Risk factors for persistent pain after breast and thoracic surgeries: a systematic literature review and meta-analysis

Evidence summary on pain management in thoracoscopic lung cancer surgery

Objective

The study aimed to systematically retrieve, evaluate and summarize evidence on perioperative pain management in adults undergoing thoracoscopic lung cancer surgery, to assist oncology nurses in improving pain assessment and management.

Methods

The research question was established using PIPOST model and a systematic search was conducted in English and Chinese databases, professional society websites and guideline platforms for literature published between January 2017 and December 2024. Included literature types comprised guidelines, systematic reviews, evidence summaries, expert consensus, and standards. After literature searching and screening in January 2025, the remaining guidelines were evaluated by four investigators, while other literature was assessed by two investigators. Evidence was then extracted and graded.

Results

Eighteen articles were included, comprising 5 systematic reviews, 3 guidelines, 2 clinical decisions, 4 evidence summaries, 3 expert consensus, and 1 standard. Twenty-five pieces of evidence across six topics were summarized, covering organizational management, high-risk patient assessment and preoperative education, pain assessment, intraoperative analgesia, multimodal pharmacological strategies, and non-pharmacological interventions.

Conclusions

This evidence summary highlights effective strategies for perioperative pain management in thoracoscopic lung cancer surgery, which could support oncology nurses in implementing comprehensive pain assessment, identifying high-risk patients, and applying diversified analgesic interventions.

A machine learning-based framework for predicting postpartum chronic pain: a retrospective study

BACKGROUND

Postpartum chronic pain is prevalent, affecting many women after delivery. Machine learning algorithms have been widely used in predicting postoperative conditions. We investigated the prevalence of and risk factors for postpartum chronic pain, and aimed to develop a machine learning model for its prediction.

METHODS

Pregnant women in our tertiary hospital were screened from July 2021 to June 2022. Postoperative pain intensity was assessed using the numerical rating scale at 1, 3, and 6 months after delivery. Six machine learning algorithms were benchmarked using the nested resampling method, and their performance was evaluated based on classification error (CE). The algorithm with the best performance evaluation was used to establish the model for predicting chronic pain 6 months after delivery. Shapley additive explanations analysis was used to assess the contribution of each variable to the model.

RESULTS

A total of 1,398 postpartum women were included for analysis, among whom 383 developed chronic pain 6 months after delivery. The least absolute shrinkage selection operator identified five relevant factors: numerical rating scale at 3 days after delivery, body mass index before delivery, newborn weight, multiparous delivery, and back pain during gestation. The CEs for the algorithms were as follows: K-nearest neighbor, 0.212; logistic regression, 0.342; linear discriminant analysis, 0.343; naive Bayes, 0.346; ranger, 0.219; and extreme gradient boosting model, 0.147. The extreme gradient boosting model exhibited the best performance (CE = 0.147, F1 = 0.851) and was selected for model establishment. Visualization using Shapley additive explanations facilitated the interpretation of the influence of the five variables in the model.

CONCLUSIONS

The extreme gradient boosting algorithm, which incorporates five risk factors, demonstrated strong performance in predicting postpartum chronic pain.

TRIAL REGISTRATION

https//www.chictr.org.cn/ (ChiCTR2300070514).

Is a Perioperative Opioid-Sparing Anesthesia-Analgesia Strategy Feasible in Open Thoracotomies? Findings from a Retrospective Matched Cohort Study

Background/Objectives: To assess the feasibility and effectiveness of a perioperative opioid-sparing anesthesia-analgesia (OSA-A) technique without regional nerve blocks compared to standard opioid-based technique (OBA-A) in open thoracotomies. Methods: This retrospective, matched cohort study was conducted at a university hospital from September 2019 to February 2021, including adult patients undergoing open thoracotomy for lung or pleura pathology. Sixty patients in the OSA-A group were matched with 40 in the OBA-A group. Outcomes included postoperative pain scores on days 0, 1, and 2; 24-h postoperative morphine consumption; PACU and hospital length of stay; time to bowel movement; and rates of nausea and vomiting. Results: Of 125 eligible patients, 100 had complete records (60 OSA-A, 40 OBA-A). Demographics were similar, but ASA status scores were higher in the OBA-A group. The OSA-A group reported significantly lower pain levels at rest, during cough, and on movement on the first two postoperative days, shorter PACU stay, and required fewer opioids. They also had better gastrointestinal motility (p < 0.0001) and lower rates of nausea and vomiting on postoperative days 1 and 2. A follow-up study with 68 patients (46 OSA-A, 22 OBA-A) assessing chronic pain prevalence found no significant differences between the groups. Conclusions: OSA-A without regional nerve blocks for open thoracotomies is feasible and safe, improving postoperative pain management, reducing opioid consumption, shortening PACU stay, and enhancing early gastrointestinal recovery compared to OBA-A.

Development and internal validation of a clinical risk tool to predict chronic postsurgical pain in adults: a prospective multicentre cohort study

ABSTRACT

Chronic postsurgical pain (CPSP) is a highly prevalent condition. To improve CPSP management, we aimed to develop and internally validate generalizable point-of-care risk tools for preoperative and postoperative prediction of CPSP 3 months after surgery. A multicentre, prospective, cohort study in adult patients undergoing elective surgery was conducted between May 2021 and May 2023. Prediction models were developed for the primary outcome according to the International Association for the Study of Pain criteria and a secondary threshold-based CPSP outcome. Models were developed with multivariable logistic regression and backward stepwise selection. Internal validation was conducted using bootstrap resampling, and optimism was corrected by shrinkage of predictor weights. Model performance was assessed by discrimination and calibration. Clinical utility was assessed by decision curve analysis. The final cohort included 960 patients, 16.3% experienced CPSP according to the primary outcome and 33.6% according to the secondary outcome. The primary CPSP model included age and presence of other preoperative pain. Predictors in the threshold-based models associated with an increased risk of CPSP included younger age, female sex, preoperative pain in the surgical area, other preoperative pain, orthopedic surgery, minimally invasive surgery, expected surgery duration, and acute postsurgical pain intensity. Optimism-corrected area-under-the-receiver-operating curves for preoperative and postoperative threshold-based models were 0.748 and 0.747, respectively. These models demonstrated good calibration and clinical utility. The primary CPSP model demonstrated fair predictive performance including 2 significant predictors. Derivation of a generalizable risk tool with point-of-care predictors was possible for the threshold-based CPSP models but requires independent validation.

