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

SP35 Transitional pain and prevention of pain chronification

The frequency of caesarean section has increased dramatically in recent decades. Despite this, robust data regarding the consequences of caesarean section in terms of developing chronic postsurgical pain (CPSP) are still lacking. This systematic review analysed the incidence and severity of CPSP in women 3 to less than 6, 6 to less than 12, and at least 12 months after caesarean section. Systematic review of prospective and retrospective observational studies and randomised controlled trials with meta-analysis. We searched MEDLINE to May 2015. We included all studies investigating the incidence and/or severity of CPSP at least 3 months after caesarean section. The primary outcome was chronic postsurgical wound pain (CPSP 'wound'). Secondary outcomes were persistent pain in the back area, pelvic region or reported as residual pain, and severity of 'birth-related' chronic pain. Meta-analysis using the random-effects model based on 15 studies (n = 4475) reporting CPSP 'wound' at 3 to less than 6 months after caesarean section revealed an incidence of 15.4% [95% confidence interval (CI): 9.9 to 20.9%]. For 6 to less than 12 and at least 12 months after caesarean section, the incidence of CPSP 'wound' was estimated at 11.5% (95% CI: 8.1 to 15.0%, n = 3345) and 11.2% (95% CI: 7.4 to 15.0%, n = 3451), respectively. Meta-regression analysis using the publication year as predictor revealed stable CPSP 'wound' incidences at each postoperative time slot from 2002 to the present. Of those patients who reported chronic pain, 9.6% (95% CI: 0.0 to 21.0%) had severe pain, 23.5% (95% CI: 10.0 to 37.0%) had moderate pain and 49.2% (95% CI: 18.9 to 79.4%) had mild pain at 6 months. Major limitations are high statistical heterogeneity of the meta-analyses and inconsistencies in reporting severity of chronic 'birth-related' pain. This meta-analysis finds a clinically relevant incidence of CPSP 'wound' after caesarean section ranging from 15% at 3 months to 11% at 12 months or longer that has been largely stable in recent years.

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.

The efficacy of perioperative pregabalin treatment for preventing chronic pain remains a matter of debate. We searched the MEDLINE, EMBASE, LILACS, Cochrane, and Clinical Trial Register databases, and other sources, for randomized controlled trials comparing the effects of pregabalin and placebo. The primary outcome was the incidence of chronic postsurgical pain (CPSP) at 3 months. The secondary endpoints were CPSP at 3, 6, and 12 months and the incidence of chronic postsurgical neuropathic pain at the same time points. A random-effect meta-analysis was performed on the combined data. Evidence quality was rated by the GRADE method. We included 18 studies (2485 patients) in the meta-analysis. Overall, 60% of the trials reporting the primary outcome at 3 months were unpublished; the unpublished trials corresponded to 1492/1884 (79%) of the patients included in these studies. No difference in CPSP incidence between pregabalin and placebo was found at any time point; the risk ratio was 0.87 (0.66, 1.14), I = 57% at 3 months. The evidence was considered to be of moderate quality. Subgroup analysis by publication status, daily dose, type of administration, and type of surgery did not highlight any differences between subgroups. Insufficient data concerning the incidence of chronic postsurgical neuropathic pain were available for any firm recommendation to be made. Pooled data from published and unpublished studies provide no support for the efficacy of pregabalin for preventing CPSP.

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

Does Immediate Long-Span Nerve Allograft Reconstruction Affect the Incidence of Chronic Postsurgical and Neuropathic Pain in the Reconstructed Mandible Following Resection for Benign and Malignant Disease

Incidence, Severity, and Interference of Chronic Postsurgical Pain After Cesarean Delivery: A Systematic Review and Meta-analysis.

BackgroundDue 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.MethodsElderly 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).ResultsA 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.ConclusionsCPSP 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.

