Predicting, preventing and managing persistent pain after breast cancer surgery: the importance of psychosocial factors

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.

Continuum of somatosensory profiles in breast cancer survivors with and without pain, compared to healthy controls and patients with fibromyalgia

CONTEXT

The prevalence of persistent pain among breast cancer survivors (BCS) is high, and it is unclear what distinguishes those with persistent pain from those without. Research suggests that differences in somatosensory function evaluated by quantitative sensory testing (QST) may be responsible.

OBJECTIVES

This study aimed to describe somatosensory profiles in terms of hyper- and hypoesthesia in BCS with and without persistent pain using reference data from healthy controls. Second, QST parameters of BCS with and without pain were compared with those of healthy controls (i.e., a negative control group) and patients with fibromyalgia (i.e., a positive control group).

METHODS

Participants (n = 128) were divided into four equal groups: healthy controls, BCS with persistent pain, BCS without persistent pain, and patients with fibromyalgia. Nine QST parameters were evaluated at the trunk and at a remote location. Somatosensory profiles were determined by Z-score transformation of QST data using normative data from healthy controls.

RESULTS

At the trunk, compared to healthy controls, BCS with persistent pain exhibited sensory aberrations across five out of seven QST parameters: pressure pain threshold, mechanical detection, and thermal thresholds. Pain-free BCS showed similar sensory aberrations across the four QST parameters compared to healthy controls: mechanical detection and thermal thresholds. Temporal summation and conditioned pain modulation were not significantly different between groups.

CONCLUSION

BCS with persistent pain exert aberrations in peripheral processing of nociceptive signals, heightened facilitation of nociceptive signals, and higher psychosocial burden when compared to pain-free BCS, healthy controls, and patients with fibromyalgia.

SIGNIFICANCE

This study investigates the somatosensory function of breast cancer survivors with and without persistent pain using quantitative sensory testing and two control group (i.e., patients with fibromyalgia and healthy controls). Our results indicate somatosensory aberrations within the peripheral, but not central pathways in breast cancer survivors with persistent pain. Our findings contribute to a better understanding of the somatosensory mechanisms underlying persistent pain, which may inform future interventions to prevent the development of persistent pain, and improve treatment modalities.

Lessons learnt in evidence-based perioperative pain medicine: changing the focus from the medication and procedure to the patient

Over time, the focus of evidence-based acute pain medicine has shifted, from a focus on drugs and interventions (characterized by numbers needed to treat), to an appreciation of procedure-specific factors (characterized by guidelines and meta-analyses), and now anesthesiologists face the challenge to integrate our current approach with the concept of precision medicine. Psychometric and biopsychosocial markers can potentially guide clinicians on who may need more aggressive perioperative pain management, or who would respond particularly well to a given analgesic intervention. The challenge will be to identify an easily assessable set of parameters that will guide perioperative physicians in tailoring the analgesic strategy to procedure and patient.

Altered somatosensory functioning and mechanism-based classification in breast cancer patients with persistent pain

Pain is one of the most frequent and persistent side effects of breast cancer treatment. Besides pain, breast cancer survivors (BCS) are prone to experience a myriad of other signs and symptoms related to altered somatosensory function, including for example, hypoesthesia, allodynia, and hyperalgesia, both at the local site of cancer and in remote body parts. Different breast cancer treatments can have a direct effect on somatosensory functioning, resulting in a wide range of these signs and symptoms. To our knowledge, currently no comprehensive overview exists on altered somatosensory functioning and resulting signs and symptoms in BCS with persistent pain. Investigating altered somatosensory functioning in this population could provide more insights in the underpinning pathophysiological mechanisms and consequently improve prevention and treatment in the future. Therefore, in this paper, first, normal somatosensory functioning is described. Second, quantitative sensory testing is presented as the recommend method to evaluate somatosensory functioning. Third, existing evidence on altered somatosensory functioning in BCS with persistent pain is summarized. Altered somatosensory functioning related to the most common cancer treatment modalities, including surgery and radiotherapy, hormone therapy, and chemotherapy are discussed. In addition, evidence on the presence of nociplastic pain as pain resulting from altered somatosensory functioning without evidence for nociception and/or neuropathy in BCS is summarized. At last, a discussion on this available evidence, limitations, and perspectives for clinical practice and for research are made.