Chronic postsurgical pain and transitional pain services: a narrative review highlighting European perspectives

BACKGROUND/IMPORTANCE

Chronic postsurgical pain (CPSP) is a significant, often debilitating outcome of surgery, impacting patients' quality of life and placing a substantial burden on healthcare systems worldwide. CPSP (pain persisting for more than 3 months postsurgery) leads to both physical and psychological distress. Recognized as a distinct chronic pain entity in International Classification of Diseases, 11th Revision, CPSP enables better reporting and improved management strategies. Despite advancements in surgical care, CPSP remains prevalent, affecting 5%-85% of patients, with higher rates following thoracotomies, amputations, mastectomies and joint replacements.

OBJECTIVE

The acute to chronic pain transition involves complex interactions between peripheral and central mechanisms, with central sensitization playing a key role. Identifying high-risk patients is crucial for prevention, with factors such as surgical type, nerve injury, neuropathic elements in acute postoperative pain, and psychosocial conditions being significant contributors.

EVIDENCE REVIEW

Current pain management strategies, including multimodal therapy and regional anesthesia, show limited effectiveness in preventing CPSP. Neuromodulation interventions, though promising, are not yet established as preventive modalities.

FINDINGS

Transitional pain services (TPSs) offer a comprehensive, multidisciplinary approach to managing CPSP and reducing opioid dependence, addressing both physical and psychosocial aspects of functional recovery. While promising results have been seen in Canada and Finland, TPSs are not yet widely implemented in Europe. There is also growing interest in pain biomarkers, through initiatives such as the A2CPS program, aiming to improve CPSP prediction and develop targeted interventions.

CONCLUSIONS

Future research should focus on large-scale studies integrating various factors to facilitate CPSP prediction, refine prevention strategies and reduce its long-term impact.

Preoperative predictors of acute postoperative anxiety and depression using ecological momentary assessments: a secondary analysis of a single-centre prospective observational study

BACKGROUND

Postoperative anxiety and depression can negatively affect surgical outcomes and patient wellbeing. This study aimed to quantify the incidence of postoperative worsening anxiety and depression symptoms and to identify preoperative predictors of these conditions.

METHODS

This prospective, observational cohort study included 1168 patients undergoing surgery lasting >1 h with overnight admission at a university-affiliated quaternary referral centre. Postoperative anxiety and depression symptoms were measured using standardised, thrice-daily ecological momentary assessments (EMAs) for 30 days. Co-primary outcomes were worsening anxiety and depression symptoms, each defined as a slope >0 when EMA was modelled as a linear function of time. Multivariable logistic regression was performed to identify independent preoperative predictors of each outcome.

RESULTS

Postoperative worsening anxiety occurred in 60 patients (5%), and postoperative worsening depression occurred in 86 patients (7%). Predictors of postoperative worsening of anxiety symptoms included preoperative Patient-Reported Outcome Measurement Information System (PROMIS) anxiety symptoms (adjusted odds ratio [aOR] 2.48, 95% credible interval [CI] 1.29-4.79, for mild symptoms; aOR 2.22, 95% CI 1.10-4.51, for moderate to severe symptoms), and preoperative pain (aOR 3.46, 95% CI 1.32-9.12). Predictors of postoperative worsening depression symptoms included preoperative PROMIS depression symptoms (aOR 2.26, 95% CI 1.24-4.14, for mild symptoms; aOR 3.79, 95% CI 2.10-6.81, for moderate to severe symptoms). Self-reported history of anxiety or depression did not independently predict either outcome.

CONCLUSIONS

Postoperative worsening anxiety and depression appear to be associated more closely with preoperative active mental health or pain symptoms rather than self-reported history of these conditions. Preoperative identification of at-risk patients will require screening for symptoms rather than simple history taking.

Preoperative susceptibility to developing secondary hyperalgesia is associated with post-thoracotomy pain at 2 months

BACKGROUND

Identifying the subset of patients at risk for developing persistent pain after surgery is clinically important as they could benefit from targeted prevention measures. In this prospective study, we investigated if the preoperative assessment of the individual susceptibility to developing experimentally induced secondary hyperalgesia is associated with post-thoracotomy pain at 2 months.

METHODS

Forty-one patients scheduled to undergo a posterolateral thoracotomy were recruited before surgery and followed prospectively for 2 months. The day before surgery, we experimentally induced secondary hyperalgesia at one of the two forearms and measured the change of perception to mechanical pinprick stimuli and the area of hyperalgesia. On postoperative Day 4, Day 15 and at the 2-month follow-up, patients were asked about their pain intensity at rest and during coughing and the area of secondary hyperalgesia around the scar as well as the change in perception to mechanical pinprick stimuli was measured.

RESULTS

Of the 41 patients that were recruited only 20 could be analysed. Forty per cent reported pain at the 2-month follow-up. All of them reported cough-evoked pain and 10 per cent also reported pain at rest. A binary logistic regression model with both the magnitude and extent of experimentally induced secondary hyperalgesia was statistically significant (chi-squared = 12.439, p = 0.002, McFadden R2 = 0.462) and showed excellent discriminative power (AUC = 0.938) for the presence or absence of cough-evoked pain at the 2 month follow-up.

CONCLUSION

Our findings indicate that the individual susceptibility to developing experimentally induced secondary hyperalgesia preoperatively may identify patients who are potentially vulnerable to develop persistent post-thoracotomy pain.

SIGNIFICANCE

Our data suggests that preoperatively assessed experimentally induced secondary hyperalgesia displays excellent discriminative power for the presence or absence of cough-evoked pain 2 months after thoracotomy.

Predictive Scores for Identifying Chronic Opioid Dependence After General Anesthesia Surgery

Purpose

To address the prevalence and risk factors of postoperative chronic opioid dependence, focusing on the development of a predictive scoring system to identify high-risk populations.