Pain ManagementVol. 8, No. 5 EditorialAcute neuropathic pain and the transition to chronic postsurgical painAlexander SchnabelAlexander Schnabel*Author for correspondence: Tel.: 0049-251-830; E-mail Address: alexander.schnabel@ukmuenster.de Department of Anesthesiology, Intensive Care and Pain Medicine, University Hospital of Muenster, Albert-Schweitzer Campus 1A, 48149 Muenster, Germany Department of Anaesthesiology, University Hospital of Wuerzburg, Oberdürrbacherstr. 6, 97080 Würzburg, GermanySearch for more papers by this authorPublished Online:3 Oct 2018https://doi.org/10.2217/pmt-2018-0026AboutSectionsView ArticleView Full TextPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareShare onFacebookTwitterLinkedInReddit View articleReferences1 Johansen A, Romundstad L, Nielsen CS, Schirmer H, Stubhaug A. Persistent postsurgical pain in a general population: prevalence and predictors in the Tromsøstudy. Pain 153(7), 1390–1396 (2012).Crossref, Medline, Google Scholar2 Dualé C, Ouchchane L, Schoeffler P, Dubray C; EDONIS Investigating Group. Neuropathic aspects of persistent postsurgical pain: a French multicenter survey with a 6-month prospective follow-up. J. Pain 15(1), 24.e1–24.e20 (2014).Crossref, Google Scholar3 Beloeil H, Sion B, Rousseau C et al.; SFAR Research Network. Early postoperative neuropathic pain assessed by the DN4 score predicts an increased risk of persistent postsurgical neuropathic pain. Eur. J. Anaesthesiol. 34(10), 652–657 (2017).Crossref, Medline, Google Scholar4 Fletcher D, Stamer UM, Pogatzki-Zahn E et al. euCPSP group for the Clinical Trial Network group of the European Society of Anaesthesiology. Chronic postsurgical pain in Europe: an observational study. Eur. J. Anaesthesiol. 32(10), 725–734 (2015).Crossref, Medline, Google Scholar5 Martinez V, Ben Ammar S, Judet T, Bouhassira D, Chauvin M, Fletcher D. Risk factors predictive of chronic postsurgical neuropathic pain: the value of the iliac crest bone harvest model. Pain 153(7), 1478–1483 (2012).Crossref, Medline, Google Scholar6 Searle RD, Simpson MP, Simpson KH, Milton R, Bennett MI. Can chronic neuropathic pain following thoracic surgery be predicted during the postoperative period? Interact. Cardiovasc. Thorac. Surg. 9(6), 999–1002 (2009).Crossref, Medline, Google Scholar7 Schug SA, Palmer GM, Scott DA, Halliwell R, Trinca J. Acute pain management: scientific evidence, fourth edition, 2015. Med. J. Aust. 204(8), 315–317 (2016).Crossref, Medline, Google Scholar8 Searle RD1, Howell SJ, Bennett MI. Diagnosing postoperative neuropathic pain: a Delphi survey. Br. J. Anaesth. 109(2), 240–244 (2012).Crossref, Medline, CAS, Google Scholar9 Hayes C, Browne S, Lantry G, Burstal R. Neuropathic pain in the acute pain service: a prospective survey. Acute Pain 4, 45–48 (2002).Crossref, Google Scholar10 Martinez V, Üçeyler N, Ben Ammar S et al. Clinical, histological, and biochemical predictors of postsurgical neuropathic pain. Pain 156(11), 2390–2398 (2015).Crossref, Medline, CAS, Google Scholar11 Hina N, Fletcher D, Poindessous-Jazat F, Martinez V. Hyperalgesia induced by low-dose opioid treatment before orthopaedic surgery: an observational case-control study. Eur. J. Anaesthesiol. 32(4), 255–261 (2015).Crossref, Medline, CAS, Google Scholar12 Wildgaard K1, Ringsted TK, Aasvang EK, Ravn J, Werner MU, Kehlet H. Neurophysiological characterization of persistent postthoracotomy pain. Clin. J. Pain 28(2), 136–142 (2012).Crossref, Medline, Google Scholar13 Chaparro LE, Smith SA, Moore RA, Wiffen PJ, Gilron I. Pharmacotherapy for the prevention of chronic pain after surgery in adults. Cochrane Database Syst. Rev. (7), CD008307 (2013).Google Scholar14 Martinez V, Pichard X, Fletcher D. Perioperative pregabalin administration does not prevent chronic postoperative pain: systematic review with a meta-analysis of randomized trials. Pain 158(5), 775–783 (2017).Crossref, Medline, CAS, Google Scholar15 Tiippana E, Hamunen K, Heiskanen T, Nieminen T, Kalso E, Kontinen VK. New approach for treatment of prolonged postoperative pain: APS Out-Patient Clinic. Scand. J. Pain 12, 19–24 (2016).Crossref, Medline, Google Scholar16 Katz J, Weinrib A, Fashler SR et al. The Toronto General Hospital Transitional Pain Service: development and implementation of a multidisciplinary program to prevent chronic postsurgical pain. J. Pain Res. 8, 695–702 (2015).Crossref, Medline, Google ScholarFiguresReferencesRelatedDetailsCited ByAnalgesia after Labor and Cesarean Section: Chronic Pain after PregnancyFamilial Episodic Pain Syndromes1 August 2022 | Journal of Pain Research, Vol. Volume 15A systematic review on diagnostic test accuracy of magnetic resonance neurography versus clinical neurosensory assessment for post-traumatic trigeminal neuropathy in patients reporting neurosensory disturbance27 May 2020 | Dentomaxillofacial Radiology, Vol. 18Pain Management and the Urology Patient1 August 2020Acute and chronic neuropathic pain profiles after video-assisted thoracic surgery1 March 2020 | Medicine, Vol. 99, No. 13 Vol. 8, No. 5 Follow us on social media for the latest updates Metrics Downloaded 173 times History Received 7 May 2018 Accepted 5 June 2018 Published online 3 October 2018 Published in print September 2018 Information© 2018 Future Medicine LtdFinancial & competing interests disclosureThe author has no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.No writing assistance was utilized in the production of this manuscript.PDF download

