Prevention Of Chronic Postsurgical Pain Research Articles

Mechanisms and Preventative Strategies for Persistent Pain following Knee and Hip Joint Replacement Surgery: A Narrative Review.

Chronic postsurgical pain (CPSP) following total knee arthroplasty (TKA) and total hip arthroplasty (THA) is a prevalent complication of joint replacement surgery which has the potential to decrease patient satisfaction, increase financial burden, and lead to long-term disability. The identification of risk factors for CPSP following TKA and THA is challenging but essential for targeted preventative therapy. Recent meta-analyses and individual studies highlight associations between elevated state anxiety, depression scores, preoperative pain, diabetes, sleep disturbances, and various other factors with an increased risk of CPSP, with differences observed in prevalence between TKA and THA. While the etiology of CPSP is not fully understood, several factors such as chronic inflammation and preoperative central sensitization have been identified. Other potential mechanisms include genetic factors (e.g., catechol-O-methyltransferase (COMT) and potassium inwardly rectifying channel subfamily J member 6 (KCNJ6) genes), lipid markers, and psychological risk factors (anxiety and depression). With regards to therapeutics and prevention, multimodal pharmacological analgesia, emphasizing nonopioid analgesics like acetaminophen and non-steroidal anti-inflammatory drugs (NSAIDs), has gained prominence over epidural analgesia. Nerve blocks and local infiltrative anesthesia have shown mixed results in preventing CPSP. Ketamine, an N-methyl-D-aspartate (NMDA)-receptor antagonist, exhibits antihyperalgesic properties, but its efficacy in reducing CPSP is inconclusive. Lidocaine, an amide-type local anesthetic, shows tentative positive effects on CPSP. Selective serotonin reuptake inhibitors (SSRIs) and serotonin norepinephrine reuptake inhibitors (SNRIs) have mixed results, while gabapentinoids, like gabapentin and pregabalin, present hopeful data but require further research, especially in the context of TKA and THA, to justify their use for CPSP prevention.

Optimizing the use of ketamine to reduce chronic postsurgical pain in women undergoing mastectomy for oncologic indication: study protocol for the KALPAS multicenter randomized controlled trial

BackgroundMastectomies are commonly performed and strongly associated with chronic postsurgical pain (CPSP), more specifically termed postmastectomy pain syndrome (PMPS), with 25–60% of patients reporting pain 3 months after surgery. PMPS interferes with function, recovery, and compliance with adjuvant therapy. Importantly, it is associated with chronic opioid use, as a recent study showed that 1 in 10 patients continue to use opioids at least 3 months after curative surgery. The majority of PMPS patients are women, and, over the past 10 years, women have outpaced men in the rate of growth in opioid dependence. Standard perioperative multimodal analgesia is only modestly effective in prevention of CPSP. Thus, interventions to reduce CPSP and PMPS are urgently needed. Ketamine is well known to improve pain and reduce opioid use in the acute postoperative period. Additionally, ketamine has been shown to control mood in studies of anxiety and depression. By targeting acute pain and improving mood in the perioperative period, ketamine may be able to prevent the development of CPSP.MethodsKetamine analgesia for long-lasting pain relief after surgery (KALPAS) is a phase 3, multicenter, randomized, placebo-controlled, double-blind trial to study the effectiveness of ketamine in reducing PMPS. The study compares continuous perioperative ketamine infusion vs single-dose ketamine in the postanesthesia care unit vs placebo for reducing PMPS. Participants are followed for 1 year after surgery. The primary outcome is pain at the surgical site at 3 months after the index surgery as assessed with the Brief Pain Inventory-short form pain severity subscale.DiscussionThis project is part of the NIH Helping to End Addiction Long-term (HEAL) Initiative, a nationwide effort to address the opioid public health crisis. This study can substantially impact perioperative pain management and can contribute significantly to combatting the opioid epidemic.Trial registrationClinicalTrials.gov NCT05037123. Registered on September 8, 2021.

Efficacy and safety of perioperative ketamine for the prevention of chronic postsurgical pain: A meta-analysis.

