LSS due to participant tolerance and retention. The results provide preliminary framework for future confirmatory studies that can assess the potential benefits of yoga in reducing pain, catastrophizing behavior, and opioid use and improving function. A modified yoga program focusing on diaphragmatic breathing, relaxation, and core isometric contraction exercises can be an important adjunct intervention for patients undergoing LSS. CTR Number: This trial was registered in UMIN CTR (https://rctportal.niph.go.jp/en/) with registration number: UMIN000032595.

Genome-wide association studies with experimental validation identify a protective role for B lymphocytes against chronic post-surgical pain

BACKGROUND

Chronic post-surgical pain (CPSP) significantly impacts patients' recovery and quality of life. Although environmental risk factors are well-established, genetic risk remains less understood.

METHODS

A meta-analysis of genome-wide association studies followed by partitioned heritability was performed on 1350 individuals across five surgery types: hysterectomy, mastectomy, abdominal, hernia, and knee. In subsequent animal studies, withdrawal thresholds to evoked mechanical stimulation were measured in Rag1 null mutant and wild-type mice after plantar incision and laparotomy. Cell sorting by flow cytometry tracked recruitment of immune cell types.

RESULTS

We discovered 77 genome-wide significant single-nucleotide polymorphism (SNP) hits, distributed among 24 loci and 244 genes. Meta-analysis of all cohorts estimated a SNP-based narrow-sense heritability for CPSP at ∼39%, indicating a substantial genetic contribution. Partitioned heritability analysis across a wide variety of tissues revealed enrichment of heritability in immune system-related genes, particularly those associated with B and T cells. Rag1 null mutant mice lacking both T and B cells exhibited exacerbated and prolonged allodynia up to 42 days after surgery, which was rescued by B-cell transfer. Recruitment patterns of B cells but not T cells differed significantly during the first 7 days after injury in the footpad, lymph nodes, and dorsal root ganglia.

CONCLUSIONS

These findings suggest a key protective role for the adaptive immune system in the development of chronic post-surgical pain.

Perioperative pain perception in patients undergoing dermatologic surgery with local anesthesia - A prospective observational study

BACKGROUND

Dermatosurgical procedures are predominantly performed under local anesthesia, yet there are few studies on perioperative pain management for extensive or staged procedures under local anesthesia. The purpose of this study was to assess pain during dermatologic surgery, describe perioperative pain management, and identify factors that influence pain perception.

PATIENTS AND METHODS

This prospective, monocentric study included inpatients undergoing dermatologic surgery under local anesthesia from April to December 2021. Preoperative demographic data, a pain questionnaire, and four psychometric questionnaires (PCS, LOT-R, SFQ, PHQ-9) were collected. Postoperative pain and analgesic use during the first 24 hours were recorded.

RESULTS

A total of 120 patients (with a total of 191 interventions) were included in the study. Mean postoperative pain was reported to be very low (NRS < 2). Preoperative pain and expected postoperative pain were found to be predictive of postoperative pain. There was a strong correlation between catastrophizing and preoperative anxiety (r = 0.65) and a moderate correlation between depression and preoperative anxiety (r = 0.46).

CONCLUSIONS

Dermatologic surgery under local anesthesia is generally considered painless. During preoperative counseling and assessment, attention should be paid to patients who fear surgery, report pain, or anticipate postoperative pain, as they have an increased risk of experiencing postoperative pain.

Identification of Presurgical Risk Factors for the Development of Chronic Postsurgical Pain in Adults: A Comprehensive Umbrella Review

Purpose

Risk factors for the development of chronic postsurgical pain (CPSP) have been reported in primary studies and an increasing number of reviews. The objective of this umbrella review was to compile and understand the published presurgical risk factors associated with the development of CPSP for various surgery types.

Methods

Six databases were searched from January 2000 to June 2023 to identify meta-analyses, scoping studies, and systematic reviews investigating presurgical CPSP predictors in adult patients. Articles were screened by title/abstract and subsequently by full text by two independent reviewers. The selected papers were appraised for their scientific quality and validity. Data were extracted and descriptively analyzed.

Results

Of the 2344 retrieved articles, 36 reviews were selected for in-depth scrutiny. The number of primary studies in these reviews ranged from 4 to 317. The surgery types assessed were arthroplasty (n = 13), spine surgery (n = 8), breast surgery (n = 4), shoulder surgery (n = 2), thoracic surgery (n = 2), and carpal tunnel syndrome (n = 1). One review included a range of orthopedic surgeries; six reviews included a variety of surgeries. A total of 39 presurgical risk factors were identified, some of which shared the same defining tool. Risk factors were themed into six broad categories: psychological, pain-related, health-related, social/lifestyle-related, demographic, and genetic. The strength of evidence for risk factors was inconsistent across different reviews and, in some cases, conflicting. A consistently high level of evidence was found for preoperative pain, depression, anxiety, and pain catastrophizing.

Conclusion

This umbrella review identified a large number of presurgical risk factors which have been suggested to be associated with the development of CPSP after various surgeries. The identification of presurgical risk factors is crucial for the development of screening tools to predict CPSP. Our findings will aid in designing screening tools to better identify patients at risk of developing CPSP and inform strategies for prevention and treatment.

One-year opioid consumption trajectories among individuals receiving multidisciplinary postsurgical care: a single-center observational study from the Toronto General Hospital Transitional Pain Service

INTRODUCTION

The Transitional Pain Service (TPS) is an innovative, personalized approach to postsurgical opioid consumption and pain management. The objectives of this study were to identify trajectories of opioid consumption and pain intensity within 12 months after initiating treatment through the TPS, identify biopsychosocial factors associated with trajectory membership, and examine the relationship between trajectory membership and other outcomes of interest over the same 12-month period.

METHODS

Consecutive patients referred to the TPS were included in the present study (n=466). After providing informed consent, they completed self-report questionnaires at the initial visit at the TPS (either pre surgery or post surgery) and at every TPS visit until 12 months. Growth mixture modeling was used to derive trajectories and identify associated factors.

RESULTS

Results showed three distinct opioid consumption trajectories for both presurgical opioid consumers and opioid-naïve patients. These trajectories all decreased over time and among those who were consuming opioids before surgery that returned to presurgical levels. Being man, having a substance use disorder, or reporting higher levels of pain interference were associated with higher daily opioid consumption for presurgical opioid consumers. For presurgical opioid-naïve individuals, higher opioid consumption trajectories were associated with higher levels of psychological distress. Five pain intensity trajectories were identified, and there were no significant association between opioid consumption and pain intensity trajectories.

CONCLUSIONS

Results suggest that opioid consumption and pain intensity trajectories mostly decrease after surgery in a high-risk population enrolled in a TPS. Results also show heterogeneity in postsurgical recovery and highlight the importance of using personalized interventions to optimize individual trajectories.

Preoperative psychological factors influence analgesic consumption and self-reported pain intensity following breast cancer surgery

BACKGROUND

Psychological factors such as anxiety and mood appear to influence acute postoperative pain; however, there is conflicting evidence on the relationship between preoperative psychological parameters and the severity of postoperative pain. In the context of the stressful setting of initial surgery for breast cancer, we conducted a prospective observational study of patients who were scheduled to undergo initial breast cancer surgery.

METHODS

The objectives were to examine the potential associations between predefined preoperative psychological parameters and (i) Self-reported pain scores at discharge from the postoperative acute care unit, (ii) Cumulative perioperative opioid consumption at four hours postoperatively and (iii) Self-reported pain as measured during the first seven days after surgery. Patients completed the following questionnaires during the three hours prior to surgery: the Spielberger State Trait Anxiety Inventory (STAI State and Trait), the Pain Catastrophizing Scale (PCS), the Cohen Stress Questionnaire (CSQ), the Hospital Anxiety and Depression Scale (HADS A and D), and the short-form McGill Pain Questionnaire. Postoperative pain experience was assessed using patient self-reports of pain (SF Magill Pain questionnaire on discharge from the postanaesthesia care unit and a pain diary for seven days postoperatively) and records of analgesic consumption.

