Analysis of risk factors and development of a predictive nomogram for chronic postsurgical pain after hip arthroplasty: a study protocol in a Chinese tertiary hospital.

SP35 Transitional pain and prevention of pain chronification

Lacking preoperative chronic postsurgical pain (CPSP) risk factors that cover all surgical modalities, are based on large-scale databases, and are free from patients' subjective elements and compliance. This study utilized the UK Biobank, whose baseline assessment was conducted between 2006 and 2010. It centered on participants who responded to the CPSP questionnaire during January to February 2019. In conjunction with previous reviews, 67 potential risk factors were identified and categorized into 10 domains. The Cox proportional hazards regression model was employed to analyze the relationships between these factors and CPSP. Finally, interaction and sensitivity analyses were performed to mitigate biases arising from potential reverse causalities among the risk factors, as well as the matching of the operation time with the CPSP occurrence time and data imputation. Of 125939 included participants with 74046 (58.8%) women and 56.8years mean age at baseline, 3609 incident CPSP cases were observed. After stepwise Cox regression, 21 factors were significantly associated with a higher CPSP risk. Among them, 15 factors demonstrated a significant association with increased CPSP risk ( P < 0.001). These factors include older age, obesity, lower educational attainment, lower income, a higher surgery times before baseline, elevated polygenic risk score, insufficient sleep, smoking, longer time spent outdoors in summer or winter, maternal smoking around birth, chronic condition or disability, regular analgesic use, and elevated cystatin C and gamma-glutamyltransferase. Additionally, high-sodium diets, higher mismatched count, hypertension, and related hematological indicators such as increased mean corpuscular hemoglobin concentration, red blood cell distribution width (RDW), and monocyte count were also found to significantly elevate the risk of CPSP ( P < 0.05). Our findings contribute to a more comprehensive understanding of CPSP risk factors and pathogenesis, which hold significant implications for developing targeted preventive strategies, optimizing perioperative pain management, and improving the allocation of healthcare resources.

Potential role for immune cell signatures as predictors of acute and chronic pain in adolescents post major musculoskeletal surgery.

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

IntroductionPatients with either surgery-related or patient-related risk factors are at an increased risk of acute and chronic postsurgical pain (CPSP) and long-term opioid use. To improve recovery, prevent CPSP and...

Poster #T19 ANIMAL MODELS OF SCHIZOPHRENIA SYMPTOMS: POLYDIPSIA FOLLOWING SUBCHRONIC MK-801 POST-WEANING SOCIAL ISOLATION OR AMPHETAMINE SENSITIZATION IN RATS

Pediatric Pain Screening Tool: A Simple 9-Item Questionnaire Predicts Functional and Chronic Postsurgical Pain Outcomes After Major Musculoskeletal Surgeries

The purpose of this study was to evaluate the association between single-nucleotide polymorphisms and chronic postsurgical pain. Using GoldenGate genotyping assays, we genotyped 638 polymorphisms within 54 pain-related genes in 1,152 surgical patients who were enrolled in our Persistent Pain after Surgery Study. Patients were contacted by phone to determine whether they had chronic postsurgical pain at 12 months. Polymorphisms identified were validated in a matched cohort of 103 patients with chronic postsurgical pain and 103 patients who were pain free. The functions of targeted polymorphisms were tested in an experimental plantar incisional nociception model using knock-in mice. At 12 months after surgery, 246 (21.4%) patients reported chronic postsurgical pain. Forty-two polymorphisms were found to be associated with chronic postsurgical pain, 19 decreased the risk of pain, and 23 increased the risk of pain. Patients carrying allele A of rs6265 polymorphism in brain-derived neurotrophic factor (BDNF) had a lower risk of chronic postsurgical pain in the discovery and validation cohorts, with an adjusted odds ratio (95% CI) of 0.62 (0.43 to 0.90) and 0.57 (0.39 to 0.85), respectively. Age less than 65 yr, male sex, and prior history of pain syndrome were associated with an increased risk of pain. Genetic polymorphisms had higher population attributable risk (7.36 to 11.7%) compared with clinical risk factors (2.90 to 5.93%). Importantly, rs6265 is a substitution of valine by methionine at amino acid residue 66 (Val66Met) and was associated with less mechanical allodynia in BDNF mice compared with BDNF group after plantar incision. This study demonstrated that genetic variant of BDNF rs6265G>A is associated with decreased risk of chronic postsurgical pain.