Assessment of the efficacy and safety of perioperative intravenous ketamine in reducing incidence and severity of chronic postsurgical pain. A systematic review and meta-analysis of randomized controlled trials (RCTs). The following data sources were systematically searched: MEDLINE, CENTRAL, and EMBASE (till 02/2021). Adult patients undergoing any surgery. Perioperative use of intravenous ketamine as an additive analgesic drug compared to placebo, no active control treatment, and other additive drugs. Primary outcomes were number of patients with chronic postsurgical pain after 6 months and ketamine related adverse effects. Secondary outcomes were chronic postsurgical pain incidence after 3 and 12 months, chronic postsurgical neuropathic pain incidence, chronic postsurgical moderate to severe pain incidence, intensity of chronic postsurgical pain at rest, and during movement, oral morphine consumption after 3, 6, and 12 months and incidence of opioid-related adverse effects. Thirty-six RCTs were included with a total of 3572 patients. Ketamine compared to placebo may result in no difference in the number of patients with chronic postsurgical pain after 6 months (risk ratio (RR) 0.86, 95% confidence interval (CI) 0.71-1.05; I2 = 34%; 16 studies; low-certainty evidence). Ketamine may reduce the incidence of chronic postsurgical neuropathic pain after 3 months in comparison to placebo (RR 0.78, 95% CI 0.62-0.99, I2 = 31%, seven trials, low-certainty evidence). Ketamine compared to placebo may increase the risk for postoperative nystagmus (RR 9.04, 95% CI 1.15-70.90, I2 30%, two trials, low-certainty evidence) and postoperative visual disturbances (RR 2.29, 95% CI 1.05-4.99, I2 10%, seven trials, low-certainty evidence). There is low-certainty evidence that perioperative ketamine has no effect on chronic postsurgical pain in adult patients. Low-certainty evidence suggests that ketamine compared to placebo may reduce incidence of chronic postsurgical neuropathic pain after 3 months. Questions like ideal dosing, treatment duration and more patient-related outcome measures remain unanswered, which warrants further studies. Prospero CRD42021223625, 07.01.2021.

Efficacy of regional analgesia in prevention of chronic postsurgical pain in children on the PEDSQL General Well-Being Scale and Pediatric Pain Questionnaire

Introduction. In pediatrics, regional anesthesia is one of the most valuable and safest means of perioperative pain management and chronic pain prevention. Pediatric Quality of Life Inventory 3.0 General Well-Being Scale and Pediatric Pain Questionnaire allow for assessing the impact of pain on children and their families via studying changes in Quality of Life scores for the scales of Present Pain and Worst Pain, General Well-Being and General Health. Purpose - to assess the impact of regional analgesia on the prevention of chronic postsurgical pain using PedsQL™ 3.0 questionnaires. Materials and methods. Following the inclusion and exclusion criteria, a total of 80 children were enrolled in the study. Among them, there were 60 children who underwent anterior abdominal wall surgery with various types of anesthetic management and were treated at the surgical department of a Communal Non-Profit Enterprise “Ivano-Frankivsk Regional Children’s Clinical Hospital of Ivano-Frankivsk Regional Council”. All patients were divided into 4 groups. The Group 0, the control group, included 20 children who had no surgical pathology and met inclusion criteria. The Group I comprised 20 children who underwent anterior abdominal wall surgery under general anesthesia using the transversalis fascia plane block combined with the quadratus lumborum block-4 via a single injection. The Group II included 20 children who underwent anterior abdominal wall surgery under general anesthesia using morphine. The Group III comprised 20 children who underwent anterior abdominal wall surgery under general anesthesia using the transversalis fascia plane block. Results. The prevalence of chronic pain syndrome in children who received conventional analgesia was the highest - 19.81±0.21%. Children who underwent conventional analgesia, while staying in the surgical department, had significantly higher the Face, Legs, Activity, Cry, Consolability scale and Visual Analogue Scale scores as compared to those who received other forms of regional analgesia. Discussion. Three and six months after surgery, in patients who received conventional analgesia, quality of life significantly reduced (p<0.001) on the scales of General Well-Being, General Health, Present Pain, and Worst Pain. This shows the need for using effective minimally invasive regional analgesia techniques in the perioperative period. Conclusions. Chronic pain syndrome reduces quality of life in children by reducing their general well-being and general health due to high indicators of present and worst pain. Regional analgesia techniques are a priority for the prevention of chronic pain syndrome. The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of the participating institution. The informed consent of the patient was obtained for conducting the studies. No conflict of interests was declared by the author.