Chronic pain after breast surgery: incidence, risk factors and impact on quality of life

INTRODUCTION AND OBJECTIVES

Breast cancer is the most frequently diagnosed malignancy, and chronic pain after breast surgery (CPBS) is an increasingly recognized therapy-related problem. We evaluated CPBS incidence, characteristics, associated factors, and impact on patient quality of life (QoL).

MATERIALS AND METHODS

Six-month observational prospective study conducted in patients undergoing breast surgery in a tertiary university hospital. Data were collected using several questionnaires: Pain Catastrophizing Scale, Brief Pain Inventory-Short Form, Douleur Neuropathique 4 Questionnaire, and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire and its Breast Cancer Module.

RESULTS

A total of 112 patients completed the study. Approximately, one third (34.8%) developed CPBS, and almost all with potentially neuropathic pain. CPBS interfered with patients' daily life and reduced their QoL. Diabetes (p = 0.028), catastrophizing (p = 0.042), and acute postoperative pain severity (p < 0.001) were associated with CPBS.

CONCLUSIONS

This study broadens our understanding of CPBS and shows the impact of this syndrome. Healthcare workers need to be aware of CPBS and take steps to prevent and treat it, and provide patients with adequate information.

Concurrent validity of dynamic bedside quantitative sensory testing paradigms in breast cancer survivors with persistent pain

BACKGROUND

Studies on the concurrent validity of clinically applicable testing protocols for conditioned pain modulation (CPM) and temporal summation of pain (TSP) in breast cancer survivors (BCS) with persistent pain are lacking.

OBJECTIVES

This study investigated the concurrent validity of two bedside protocols for CPM and TSP in comparison to a respective reference protocol. The participants' preferences for bedside CPM and TSP protocols were assessed.

METHODS

Thirty BCS experiencing persistent pain were included in this study. Each participant underwent a reference test along with two bedside alternatives for assessing both TSP and CPM. For CPM, a cold pressor test (CPT) and blood pressure cuff (BPC) were used as conditioning stimulus. The test stimulus was elicited in parallel by pressure pain threshold after 45 and 90 s of conditioning at the lower limb. The CPM reference test consisted of parallel heat stimuli at the forearms using a two-thermode system. TSP was elicited using a von Frey monofilament (256 mN) and an algometer (98 kPa) at the affected site and opposite lower limb. The TSP reference test consisted of heat stimuli at the affected site and opposite lower limb. Participants' testing preference was examined using a purpose-designed questionnaire. Spearman's rank test examined the correlation between protocols.

RESULTS

The two bedside CPM protocols were strongly correlated (r = 0.787-0.939, p < 0.005). A strong correlation was found between the BPC protocol and reference test using the relative effect magnitude (r = 0.541-0.555, p < 0.005). The bedside TSP protocols were moderately correlated with each other only at the lower limb using absolute change scores (r = 0.455, p = 0.012). No significant correlation was found between the bedside and reference TSP protocols.

CONCLUSION

The significantly moderate to very strong correlations between the bedside protocols validate their interchangeability. Researchers and clinicians should be able to choose which bedside protocol they utilize; however, participants favored the use of a BPC and algometer for the evaluation of CPM and TSP, respectively.

Development and prospective validation of postoperative pain prediction from preoperative EHR data using attention-based set embeddings

Preoperative knowledge of expected postoperative pain can help guide perioperative pain management and focus interventions on patients with the greatest risk of acute pain. However, current methods for predicting postoperative pain require patient and clinician input or laborious manual chart review and often do not achieve sufficient performance. We use routinely collected electronic health record data from a multicenter dataset of 234,274 adult non-cardiac surgical patients to develop a machine learning method which predicts maximum pain scores on the day of surgery and four subsequent days and validate this method in a prospective cohort. Our method, POPS, is fully automated and relies only on data available prior to surgery, allowing application in all patients scheduled for or considering surgery. Here we report that POPS achieves state-of-the-art performance and outperforms clinician predictions on all postoperative days when predicting maximum pain on the 0-10 NRS in prospective validation, though with degraded calibration. POPS is interpretable, identifying comorbidities that significantly contribute to postoperative pain based on patient-specific context, which can assist clinicians in mitigating cases of acute pain.