RESULTS

Pre- to postoperative self-reported pain was significantly different with respect to the STAI State, Cohen score and PCS for both low and high values (p < 0.001), but only patients categorized as having low STAI Trait, HADS A, and HADS D values achieved significant differences (p < 0.001). A significant positive correlation was demonstrated between preoperative state anxiety (STAI) and the most severe pain reported during the first seven days postoperatively (r = 0.271, p = 0.013). Patients who were categorized preoperatively as having a "high value" for each of the psychological parameters studied (HADS A and D, STAI State and Trait and PCS) tended to have greater perioperative opioid consumption (up to four hours postoperatively); this trend was statistically significant for HADS D and HADS A only. Using a linear regression model, state anxiety was found to be a significant predictor of postoperative pain based on self-reports during the first seven postoperative days (standardized β = 0.271, t = 2.286, p = 0.025).

CONCLUSION

Preoperative state anxiety, in particular, is associated with the severity of postoperative pain experienced by women undergoing initial breast cancer surgery. Formal preoperative assessment of anxiety may be warranted in this setting with a view to optimize perioperative analgesia and wellbeing.

Postoperative pain at Landspitali: A prospective study

BACKGROUND

Moderate or severe postoperative pain is common despite advances in surgical technique and perioperative analgesia. This study aimed to assess the prevalence and severity of postoperative pain following procedures requiring anaesthesia and identify factors associated with increased risk of postoperative pain.

METHODS

Surgical patients ≥18 years of age were prospectively questioned on level of current pain on a numerical rating scale (NRS) from 0 to 10 in the post-anaesthesia care unit (PACU) and on resting, active and worst pain experienced in the first 24 h postoperatively. Clinical data was obtained from medical records. Descriptive statistics were applied, and predictors of worst pain assessed as moderate/severe (NRS ≥ 5) on postoperative day one were assessed using multivariable logistic regression.

RESULTS

Of 438 included participants, moderate/severe pain occurred in 29% on the day of surgery and 70% described their worst pain as moderate/severe on postoperative day one. Procedures with the highest incidence of moderate/severe pain on the day of surgery were gynaecology-, plastic-, abdominal-, breast-, and orthopaedic procedures. On postoperative day one, patients undergoing vascular-, orthopaedic-, and abdominal operations most commonly rated their worst pain as moderate/severe. Female sex (OR = 2.15, 95% Cl 1.21-3.88, p = .010), chronic preoperative pain (OR = 4.20, 95% Cl 2.41-7.51, p < .001), undergoing a major procedure (OR = 2.07, 95% Cl 1.15-3.80, p = .017), and any intraoperative remifentanil administration (OR = 2.16, 95% Cl 1.20-3.94, p = .01) had increased odds of rating the worst pain as moderate/severe. Increased age (OR = 0.66 per 10 years (95% Cl 0.55-0.78, p < .001)) and undergoing breast-, gynaecology-, otolaryngology-, and neurosurgery (OR = 0.15-0.34, p < .038) was associated with lower odds of moderate/severe pain on postoperative day one.

DISCUSSION

In our cohort, patients rated their current pain in the PACU similarly to other studies. However, the ratio of patients rating the worst pain experienced as moderate/severe on postoperative day one was relatively high. The identified patient- and procedural-related factors associated with higher odds of postoperative pain highlight a subgroup of patients who may benefit from enhanced perioperative monitoring and pain management strategies.

The autobiographical memory system and chronic pain: A neurocognitive framework for the initiation and maintenance of chronic pain

Chronic pain affects approximately 20% of the world's population, exerting a substantial burden on the affected individual, their families, and healthcare systems globally. Deficits in autobiographical memory have been identified among individuals living with chronic pain, and even found to pose a risk for the transition to chronicity. Recent neuroimaging studies have simultaneously implicated common brain regions central to autobiographical memory processing in the maintenance of and susceptibility to chronic pain. The present review proposes a novel neurocognitive framework for chronic pain explained by mechanisms underlying the autobiographical memory system. Here, we 1) summarize the current literature on autobiographical memory in pain, 2) discuss the role of the hippocampus and cortical brain regions including the ventromedial prefrontal cortex, anterior temporal lobe, and amygdala in relation to autobiographical memory, memory schemas, emotional processing, and pain, 3) synthesize these findings in a neurocognitive framework that explains these relationships and their implications for patients' pain outcomes, and 4) propose translational directions for the prevention, management, and treatment of chronic pain.

Prolonged Opioid Use Is Associated With Poor Pain Alleviation After Orthopaedic Surgery

INTRODUCTION

Severe pain after orthopaedic surgery is common and often results in chronic postsurgical pain and chronic opioid use (COU). Poor pain alleviation (PPA) after surgery is a well-described modifiable risk factor of COU. Although PPA's role in inducing COU is recognized in other areas, it is not well defined in orthopaedic surgery. The aim of this study was to evaluate the influence of PPA on COU in the population who underwent orthopaedic surgery.

METHODS

Medical records from a large academic medical center from 2015 to 2018 were available for analysis. Patients undergoing nononcologic surgical procedures by the orthopaedic surgery service that also required at least 24 hours of hospital stay for pain control were included in the study. Surgery type, body location, basic demographics, preoperative opioid use, comorbidities, medications administered in the hospital, opioid prescription after discharge, and length of stay were recorded. COU was defined as a continued opioid prescription at ≥ 3 months, ≥ 6 months, or ≥ 9 months after surgery. PPA was defined as having a recorded pain score of eight or more, between 4 and 12 hours apart, three times during the hospital stay.

RESULTS

A total of 7,001 patients were identified. The overall rate of COU was 25.3% at 3 months after surgery. Charlson Comorbidity Index > 0 and PPA were statistically significant predictors of opioid use at all time points. Preoperative opioid naivety was associated with decreased COU. The type and location of surgical procedures were not associated with COU, after controlling for baseline variables.

CONCLUSION

Our findings demonstrated an overall high rate of COU. The known risk factors of COU were evident in our study population, particularly the modifiable risk factor of acute postsurgical PPA. Better management of postsurgical pain in orthopaedic patients may lead to a decrease in the rates of COU in this group.

Randomized Placebo-Controlled Trial of 60-Day Percutaneous Peripheral Nerve Stimulation Treatment Indicates Relief of Persistent Postoperative Pain, and Improved Function After Knee Replacement

OBJECTIVES

Total knee arthroplasty (TKA) is an effective surgery for end-stage knee osteoarthritis, but chronic postoperative pain and reduced function affect up to 20% of patients who undergo such surgery. There are limited treatment options, but percutaneous peripheral nerve stimulation (PNS) is a promising nonopioid treatment option for chronic, persistent postoperative pain. The objective of the present study was to evaluate the effect of a 60-day percutaneous PNS treatment in a multicenter, randomized, double-blind, placebo-controlled trial for treating persistent postoperative pain after TKA.

MATERIALS AND METHODS

Patients with postoperative pain after knee replacement were screened for this postmarket, institutional review board-approved, prospectively registered (NCT04341948) trial. Subjects were randomized to receive either active PNS or placebo (sham) stimulation. Subjects and a designated evaluator were blinded to group assignments. Subjects in both groups underwent ultrasound-guided placement of percutaneous fine-wire coiled leads targeting the femoral and sciatic nerves on the leg with postoperative pain. Leads were indwelling for eight weeks, and the primary efficacy outcome compared the proportion of subjects in each group reporting ≥50% reduction in average pain relative to baseline during weeks five to eight. Functional outcomes (6-minute walk test; 6MWT and Western Ontario and McMaster Universities Osteoarthritis Index) and quality of life (Patient Global Impression of Change) also were evaluated at end of treatment (EOT).

RESULTS

A greater proportion of subjects in the PNS groups (60%; 12/20) than in the placebo (sham) group (24%; 5/21) responded with ≥50% pain relief relative to baseline (p = 0.028) during the primary endpoint (weeks 5-8). Subjects in the PNS group also walked a significantly greater distance at EOT than did those in the placebo (sham) group (6MWT; +47% vs -9% change from baseline; p = 0.048, n = 18 vs n = 20 completed the test, respectively). Prospective follow-up to 12 months is ongoing.

CONCLUSIONS

This study provides evidence that percutaneous PNS decreases persistent pain, which leads to improved functional outcomes after TKA at EOT.