Effectiveness of Communication Strategies in the Management of Chronic Postsurgical Pain: Protocol for a Systematic Review and Meta-Analysis.

To describe the details of a systematic review to assess the current evidence about the efficacy of communication strategies on the prevention of chronic postsurgical pain (CPSP). The protocol for this systematic review was based on the Cochrane Handbook methodology and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P) recommendations. A systematic search of the literature on electronic databases Medline, Embase, Cochrane Library, CINAHL, PsycINFO, and Web of Science (from the inception to 19 June 2022) was carried out using predefined search terms to identify relevant studies. This review will include randomized clinical trials or observational studies. The search strategy consisted of keywords and index terms related to "clinician", "communication" or "post-surgical pain". Inclusion criteria are as follows: randomized clinical trials or observational studies using a parallel group design that assess the efficacy of communication interventions in patients undergoing surgery and that assess pain and pain-related disability. We considered interventions that included any type of written, verbal, and non-verbal communication in combination with other interventions or without. Control groups may include no communication intervention or another intervention distinctly different. We excluded studies with follow-up duration of less than 3 months, patients aged <18 years, and studies for which no reviewer had language proficiency (eg, Chinese, Korean). Descriptive statistics will be used to summarize quantitative findings. Meta-analysis will only be considered if at least three studies used the same outcome with comparable interventions, as we expect a wide heterogeneity of study population and settings. This systematic review and meta-analysis will be an important source for clinicians and researchers to understand the influence of communication to prevent CPSP. This protocol is registered with the International Prospective Register of Systematic Reviews (PROSPERO). Registration number: CRD42021241596.

Can perioperative psychological interventions reduce chronic pain after surgery?

Chronic post-surgical pain is a relatively common adverse effect following surgery. Several prognostic factors for chronic post-surgical pain have been identified, including psychological states and traits. Psychological factors are modifiable, and perioperative psychological interventions may reduce the incidence of chronic post-surgical pain. A meta-analysis showed preliminary evidence for the benefits of such interventions for the prevention of chronic post-surgical pain. Further research must be conducted to better understand the specific type, intensity, duration and timing of interventions that are most effective. The number of studies in this area has recently increased, with additional randomised controlled trials currently being carried out, which may allow for the development of more robust conclusions in the coming years. In order to implement perioperative psychological care alongside routine surgical interventions, efficient and accessible interventions should be available. In addition, demonstration of cost-effectiveness may be a prerequisite for wider adoption of perioperative psychological interventions in regular healthcare. Offering psychological interventions selectively to patients at risk of chronic post-surgical pain could be a means to increase cost-effectiveness. Stepped-care approaches should also be considered, where the intensity of psychological support is adapted to the needs of the patient.

Autobiographical memory predicts postsurgical pain up to 12 months after major surgery.

Recent cross-sectional studies have identified differences in autobiographical memory (AM) among individuals with chronic pain, but the temporal relationship between the 2 is unknown. Moreover, AM has yet to be studied in patients undergoing major surgery. This study addressed these gaps by conducting a prospective, longitudinal study of memory performance, postsurgical pain, and psychosocial factors in 97 adult participants scheduled for major surgery. Memories were evaluated using the Autobiographical Memory Test before and one month after surgery when participants were asked to recall personal events related to positive and pain-related word cues. Responses were coded for level of specificity, emotional valence, and surgery-related content. Questionnaires assessing presence/absence of pain and psychological functioning were administered before and at 1-, 3-, 6-, and 12-month follow-ups. Generalized estimating equations modelled pain at each postsurgical time point with memory variables as predictors. As hypothesized, higher numbers of specific pain memories recalled before surgery predicted lower odds of pain across all time points (OR = 0.58, 95% CI [0.37-0.91]). Participants who took longer to recall pain memories before surgery (OR = 2.65, 95% CI [1.31-5.37]) and those who produced more surgery-related content at the one-month assessment (OR = 1.31, 95% CI [1.02-1.68]) had greater odds of reporting postsurgical pain up to 12 months later. These findings indicate that presurgical AM biases are risk factors for development and maintenance of postsurgical pain. To the extent that these biases are causal, presurgical interventions that modify the quality and content of patients' memories may prove to be promising strategies in the prevention of chronic postsurgical pain.