The Interconnection Between Social Support and Emotional Distress Among Individuals with Chronic Pain: A Narrative Review

Chronic pain is a public health concern affecting over 100 million U.S. adults. Because chronic pain is multifactorial, it requires a biopsychosocial approach to understand how biological, psychological, and social factors contribute to both the development and maintenance of pain. On average, individuals with chronic pain report higher levels of emotional distress compared to pain-free individuals. Research has demonstrated that social support is associated with better pain outcomes and less emotional distress. It has been proposed that social support may improve pain outcomes by reducing the influence of stressors. However, the majority of research exploring the relationships between social support and pain-related outcomes has focused on the direct relationship between these variables, largely overlooking the process by which social support has a positive influence on pain. This narrative review synthesizes research on how chronic pain, emotional distress, and social support are highly interconnected, yet research investigating chronic pain and emotional distress within a social context is limited. We then highlight disparities in chronic pain, such that the burden of chronic pain is unequal between demographic groups. Next, we discuss existing evidence for the use of group-based interventions to address pain-related outcomes. Lastly, we summarize limitations of prior research studies and highlight gaps in the current literature. Overall, longitudinal research comprehensively investigating the distinct nuances in the measurement of social support and how these nuances relate to emotional distress and pain outcomes is needed and may provide insight into the unique needs of individuals or subgroups. Further, demographically diverse randomized controlled trials are needed to identify the process by which group-based interventions improve pain outcomes and whether these interventions are more effective for particular groups in order to personalize treatment approaches and address inequities in pain care.

Postoperative effect of sufentanil preemptive analgesia combined with psychological intervention on breast cancer patients

OBJECTIVES

To explore the postoperative effects of sufentanil preemptive analgesia combined with psychological intervention on breast cancer patients undergoing radical surgery.

METHODS

112 female breast cancer patients aged 18-80 years old who underwent radical surgery by the same surgeon were randomly divided into 4 groups, and there were 28 patients in each group. Patients in group A were given 10 µg sufentanil preemptive analgesia combined with perioperative psychological support therapy (PPST), group B had only 10 µg sufentanil preemptive analgesia, group C had only PPST, and group D were under general anesthesia with conventional intubation. Visual analogue scoring (VAS) was used for analgesic evaluation at 2, 12 and 24 h after surgery and compared among the four groups by ANOVA method.

RESULTS

The awakening time of patients in group A or B was significantly shorter than that in group C or D, and the awakening time in group C was significantly shorter than that in group D. Moreover, patients in group A had the shortest extubation time, while the group D had the longest extubation time. The VAS scores at different time points showed significant difference, and the VAS scores at 12 and 24 h were significantly lower than those at 2 h (P < 0.05). The VAS scores and the changing trend of VAS scores were varied among the four groups (P < 0.05). In addition, we also found that patients in group A had the longest time to use the first pain medication after surgery, while patients in group D had the shortest time. But the adverse reactions among the four groups showed no difference.

CONCLUSIONS

Sufentanil preemptive analgesia combined with psychological intervention can effectively relieve the postoperative pain of breast cancer patients.

Optimising psychological treatment for pain after breast cancer: a factorial design study protocol in Denmark

INTRODUCTION

One in five breast cancer (BC) survivors are affected by persistent pain years after completing primary treatment. While the efficacy of psychological interventions for BC-related pain has been documented in several meta-analyses, reported effect sizes are generally modest, pointing to a need for optimisation. Guided by the Multiphase Optimization Strategy, the present study aims to optimise psychological treatment for BC-related pain by identifying active treatment components in a full factorial design.