A prospective cohort study of chronic postsurgical pain after ambulatory surgeries

OBJECTIVE

The incidence and factors associated with chronic postsurgical pain (CPSP) after ambulatory surgeries have not been well studied. Our primary objective was to determine the incidence of CPSP and secondary objectives included assessment of intensity of CPSP, incidence of moderate-to-severe CPSP, and exploration of factors associated with CPSP.

METHODS

This is a prospective cohort study of ambulatory surgery patients having procedures with a potential to cause moderate-to-severe postoperative pain. All patients had participated in a randomized controlled trial (RCT) showing no difference in achieving satisfactory analgesia in a recovery unit with either morphine or hydromorphone. CPSP was defined as chronic pain that developed or increased in intensity after the surgical procedure and is localized to the surgical field or within the innervation territory of a nerve in the surgical field, and has persisted for 3 months post-surgery, with the exclusion of other causes of pain. Incidences of CPSP were reported as rate (%) with 95% CI, and intensity using a 0-10 numerical rating scale (95% CI). We used logistic regression to explore factors associated with CPSP adjusting for baseline catastrophizing and depression.

RESULTS

Among 402 RCT patients, 208 provided data for the 3-month outcome. Incidence of CPSP was 18.8% (39/208), 95% CI = 13.7%-24.7% and 78% (28/39) of them had moderate-to-severe CPSP. Average CPSP intensity was 5.5, 95% CI = 4.7-6.4. Every unit increase in pain over the first 24 h was significantly associated with increased odds of moderate-to-severe CPSP at 3 months; odds ratio = 1.28, 95% CI = 1.04-1.58.

CONCLUSIONS

Nearly one in five patients develop CPSP after ambulatory surgeries with the majority of them having moderate-to-severe pain. Considering that acute pain after discharge is associated with CPSP and that there are no formal care pathways to address this need, studies need to focus on evaluating feasible strategies to provide continuing care.

Educational needs and preferences of adult patients with acute pain: a mixed-methods systematic review

ABSTRACT

Many patients experience acute pain, which has been associated with numerous negative consequences. Pain education has been proposed as a strategy to improve acute pain management. However, studies report limited effects with educational interventions for acute pain in adults, which can be explained by the underuse of the person-centered approach. Thus, we aimed to systematically review and synthetize current evidence from quantitative, qualitative and mixed-methods studies describing patients' needs and preferences for acute pain education in adults. We searched original studies and gray literature in 7 databases, from January 1990 to October 2023. Methodological quality was assessed with the Mixed Methods Appraisal Tool. A total of 32 studies were included (n = 1847 patients), two-thirds of which were qualitative studies of high methodological quality. Most of the studies were conducted over the last 15 years in patients with postsurgical and posttraumatic pain, identified as White, with a low level of education. Patients expressed the greatest need for education when it came to what to expect in pain intensity and duration, as well how to take the medication and its associated adverse effects. The most frequently reported educational preferences were for in-person education while involving caregivers and to obtain information first from physicians, then by other professionals. This review has highlighted the needs and preferences to be considered in pain education interventions, which should be embedded in an approach cultivating communication and partnership with patients and their caregivers. The results still need to be confirmed with different patient populations.

Liposomal bupivacaine in transversus abdominis plane blocks for lower abdominal surgery

BACKGROUND

Transversus abdominis plane blocks are an established method of postoperative analgesia for abdominopelvic surgeries. Liposomal bupivacaine is an extended-release formulation of bupivacaine providing up to 72 h of analgesia. This study aims to determine if transversus abdominis plane blocks performed with liposomal bupivacaine are associated with reduced opioid consumption and level of pain intensity compared to conventional bupivacaine in patients undergoing lower abdominal surgery.

METHODS

This retrospective cohort study was conducted at a single institution between December 2020 and December 2021. After institutional review board approval, we identified patients who underwent lower abdominopelvic surgery with transversus abdominis plane blocks done with liposomal or conventional bupivacaine and collected demographic, clinical, and procedural information for analysis. We compared total opioid consumption over 72-h postoperatively in milligram morphine equivalents (MME), frequency of opioid utilization, and average level of pain intensity between groups. These outcomes were also evaluated after adjusting for covariates. Data were presented as mean ± SD, median [IQR] or frequency (%), as appropriate; p < 0.05 was accepted as significant.

RESULTS

A total of 178 patients met inclusion criteria, with 79 patients receiving an admixture of liposomal bupivacaine and conventional bupivacaine and 99 patients receiving conventional bupivacaine. The liposomal bupivacaine group had a median opioid consumption 72-h postoperatively of 47.5 [18-91.8] MME compared to 88 [43.8-160] MME in the conventional bupivacaine group, p = 0.045. Differences in opioid consumption between the groups did not reach statistical significance after adjustment for demographic and clinical characteristics, p = 0.11. There was no significant difference in frequency of opioid use or average pain intensity.

CONCLUSION

Transversus abdominis plane blocks using an admixture of liposomal bupivacaine conventional bupivacaine are not associated with decreased opioid consumption or reduced pain up to 72 h following elective abdominopelvic surgery.

Intraoperative clonidine in endometriosis and spine surgery: A protocol for two randomised, blinded, placebo-controlled trials

BACKGROUND

A high proportion of patients who undergo surgery continue to suffer from moderate to severe pain in the early postoperative period despite advances in pain management strategies. Previous studies suggest that clonidine, an alpha2 adrenergic agonist, administered during the perioperative period could reduce acute postoperative pain intensity and opioid consumption. However, these studies have several limitations related to study design and sample size and hence, further studies are needed.

AIM

To investigate the effect of a single intravenous (IV) dose of intraoperative clonidine on postoperative opioid consumption, pain intensity, nausea, vomiting and sedation after endometriosis and spine surgery.

METHODS

Two separate randomised, blinded, placebo-controlled trials are planned. Patients scheduled for endometriosis (CLONIPAIN) will be randomised to receive either 150 μg intraoperative IV clonidine or placebo (isotonic saline). Patients undergoing spine surgery (CLONISPINE) will receive 3 μg/kg intraoperative IV clonidine or placebo. We aim to include 120 patients in each trial to achieve power of 90% at an alpha level of 0.05.

OUTCOMES

The primary outcome is opioid consumption within the first three postoperative hours. Secondary outcomes include pain intensity at rest and during coughing, nausea, vomiting and sedation within the first two postoperative hours and opioid consumption within the first six postoperative hours. Time to discharge from the PACU will be registered.

CONCLUSION

This study is expected to provide valuable information on the efficacy of intraoperative clonidine in acute postoperative pain management in patients undergoing endometriosis and spine surgery.

"It's Incapacitated Me in so Many Ways": Older Adults' Lived Experience With Postoperative Symptoms at Home After Major Elective Surgery

OBJECTIVE

This qualitative study aimed to explore the challenges faced by older adults regarding the postoperative symptom experience after major elective surgery.

BACKGROUND

Although extensively studied in oncology settings, the impact of postoperative symptom burden remains largely underexplored in elective major surgery among older adults.

METHODS

We employed convenience sampling to recruit adults aged 65 years or above undergoing major elective surgery at the University of California, San Francisco. Semistructured interviews regarding the surgical experience were conducted at 1 and 3 months postoperatively. An inductive qualitative approach was used to identify emerging themes. Symptoms revealed by participants during interviews were also captured.

RESULTS

Nineteen participants completed a 1-month postoperative interview, and 17 additionally completed a 3-month interview. Three themes emerged: (1) postoperative symptoms significantly impacted valued life activities and psychosocial well-being, (2) participants felt "caught off guard" by the intensity and duration of postoperative symptoms, and (3) participants expressed the need for additional support, resources, and education on symptom management. The most frequently mentioned symptoms were postoperative pain (n=12, 63.1%), gastrointestinal discomfort (n=8, 42.1%), and anxiety/stress (n=8, 42.1%) at 1-month postsurgery compared with pain and depression (both n=6, 35.3%) at 3 months.

CONCLUSIONS

Study participants were surprised by the negative impact of postoperative symptoms on their psychosocial well-being and ability to engage in valued life activities. Symptom burden is an important patient-reported outcome that should be assessed postoperatively. Interventions to minimize postoperative symptom burden in older adults could optimize quality of life and participation in meaningful activities during surgical recovery.