Chronic postsurgical pain (CPSP) has been linked to many surgical settings. The authors aimed to analyze functional genetic polymorphisms and clinical factors that might identify CPSP risk after inguinal hernia repair, hysterectomy, and thoracotomy. This prospective multicenter cohort study enrolled 2,929 patients scheduled for inguinal hernia repair, hysterectomy (vaginal or abdominal), or thoracotomy. The main outcome was the incidence of CPSP confirmed by physical examination 4 months after surgery. The secondary outcome was CPSP incidences at 12 and 24 months. The authors also tested the associations between CPSP and 90 genetic markers plus a series of clinical factors and built a CPSP risk model. Within a median of 4.4 months, CPSP had developed in 527 patients (18.0%), in 13.6% after hernia repair, 11.8% after vaginal hysterectomy, 25.1% after abdominal hysterectomy, and 37.6% after thoracotomy. CPSP persisted after a median of 14.6 months and 26.3 months in 6.2% and 4.1%, respectively, after hernia repair, 4.1% and 2.2% after vaginal hysterectomy, 9.9% and 6.7% after abdominal hysterectomy, and 19.1% and 13.2% after thoracotomy. No significant genetic differences between cases and controls were identified. The risk model included six clinical predictors: (1) surgical procedure, (2) age, (3) physical health (Short Form Health Survey-12), (4) mental health (Short Form Health Survey-12), (5) preoperative pain in the surgical field, and (6) preoperative pain in another area. Discrimination was moderate (c-statistic, 0.731; 95% CI, 0.705 to 0.755). Until unequivocal genetic predictors of CPSP are understood, the authors encourage systematic use of clinical factors for predicting and managing CPSP risk.

BackgroundA significant portion of total knee and hip arthroplasty (TKA/THA) patients experience chronic postsurgical pain (CPSP). The prevalence of afflicted individuals ranges from 10 to 34%. CPSP is the main cause of postoperative dissatisfaction. For prevention purposes it is essential to know which preoperative factors are predictive for CPSP. It is unknown whether neuropathic-like symptoms add predictive value to known predictors for CPSP and dissatisfaction after TKA/THA.MethodsA prospective cohort study including 453 TKA/THA patients (TKA 208, THA 245) was conducted. Pain intensity (numeric rating scale [NRS]) and neuropathic-like symptoms (modified-painDETECT questionnaire [mPDQ]; score ≥ 13) were obtained preoperatively. One year postoperatively, CPSP and dissatisfaction (single NRS item (0–10); dissatisfied: ≤ 5) were captured: CPSP by means of the Oxford Knee/Hip Score (moderate or severe pain on question 1) as well by pain intensity at rest and with movement (NRS ≥ 1). Multivariate logistic regression modeling was used to determine the additive predictive value of preoperative neuropathic-like symptoms (mPDQ ≥ 13) on experiencing CPSP and dissatisfaction for the total group and for knee and hip patients separately.ResultsPreoperative neuropathic-like symptoms (m-PDQ ≥ 13) had an additional value for experiencing CPSP after one year, with odds ratios (p < 0.05) ranging from 2.16 (total group) to 4.15 (hip patients). Neuropathic-like symptoms had no additional value for predicting CPSP in knee patients or for predicting dissatisfaction.ConclusionThe results of this study showed that neuropathic-like symptoms (m-PDQ ≥ 13) have an additional predictive value over known predictors, especially in hip patients. Patients with neuropathic-like symptoms have over twice the odds of suffering from CPSP one year after TKA/THA. Neuropathic-like symptoms had no additional value for predicting dissatisfaction.