Methods

We analyzed data from the Taiwan Health Insurance Research Database spanning January 2016 to December 2018, encompassing adults undergoing major elective surgeries with general anesthesia. Patient demographics, surgical details, comorbidities, and preoperative medication use were scrutinized. Wu and Zhang's scores, a predictive system, were developed through a stepwise multivariate model, incorporating factors significantly linked to chronic opioid dependence. Internal validation was executed using bootstrap sampling.

Results

Among 111,069 patients, 1.6% developed chronic opioid dependence postoperatively. Significant risk factors included age, gender, surgical type, anesthesia duration, preoperative opioid use, and comorbidities. Wu and Zhang's scores demonstrated good predictive accuracy (AUC=0.83), with risk categories (low, moderate, high) showing varying susceptibility (0.7%, 1.4%, 3.5%, respectively). Internal validation confirmed the model's stability and potential applicability to external populations.

Conclusion

This study provides a comprehensive understanding of postoperative chronic opioid dependence and introduces an effective predictive scoring system. The identified risk factors and risk stratification allow for early detection and targeted interventions, aligning with the broader initiative to enhance patient outcomes, minimize societal burdens, and contribute to the nuanced management of postoperative pain.

Sex Differences in Chronic Postsurgical Pain after Open Thoracotomy

STUDY OBJECTIVE

To determine the incidence of chronic postsurgical pain (CPSP) in women after open thoracotomy. Secondary objectives were to compare relevant patient and procedural variables between women and men.

DESIGN

Observational cohort study.

SETTING

Ten university-affiliated hospitals.

SUBJECTS

Ninety-six women and 137 men.

INTERVENTIONS

Scheduled open thoracotomy.

MEASUREMENTS

Pain histories, psychological measures, and perceived health status and catastrophizing scores were obtained. The diagnosis of chronic postsurgical pain was by physical examination at 4 months. Standard preoperative, intraoperative, and postoperative data were also recorded.

MAIN RESULTS

The chronic postsurgical pain incidence was significantly higher in women (53.1%) than in men (38.0%) (p = 0.023). At baseline, women had significantly worse scores on psychological measures (perception of mental state [p = 0.01], depression [p = 0.006], and catastrophizing [p < 0.001]). Women also reported more preoperative pain in the operative area (p = 0.011) and other areas (p = 0.030).

CONCLUSION

These findings show that the incidence of physician-diagnosed chronic postsurgical pain is higher in women than in men after surgeries involving thoracotomy. Sex and gender should be included in future clinical research on pain in surgical settings.

Dexmedetomidine attenuates inflammatory response and chronic pain following video-assisted thoracoscopic surgery for lung cancer

BACKGROUND

The objective of the present study was to evaluate the effect of dexmedetomidine administration during video-assisted thoracoscopic surgery for lung cancer on perioperative inflammatory response and chronic post-surgical pain.

METHODS

A cohort of 152 patients with lung cancer scheduled for elective video-assisted thoracoscopic surgery participated in this randomized controlled trial. Patients were randomly divided into 2 groups and administered an equivalent volume of dexmedetomidine (n = 63) or normal saline (n = 63). Dexmedetomidine was administered at a dose of 0.6 μg/kg 10 minutes before anesthesia induction and maintained at 0.5 μg/kg/h until 0.5 hours before surgery completed. Anesthesia and postoperative pain management protocols were standardized for both groups. The analysis included vital signs, numerical rating scales of pain, blood inflammatory and oxidative stress biomarkers, pain type and location, patient-controlled intravenous analgesia usage, consumption of general anesthetics and pain rescue medications, as well as complications.

RESULTS

The administration of dexmedetomidine resulted in decreased levels of inflammatory cytokines (interleukin-1 beta, interleukin-6, alongside tumor necrosis factor-alpha) and oxidative stress biomarkers (reactive oxygen species alongside malondialdehyde) but elevated levels of interleukin-10 and superoxide dismutase. In addition, the dexmedetomidine group showed lower postoperative numerical rating scale scores, reduced consumption of anesthetics, faster chest-tube removal, fewer patient-controlled intravenous analgesia presses, and shorter postoperative hospital stays.

CONCLUSION

The administration of dexmedetomidine effectively attenuated surgical inflammation, oxidative stress, and postoperative pain, thereby promoting patient recovery after lung cancer surgery without increasing the risk of adverse effects or complications.

Assessment of LGBTQ+ Diversity, Equity, and Inclusion in Subspecialty Surgery Literature: A Scoping Review

OBJECTIVE

To identify LGBTQ+ diversity, equity, and inclusion (DEI) publications and contextualize the current frequency of the literature across subspecialty surgical fields.

METHODS

A PRISMA systematic review using PubMed, MEDLINE, and Web of Science was conducted in April 2024. The main inclusion criterion was intrafield DEI content for defined subspecialties; exclusion criteria were foreign language, poor methodology, and duplicates. The primary endpoint was the number of publications across subspecialties. Secondary endpoints included publication dates, study design, and sample size.

RESULTS

Of the 702 articles identified, 27 were included in the analysis. Neurologic surgery had 2 studies; plastic surgery, 11 studies; orthopedic surgery, 7 studies; otolaryngology, 5 studies; and thoracic surgery, 2 studies. There was a statistically significant different frequency of publications across subspecialties (P = 0.031). Post hoc residual analysis indicated that neurosurgery and thoracic surgery had statistically fewer publications, while plastic surgery had statistically more publications (P = 0.04, 0.002, 0.21, 0.42, and 0.04 for neurologic surgery, plastic surgery, orthopedic surgery, otolaryngology, and thoracic surgery, respectively). Secondary outcomes found a majority of publications between 2022 and 2024. Study methodologies involved cross-sectional studies, editorials, and retrospective reviews (14, 11, and 3 respectively) and had a median sample size of 248.5.

CONCLUSIONS

This systematic review provides objective data to contextualize DEI literature across surgical subspecialties. Overall, this review highlights the lack of LGBTQ+ DEI literature in neurosurgery and advocates for correcting this gap for the benefit of both surgeons and patients. Understanding the current numbers and evaluating progress in other surgical fields might provide solutions.