Opioid use disorder in pediatric populations: considerations for perioperative pain management and precision opioid analgesia

INTRODUCTION

Opioids are commonly used for perioperative analgesia, yet children still suffer high rates of severe post-surgical pain and opioid-related adverse effects. Persistent and severe acute surgical pain greatly increases the child's chances of chronic surgical pain, long-term opioid use, and opioid use disorder.

AREAS COVERED

Enhanced recovery after surgery (ERAS) protocols are often inadequate in treating a child's severe surgical pain. Research suggests that 'older' and longer-acting opioids such as methadone are providing better methods to treat acute post-surgical pain. Studies indicate that lower repetitive methadone doses can decrease the incidence of chronic persistent surgical pain (CPSP). Ongoing research explores genetic components influencing severe surgical pain, inadequate opioid analgesia, and opioid use disorder. This new genetic research coupled with better utilization of opioids in the perioperative setting provides hope in personalizing surgical pain management, reducing pain, opioid use, adverse effects, and helping the fight against the opioid pandemic.

EXPERT OPINION

The opioid and analgesic pharmacogenomics approach can proactively 'tailor' a perioperative analgesic plan to each patient based on underlying polygenic risks. This transition from population-based knowledge of pain medicine to individual patient knowledge can transform acute pain medicine and greatly reduce the opioid epidemic's socioeconomic, personal, and psychological strains globally.

Mental health markers and protective factors in students with symptoms of physical pain across WEIRD and non-WEIRD samples - a network analysis

BACKGROUND

Studies conducted in Western societies have identified variables associated with chronic pain, but few have done so across cultures. Our study aimed to clarify the relationship between specific mental health markers (i.e., depression, anxiety, posttraumatic stress disorder [PTSD], perceived stress) as well as specific protective factors (i.e., social support and self-efficacy) related to physical pain among university students across non-WEIRD and WEIRD samples.

METHOD

A total of 188 university students (131 women and 57 men) were included in the study. We used network analysis to ascertain mental health markers especially central to the experience of physical pain.

RESULTS

No statistically significant difference was found between mental health markers (i.e., depression, anxiety, perceived stress, and PTSD) and protective factors (i.e., social support and self-efficacy) associated with physical pain symptoms for Swiss students versus Indian students (M = 0.325, p = .11). In addition, networks for Swiss versus Indian students did not differ in global strength (S = 0.29, p = .803). Anxiety was the most central mental health marker, and social support was the most important protective factor related to physical pain in both countries. However, for Swiss students, perceived stress, and for Indian students, PTSD symptoms were central mental health markers related to physical pain.

CONCLUSION

Our results identify factors that may serve as important treatment targets for pain interventions among students of both countries before it becomes chronic.

The long-term incidence of chronic post-surgical pain after coronary artery bypass surgery - A prospective observational study

BACKGROUND

Chronic post-surgical pain (CPSP) represents a significant issue for many patients following surgery; however, the long-term incidence and impact have not been well described following cardiac surgery. Our aim was to characterize CPSP at least 5 years following coronary artery bypass grafting (CABG) surgery.

METHODS

This prospective observational study investigated a cohort of patients from a larger trial investigating cognitive outcomes following CABG surgery, with 89 of 148 eligible patients (60.1%) assessed for CPSP at a mean (standard deviation [SD]) of 6.8 [1.2] years. Questionnaires interrogated pain presence, intensity, location, neuropathic characteristics, Geriatric Depression Scale scores (GDS) and instrumental activities of daily living (IADL).

RESULTS

CPSP was described in 21/89 (23.6%), with 10 rating it as moderate to severe. Six of the CPSP patients (29%) met criteria for neuropathic pain (6.7% overall). The highest rate of CPSP was associated with the leg surgical site (chest 12/89 [13.5%], arm 8/68 [11.8%] and leg (saphenous vein graft-SVG) 11/37 [29.7%]; χ2  = 6.523, p = 0.038). IADL scores were significantly lower for patients with CPSP (mean [SD]: 36.7 [1.6] vs. no CPSP 40.6 [0.6]; p = 0.006). Patients had GDS scores consistent with moderate depression (GDS >8) in 3/21 (14.3%) with CPSP, versus 3/68 (4.4%) non-CPSP patients (χ2  = 3.20, p = 0.073).

CONCLUSIONS

This study identified a CPSP incidence of 23.6% at a mean of 6.8 years after CABG surgery, with the highest pain proportion at SVG harvest sites. CPSP was associated with neuropathic pain symptoms and had a significant impact on IADLs. This emphasizes the need for long-term follow-up of CABG patients.

SIGNIFICANCE

This study highlights the impact of CPSP 7 years following cardiac surgery and highlights the effect of surgical site, neuropathic pain and the importance of including pain assessment and management in the long-term follow-up of cardiac surgical patients. Strategies to address and prevent chronic pain following cardiac surgery should be further explored.

The impact of pre-operative depression on pain outcomes after major surgery: a systematic review and meta-analysis

Symptoms of depression are common among patients before surgery. Depression may be associated with worse postoperative pain and other pain-related outcomes. This review aimed to characterise the impact of pre-operative depression on postoperative pain outcomes. We conducted a systematic review of observational studies that reported an association between pre-operative depression and pain outcomes after major surgery. Multilevel random effects meta-analyses were conducted to pool standardised mean differences and 95%CI for postoperative pain scores in patients with depression compared with those without depression, at different time intervals. A meta-analysis was performed for studies reporting change in pain scores from the pre-operative period to any time-point after surgery. Sixty studies (n = 501,962) were included in the overall review, of which 18 were eligible for meta-analysis. Pre-operative depression was associated with greater pain scores at < 72 h (standardised mean difference 0.97 (95%CI 0.37-1.56), p = 0.009, I2  = 41%; moderate certainty) and > 6 months (standardised mean difference 0.45 (95%CI 0.23-0.68), p < 0.001, I2  = 78%; low certainty) after surgery, but not at 3-6 months after surgery (standardised mean difference 0.54 (95%CI -0.06-1.15), p = 0.07, I2  = 83%; very low certainty). The change in pain scores from pre-operative baseline to 1-2 years after surgery was similar between patients with and without pre-operative depression (standardised mean difference 0.13 (95%CI -0.06-0.32), p = 0.15, I2  = 54%; very low certainty). Overall, pre-existing depression before surgery was associated with worse pain severity postoperatively. Our findings highlight the importance of incorporating psychological care into current postoperative pain management approaches in patients with depression.

Moderating effects of preoperative knee pain and pain catastrophizing on the relation between COMT rs4680 genotypes and chronic postsurgical pain in total knee arthroplasty patients

BACKGROUND

The Catechol-O-methyltransferase (COMT) gene, responsible for encoding an enzyme crucial in the metabolism of catecholamines, is known to play a significant role in pain perception. Polymorphisms within this gene, particularly the COMT rs4680 genotypes, have been linked to various acute pain phenotypes. This prospective cohort study examines interactions among the genetic polymorphism COMT rs4680 genotypes, preoperative knee pain, and pain catastrophizing in chronic postsurgical pain (CPSP) at 3, 6, and 12 months post-total knee arthroplasty (TKA).

STUDY DESIGN

A total of 280 patients undergoing primary unilateral TKA participated, sharing demographic details, preoperative knee pain levels, psychological variables (pain catastrophizing), and COMT rs4680 genotyping via venous blood samples. Telephone interviews at specified intervals enabled the application of binary logistic regressions and interaction models.

RESULTS

Significant influences of preoperative knee pain and pain catastrophizing on postsurgical outcomes were observed. Specifically, at the first time point (T1, 3 months post-TKA), a notable moderation effect was identified in preoperative knee pain (R2 change = 0.026, p = 0.026). The Johnson-Neyman regions of significance (RoS) indicated these moderation effects were significant above a threshold of 17.18 (p = 0.05), accounting for 26.4%. At the third time point (T3, 12 months post-TKA), a complex three-way interaction among genotypes (GG, GA, and AA carriers) was evident, resulting in an R2 change of 0.051 (p = 0.009). Here, the RoS for pain catastrophizing was above 32.74 for 30.5% of GG genotype carriers, above 22.38 for 50.8% of GA carriers, and below 11.94 for 63.2% of AA carriers.