WE all know them. Perhaps it is the “funny uncle” you see only at family reunions, or the high-school friend who was sent away to live with relatives in a “better environment.” Every profession has their share, those things that all too often get “tucked away into some closet,” or “swept under a rug.” In social work services, they might come under the guise of “domestic violence” or “sexual abuse.” In the military, there are lots of them: “friendly fire” casualties for line officers, and nonbattle injuries (e.g., back pain) for medical officers. For medicine in general, medical errors seem to occupy this exalted slot at the top of the publicity pyramid. It is our opinion that chronic postsurgical pain (CPSP) is the anesthesia equivalent of this phenomenon, the 800-pound gorilla in the room that everyone notices, but until recently few people acknowledged.In this double-blind study by Albi-Feldzer et al.,1 the authors sought to determine whether deep infiltration with local anesthetic could decrease the incidence of CPSP. A case in point for how our thinking about how CPSP has evolved is postamputation pain. In the aftermath of World War II, the most widely cited studies on postamputation pain routinely reported prevalence rates less than 5%, with many investigators attributing the phenomenon to concurrent psychosocial morbidity.2 Today, the incidence of postamputation pain is generally considered to be between 50 and 80%.3 The evolution of our understanding of postmastectomy pain parallels that of postamputation and other forms of CPSP, with the estimated prevalence rates having risen from approximately 25% in the 1980s,4 to above 40% by current estimates.5Part of this disparity has to do with the frequency and method of surveillance. Even my daughter in first grade (SPC) knows that the more frequently she asks a question, the more likely she is to hear an answer she likes. But as the number of surgical procedures and the operative mortality rate continue to move in opposite directions, the looming question about how to prevent CPSP takes on increasing importance. Previous studies evaluating membrane stabilizers, regional anesthesia, and N-methyl-D-aspartate receptor antagonists have all yielded mixed results to date.6,7 This issue is even more paramount when one considers our poor track record in treating CPSP.In this randomized, multicenter study,1 the authors allocated 260 patients to receive local wound infiltration with either ropivacaine or saline approximately 1 h before the end of breast cancer surgery. What distinguishes this from other similar studies is the large number of patients enrolled (which should be sufficient to detect small differences), the different sites (which should enhance generalization), and the long-term surveillance using a wide array of validated instruments (which increases relevance). Not surprisingly, in the first 24 h postprocedure the treatment group reported lower pain scores than the saline group in the context of similar analgesic consumption. However, this pain reduction did not translate into lower pain scores after 24 h, less opioid-related side effects, or a lower incidence of CPSP. Although patients who received ropivacaine experienced a trend toward less neuropathic pain as measured by DN-4 at 12 months, the significance of this finding under the umbrella of similar overall pain scores at 12 months and similar DN-4 scores at 6 months, is unclear. One way the authors could have done more to tease out any possible benefit in reducing the incidence of neuropathic pain would have been to separately survey the different types of postsurgical pain (i.e., the intercostobrachial neuralgia/arm pain, scar pain, phantom pain), as each are mechanistically distinct. This has previously been done not only for CPSP,5 but also for a host of other chronic pain conditions.These findings are consistent with most,8–10 but not all,11 studies that failed to demonstrate even short-term meaningful benefit from pre- or intraoperative wound infiltration. This latter distinction is important, because the ability of an intervention administered before tissue injury to reduce the incidence of CPSP would likely come as a consequence of its ability to reduce the inflammatory cascade and resultant postoperative pain that follows tissue injury.6,7,12 Yet in view of the clear-cut, short-term benefits demonstrated by this large, rigorously conducted multicenter study, the possible long-term benefits in select patients, and low risks associated with open wound infiltration in a monitored setting, one should be very cautious in flippantly dismissing this simple intervention as a possible tool in individuals at high risk for poorly treated postoperative pain. In those individuals who may be spared postoperative vomiting or posttraumatic neuropathic pain—which is associated with greater levels of disability than nonneuropathic pain states13—the advantages of this simple intervention by the surgical team might possibly outweigh the relatively low risks associated with the controlled administration of high amounts (3 mg/kg) of ropivacaine.But we are still left with the seemingly Sisyphean task of how to prevent CPSP, and the question of whether or not the Holy Grail of preventive analgesia is even obtainable. These questions, and the search for this elusive magic bullet, are by no means unique to anesthesiologists. Currently, physicists are consumed by the search for the Higgs-Boson (a.k.a. “God”) particle, and philosophers have wrestled with the “Meaning of Life” for at least as long as language has existed.The factors that affect whether or not someone experiences CPSP include not only the magnitude of postoperative pain, but also the extent of preoperative pain, trauma during surgery, and a host of psychosocial variables, including but not limited to depression, psychological vulnerability, and anxiety6,7,14—all of which occur with increased frequency in cancer patients.15 Whereas the effects of truly preemptive interventions such as gabapentinoid drugs and preoperative regional anesthesia are conflicting, the evidence supporting preemptive “treatment” is still more robust than for interventions performed after tissue injury has already occurred.6,7 Another factor to consider is that postoperative pain scores were relatively low in this cohort. Not only will low pain scores decrease the likelihood of detecting a statistical difference between groups, but they will also mitigate the impact of any intervention designed to reduce pain. In addition, the fact that Brief Pain Inventory scores and pain interference actually increased over the course of this study—which defies the natural course of healing—suggests that undocumented confounding factors may have contributed to the lack of effect. These factors could include nonoperative interventions such as chemo- and radiation therapy and emotional factors such as depression and anxiety secondary to a prognosis that proved worse than anticipated.So where does this study leave us with regard to postoperative analgesia in general and wound infiltration in particular? The findings clearly demonstrate a short-term benefit for local wound infiltration in breast cancer surgery, but taken in the context of the conflicting (though mostly negative) extant literature, they fail to definitively prove a long-term benefit. Similar to friendly fire, medical errors, “funny uncles” and other hot-button topics, our appreciation of the impact CPSP has on breast cancer survivors and other patients is just beginning to emerge, and the complete picture has not fully materialized. However, given the enormous impact that identifying a preventive anesthetic regimen that can reliably reduce CPSP would have on society, our search for the Holy Grail of Anesthesia will (and should) continue.