Prospective Study of Preoperative Negative Affect and Postoperative Pain in Patients Undergoing Thoracic Surgery: The Moderating Role of Sex

Objective: Preoperative negative affect is a risk factor for worse postoperative pain, but research investigating this association among patients undergoing thoracic surgery is inconsistent. Additionally, female patients often report greater negative affect and postoperative pain than males. This prospective observational study investigated the association between preoperative negative affect and postoperative pain after thoracic surgery and whether this association differed by sex. Methods: Patients (n = 105) undergoing thoracic surgery completed preoperative assessments of pain and negative affect (PROMIS anxiety and depression short forms). Patients reported their daily worst pain over the first 7 postoperative days, and an index score of acute postoperative pain was created. Six months after surgery, a subsample of patients (n = 60) reported their worst pain. Results: Higher levels of preoperative anxiety (r = 0.25, p = 0.011) and depression (r = 0.20, p = 0.042) were associated with greater acute postoperative pain, but preoperative negative affect was not related to chronic postsurgical pain (anxiety: r = 0.19, p = 0.16; depression: r = -0.01, p = 0.94). Moderation analyses revealed that the associations between both preoperative anxiety (b = 0.12, 95% CI [0.04, 0.21], p = 0.004) and depression (b = 0.15, 95% CI [0.04, 0.26], p = 0.008) with acute postoperative pain were stronger among females than males. Similarly, the association between preoperative anxiety and chronic postsurgical pain was stronger among females (b = 0.11, 95% CI [0.02, 0.20], p = 0.022), but the association between preoperative depression and chronic pain did not differ based on sex (b = 0.13, 95% CI [-0.07, 0.34], p = 0.201]). Conclusions: Our findings suggest that negative affect may be especially important to the experience of pain following thoracic surgery among female patients, whose degree of preoperative anxiety may indicate vulnerability to progress to a chronic pain state. Preoperative interventions aimed at reducing negative affect and pain may be particularly useful among females with high negative affect before thoracic surgery.

Perioperative Risk Factors for Persistent Postsurgical Pain After Inguinal Hernia Repair: Systematic Review and Meta-Analysis

Persistent postsurgical pain (PPSP) is one of the most bothersome and disabling long-term complications after inguinal hernia repair surgery. Understanding perioperative risk factors that contribute to PPSP can help identify high-risk patients and develop risk-mitigation approaches. The objective of this study was to systematically review and meta-analyze risk factors that contribute to PPSP after inguinal hernia repair. The literature search resulted in 303 papers included in this review, 140 of which were used for meta-analyses. Our results suggest that younger age, female sex, preoperative pain, recurrent hernia, postoperative complications, and postoperative pain are associated with a higher risk of PPSP. Laparoscopic techniques reduce the PPSP occurrence compared to anterior techniques such as Lichtenstein repair, and tissue-suture techniques such as Shouldice repair. The use of fibrin glue for mesh fixation was consistently associated with lower PPSP rates compared to tacks, staples, and sutures. Considerable variability was observed with PPSP assessment and reporting methodology in terms of study design, follow-up timing, clarity of pain definition, as well as pain intensity or interference threshold. High or moderate risk of bias in at least one domain was noted in >75% of studies. These may limit the generalizability of our results. Future studies should assess and report comprehensive preoperative and perioperative risk factors for PPSP adjusted for confounding factors, and develop risk-prediction models to drive stratified PPSP-mitigation trials and personalized clinical decision-making. PERSPECTIVE: This systematic review and meta-analysis summarizes the current evidence on risk factors for persistent pain after inguinal hernia repair. The findings can help identify patients at risk and test personalized risk-mitigation approaches to prevent pain. PROSPERO REGISTRATION: htttps://www.crd.york.ac.uk/prospero/display_record.php?RecordID=154663.

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.

Perioperative mental health intervention for depression and anxiety symptoms in older adults study protocol: design and methods for three linked randomised controlled trials

INTRODUCTION

Preoperative anxiety and depression symptoms among older surgical patients are associated with poor postoperative outcomes, yet evidence-based interventions for anxiety and depression have not been applied within this setting. We present a protocol for randomised controlled trials (RCTs) in three surgical cohorts: cardiac, oncological and orthopaedic, investigating whether a perioperative mental health intervention, with psychological and pharmacological components, reduces perioperative symptoms of depression and anxiety in older surgical patients.

METHODS AND ANALYSIS

Adults ≥60 years undergoing cardiac, orthopaedic or oncological surgery will be enrolled in one of three-linked type 1 hybrid effectiveness/implementation RCTs that will be conducted in tandem with similar methods. In each trial, 100 participants will be randomised to a remotely delivered perioperative behavioural treatment incorporating principles of behavioural activation, compassion and care coordination, and medication optimisation, or enhanced usual care with mental health-related resources for this population. The primary outcome is change in depression and anxiety symptoms assessed with the Patient Health Questionnaire-Anxiety Depression Scale from baseline to 3 months post surgery. Other outcomes include quality of life, delirium, length of stay, falls, rehospitalisation, pain and implementation outcomes, including study and intervention reach, acceptability, feasibility and appropriateness, and patient experience with the intervention.

ETHICS AND DISSEMINATION

The trials have received ethics approval from the Washington University School of Medicine Institutional Review Board. Informed consent is required for participation in the trials. The results will be submitted for publication in peer-reviewed journals, presented at clinical research conferences and disseminated via the Center for Perioperative Mental Health website.

TRIAL REGISTRATION NUMBERS

NCT05575128, NCT05685511, NCT05697835, pre-results.

Pain trajectories and neuropathic pain symptoms following lung cancer surgery: A prospective cohort study

BACKGROUND

Persistent postsurgical pain (PPSP) after lung cancer surgery is common and current definitions are based on evaluations at a single time point after surgery. Pain intensity and symptoms may however fluctuate and change over time, and be impacted by multiple and shifting factors. Studies of postoperative recovery patterns and transition from acute to chronic pain are needed for further investigation of preventive measures and treatments to modify unfavourable recovery paths.