CONCLUSION

This study illuminates the significant role of the COMT Val158Met rs4680 polymorphism in susceptibility to prolonged pain following TKA. It also elucidates how these genetic genotypes interplay with preoperative knee pain and pain catastrophizing. Such intricate genetic-psychological-pain relationships necessitate additional investigation to confirm these findings and potentially guide post-TKA pain management strategies.

Improvement in functional outcome 1 year after nonsurgical multidisciplinary treatment for chronic pain after total knee arthroplasty: A prospective cohort study

PURPOSE

The purpose of this study was to evaluate a multidisciplinary intervention developed for patients with debilitating chronic pain after total knee arthroplasty (TKA) unresponsive to existing treatment options.

METHODS

A treatment-based prospective cohort study was caried out in 30 TKA patients with debilitating chronic pain at least 1 year after TKA. The treatment was a multidisciplinary intervention. Main inclusion criteria: no indication for surgery. Primary outcome was function measured by KOOS-PS, OKS, OKS-APQ and WORQ. Secondary outcome measures were pain, fear of movement, self-efficacy, quality of life (QoL), health care and pain medication use, work rehabilitation and patient satisfaction. The assessments took place pre- and directly posttreatment, at 1, 3 and 12 months follow-up. The clinical relevance was assessed by predefined minimal important clinical change (MCIC).

RESULTS

At baseline patients were on average 64.7 (±7.9) years old, 67% were female, and they had knee pain for 42 (10-360) months. The results at 12-month follow-up: first, a significant improvement was shown in function, pain, fear of movement, self-efficacy and QoL. Second, in 38.5%-69.2% of patients clinical relevant improvement was shown for functional outcome, 31% for pain, and 50% for self-efficacy. Third, 42% of patients reported 'no healthcare use in the past three months'.

CONCLUSION

One year after a multidisciplinary treatment a clinically relevant improvement was shown in terms of function, pain, self-efficacy and QoL. It seems to be a promising treatment option in this difficult-to-treat patient group with debilitating chronic pain after TKA. Future research should examine the effect of the treatment in a larger study population, considering a control group, and focusing on the working population and evaluating cost-efficacy.

LEVEL OF EVIDENCE

Level II.

Sex moderates the association between quantitative sensory testing and acute and chronic pain after total knee/hip arthroplasty

OBJECTIVES

Acute postsurgical pain (APSP) may persist over time and become chronic. Research on predictors for APSP and chronic postsurgical pain (CPSP) has produced inconsistent results. This observational study aimed to analyze psychological and psychophysical variables associated with APSP and CPSP after total knee or hip arthroplasty, and to explore the role of sex.

METHODS

Assessments were conducted before surgery, 48 h, and 3 months postsurgery, including questionnaires (sociodemographic, pain related, and psychological) and quantitative sensory testing (QST). Hierarchical linear regression models analyzed potential predictors of APSP and CPSP, and moderation analyses evaluated the role of sex.

RESULTS

The study included 63 participants undergoing total knee (34, 54%) or hip (29, 46%) arthroplasty. Thirty-one (49.2%) were female and 32 (50.8%) were male. APSP (48 h) was associated with impaired conditioned pain modulation (CPM) (β = 0.301, p = 0.019). CPSP (3 months) was associated with being female (β = 0.282, p = 0.029), longer presurgical pain duration (β = 0.353, p = 0.006), knee arthroplasty (β = -0.312, p = 0.015), higher APSP intensity (β = 373, p = 0.004), and impaired CPM (β = 0.126, p = 0.004). In multivariate analysis, these clinical variables were significant predictors of CPSP, unlike sex, and CPM (adj. R 2 = 0.349). Moderation analyses showed that wind-up ratio (WUR) was a significant predictor of APSP in men (WUR × sex: b = -1.373, p = 0.046) and CPM was a significant predictor of CPSP in women (CPM × sex: b = 1.625, p = 0.016).

CONCLUSIONS

Specific QST parameters could identify patients at risk for high-intensity APSP and CPSP, with sex as a moderator. This has important clinical implications for patient care, paving the way for developing tailored preventive pain management strategies.

Cosmetic surgery and associated chronic postsurgical pain: A cross-sectional study from Norway

OBJECTIVES

Chronic postsurgical pain (CPSP) is a common postoperative sequela. Despite the increasing popularity of cosmetic surgeries, there is a notable lack of research on CPSP in this context, with existing studies focusing on breast surgeries only. To address existing gaps in knowledge, the objective of the present study was to investigate the self-reported prevalence of cosmetic surgery and associated CPSP among Norwegian adults.

METHODS

An online questionnaire consisting of three questions inquiring prior cosmetic surgeries, associated CPSP, and whether participants had sought for pain management was constructed and distributed among adults residing in Norway.

RESULTS

Between November 30, 2022 and December 16, 2022, 1,746 participants were recruited. 10% of respondents, 73.3% of which were female, affirmed to have undergone cosmetic surgery. About 1 in 4 of these was aged 18-29 years. The prevalence of CPSP was 12.6%. CPSP was five times more common among male, compared to female respondents. While about two thirds of participants indicating to have experienced CPSP were aged 18-29 years, CPSP was much less common among individuals of other ages.

CONCLUSION

Consistent with international trends, there appears to be a young and growing population of cosmetic surgery consumers in Norway. According to our results, about 1 in 8 of these might be affected by CPSP, a condition that is notoriously hard to treat and weighting heavily on public healthcare and social welfare systems. Large-scale longitudinal studies further investigating the topic are thus urgently needed.

Pain associated with breast cancer: etiologies and therapies

Pain associated with breast cancer is a prevalent problem that negatively affects quality of life. Breast cancer pain is not limited to the disease course itself but is also induced by current therapeutic strategies. This, combined with the increasing number of patients living with breast cancer, make pain management for breast cancer patients an increasingly important area of research. This narrative review presents a summary of pain associated with breast cancer, including pain related to the cancer disease process itself and pain associated with current therapeutic modalities including radiation, chemotherapy, immunotherapy, and surgery. Current pain management techniques, their limitations, and novel analgesic strategies are also discussed.

Association of Genetic Variants with Postsurgical Pain: A Systematic Review and Meta-analyses

BACKGROUND

Postsurgical pain is a key component of surgical recovery. However, the genetic drivers of postsurgical pain remain unclear. A broad review and meta-analyses of variants of interest will help investigators understand the potential effects of genetic variation.

METHODS

This article is a systematic review of genetic variants associated with postsurgical pain in humans, assessing association with postsurgical pain scores and opioid use in both acute (0 to 48 h postoperatively) and chronic (at least 3 months postoperatively) settings. PubMed, Embase, and the Cochrane Central Register of Controlled Trials were searched from 2000 to 2022 for studies using search terms related to genetic variants and postsurgical pain in humans. English-language studies in adult patients examining associations of one or more genetic variants with postsurgical pain were included. The primary outcome was association of genetic variants with either acute or chronic postsurgical pain. Pain was measured by patient-reported pain score or analgesic or opioid consumption.

RESULTS

A total of 163 studies were included, evaluating 129 unique genes and 594 unique genetic variants. Many of the reported significant associations fail to be replicated in other studies. Meta-analyses were performed for seven variants for which there was sufficient data (OPRM1 rs1799971; COMT rs4680, rs4818, rs4633, and rs6269; and ABCB1 rs1045642 and rs2032582). Only two variants were associated with small differences in postsurgical pain: OPRM1 rs1799971 (for acute postsurgical opioid use standard mean difference = 0.25; 95% CI, 0.16 to 0.35; cohort size, 8,227; acute postsurgical pain score standard mean difference = 0.20; 95% CI, 0.09 to 0.31; cohort size, 4,619) and COMT rs4680 (chronic postsurgical pain score standard mean difference = 0.26; 95% CI, 0.08 to 0.44; cohort size, 1,726).

CONCLUSIONS

Despite much published data, only two alleles have a small association with postsurgical pain. Small sample sizes, potential confounding variables, and inconsistent findings underscore the need to examine larger cohorts with consistent outcome measures.