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

Adolescent idiopathic scoliosis (AIS) patients frequently experience depressive symptoms, which may influence postoperative pain outcomes. However, high-quality prospective evidence remains scarce. This study aimed to investigate the association between preoperative depressive symptoms and postoperative pain trajectories in AIS. This was a prospective study involving AIS patients aged 10-17years who underwent surgical management for scoliosis correction under general anesthesia. Depressive symptoms, pain, functional activity, sleep quality, and quality of life were pre-operatively assessed using scales. Dynamic trajectories of acute postsurgical pain (APSP) and chronic postsurgical pain (CPSP) were evaluated during a 90-day follow-up. The primary outcome was the incidence of APSP. Secondary outcomes included the incidence of CPSP, oral morphine milligram equivalents (MME) during POD 1-5, early complications, postoperative length of stay, and long-term rehabilitation status. Preoperative depressive symptoms (odds ratio [OR] = 28.30), female sex (OR = 4.87), and a higher number of surgical segments (OR = 1.27) were identified as independent risk factors for CPSP. A risk prediction model (nomogram) constructed by incorporating the above variables effectively predicted CPSP in these patients, with an area under the curve (AUC) of 0.854 (95% confidence intervals [CI]: 0.774-0.934, P < 0.01). The incidence of CPSP was significantly higher in postoperative AIS patients with persistent depressive symptoms than those with relieved depression or persistently non-depressed symptoms (100% vs. 67.86% vs. 10.40%, P < 0.001). Preoperative depressive symptoms are risk factors for both APSP and CPSP in postoperative AIS patients, demonstrating a gradient association with the incidence of CPSP. A nomogram that incorporates female sex, the number of surgical segments, and preoperative depressive symptoms can effectively predict CPSP in this population. An integrative psychological and analgesic intervention centered on preoperative depressive symptoms is expected to benefit high-risk AIS patients. Trial registration According to the Helsinki Declaration, the research protocol has been registered with the Chinese Clinical Trial Registry (ChiCTR;https://www.chictr.org.cn/) (Registration No: ChiCTR2300077637).

Chronic post-surgical pain

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