METHODS

In this explorative study, 85 patients undergoing surgery due to either presumptive or confirmed lung cancer reported pain intensities bi-monthly for 12 months. Pain trajectories during recovery were investigated, using group-based trajectory modelling. Associations with possible risk factors for PPSP, including clinical variables and anxiety and depression score (HADS), were also explored.

RESULTS

A trajectory model containing three 12-month pain recovery groups was computed. One group without PPSP fully recovered (50%) within two to three months. Another group with mild-intensity PPSP followed a protracted recovery trajectory (37%), while incomplete recovery was observed in the last group (13%). Acute postoperative pain and younger age were associated with a less favourable recovery trajectory. More neuropathic pain symptoms were observed in patients with incomplete recovery.

CONCLUSIONS

Three clinically relevant recovery trajectories were identified, based on comprehensive pain tracking. Higher acute postoperative pain intensity was associated with an unfavourable pain recovery trajectory.

SIGNIFICANCE STATEMENT

Understanding the transition from acute to chronic postoperative pain and identifying preoperative risk factors is essential for the development of targeted treatments and the implementation of preventive measures. This study (1) identified distinct recovery trajectories based on frequent pain assessment follow-ups for 12 months after surgery and (2) evaluated risk factors for unfavourable postoperative pain recovery paths. Findings suggest that early higher postoperative pain intensity is associated with an unfavourable long-term recovery path.

Analgesic efficacy and safety of erector spinae versus serratus anterior plane block in thoracic surgery: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Erector spinae plane block (ESPB) and serratus anterior plane block (SAPB) are regional anesthesia techniques that have shown favorable results in pain management following thoracic surgeries; however, their relative superiority is unclear. This review (PROSPERO: CRD42023443018) aims to compare the analgesic efficacy of ESPB and SAPB in patients undergoing thoracic surgeries through the pooled analysis of co-primary outcomes: postoperative oral-morphine-equivalent (mg) consumption in 24 h and pain scores (static) at 24 h.

METHODS

A literature search was conducted across PubMed, Cochrane Library, and Google Scholar to identify randomized controlled trials (RCTs) from inception to May 2023, comparing ESPB and SAPB in thoracic surgeries. Statistical pooling was done using Review Manager 5.4.1. Bias assessment employed the Cochrane Collaboration Risk-of-Bias 2.0 tool. The strength of evidence was assessed using the guidelines from the GRADE working group.

RESULTS

Nine RCTs (485 patients) were included in the study. Postoperative pain scores (static) at 24 h (mean difference (MD) =  - 0.31 [- 0.57, 0.05], p = 0.02) and postoperative oral-morphine-equivalent (mg) consumption in 24 h (MD =  - 19.73 [- 25.65, - 13.80], p < 0.00001) were significantly lower in the ESBP group. However, the MDs did not exceed the set threshold for clinical importance. No significant differences were observed in the opioid-related adverse effects and block-related complications.

CONCLUSION

Our statistically significant results imply that ESPB has superior analgesic efficacy compared to SAPB; however, this difference is clinically unimportant. The safety profile of the two blocks is comparable; hence, current evidence cannot define the relative superiority of one block over the other. Our findings warrant further research with standardized methodologies and a longer duration of analgesic efficacy assessment to yield robust evidence for better clinical applications.

How to Modulate Peripheral and Central Nervous System to Treat Acute Postoperative Pain and Prevent Pain Persistence

Chronic postoperative pain (CPSP) is a major issue after surgery, which may impact on patient's quality of life. Traditionally, CPSP is believed to rely on maladaptive hyperalgesia and risk factors have been identified that predispose to CPSP, including acute postoperative pain. Despite new models of prediction are emerging, acute pain is still a modifiable factor that can be challenged with perioperative analgesic strategies. In this review we present the issue of CPSP, focusing on molecular mechanism underlying the development of acute and chronic hyperalgesia. Also, we focus on how perioperative strategies can impact directly or indirectly (by reducing postoperative pain intensity) on the development of CPSP.

Prognostic Factors for Postoperative Chronic Pain after Knee or Hip Replacement in Patients with Knee or Hip Osteoarthritis: An Umbrella Review

Knee and hip osteoarthritis are highly prevalent in the older population. Management of osteoarthritis-related pain includes conservative or surgical treatment. Although knee or hip joint replacement is associated with positive outcomes, up to 30% of patients report postoperative pain in the first two years. This study aimed to synthesize current evidence on prognostic factors for predicting postoperative pain after knee or hip replacement. An umbrella review of systematic reviews was conducted to summarize the magnitude and quality of the evidence for prognostic preoperative factors predictive of postoperative chronic pain (>6 months after surgery) in patients who had received knee or hip replacement. Searches were conducted in MEDLINE, CINAHL, PubMed, PEDro, SCOPUS, Cochrane Library, and Web of Science databases from inception up to 5 August 2022 for reviews published in the English language. A narrative synthesis, a risk of bias assessment, and an evaluation of the evidence confidence were performed. Eighteen reviews (nine on knee surgery, four on hip replacement, and seven on both hip/knee replacement) were included. From 44 potential preoperative prognostic factors, just 20 were judged as having high or moderate confidence for robust findings. Race, opioid use, preoperative function, neuropathic pain symptoms, pain catastrophizing, anxiety, other pain sites, fear of movement, social support, preoperative pain, mental health, coping strategies, central sensitization-associated symptoms, and depression had high/moderate confidence for an association with postoperative chronic pain. Some comorbidities such as heart disease, stroke, lung disease, nervous system disorders, and poor circulation had high/moderate confidence for no association with postoperative chronic pain. This review has identified multiple preoperative factors (i.e., sociodemographic, clinical, psychological, cognitive) associated with postoperative chronic pain after knee or hip replacement. These factors may be used for identifying individuals at a risk of developing postoperative chronic pain. Further research can investigate the impact of using such prognostic data on treatment decisions and patient outcomes.

The incidence, impact, and risk factors for moderate to severe persistent pain after breast cancer surgery: a prospective cohort study

BACKGROUND

Few Australasian studies have evaluated persistent pain after breast cancer surgery.