EDITOR’S PERSPECTIVE

The Impact of Preoperative Patient Education on Postoperative Pain, Opioid Use, and Psychological Outcomes: A Narrative Review

Background

Recent studies have shown that preoperative education can positively impact postoperative recovery, improving postoperative pain management and patient satisfaction. Gaps in preoperative education regarding postoperative pain and opioid use may lead to increased patient anxiety and persistent postoperative opioid use.

Objectives

The objective of this narrative review was to identify, examine, and summarize the available evidence on the use and effectiveness of preoperative educational interventions with respect to postoperative outcomes.

Method

The current narrative review focused on studies that assessed the impact of preoperative educational interventions on postoperative pain, opioid use, and psychological outcomes. The search strategy used concept blocks including "preoperative" AND "patient education" AND "elective surgery," limited to the English language, humans, and adults, using the MEDLINE ALL database. Studies reporting on preoperative educational interventions that included postoperative outcomes were included. Studies reporting on enhanced recovery after surgery protocols were excluded.

Results

From a total of 761 retrieved articles, 721 were screened in full and 34 met criteria for inclusion. Of 12 studies that assessed the impact of preoperative educational interventions on postoperative pain, 5 reported a benefit for pain reduction. Eight studies examined postoperative opioid use, and all found a significant reduction in opioid consumption after preoperative education. Twenty-four studies reported on postoperative psychological outcomes, and 20 of these showed benefits of preoperative education, especially on postoperative anxiety.

Conclusion

Preoperative patient education interventions demonstrate promise for improving postoperative outcomes. Preoperative education programs should become a prerequisite and an available resource for all patients undergoing elective surgery.

A random forest algorithm-based prediction model for moderate to severe acute postoperative pain after orthopedic surgery under general anesthesia

BACKGROUND

Postoperative pain is one of the most common complications after surgery. In order to detect early and intervene in time for moderate to severe postoperative pain, it is necessary to identify risk factors and construct clinical prediction models. This study aimed to identify significant risk factors and establish a better-performing model to predict moderate to severe acute postoperative pain after orthopedic surgery under general anesthesia.

METHODS

Patients who underwent orthopedic surgery under general anesthesia were divided into patients with moderate to severe pain group (group P) and patients without moderate to severe pain group (group N) based on VAS scores. The features selected by Lasso regression were processed by the random forest and multivariate logistic regression models to predict pain outcomes. The classification performance of the two models was evaluated through the testing set. The area under the curves (AUC), the accuracy of the classifiers, and the classification error rate for both classifiers were calculated, the better-performing model was used to predict moderate to severe acute postoperative pain after orthopedic surgery under general anesthesia.

RESULTS

A total of 327 patients were enrolled in this study (228 in the training set and 99 in the testing set). The incidence of moderate to severe postoperative pain was 41.3%. The random forest model revealed a classification error rate of 25.2% and an AUC of 0.810 in the testing set. The multivariate logistic regression model revealed a classification error rate of 31.3% and an AUC of 0.764 in the testing set. The random forest model was chosen for predicting clinical outcomes in this study. The risk factors with the greatest and second contribution were immobilization and duration of surgery, respectively.

CONCLUSIONS

The random forest model can be used to predict moderate to severe acute postoperative pain after orthopedic surgery under general anesthesia, which is of potential clinical application value.

Development and expansion of a pediatric transitional pain service to prevent complex chronic pain

The prevention of chronic pain is a key priority in North America and around the world. A novel pediatric Transitional Pain Service (pTPS) at the Hospital for Sick Children was established to address four main areas of need, which the authors will describe in more detail: (1) provide comprehensive multi-modal pain management and prevention techniques to children at-risk for the development of chronic pain, (2) provide opioid stewardship for children at-risk for chronic pain and their families at home after discharge, (3) facilitate continuity of pain care for children across transitions between inpatient and outpatient care settings, and (4) support caregivers to manage their child's pain at home. The pTPS works with healthcare providers, patients, and their families to address these areas of need and improve quality of life. Furthermore the service fills the gap between inpatient acute pain services and outpatient chronic pain services (accessible only once pain has persisted for >3 months). In pediatric patients who experience pain in hospital and who have been prescribed opioids, discharge to home or rehabilitation may represent a vulnerable time in which pain may persist and during which analgesic requirements may change. This offers an important opportunity to address and prevent the development of chronic pain, and to monitor opioids while ensuring alternative pain therapy is available. The authors will outline risk factors for persistent postsurgical pain, the development and implementation of a pTPS, present initial clinical outcomes andsuggest areas for future research in this evolving area of care.

The Effects of Anthroposophic Medicine in Chronic Pain Conditions: A Systematic Review

Background: The currently available evidence is unclear in regard to pain-related outcomes of patients with chronic pain conditions who undergo treatment with anthroposophic medicine (AM). Aim: To identify and synthesize the evidence in patients with chronic pain before and after AM therapy. Methods: The following databases and search interfaces were searched on October 21, 2021: Embase (via Embase.com), Medline (via PubMed), and the Cochrane Library. Additional references were identified via bibliographies of included studies. In at least one experimental arm that used anthroposophic therapy to treat chronic pain, AM treatments were required to be documented. Included studies reported on pain severity and physical and emotional functioning. Two authors independently assessed the studies for inclusion criteria, extracted the data, and conducted the quality evaluation of the included studies based on the critical appraisal tools provided by the Joanna Briggs Institute. Results: Seven studies (eight publications) were included in the review, of which were three randomized controlled trials (RCTs), two non-RCTs, and two pretest-post-test studies. A total number of 600 patients participated in the identified experimental studies, of whom all were adults. Three studies included patients with low back pain, one study each assessed patients with fibromyalgia, migraine, dysmenorrhea, and postpolio syndrome, respectively. The identified clinical studies reported considerable reductions in symptoms and effect sizes of pain outcomes after AM therapies being predominantly large, with no notable adverse effects. Conclusion: The findings of this systematic review of studies assessing AM therapies in patients with chronic pain problems revealed that there is a scarcity of evidence currently available, with unclear effects of AM treatments in reducing pain intensity and improving quality of life in the evaluated health conditions. Although most of the studies revealed a favorable benefit on one or more pain-related outcomes, the variability of the research did not allow for generalization across different studies, health conditions, and populations.

Socioeconomic Characteristics Associated With the Development of Chronic Pain After Pain Interference Experienced in Early Adulthood

OBJECTIVE

Predictors of pain persistence have been identified among patients undergoing treatment for chronic pain or related conditions, but correlates of pain persistence in the general population remain underexplored. We identify socioeconomic variables associated with pain onset or persistence over a 6 to 10 year period in a nationally representative cohort.

METHODS

Using panel data from the National Longitudinal Survey of Youth-1997, we examined the presence of pain interference at age 29 and chronic pain at ages 35 to 39. Persistent pain was defined as pain present at both interview time points; new-onset pain was defined as pain not reported at age 29, but present at ages 35 to 39; and transient pain was defined as experiencing pain interference at age 29 with no report of chronic pain at ages 35 to 39.

RESULTS

Based on a sample of 6188 participants, we estimated that 4% experienced persistent pain, 11% experienced transient pain, and 7% experienced new-onset pain. Pain persistence was less likely among non-Hispanic Black respondents but more likely among formerly married respondents and those with poor health, health-related work limitation, or greater pain interference at the age 29 baseline. New-onset pain was most likely among female respondents, respondents with some college education, and respondents with poor self-rated health or obesity at baseline.

DISCUSSION

Development of chronic pain by the mid-late 30s was common among young adults experiencing pain interference at age 29. Race/ethnicity, gender, and educational attainment exhibited different associations with persistence as compared with new onset of pain problems.

Anterior cingulate cortex regulates pain catastrophizing-like behaviors in rats

Negative pain expectation including pain catastrophizing is a well-known clinical phenomenon whereby patients amplify the aversive value of a painful or oftentimes even a similar, non-painful stimulus. Mechanisms of pain catastrophizing, however, remain elusive. Here, we modeled pain catastrophizing behavior in rats, and found that rats subjected to repeated noxious pin pricks on one paw demonstrated an aversive response to similar but non-noxious mechanical stimuli delivered to the contralateral paw. Optogenetic inhibition of pyramidal neuron activity in the anterior cingulate cortex (ACC) during the application of repetitive noxious pin pricks eliminated this catastrophizing behavior. Time-lapse calcium (Ca2+) imaging in the ACC further revealed an increase in spontaneous neural activity after the delivery of noxious stimuli. Together these results suggest that the experience of repeated noxious stimuli may drive hyperactivity in the ACC, causing increased avoidance of subthreshold stimuli, and that reducing this hyperactivity may play a role in treating pain catastrophizing.