A Conceptual Framework for Prevention of Chronic Postsurgical Pain

Chronic postsurgical pain is one of the most common adverse events of surgery. The pain characteristics can occur as nociceptive pain and neuropathic pain or mixed, creating long-term suffering for patients. At present, there are no techniques for the prevention of this pain. However, anticipation of this condition must be done based on predictive concepts to control the risk factors, such as careful preoperative assessment, adequate perioperative pain management, adjusting surgical techniques that reduce tissue destruction, psychological support, improving physical function, and a multidisciplinary team working. Moreover, patient care needs to be considered individually in conjunction with formulating a patient care plan for each type of surgery. In particular, the International Association for the Study of Pain and the World Health Organization collaborated by establishing a definition of chronic postoperative pain and implemented it in the International Classification of Disease-11 for guidance in the study of prevalence and clinical symptoms. It will improve the strategy for the prevention and treatment of this condition. Keywords: Prevention; Chronic pain; Persistent; Postsurgical pain

Web- and Mindfulness-Based Intervention to Prevent Chronic Pain After Cardiac Surgery: Protocol for a Pilot Randomized Controlled Trial.

BackgroundCardiac surgery is a frequently performed procedure. However, pain after cardiac surgery may become chronic (lasting >3 months) in adults. Once discharged from the hospital, patients are at greater risk of developing chronic postsurgical pain (CPSP) and of prolonged opioid use, as they need to self-manage their pain. Psychological risk and protective factors such as pain-related catastrophic thoughts and pain acceptance determine their ability to cope and their use of opioids, which is crucial for self-management of pain. Studies on mindfulness-based cognitive therapy (MBCT) have multiplied their potential effects on pain acceptance and catastrophic thoughts. However, web-based MBCT for the prevention of CPSP has not yet been examined.ObjectiveThe aim of this study is to pilot test a 4-week-long web-based MBCT intervention for adults following discharge from the hospital by assessing the acceptability or feasibility of the intervention and examining preliminary effects on pain intensity, pain interference with activities and opioid use, and pain acceptance and catastrophic thoughts in the 6 months following surgery.MethodsA double-blinded pilot randomized controlled trial will be used to assess a web-based MBCT intervention. Patients will be selected according to the following criteria: age ≥18 years; first-time elective cardiac surgery via a median sternotomy; worst pain in the past week score ≥4/10; ability to understand and complete questionnaires in English; and ability to use an electronic device such as a smartphone, computer, or tablet. After baseline measures, 32 participants will be randomized into two groups: one receiving both the brief, 4-week-long web-based MBCT intervention and usual care (experimental group) and the other receiving only one standardized, web-based educational session with weekly reminders and usual care (attention control group). Peer-reviewed competitive funding was received from Florida State University’s Council on Research & Creativity in January 2021, as well as research ethics approval from Florida State University's institutional review board.ResultsRecruitment began in June 2021. Unfortunately, because of the current COVID-19 pandemic, recruitment is not progressing as expected. Recruitment strategies are constantly monitored and updated according to latest data and restrictions surrounding the pandemic.ConclusionsThis research is significant because it targets the trajectory of CPSP, a leading cause of disability and opioid misuse. This is the first study to assess MBCT for the prevention of CPSP after cardiac surgery in the recovery phase. This approach is innovative because it promotes self-management of pain through the modulation of individual factors. If successful, the intervention could be expanded to numerous populations at risk of chronic pain.International Registered Report Identifier (IRRID)DERR1-10.2196/30951

Publication Trends and Hot Spots in Chronic Postsurgical Pain (CPSP) Research: A 10-Year Bibliometric Analysis.