OBJECTIVE

To evaluate the incidence, impact, and risk factors of moderate to severe persistent pain after breast cancer surgery in a New Zealand cohort.

DESIGN

Prospective cohort study.

METHODS

Consented patients were reviewed at 3 timepoints (preoperative, 2 weeks and 6 months postoperative). Pain incidence and interference, psychological distress and upper limb disability were assessed perioperatively. Clinical, demographic, psychological, cancer treatment-related variables, quantitative sensory testing, and patient genotype (COMT, OPRM1, GCH1, ESR1, and KCNJ6) were assessed as risk factors using multiple logistic regression.

RESULTS

Of the 173 patients recruited, 140 completed the 6-month follow-up. Overall, 15.0% (n = 21, 95% CI: 9.5%-22.0%) of patients reported moderate to severe persistent pain after breast cancer surgery with 42.9% (n = 9, 95% CI: 21.9%-66.0%) reporting likely neuropathic pain. Pain interference, upper limb dysfunction and psychological distress were significantly higher in patients with moderate to severe pain (P < .004). Moderate to severe preoperative pain (OR= 3.60, 95% CI: 1.13-11.44, P = .03), COMT rs6269 GA genotype (OR = 5.03, 95% CI: 1.49-17.04, P = .009) and psychological distress at postoperative day 14 (OR= 1.08, 95% CI: 1.02-1.16, P = .02) were identified as risk factors. Total intravenous anesthesia (OR= 0.31, 95% CI: 0.10 - 0.99, P = .048) was identified as protective.

CONCLUSION

The incidence of moderate to severe persistent pain after breast cancer surgery is high with associated pain interference, physical disability, and psychological distress. Important modifiable risk factors were identified to reduce this important condition.

Chronic post-thoracotomy pain after lung cancer surgery: a prospective study of preoperative risk factors

OBJECTIVES

The objective of this longitudinal cohort study was to investigate if preoperative pain mechanisms, anxiety, and depression increase risk of developing chronic post-thoracotomy pain (CPTP) after lung cancer surgery.

METHODS

Patients with suspected or confirmed lung cancer undergoing surgery by either video-assisted thoracoscopic surgery or anterior thoracotomy were recruited consecutively. Preoperative assessments were conducted by: quantitative sensory testing (QST) (brush, pinprick, cuff pressure pain detection threshold, cuff pressure tolerance pain threshold, temporal summation and conditioned pain modulation), neuropathic pain symptom inventory (NPSI), and the Hospital Anxiety and Depression Scale (HADS). Clinical parameters in relation to surgery were also collected. Presence of CPTP was determined after six months and defined as pain of any intensity in relation to the operation area on a numeric rating scale form 0 (no pain) to 10 (worst pain imaginable).

RESULTS

A total of 121 patients (60.2 %) completed follow-up and 56 patients (46.3 %) reported CPTP. Development of CPTP was associated with higher preoperative HADS score (p=0.025), higher preoperative NPSI score (p=0.009) and acute postoperative pain (p=0.042). No differences were observed in relation to preoperative QST assessment by cuff algometry and HADS anxiety and depression sub-scores.

CONCLUSIONS

High preoperative HADS score preoperative pain, acute postoperative pain intensity, and preoperative neuropathic symptoms were was associated with CPTP after lung cancer surgery. No differences in values of preoperative QST assessments were found. Preoperative assessment and identification of patients at higher risk of postoperative pain will offer opportunity for further exploration and development of preventive measures and individualised pain management depending on patient risk profile.

Prevalence and Characteristics of Persistent Postoperative Pain After Thoracic Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

A systematic review and meta-analysis was conducted to investigate the prevalence and characteristics of persistent (≥3 months) postoperative pain (PPP) after thoracic surgery.

METHODS

For this purpose, Medline, Embase, and CINAHL databases were searched for the prevalence and characteristics of PPP after thoracic surgery from their inception to May 1, 2022. Random-effect meta-analysis was used to estimate pooled prevalence and characteristics.

RESULTS

We included 90 studies with 19,001 patients. At a median follow-up of 12 months, the pooled overall prevalence of PPP after thoracic surgery was 38.1% (95% confidence interval [CI], 34.1-42.3). Among patients with PPP, 40.6% (95% CI, 34.4-47.2) and 10.1% (95% CI, 6.8-14.8) experienced moderate-to-severe (rating scale ≥4/10) and severe (rating scale ≥7/10) PPP, respectively. Overall, 56.5% (95% CI, 44.3-67.9) of patients with PPP required opioid analgesic use, and 33.0% (95% CI, 22.5-44.3) showed a neuropathic component.

CONCLUSIONS

One in 3 thoracic surgery patients developed PPP. There is a need for adequate pain treatment and follow-up in patients undergoing thoracic surgery.

Sex and age differences in chronic postoperative pain among patients undergoing thoracic surgery: a retrospective cohort study

Background

The effect of sex and age on chronic post-thoracic surgical pain (CPTP) at rest and with activity remains unclear. The main purpose of this study was to investigate the relationship between the incidence of chronic postoperative pain (at rest and with activity) and sex/age differences.

Methods

This was a single-center retrospective study that included adult patients who had undergone elective thoracic surgery. Patients were divided into two groups based on sex. Demographic and perioperative data were collected, including age, sex, education level, Body Mass Index (BMI), American Society of Anesthesiologists (ASA) physical status, and medical history (hypertension, diabetes mellitus). Chronic postoperative pain data were collected by telephone follow-up.

Results

Among the 3,159 patients enrolled, 1,762 were male, and 1,397 were female. After creating a matched-pairs cohort, 1,856 patients were analyzed. The incidence of CPTP at rest was 14.9% among males and 17.8% among females (p = 0.090). The incidence of CPTP with activity was 28.4% among males and 35.0% among females (p = 0.002). We analyzed three different models after propensity matching to validate the stability of the prediction model between sex and CPTP, and female sex was a significant predictor of CPTP with activity 3 months after surgery. Further analysis showed that females in the 45-55-year-old age group were more prone to develop CPTP.

Conclusion

Females have a higher incidence of chronic postoperative pain with activity after thoracic surgery. Females in the 45-55-year-old age group are more prone to develop CPTP than females in other age groups.