Exploration of the clinical course and longitudinal correlations in frozen shoulder: The role of autonomic function, central pain processing, and psychological variables. A longitudinal multicenter prospective observational study

BACKGROUND

Altered central pain processing (CPP) and dysautonomia might play a role in the clinical course of frozen shoulder and psychological factors, like pain catastrophizing and hypervigilance, might influence clinical variables in frozen shoulder.

OBJECTIVES

To explore the clinical course of frozen shoulder regarding CPP, dysautonomia, pain catastrophizing, and hypervigilance and to explore whether longitudinal correlations between these outcomes and pain intensity were present.

DESIGN

prospective longitudinal observational study.

METHOD

Participants with frozen shoulder were recruited at hospitals and general practitioner practices and followed for 9 months. They completed six questionnaires (about demographics, shoulder pain and disability, pain intensity, pain catastrophizing, pain hypervigilance, and autonomic symptoms) and underwent tactile sensitivity (allodynia), pressure pain thresholds (hyperalgesia), temporal summation, and conditioned pain modulation during four timeframes (3-month intervals).

RESULTS

Initially, 149 participants with frozen shoulder were recruited and 88 completed all the measurements. An improvement from baseline to at least one follow-up measurement was found for shoulder pain and disability, pain intensity, pain catastrophizing, hypervigilance, and dysautonomia. A fair longitudinal correlation was found between pain intensity and catastrophizing and hypervigilance (r = 0.301-0.397). Poor longitudinal correlations were found between pain intensity and allodynia and hyperalgesia (r = -0.180-0.193), between pain catastrophizing and dysautonomia (r = 0.209) and between hypervigilance and hyperalgesia (r = -0.159).

CONCLUSION

Patients with frozen shoulder showed an early improvement that flattened with time in several pain and psychological variables over the course of 9 months. However, autonomic symptoms rather showed a late improvement over 9 months.

Descending Control of Nociception Poorly Predicts the Development of Persistent Postsurgical Pain-like Behavior in Consomic Dahl S Rat Strains

BACKGROUND

Chronic postsurgical pain is a poorly recognized outcome of surgery where patients experience pain long after healing from the surgical insult. Descending control of nociception, a phenomenon whereby application of a strong nociceptive stimulus to one part of the body of animals inhibits pain in remote body regions, offers one strategy to identify a propensity to develop chronic postsurgical pain-like behavior. Here, consomic rat panel was used to test the hypothesis that pain persistence is mechanistically linked to ineffective descending control of nociception.

METHODS

Male and female Brown Norway, Dahl S, and eight consomic strains (SS-xBN) were used to determine the presence of chronic postsurgical pain-like behaviors by using paw-withdrawal threshold evaluation (von Frey method) in the area adjacent to a hind paw plantar incision. Descending control of nociception was assessed by measuring hind paw-withdrawal thresholds (Randall-Selitto method) after capsaicin (125 µg) injection into a forepaw. Consomic rats were developed by introgressing individual Brown Norway chromosomes on the Dahl S rat genetic background, as Dahl S rats lack preoperative descending control of nociception.

RESULTS

Substitution of several chromosomes from the "pain-resistant" Brown Norway to the "pain-prone" Dahl S/Medical College of Wisconsin reduced mechanical nociceptive sensitivity and increased endogenous pain modulation capacity by differing degrees. Statistical modeling of these data revealed that descending control of nociception is a poor general predictor of the propensity to develop chronic postsurgical pain-like behavior (poor fit for model 1). However, a significant strain-by-descending control of nociception interaction was revealed (model 3, -2*log likelihood; 550.668, -2ll change; 18.093, P = 0.034) with SS-13BN and SS-15BN strains showing a negative descending control of nociception relationship with chronic postsurgical pain-like behavior.

CONCLUSIONS

Descending control of nociception poorly predicted which rat strains developed chronic postsurgical pain-like behavior despite controlling for genetic, environmental, and sex differences. Two consomic strains that mimic clinical chronic postsurgical pain criteria and display a strong negative correlation with descending control of nociception were identified, offering novel candidates for future experiments exploring mechanisms that lead to chronic postsurgical pain.

EDITOR’S PERSPECTIVE

Predicting chronic postsurgical pain: current evidence and a novel program to develop predictive biomarker signatures

ABSTRACT

Chronic pain affects more than 50 million Americans. Treatments remain inadequate, in large part, because the pathophysiological mechanisms underlying the development of chronic pain remain poorly understood. Pain biomarkers could potentially identify and measure biological pathways and phenotypical expressions that are altered by pain, provide insight into biological treatment targets, and help identify at-risk patients who might benefit from early intervention. Biomarkers are used to diagnose, track, and treat other diseases, but no validated clinical biomarkers exist yet for chronic pain. To address this problem, the National Institutes of Health Common Fund launched the Acute to Chronic Pain Signatures (A2CPS) program to evaluate candidate biomarkers, develop them into biosignatures, and discover novel biomarkers for chronification of pain after surgery. This article discusses candidate biomarkers identified by A2CPS for evaluation, including genomic, proteomic, metabolomic, lipidomic, neuroimaging, psychophysical, psychological, and behavioral measures. Acute to Chronic Pain Signatures will provide the most comprehensive investigation of biomarkers for the transition to chronic postsurgical pain undertaken to date. Data and analytic resources generatedby A2CPS will be shared with the scientific community in hopes that other investigators will extract valuable insights beyond A2CPS's initial findings. This article will review the identified biomarkers and rationale for including them, the current state of the science on biomarkers of the transition from acute to chronic pain, gaps in the literature, and how A2CPS will address these gaps.

Pain Management in the Elderly: A Narrative Review

With the increase in life expectancy in the United States, octogenarians and nonagenarians are more frequently seen in clinical practice. The elderly patients have multiple preexisting comorbidities and are on multiple medications, which can make pain management complex. Moreover, the elderly population often suffers from chronic pain related to degenerative processes, making medical management challenging. In this review, the authors collated available evidence for best practices for pain management in the elderly.

Advances in the Management of Acute Postsurgical Pain: A Review

Despite the millions of surgeries performed every year around the world, postoperative pain remains prevalent and is often addressed with inadequate or suboptimal treatments. Chronic postsurgical pain is surprisingly prevalent, and its rate varies with the type of surgery, as well as with certain patient characteristics. Thus, better clinical training is needed as well as patient education. As pain can be caused by more than one mechanism, multimodal or balanced postsurgical analgesia is appropriate. Pharmacological agents such as opioid and nonopioid pain relievers, as well as adjuvants and nonpharmacologic approaches, can be combined to provide better and opioid-sparing pain relief. Many specialty societies have guidelines for postoperative pain management that emphasize multimodal postoperative analgesia. These guidelines are particularly helpful when dealing with special populations such as pregnant patients or infants and children. Pediatric pain control, in particular, can be challenging as patients may be unable to communicate their pain levels. A variety of validated assessment tools are available for diagnosis. Related to therapy, most guidelines agree on the fact that codeine should be used with extreme caution in pediatric patients as some may be "rapid metabolizers" and its use may be life-threatening. Prehabilitation is a preoperative approach that prepares patients in advance of elective surgery with conditioning exercises and other interventions to optimize their health. Prehabilitation may have aerobic, strength-training, nutritional, and counseling components. Logistical considerations and degree of patient adherence represent barriers to effective prehabilitation programs. Notwithstanding all this, acute postoperative pain represents a clinical challenge that has not yet been well addressed.

A Systematic Review on Long-Term Postsurgical Pain Outcomes; What Is the Effect of Upper Extremity Regional Anesthesia?

BACKGROUND

Chronic pain is a recognized complication of surgery, and it has been hypothesized that regional anesthesia might reduce the risk of development of chronic pain after upper extremity surgery.