PurposeAging populations and increasing quality of life requirements have attracted growing efforts to study chronic postsurgical pain (CPSP). However, a diverse range of factors are involved in CPSP development, which complicates efforts to predict and treat this disease. To advance research in this field, our study aimed to use bibliometric analysis to quantitatively and qualitatively evaluate CPSP research and predict research hot spots over the last 10 years.MethodsRelevant publications between 2011 and 2020 were extracted from the Web of Science Core Collection database. CiteSpace software (v5.7.R2) and the Online Analysis Platform of Literature Metrology were used to analyze research attributes including countries and authors, keywords and co-occurrence, and burst detection to predict trends and hot spots.ResultsA total of 2493 publications were collected with the number of annual publications showing nearly threefold increase over the past decade. Articles were the primary publication type with the United States as the leading country and the center of national collaboration. Johns Hopkins University provided the leading influence within the CPSP field. Postoperative pain, multimodal analgesia, quality of life, opioid, microglia, cesarean delivery, inguinal hernia, chronification, genetic polymorphism, and lidocaine were the top 10 clusters in co-occurrence cluster analysis. Moreover, burst detection was shown that epidural analgesia, nerve injury, total hip arthroplasty were the new hot spots within the CPSP field.ConclusionBibliometric mapping not only defined the overall structure of CPSP-related research but its collective information provides crucial assistance to direct ongoing research efforts. The prominent keywords including ”risk factor” and “multimodal analgesia” indicate that CPSP prevention and new treatment methods remain hot spots. Nonetheless, the recognition that CPSP is complex and changeable, proposes comprehensive biopsychosocial approaches are needed, and these will be essential to improve CPSP interventions and outcomes.

Effects of magnesium sulfate administration in attenuating chronic postsurgical pain in rats

Chronic postsurgical pain (CPSP) is a serious issue for many postoperative patients. Though there are numerous treatment options for the prevention of CPSP, none of them is optimal as the mechanisms of the transition from acute to chronic postoperative pain have not been elucidated. Ketamine and opioids have been administered for chronic postoperative pain treatment but induce severe adverse reactions and/or physical dependency.Here, we examined whether pre-administration of the nonselective N-methyl-d-aspartate (NMDA) receptor antagonist magnesium sulfate attenuates CPSP behavior and alters the expression of glutamate ionotropic receptor NMDA type subunit 1a (Grin1 mRNA) in a rat skin/muscle incision and retraction (SMIR) model. We assessed the effects of a single subcutaneous magnesium sulfate injection on nociceptive behaviors including guarding pain, mechanical hyperalgesia, and heat hypersensitivity in rats after SMIR surgery. We used reverse transcription-quantitative PCR (RT-qPCR) to evaluate Grin1 mRNA expression in the dorsal horn of the spinal cord on postoperative day 14. Compared with the vehicle, magnesium sulfate administration before SMIR surgery reduced mechanical hyperalgesia for 17 d Grin1 gene expression was significantly higher on the ipsilateral side than the contralateral side (P = 0.001) on postoperative day 14. The magnesium sulfate injection prevented Grin1 mRNA upregulation in the spinal cord dorsal horn. A single magnesium sulfate injection mitigated SMIR-induced mechanical hyperalgesia possibly by modulating Grin1 expression. Preoperative magnesium sulfate administration could prove to be a simple and safe CPSP treatment.

Barriers and Facilitators to the Prevention of Chronic Pain in the Subacute Phase After Cardiac Surgery