METHODS AND ANALYSIS

The study uses a 2×3 factorial design, randomising 192 women with BC-related pain (18-75 years) to eight experimental conditions. The eight conditions consist of three contemporary cognitive-behavioural therapy components, namely: (1) mindful attention, (2) decentring, and (3) values and committed action. Each component is delivered in two sessions, and each participant will receive either zero, two, four or six sessions. Participants receiving two or three treatment components will be randomised to receive them in varying order. Assessments will be conducted at baseline (T1), session by session, every day for 6 days following the first session in each treatment component, at post-intervention (T2) and at 12-week follow-up (T3). Primary outcomes are pain intensity (Numerical Rating Scale) and pain interference (Brief Pain Inventory interference subscale) from T1 to T2. Secondary outcomes are pain burden, pain quality, pain frequency, pain catastrophising, psychological distress, well-being and fear of cancer recurrence. Possible mediators include mindful attention, decentring, and pain acceptance and activity engagement. Possible moderators are treatment expectancy, treatment adherence, satisfaction with treatment and therapeutic alliance.

ETHICS AND DISSEMINATION

Ethical approval for the present study was received from the Central Denmark Region Committee on Health Research Ethics (no: 1-10-72-309-40). Findings will be made available to the study funders, care providers, patient organisations and other researchers at international conferences, and published in international, peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT05444101).

Towards precision pain medicine for pain after cancer: the Cancer Pain Phenotyping Network multidisciplinary international guidelines for pain phenotyping using nociplastic pain criteria

Pain after cancer remains underestimated and undertreated. Precision medicine is a recent concept that refers to the ability to classify patients into subgroups that differ in their susceptibility to, biology, or prognosis of a particular disease, or in their response to a specific treatment, and thus to tailor treatment to the individual patient characteristics. Applying this to pain after cancer, the ability to classify post-cancer pain into the three major pain phenotypes (i.e. nociceptive, neuropathic, and nociplastic pain) and tailor pain treatment accordingly, is an emerging issue. This is especially relevant because available evidence suggests that nociplastic pain is present in an important subgroup of those patients experiencing post-cancer pain. The 2021 International Association for the Study of Pain (IASP) clinical criteria and grading system for nociplastic pain account for the need to identify and correctly classify patients according to the pain phenotype early in their treatment. These criteria are an important step towards precision pain medicine with great potential for the field of clinical oncology. Within this framework, the Cancer Pain Phenotyping (CANPPHE) Network, an international and interdisciplinary group of oncology clinicians and researchers from seven countries, applied the 2021 IASP clinical criteria for nociplastic pain to the growing population of those experiencing post-cancer pain. A manual is provided to allow clinicians to differentiate between predominant nociceptive, neuropathic, or nociplastic pain after cancer. A seven-step diagnostic approach is presented and illustrated using cases to enhance understanding and encourage effective implementation of this approach in clinical practice.

Applying the Rapid OPPERA Algorithm to Predict Persistent Pain Outcomes Among a Cohort of Women Undergoing Breast Cancer Surgery

Persistent postmastectomy pain after breast surgery is variable in duration and severity across patients, due in part to interindividual variability in pain processing. The Rapid OPPERA Algorithm (ROPA) empirically identified 3 clusters of patients with different risk of chronic pain based on 4 key psychophysical and psychosocial characteristics. We aimed to test this type of group-based clustering within in a perioperative cohort undergoing breast surgery to investigate differences in postsurgical pain outcomes. Women (N = 228) scheduled for breast cancer surgery were prospectively enrolled in a longitudinal observational study. Pressure pain threshold (PPT), anxiety, depression, and somatization were assessed preoperatively. At 2-weeks, 3, 6, and 12-months after surgery, patients reported surgical area pain severity, impact of pain on cognitive/emotional and physical functioning, and pain catastrophizing. The ROPA clustering, which used patients' preoperative anxiety, depression, somatization, and PPT scores, assigned patients to 3 groups: Adaptive (low psychosocial scores, high PPT), Pain Sensitive (moderate psychosocial scores, low PPT), and Global Symptoms (high psychosocial scores, moderate PPT). The Global Symptoms cluster, compared to other clusters, reported significantly worse persistent pain outcomes following surgery. Findings suggest that patient characteristic-based clustering algorithms, like ROPA, may generalize across diverse diagnoses and clinical settings, indicating the importance of "person type" in understanding pain variability. PERSPECTIVE: This article presents the practical translation of a previously developed patient clustering solution, based within a chronic pain cohort, to a perioperative cohort of women undergoing breast cancer surgery. Such preoperative characterization could potentially help clinicians apply personalized interventions based on predictions concerning postsurgical pain.