METHODS

A systematic literature review was performed to assess whether in patients undergoing elective upper extremity surgery (P), regional anesthesia (I), compared to general anesthesia (C), would result in lower long-term (>3 months) postoperative pain intensity (O). We included randomized and nonrandomized controlled trials (RCTs). Our primary outcome was numerical rating score or visual analogue scale for pain, at >3 months postoperatively. The Embase, Medline ALL, Web of Science Core Collections, Cochrane Central Register of Controlled Trials, and Google Scholar databases were searched for all reports assessing pain at >3 months after upper extremity surgery under general versus regional anesthesia. Secondary outcomes were: opioid prescription filling, complex regional pain syndrome (CRPS) incidence, the Mayo Wrist Score (MWS), and scores on the Disability of the Arm, Shoulder and Hand (DASH) questionnaire. Quality (or certainty) of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE). Risk-of-bias was assessed using the Cochrane tool for randomized trials (RoB 2.0) and nonrandomized trials (ROBINS-I).

RESULTS

This review included 14 studies, comprising 7 RCTs and 7 nonrandomized studies. Six of the 7 studies (4 RCTs, N = 273; 2 nonrandomized studies, N = 305) using a pain score, our primary outcome, report comparable long-term postoperative pain scores after regional and general anesthesia. Six of the 7 studies using our secondary outcomes report comparable long-term outcomes in terms of opioid prescription filling (2 retrospective cohort studies [RCSs], N = 89,256), CRPS incidence (1 RCT, N = 301), MWS (1 RCT and 1 RCS, N = 215), and DASH score (1 RCT, N = 36). Comparable outcomes were reported in all 7 RCTs (N = 778) and in 5 of the 7 nonrandomized studies, comprising 5 RCSs (N = 89,608). Two prospective observational studies (POSTs), comprising 279 patients, report a statistically significant difference in outcomes, with less pain and better DASH scores after brachial plexus anesthesia. All 14 studies provided moderate to very low certainty evidence, and there was a serious risk of bias due to confounding bias in 5 of the 7 nonrandomized studies (N = 631).

CONCLUSIONS

The results of this review indicate that upper extremity regional anesthesia, compared to general anesthesia, is unlikely to change pain intensity at >3 months postoperatively.

The mechanisms and management of persistent postsurgical pain

An estimated 10%-50% of patients undergoing a surgical intervention will develop persistent postsurgical pain (PPP) lasting more than 3 months despite adequate acute pain management and the availability of minimally invasive procedures. The link between early and late pain outcomes for surgical procedures remains unclear-some patients improve while others develop persistent pain. The elective nature of a surgical procedure offers a unique opportunity for prophylactic or early intervention to prevent the development of PPP and improve our understanding of its associated risk factors, such as pre-operative anxiety and the duration of severe acute postoperative pain. Current perioperative pain management strategies often include opioids, but long-term consumption can lead to tolerance, addiction, opioid-induced hyperalgesia, and death. Pre-clinical models provide the opportunity to dissect mechanisms underpinning the transition from acute to chronic, or persistent, postsurgical pain. This review highlights putative mechanisms of PPP, including sensitisation of peripheral sensory neurons, neuroplasticity in the central nervous system and nociceptive signalling along the neuro-immune axis.

Genetic risk factors for chronic postsurgical pain in children: A narrative review

Genetic risk factors for chronic postsurgical pain in adults have been established, but little is known whether the same associations exist in children. It is even less clear how much influence single nucleotide polymorphisms can exert on the phenotypic expression of chronic postsurgical pain in children in general. To this effect, a search was made for original articles which met the following criteria: evaluation of postsurgical pain in children with known genetic mutations or, conversely, evaluation of atypical pain trajectories of postsurgical children assessing for possible genetic mutations that may explain the phenotype. All titles and abstracts retrieved were reviewed for suitability for inclusion. The references of the selected articles were also checked for additional relevant papers. To assess the transparency and quality of the genetic studies both STrengthening the REporting of Genetic Association studies scores and Q-Genie scores were applied. Overall, there is a paucity of information regarding the link between genetic mutations and eventual chronic postsurgical pain development although there is some information on acute postoperative pain. Evidence has shown that the contribution of genetic risk factors to chronic postsurgical pain development appears to be minor, with its clinical relevance yet to be described. More advanced techniques in systems biology (proteomics, transcriptomics) suggest promising avenues for investigating the disease.

Effectiveness of Acceptance and Commitment Therapy (ACT) for the Management of Postsurgical Pain: Study Protocol of a Randomized Controlled Trial (SPINE-ACT Study)

Research on the use of Acceptance and Commitment Therapy (ACT) for patients with degenerative lumbar pathology awaiting surgery are limited. However, there is evidence to suggest that this psychological therapy may be effective in improving pain interference, anxiety, depression, and quality of life. This is the protocol for a randomized controlled trial (RCT) to evaluate the effectiveness of ACT compared to treatment as usual (TAU) for people with degenerative lumbar pathology who are candidates for surgery in the short term. A total of 102 patients with degenerative lumbar spine pathology will be randomly assigned to TAU (control group) or ACT + TAU (intervention group). Participants will be assessed after treatment and at 3-, 6-, and 12-month follow-ups. The primary outcome will be the mean change from baseline on the Brief Pain Inventory (pain interference). Secondary outcomes will include changes in pain intensity, anxiety, depression, pain catastrophizing, fear of movement, quality of life, disability due to low back pain (LBP), pain acceptance, and psychological inflexibility. Linear mixed models will be used to analyze the data. Additionally, effect sizes and number needed to treat (NNT) will be calculated. We posit that ACT may be used to help patients cope with the stress and uncertainty associated with their condition and the surgery itself.

A prospective study of chronic postsurgical pain in elderly patients: incidence, characteristics and risk factors

BACKGROUND

Due to the continued growth of surgical procedures in older adults and the significant impact of chronic postsurgical pain (CPSP), it is crucial to improve our understanding of the occurrence of CPSP as well as the appropriate prevention and treatment. We therefore conducted this study to determine the incidence, characteristics and risk factors of CPSP in elderly patients at both 3 and 6 months after surgery.

METHODS

Elderly patients (aged ≥ 60 years) undergoing elective surgery in our institution between April 2018 and March 2020 were prospectively enrolled in this study. Data on demographics, preoperative psychological well-being, intraoperative surgical and anesthesia management, and acute postoperative pain intensity were collected. At 3 and 6 months after surgery, patients received telephone interview and completed the questionnaires regarding chronic pain characteristics, analgesic consumption, and interference of the pain with activities of daily living (ADL).

RESULTS

A total of 1065 elderly patients were followed up for 6 postoperative months and included in final analysis. At 3 and 6 months after operation, the incidence of CPSP was 35.6% [95% confidence interval (95% CI) 32.7 - 38.8%] and 21.5% (95% CI 19.0% - 23.9%), respectively. CPSP cause negative impacts on patient's ADL and most particularly on mood. Neuropathic features were found in 45.1% of the patients with CPSP at 3 months. At 6 months, 31.0% of those with CPSP reported that the pain had neuropathic features. Preoperative anxiety [3 months: Odds ratio (OR) 2.244, 95% CI 1.693 to 2.973; 6 months: OR 2.397, 95% CI 1.745 to 3.294], preoperative depression (3 months: OR 1.709, 95% CI 1.292 to 2.261; 6 months: OR 1.565, 95% CI 1.136-2.156), orthopedic surgery (3 months: OR 1.927, 95% CI 1.112 to 3.341; 6 months: OR 2.484, 95% CI 1.220 to 5.061), higher pain severity on movement within postoperative 24 h (3 months: OR 1.317, 95% CI 1.191 to 1.457; 6 months: OR 1.317, 95% CI 1.177 to 1.475) were associated with a higher risk for CPSP independently at both 3 and 6 months after surgery.

CONCLUSIONS

CPSP is a common postoperative complication in elderly surgical patients. Preoperative anxiety and depression, orthopedic surgery, and greater intensity of acute postoperative pain on movement are associated with an increased risk for CPSP. It should be kept in mind that developing psychological interventions to reduce anxiety and depression and optimizing the management of acute postoperative pain will be effective in reducing the development of CPSP in this population.