BackgroundAlthough a transitional approach promoting continuity of care is warranted to prevent chronic post-surgical pain (CPSP) and opioid misuse, there is limited research examining interventions targeting the subacute phase after cardiac surgery. Contextual multi-level factors may explain this scarcity. AimsThe purpose of this study was to explore the potential implementation of a nursing intervention to prevent CPSP in the subacute phase by describing nurses' viewpoints of current barriers and facilitators. DesignA descriptive qualitative study was conducted using secondary data analysis. SettingsA Web-based survey was used along with in-person interviews. Participants: 75 perioperative nurses. MethodsQualitative data from individual interviews (n=10) and open-ended responses to a survey (n=65) regarding the intervention's acceptability were used. Content analysis was conducted using a deductive approach. ResultsThe introduction of nurses from various clinical settings to a new intervention allowed reflection on current practice and represented a shift toward a preventive approach. The main barrier expressed was the lack of communication and continuity of care between clinical settings. Several policy implications were outlined such as increasing the involvement of rehabilitation programs and strengthening collaboration between pain specialists and primary care providers. ConclusionsBased on perceptions of nurses involved at different stages of the continuum, the findings provide a preliminary picture of clinical challenges and potential avenues for the prevention of CPSP in the subacute phase after cardiac surgery. An expanded pain management nursing role in primary care would allow earlier interventions and contribute to the prevention of CPSP for a tremendous number of patients undergoing surgeries.

Effects of nicorandil on p120 expression in the spinal cord and dorsal root ganglion of rats with chronic postsurgical pain.

Chronic postsurgical pain (CPSP) has a high incidence, but the underlying mechanism is not well understood. Accumulating evidence has suggested that central sensitization is the main mechanism of pain. To study the role of p120 in CPSP, a skin/muscle incision and retraction (SMIR) model was established, and immunofluorescence staining and western blotting were performed to analyze the expression of p120 in the spinal cord and dorsal root ganglion (DRG). The results demonstrated that SMIR increased the expression of p120 in the DRG and the spinal cord compared with the naive group. Furthermore, it was demonstrated that p120 was mainly distributed in the glial fibrillary acidic protein-positive astrocytes in the spinal cord, and in the neurofilament 200-positive medium and large neurons in the DRG. Our previous studies have shown that adenosine triphosphate-sensitive potassium channel (KATP) agonists can reduce postoperative pain in rats. Therefore, the changes in p120 were observed in the DRG and spinal cord of rats following the intraperitoneal injection of nicorandil, a KATP agonist. It was demonstrated that nicorandil administration could relieve mechanical pain experienced following SMIR in rats, and decrease the expression of p120 in the DRG and spinal cord. The results revealed that p120 may contribute to the prophylactic analgesic effect of nicorandil, thus providing a novel insight into the mechanism of CPSP prevention.

Comparative Efficacy of Pharmacologic Interventions for the Prevention of Chronic Postsurgical Pain. A Systematic Review and Network Meta-Analysis

Comparative Efficacy of Pharmacologic Interventions for the Prevention of Chronic Postsurgical Pain. A Systematic Review and Network Meta-Analysis

A survey of perioperative intravenous lidocaine use by anaesthetists in Australia and New Zealand.

Perioperative intravenous lidocaine administration by anaesthetists is purported to confer a variety of benefits across a range of surgical procedures. It remains unclear whether the available evidence regarding efficacy and safety is sufficient to influence Australasian practice broadly, and whether significant barriers to uptake exist. We therefore conducted a survey of Fellows of the Australian and New Zealand College of Anaesthetists to evaluate patterns of lidocaine use, and perceptions relating to benefit and safety. Of 979 survey invitations, 295 (30.1%) responded. Of these, 51.9% of anaesthetists incorporate lidocaine administration into their practice. Amongst users, the most common indication is open abdominal or pelvic surgery (88.9%), with the principal intent of reducing acute pain and opioid use (both 92.2%). Only 51% perceive lidocaine to have a role in the prevention of chronic post-surgical pain, and less than a third administer it for operations strongly linked to this condition. Nearly all (91%) users deliver the drug by intraoperative bolus and infusion, with the majority using doses between 1.0 and 1.5 mg/kg for both the bolus and the hourly infusion rate. When parallel local anaesthetic techniques are employed, 44.4% restrict the dose, 37.3% turn the lidocaine infusion off first and 15.7% make no modifications. Most respondents terminate infusions by the end of surgery (52.3%) or in the post-anaesthesia care unit (26.8%). Few deliver postoperative infusions without electrocardiographic monitoring (5.9%). There were no reports of life-threatening events. The dichotomy in Australasian use of perioperative lidocaine revealed by this survey confirms that large multicentre trials are now required to guide practice accurately.