Data on chronic postsurgical pain (CPSP) after otorhinolaryngological surgery are sparse. Adult in-patients treated in 2017 were included into the prospective PAIN OUT registry. Patients’ pain on the first postoperative day (D1), after six months (M6) and 12 months (M12) were evaluated. Determining factor for CPSP was an average pain intensity ≥ 3 (numeric rating scale 0–10) at M6. Risk factors associated with CPSP were evaluated by univariate and multivariate analyses. 10% of 191 included patients (60% male, median age: 52 years; maximal pain at D1: 3.5 ± 2.7), had CPSP. Average pain at M6 was 0.1 ± 0.5 for patients without CPSP and 4.2 ± 1.2 with CPSP. Average pain with CPSP still was 3.7 ± 1.1 at M12. Higher ASA status (Odds ratio [OR] = 4.052; 95% confidence interval [CI] = 1.453–11.189; p = 0.007), and higher minimal pain at D1 (OR = 1.721; CI = 1.189–2.492; p = 0.004) were independent predictors of CPSP at M6. Minimal pain at D1 (OR = 1.443; CI = 1.008–2.064; p = 0.045) and maximal pain at M6 (OR = 1.665; CI = 1.340–2.069; p < 0.001) were independent predictors for CPSP at M12. CPSP is an important issue after otorhinolaryngological surgery. Better instrument for perioperative assessment should be defined to identify patients at risk for CPSP.

Background:Chronic post-surgical pain (CPSP) brings health and financial burdens to patients and impairs quality of life after surgery. Smoking as a lifestyle factor plays an important role in management of chronic pain and its subtypes (e.g., CPSP). However, the impact of smoking on CPSP has not been fully elucidated due to limitations in smoking classification and the lack of secondhand smoke (SHS) exposure in previous studies. Therefore, this study aimed to comprehensively evaluate the association of current smoking and SHS exposure with the risk of CPSP.Materials and methods:We conducted a cohort study using UK Biobank participants who underwent surgery between 2006–2010 and 2019–2020. Participants were categorized into non-current smokers without SHS exposure, non-current smokers with SHS exposure, and current smokers. We used logistic regression models to assess the association of current smoking and SHS exposure with the risk of CPSP reporting odds ratios with 95% confidence intervals. Subgroup analyses stratified by sociodemographic variables (sex, ethnicity, education, and deprivation) were conducted.Results:Of 97,821 participants, with a mean ± SD age of 56.5 ± 7.6 years, 3,509 (3.6%) reported CPSP. The risk of CPSP was significantly increased in non-current smokers with SHS exposure (4.6%, 1.30 [1.19–1.41]) and current smokers (4.8%, 1.37 [1.22–1.55]), compared with non-current smokers without SHS exposure (3.2%). The tendency for smoking to increase the risk of CPSP existed across all sociodemographic subgroups (e.g., males: 1.18 [1.04–1.35] in non-current smokers with SHS exposure and 1.35 [1.13 to 1.60] in current smokers; females: 1.39 [1.24–1.56] in non-current smokers with SHS exposure and 1.38 [1.16–1.64] in current smokers).Conclusion:SHS exposure may be as detrimental to the development of CPSP as being a current smoker.

Psychological factors, such as anxiety, depression, and catastrophizing, may increase the risk of chronic postsurgical pain (CPSP) following Cesarean delivery (CD). We sought to evaluate whether postpartum depression (PPD) after CD is associated with CPSP and assess the potential mediating effect of PPD on the relationship between acute severe postoperative pain and CPSP. We conducted a secondary analysis of a previous randomized trial. In the original trial, 290 patients undergoing CD in Nepal were randomized to receive either 100µg of intrathecal morphine or normal saline in addition to their spinal anesthesia with the goal to investigate the relationship between intrathecal morphine use and CPSP development. Eight weeks after CD, we used the Edinburgh Postnatal Depression Scale to identify patients with a provisional diagnosis of PPD (scores ≥ 12). The study outcomes were the occurrence of CPSP at three and six months. Out of 276 patients analyzed, 20 (7%) experienced PPD. The incidences of CPSP at three and six months were 18% (52/276) and 15% (42/276), respectively. A multivariable model revealed that the odds of experiencing CPSP at three months postpartum were significantly higher in patients with depression (odds ratio [OR], 4.24; 95% confidence interval [CI], 1.53 to 11.7; P = 0.005) than in those without depression. Similarly, PPD was independently associated with an increased incidence of CPSP at six months post CD (OR, 4.05; 95% CI, 1.42 to 11.5; P = 0.009). Causal mediation analysis showed no mediating effect of PPD between acute severe postoperative pain and CPSP. In this secondary analysis of a previous randomized trial, we found a significant association between PPD and CPSP following CD.