Prognostic factors for chronic post-surgical pain after lung and pleural surgery: a systematic review with meta-analysis, meta-regression and trial sequential analysis

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.

Risk factors for persistent pain after breast cancer surgery: a multicentre prospective cohort study

Identifying factors associated with persistent pain after breast cancer surgery may facilitate risk stratification and individualised management. Single-population studies have limited generalisability as socio-economic and genetic factors contribute to persistent pain development. Therefore, this prospective multicentre cohort study aimed to develop a predictive model from a sample of Asian and American women. We enrolled women undergoing elective breast cancer surgery at KK Women's and Children's Hospital and Duke University Medical Center. Pre-operative patient and clinical characteristics and EQ-5D-3L health status were recorded. Pain catastrophising scale; central sensitisation inventory; coping strategies questionnaire-revised; brief symptom inventory-18; perceived stress scale; mechanical temporal summation; and pressure-pain threshold assessments were performed. Persistent pain was defined as pain score ≥ 3 or pain affecting activities of daily living 4 months after surgery. Univariate associations were generated using generalised estimating equations. Enrolment site was forced into the multivariable model, and risk factors with p < 0.2 in univariate analyses were considered for backwards selection. Of 210 patients, 135 (64.3%) developed persistent pain. The multivariable model attained AUC = 0.807, with five independent associations: age (OR 0.85 95%CI 0.74-0.98 per 5 years); diabetes (OR 4.68, 95%CI 1.03-21.22); pre-operative pain score at sites other than the breast (OR 1.48, 95%CI 1.11-1.96); previous mastitis (OR 4.90, 95%CI 1.31-18.34); and perceived stress scale (OR 1.35, 95%CI 1.01-1.80 per 5 points), after adjusting for: enrolment site; pre-operative pain score at the breast; pre-operative overall pain score at rest; postoperative non-steroidal anti-inflammatory drug use; and pain catastrophising scale. Future research should validate this model and evaluate pre-emptive interventions to reduce persistent pain risk.

Neuropathy and pain after breast cancer treatment: a prospective observational study

OBJECTIVES

Neurological complications including pain are common after treatment for breast cancer. This prospective study investigated the symptoms, intensity and interference of chemotherapy-induced peripheral neuro-pathy. (CIPN) in the feet and hands compared to surgery- and radiation-induced neuropathy in the breast and upper arm.

METHODS

Consecutive patients referred to surgery for breast cancer were included in a prospective study and completed a questionnaire at baseline and a follow-up questionnaire and interview after one year. CIPN was assessed with the CIPN20 questionnaire and the Michigan Neuropathy Screening Instrument questionnaire (MNSIq). Pain intensity was rated on a numeric rating scale (NRS, 0-10).

RESULTS

In total 144 patients were included, of which 73 received chemotherapy. At one-year follow-up, symptoms of polyneuropathy were more common in patients treated with chemotherapy. Tingling or numbness in the feet in those treated/not treated with chemotherapy was reported by 44 (62%) and 15 (21%), respectively. Pain was present in 22 (30%) and 10 (14%), respectively. Pain in the area of surgery was reported by 66 (46%). Although less common, pain in the feet in those treated with chemotherapy was rated as more intense and with more daily life interference than pain in the surgical area (NRS 5.5 (SD 1.9) vs. 3.1 (SD 1.9).

CONCLUSIONS

Neurological complications including pain following surgery and chemotherapy represent a burden to breast cancer survivors. In those who had received chemotherapy, pain in the feet was less common than pain in the surgical area, but pain in the feet was more intense and had a higher interference with daily life. Our study emphasizes the need for either baseline data or a control population for improved estimation of the presence and severity of CIPN and pain from questionnaires.

Chronic pain after surgery and trauma: current situation and future directions

Chronic post-surgical pain (CPSP) stands as a major health issue. The unchanged incidence over the last two decades underlines both the failure of predictive models developed until now and the lack of efficacy of common “preventive” strategies (pharmacotherapy and regional analgesic techniques) applied in current clinical practice. The recognition of CPSP as a disease and the release of a common definition of the condition is an important progress in the field. CPSP predictive scores exist but none has presently demonstrated an impact on patient care. New clinical directions based on the resolution of postoperative pain, a complex and highly dynamic process supported by individual pain trajectories, argue for predictive models and preventive strategies extended to the subacute pain period i.e. after hospital discharge.

Use of regional analgesia to prevent the conversion from acute to chronic pain

PURPOSE OF REVIEW

Chronic post-surgical pain (CPSP) prevalence has not changed over the past decades what questions the efficacy of preventive strategies. Regional analgesia is used to control acute pain, but preventive effect on CPSP remains debated. Failures and future application of regional analgesia to prevent transition from acute to chronic pain will be discussed.

RECENT FINDINGS

After thoracotomy, perioperative regional analgesia does not seem to prevent CPSP. After breast cancer surgery, paravertebral block might prevent CPSP intensity and impact on daily life up to 12 months, particularly in high catastrophizing patients. In knee arthroplasty, perioperative regional analgesia or preoperative genicular nerve neuroablation do not prevent CPSP, although current studies present several bias. The protective role of effective regional analgesia and early pain relief in trauma patients deserves further studies.

SUMMARY

Regional analgesia failure to prevent CPSP development should prompt us to reconsider its perioperative utilization. Patients' stratification, for example high-pain responders, might help to target those who will most benefit of regional analgesia. The impact of regional analgesia on secondary pain-related outcomes such as intensity and neuropathic character despite no difference on CPSP incidence requires more studies. Finally, the preventive effect of regional analgesia targeted interventions on CPSP in patients suffering from severe subacute pain deserves to be assessed.

Development and Validation of a Prediction Model for Chronic Post-Surgical Pain After Thoracic Surgery in Elderly Patients: A Retrospective Cohort Study

Purpose

Chronic post-surgical pain (CPSP) is one of the adverse outcomes after surgery, especially in thoracotomy. However, the prevalence of CPSP in elderly adults (≥65 years), is still limited. Therefore, the present study was undertaken to establish and validate the prediction model of CPSP in those patients after thoracic surgery, including thoracotomy and video-assisted thoracoscopic surgery.