Increased Clinical Pain Locations and Pain Sensitivity in Women After Breast Cancer Surgery: Influence of Aromatase Inhibitor Therapy

OBJECTIVES

Aromatase inhibitors (AIs), which potently inhibit estrogen biosynthesis, are a standard treatment for hormone sensitive early-stage breast cancer. AIs have been associated with substantial joint pain and muscle stiffness (aromatase inhibitor-associated musculoskeletal syndrome). However, the link between AIs and number of clinical pain locations and pain sensitivity are less well understood. The aim of this study was to compare longitudinal changes in clinical pain and quantitative pain sensitivity between women who did or did not receive AI therapy.

METHODS

Women with early-stage breast cancer were prospectively enrolled and assessed for clinical pain in surgical and nonsurgical body areas using the Brief Pain Inventory and Breast Cancer Pain Questionnaire, and for pain sensitivity using quantitative sensory testing preoperatively and at 1 year postoperatively. Pain outcomes between participants who did and did not begin adjuvant AI therapy were compared using Wilcoxon Signed-Ranks and generalized estimating equation linear regression analyses.

RESULTS

Clinical pain and pain sensitivity were comparable between AI (n=49) and no-AI (n=106) groups preoperatively. After adjusting for body mass index, AI therapy was associated with a greater increase in the number of painful nonsurgical body sites (significant time by treatment interaction, P =0.024). Pain location was most frequent in knees (28%), lower back (26%), and ankles/feet (17%). Quantitative sensory testing revealed a significant decrease in pain sensitivity (increased pressure pain threshold) in the no-AI group over time, but not in the AI group.

CONCLUSIONS

AI therapy was associated with increased diffuse joint-related pain and greater post-treatment pain sensitivity, potentially implicating central sensitization as a contributing pain mechanism of aromatase inhibitor-associated musculoskeletal syndrome worthy of future investigation.

Validation of pain catastrophizing scale on breast cancer survivor

INTRODUCTION

Pain catastrophizing scale (PCS) is the most used scale to measure pain catastrophizing. In breast cancer survivors (BCS), pain catastrophizing is related to upper-limbs dysfunction and disability. This study aimed to assess the internal consistency, internal structure, and convergent validity of the Spanish version of the PCS in Spanish BCS.

MATERIAL AND METHODS

Breast cancer survivors were recruited from the service of Medical Oncology of the University Clinical Hospital Virgen de la Victoria, in Málaga (Spain). The psychometric properties were evaluated with analysis factor structure by maximum likelihood extraction (MLE), internal consistency, and construct validity by confirmatory factor analysis (CFA).

RESULTS

Factor structure was three-dimensional, and one item was removed due to cross-loading. The new 12-item PCS showed a high internal consistency for the total score (α = 0.91) and a good homogeneity, and CFA revealed a satisfactory fit. PCS showed an acceptable correlation with FACS (r = 0.53, p < 0.01).

CONCLUSION

Pain catastrophizing scale is a valid and reliable instrument to evaluate pain catastrophizing in Spanish BCS. This tool may help clinicians in the management of pain by assessing pain and by measuring the effect of interventions.

Cross-Sectional Comparative Study on Central Sensitization-Psychosocial Associated Comorbidities and Psychological Characteristics in Breast Cancer Survivors with Nociceptive Pain and Pain with Neuropathic Features and without Pain

Simple Summary

Persistent pain after breast cancer treatment is still under research due to its complex and multifactorial underlying pathogenesis, including phycological factors. Further research is needed to elucidate more information about the factors that cause and perpetuate this pain. Thus, this study defined the influence of psychosocial and psychological factors on breast cancer survivors who report pain and those who do not. The psychosocial factors assessed were those that are associated with a central sensitization process, and the psychological factors were pain catastrophizing, fear of movement, anxiety and depression. Hence, the psychosocial symptom clusters were identified related to the clinical features of pain or to not reporting pain, which may encourage health clinicians to establish a customized biopsychosocial model focused on the management of pain-catastrophizing thoughts and fear of movement. Furthermore, anxiety and depression should be detected early by health professionals and referred to psychologists to be managed.