Influence of volatile anesthesia versus total intravenous anesthesia on chronic postsurgical pain after cardiac surgery using the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials criteria: study protocol for a prospective randomized controlled trial

BackgroundMany patients develop chronic postsurgical pain (CPSP) after cardiac surgery, which interferes with their sleep, mood, and quality of life. Studies have suggested that propofol improves postoperative analgesia compared with volatile anesthetics, but its preventive effect on CPSP following cardiac surgery is still unknown. This study compares the incidence of CPSP following cardiac surgery for those receiving volatile anesthesia and those receiving propofol-based total intravenous anesthesia (TIVA) using criteria recommended by the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT).Methods/designThis is a prospective randomized controlled trial. In total, 500 adults undergoing cardiac surgery will be randomly allocated to the volatile or the TIVA group. The volatile group will receive sevoflurane or desflurane during surgery as general anesthesia. The TIVA group will receive propofol-based intravenous agents and no volatile agents during surgery. The primary outcomes will be the frequency of CPSP at 3 months, 6 months, and 1 year after surgery. In this case, CPSP is sternal or thoracic pain. It is defined as either (1) numerical rating scale (NRS) > 0 or (2) meeting all six IMMPACT criteria for CPSP. The IMMPACT criteria are validated pain instruments.DiscussionTo our knowledge, this is the first prospective randomized controlled trial to investigate the prevention of CPSP following cardiac surgery for patients receiving volatile anesthesia compared to those receiving propofol-based TIVA using validated pain instruments in accordance with the IMMPACT recommendations. This study will provide important information on which of these two anesthetic regimens is better for preventing CPSP after cardiac surgery.Trial registrationChictr.org.cn, ChiCTR1900020747. Registered on 16 January 2019.

The role of gabapentinoids in acute and chronic pain after surgery.

Gabapentinoid use has increased substantially in the past several years after initial promising data with regard to acute perioperative pain control. The purpose of this review is to critically appraise the evidence for the use of gabapentinoids for acute pain management and its impact on the development of chronic pain after surgery. Recent meta-analyses have revealed that prior data likely have overestimated the beneficial effects of gabapentinoids in acute perioperative pain while underestimating the associated adverse effects. The utility of gabapentinoids in the setting of enhanced recovery pathways and for the prevention of chronic postsurgical pain is still unclear. Moreover, there has been increasing concern regarding the potential for misuse and abuse of gabapentinoids. Current evidence does not support the routine use of gabapentinoids as part of a multimodal analgesic regimen in enhanced recovery pathways. We recommend being selective with regard to using gabapentinoids for acute postoperative pain management after careful consideration of the potential side effect profile based on patient comorbidities as well as the expected severity of postoperative pain. Large, high-quality trials are needed to identify the impact of gabapentinoids in the context of multimodal anagelsia.

Transition from Acute to Chronic Pain: Evaluating Risk for Chronic Postsurgical Pain

Background: The pathophysiology of pain involves complex nervous system interactions after initial noxious stimuli. When stimuli persist, biochemical and structural changes occur in the nociceptive pathways of the central and peripheral nervous systems, leading to pain sensitization. Peripheral and central sensitization are key in the transition from acute to chronic pain. This development of chronic pain is particularly common following various surgical procedures, with many postsurgical patients experiencing persistent pain for significant periods. Chronic pain is a common and severe complication of surgery, and preventing its development is tantamount in improving patient outcomes. Objectives: To understand underlying pathophysiology of chronic postsurgical pain (CPSP) and the underlying risk factors predisposing the transition from acute to CPSP. To review our ability to identify patients at highest risk for the development CPSP. To identify evidence-based multimodal approaches that can aid in the prevention of CPSP. Study Design: Narrative review of peer-reviewed literature. Setting: Inpatient surgical centers. Methods: Medline and Cochrane databases were reviewed to identify publications relevant to CPSP pathophysiology, risk factors, predictive models, and prevention. Publications were selected based on author expertise to summarize our current understanding of CPSP. Results: This review presents our current understanding of CPSP in the following domains: underlying pathophysiology, predisposing risk factors, predictive models of CPSP, and preventative strategies. Each section provides a structured review of key evidence base to understand the complex topic of CPSP. Limitations: This narrative review is a nonsystematic review of relevant publications aimed at presenting succinct overview of CPSP. Conclusions: The incidence of CPSP can potentially be reduced through early identification of perioperative, genetic, physiologic, and psychologic factors. Models predicting the development of CPSP continue to improve and may help focus preventative efforts in patients at highest risk. There is a growing body of evidence supporting the use of multimodal analgesia and anesthetic techniques in the reducing rates of CPSP development. Key words: Acute pain, chronic postsurgical pain, pain sensitization, chronic pain prevention, regional anesthesia, pain adjuncts, neuraxial anesthesia, chronic pain risk factors