Chronic postsurgical pain (CPSP) after cardiac surgery represents a significant clinical problem. The prevalence of CPSP varies widely between studies, but severe CPSP is present in less than 10% of the patients. Important differential diagnoses for CPSP after cardiac surgery are myocardial ischemia, sternal instability and mediastinitis. CPSP after cardiac surgery may be thoracic pain present at the site of the sternotomy or leg pain due to vein-graft harvesting. The CPSP can be neuropathic pain, visceral pain, somatic pain or mixed pain. Potential risk factors for CPSP are young age, female gender, overweight, psychological factors, preoperative pain, surgery-related factors and severe postoperative pain. In addition to standard postoperative analgesics, the use of N-methyl-D-aspartate (NMDA) antagonists, alpha-2 agonists, local anesthetics, gabapentinoids, and corticosteroids are all proposed to reduce the risk for CPSP after cardiac surgery. Still, no specific pharmacological therapy, cognitive therapy or physical therapy is established to protect against CPSP. The only convincing prevention of CSPS is adequate treatment of acute postoperative pain irrespective of method. Hence, interventions against acute pain, preferably in a step-wise approach titrating the interventions for each patient's individual needs, are essential concerning prevention of CPSP after cardiac surgery. It is also important that surgeons consider the risk for CPSP as a part of the basis for decision-making around performing a surgical procedure and that patients are informed of this risk.

Chronic post-surgical pain is known to be a common complication of thoracic surgery and has been associated with a lower quality of life, increased healthcare utilisation, substantial direct and indirect costs, and increased long-term use of opioids. This systematic review with meta-analysis aimed to identify and summarise the evidence of all prognostic factors for chronic post-surgical pain after lung and pleural surgery. Electronic databases were searched for retrospective and prospective observational studies as well as randomised controlled trials that included patients undergoing lung or pleural surgery and reported on prognostic factors for chronic post-surgical pain. We included 56 studies resulting in 45 identified prognostic factors, of which 16 were pooled with a meta-analysis. Prognostic factors that increased chronic post-surgical pain risk were as follows: higher postoperative pain intensity (day 1, 0-10 score), mean difference (95%CI) 1.29 (0.62-1.95), p < 0.001; pre-operative pain, odds ratio (95%CI) 2.86 (1.94-4.21), p < 0.001; and longer surgery duration (in minutes), mean difference (95%CI) 12.07 (4.99-19.16), p < 0.001. Prognostic factors that decreased chronic post-surgical pain risk were as follows: intercostal nerve block, odds ratio (95%CI) 0.76 (0.61-0.95) p=0.018 and video-assisted thoracic surgery, 0.54 (0.43-0.66) p < 0.001. Trial sequential analysis was used to adjust for type 1 and type 2 errors of statistical analysis and confirmed adequate power for these prognostic factors. In contrast to other studies, we found that age had no significant effect on chronic post-surgical pain and there was not enough evidence to conclude on sex. Meta-regression did not reveal significant effects of any of the study covariates on the prognostic factors with a significant effect on chronic post-surgical pain. Expressed as grading of recommendations, assessment, development and evaluations criteria, the certainty of evidence was high for pre-operative pain and video-assisted thoracic surgery, moderate for intercostal nerve block and surgery duration and low for postoperative pain intensity. We thus identified actionable factors which can be addressed to attempt to reduce the risk of chronic post-surgical pain after lung surgery.