Patients and Methods

This retrospective, observational single-center cohort study was conducted in Nanfang Hospital, Southern Medical University, which randomly and consecutively collected 577 elderly patients who underwent thoracic surgery between January 1, 2017, and December 31, 2020. According to the Akaike information criterion, the prediction model was built based on all the data and was validated by calibration with 500 bootstrap samples.

Results

The mean age of participants was 69.09±3.80 years old, and 63.1% were male. The prevalence of CPSP was 26.9%. Age more than 75 years, BMI, blood loss, longer length of hospital stays, and higher pre-operative neutrophil count were associated with CPSP. Except for these factors, we incorporated history of drinking to build up the prediction model. The areas under the curve (AUCs) of the prediction models were 0.66 (95% CI, 0.61–0.71) and 0.64 (95% CI, 0.59–0.69) in the observational and validation cohorts, respectively. And the calibration curve of the predictive model showed a good fit between the predicted risk of CPSP and observed outcomes in elderly patients.

Conclusion

The present developed model may help clinicians to find high-risk elderly patients with CPSP after thoracic surgery and take corresponding measures in advance to reduce the incidence of CPSP and improve their life quality.

Targeting Affective Mood Disorders With Ketamine to Prevent Chronic Postsurgical Pain

The phencyclidine-derivative ketamine [2-(2-chlorophenyl)-2-(methylamino)cyclohexan-1-one] was added to the World Health Organization's Model List of Essential Medicines in 1985 and is also on the Model List of Essential Medicines for Children due to its efficacy and safety as an intravenous anesthetic. In sub-anesthetic doses, ketamine is an effective analgesic for the treatment of acute pain (such as may occur in the perioperative setting). Additionally, ketamine may have efficacy in relieving some forms of chronic pain. In 2019, Janssen Pharmaceuticals received regulatory-approval in both the United States and Europe for use of the S-enantiomer of ketamine in adults living with treatment-resistant major depressive disorder. Pre-existing anxiety/depression and the severity of postoperative pain are risk factors for development of chronic postsurgical pain. An important question is whether short-term administration of ketamine can prevent the conversion of acute postsurgical pain to chronic postsurgical pain. Here, we have reviewed ketamine's effects on the biopsychological processes underlying pain perception and affective mood disorders, focusing on non-NMDA receptor-mediated effects, with an emphasis on results from human trials where available.

Development and validation of a multivariable prediction model for early prediction of chronic postsurgical pain in adults: a prospective cohort study

BACKGROUND

Early identification of patients at risk of developing chronic postsurgical pain (CPSP) is an essential step in reducing pain chronification in postsurgical patients. We aimed to develop and validate a prognostic model for the early prediction of CPSP including pain characteristics indicating altered pain processing within 2 weeks after surgery.

METHODS

A prospective cohort study was conducted in adult patients undergoing orthopaedic, vascular, trauma, or general surgery between 2018 and 2019. Multivariable logistic regression models for CPSP were developed using data from the University Medical Centre (UMC) Utrecht and validated in data from the Erasmus UMC Rotterdam, The Netherlands.

RESULTS

In the development (n=344) and the validation (n=150) cohorts, 28.8% and 21.3% of patients reported CPSP. The best performing model (area under the curve=0.82; 95% confidence interval [CI], 0.76-0.87) included preoperative treatment with opioids (odds ratio [OR]=4.04; 95% CI, 2.13-7.70), bone surgery (OR=2.01; 95% CI, 1.10-3.67), numerical rating scale pain score on postoperative day 14 (OR=1.57; 95% CI, 1.34-1.83), and the presence of painful cold within the painful area 2 weeks after surgery (OR=4.85; 95% CI, 1.85-12.68). Predictive performance was confirmed by external validation.

CONCLUSIONS

As only four easily obtainable predictors are necessary for reliable CPSP prediction, the models are useful for the clinician to be alerted to further assess and treat individual patients at risk. Identification of the presence of painful cold within 2 weeks after surgery as a strong predictor supports altered pain processing as an important contributor to CPSP development.

Pain, numbness, or both? Distinguishing the longitudinal course and predictors of positive, painful neuropathic features vs numbness after breast cancer surgery

Supplemental Digital Content is Available in the Text. Examining the divergence of prevalence and predictors of postsurgical numbness vs positive neuropathic symptoms gives insights into variation in clinical postoperative pain experienced by patients.

Introduction:

Both positive (burning, stabbing, and allodynia) and negative (numbness) neuropathic symptoms may arise after surgery but likely contribute differently to patients' postoperative pain experience. Numbness has been identified as divergent from positive neuropathic symptoms and therefore excluded from some neuropathic assessment tools (Neuropathic Pain Scale for PostSurgical patients [NeuPPS]).

Objectives:

In this prospective longitudinal study of patients undergoing breast surgery, we aimed to delineate the time course of numbness and its coincidence with NeuPPS and to contrast the association of surgical, psychosocial, and psychophysical predictors with the development of negative vs positive neuropathic symptoms.

Methods:

Patients reported surgical area sensory disturbances at 2 weeks and 3, 6, and 12 months postoperatively. Association of baseline demographic, surgical, psychosocial, and psychophysical factors with NeuPPS and numbness across time was investigated using generalized estimating equation linear and logistic regression.

Results:

Numbness was consistently reported by 65% of patients; positive neuropathic symptoms were less common, often decreasing over time. Neuropathic Pain scale for PostSurgical patients and numbness co-occurred in half of patients and were both associated with greater clinical pain severity and impact, younger age, axillary surgery, and psychosocial factors. More extensive surgery and chemotherapy were only associated with numbness. Conversely, other chronic pain, lower physical activity, perioperative opioid use, negative affect, and lower baseline pressure pain threshold and tolerance were only associated with NeuPPS. Patients reporting numbness alone did not endorse substantial clinical pain.

Conclusions:

Differentiation of predictors, prevalence, and time course of numbness vs NeuPPS in breast surgical patients revealed important distinctions, suggesting that their independent assessment is worthwhile in future studies of postsurgical pain.