Should thoracic paravertebral blocks be used to prevent chronic postsurgical pain after breast cancer surgery? A systematic analysis of evidence in light of IMMPACT recommendations.

The role of thoracic paravertebral block (PVB) in preventing chronic postsurgical pain (CPSP) after breast cancer surgery (BCS) has gained interest, but existing evidence is conflicting, and its methodological quality is unclear. This meta-analysis evaluates efficacy of PVB, compared with Control group, in preventing CPSP after BCS, in light of the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) recommendations. Electronic databases were searched for randomized trials comparing PVB with Control group for CPSP prevention after BCS. Eligible trials were assessed for adherence to IMMPACT recommendations. The primary outcomes were CPSP at 3 and 6 months, whereas secondary outcomes were PVB-related complications. Data were pooled and analyzed using random-effects modelling. Trial sequential analysis was used to evaluate evidence conclusiveness. Data from 9 studies (604 patients) were analyzed. The median (range) of IMMPACT recommendations met in these trials was 9 (5, 15) of 21. Paravertebral block was not different from Control group in preventing CPSP at 3 months, but was protective at 6 months, with relative risk reduction (95% confidence interval) of 54% (0.24-0.88) (P = 0.02). Meta-regression suggested that the relative risk of CPSP was lower when single-injection (R = 1.00, P < 0.001) and multilevel (R = 0.71, P = 0.01) PVB were used. Trial sequential analysis revealed that 6-month analysis was underpowered by at least 312 patients. Evidence quality was moderate according to the GRADE system. Evidence suggests that multilevel single-injection PVB may be protective against CPSP at 6 months after BCS, but methodological limitations are present. Larger trials observing IMMPACT recommendations are needed to confirm this treatment effect and its magnitude.

Acceptance and Commitment Therapy for Prevention of Chronic Postsurgical Pain and Opioid Use in At-Risk Veterans: A Pilot Randomized Controlled Study

High levels of pain, significant anxiety, or depressive symptoms before surgery put patients at elevated risk for chronic pain and prolonged opioid use following surgery. The purpose of this preliminary study was to assess the efficacy of a 1-day Acceptance and Commitment Therapy (ACT) workshop in “at-risk” veterans for the prevention of chronic pain and opioid use following orthopedic surgery. In a randomized controlled trial, 88 at-risk veterans undergoing orthopedic surgery were assigned to treatment as usual (TAU; n = 44) or TAU plus a 1-day ACT workshop (n = 44). Pain levels and opioid use were assessed up to 3 months following surgery. Pain acceptance and values-based behavior were assessed at baseline and 3-month follow-up. Participants who completed the ACT workshop reached pain and opioid cessation sooner than those in TAU. Postoperative complications exhibited a moderating effect on these outcomes, such that the effects of ACT were greater in patients without complications. Increases in pain acceptance and values-based behavior, processes targeted in ACT, were related to better outcomes. These promising results merit further investigation in a larger clinical trial. Providing an intervention before surgery for at-risk veterans has the potential to change clinical practice from a focus on management of postoperative pain to prevention of chronic pain in at-risk individuals. PerspectiveThis pilot study compared the effects of a 1-day preventive behavioral intervention (ACT) to TAU in at-risk veterans undergoing orthopedic surgery. Three months following the intervention, veterans receiving ACT exhibited quicker cessation of pain and opioid use. Focusing on preoperative pain management may help prevent chronic postsurgical pain.