Abstract

The frequency of a high Central Sensitization Inventory (CSI) total score and the prevalence of pain have already been established among breast cancer survivors (BCS). However, the psychological factors’ influence based on the clinical features of pain is still unknown, as well as BCS characteristics with no pain. Thus, our main aim was to evaluate the presence of a high CSI total score in BCS with pain and compare it with BCS without pain and to evaluate the influence of psychosocial factors. A cross-sectional comparative study was designed to compare BCS with nociceptive pain (n = 19), pain with neuropathic features (n = 19) or no pain (n = 19), classified by the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS). CSI, pain catastrophizing, fear of movement, anxiety and depression symptoms were analyzed and compared among the three groups. The CSI total score was higher in both BCS pain groups compared to BCS without pain, but there were no statistical differences between the pain groups. The same observation was made when comparing pain catastrophizing. The neuropathic feature group showed greater levels of fear of movement, anxiety and depression compared to the no pain group. Thus, CS-psychosocial associated comorbidities and pain-catastrophizing thoughts were more prevalent among BCS with pain, regardless of the clinical features of pain. BCS with neuropathic pain features showed greater psychological disturbances.

Questionnaire-based somatosensory profiling in breast cancer survivors: are we there yet? Associations between questionnaires and quantitative sensory testing

PURPOSE

Pain and sensory disturbances are common side effects of breast cancer treatment. Differential somatosensory functioning may reflect distinct pathophysiological backgrounds and therapeutic needs. Aim was to examine whether questionnaires evaluating signs and symptoms related to somatosensory functioning correlate sufficiently with quantitative sensory testing (QST) in breast cancer survivors to warrant consideration for somatosensory profiling in clinical practice.

METHODS

One year after breast cancer surgery, 147 women underwent QST and completed following questionnaires: Douleur Neuropathique en 4 questions (DN4), Central Sensitization Inventory, Margolis Pain Diagram and Visual Analog Scales (VAS). Associations between the questionnaires and QST were evaluated using Spearman correlation coefficients (rs).

RESULTS

Significant but weak (rs < 0.30) correlations were found between total DN4 score and QST results at the inner upper arm for detection of sharp stimuli (rs = 0.227), cold stimuli (rs = -0.186), and painful heat stimuli (rs = 0.179), as well as between QST evaluating conditioned pain modulation and the Margolis Pain Diagram on one hand (rs = 0.176) and minimum-maximum pain intensity differences (VAS) on the other (rs = -0.170).

CONCLUSION

Questionnaires evaluating signs and symptoms related to somatosensory functioning are insufficient for somatosensory profiling. Although somatosensory profiling may be valuable in a mechanism-based management, more research on the most appropriate clinical tools is needed.IMPLICATIONS FOR REHABILITATIONClinicians should be able to recognize that patients with persistent pain or sensory disturbances following breast cancer surgery may have a component of altered somatosensory processing as a significant contributor to their complaint in order to address it appropriately.Somatosensory profiling has yet to be implemented into clinical practice.No evidence-based recommendations can be made on the use of self-reported questionnaires to assess somatosensory processing in a breast cancer population based on the findings of this study.It is suggested to combine information on how individuals process and experience somatosensory stimulation with information from the patient interview or questionnaires to consider which biological, psychological and/or social factors may drive or sustain these neurophysiological processes.

Multimodal prediction of pain and functional outcomes 6 months following total knee replacement: a prospective cohort study

BACKGROUND

Knee osteoarthritis (OA) is among the most common and disabling persistent pain conditions, with increasing prevalence and impact around the globe. In the U.S., the rising prevalence of knee OA has been paralleled by an increase in annual rates of total knee arthroplasty (TKA), a surgical treatment option for late-stage knee OA. While TKA outcomes are generally good, post-operative trajectories of pain and functional status vary substantially; a significant minority of patients report ongoing pain and impaired function following TKA. A number of studies have identified sets of biopsychosocial risk factors for poor post-TKA outcomes (e.g., comorbidities, negative affect, sensory sensitivity), but few prospective studies have systematically evaluated the unique and combined influence of a broad array of factors.

METHODS

This multi-site longitudinal cohort study investigated predictors of 6-month pain and functional outcomes following TKA. A wide spectrum of relevant biopsychosocial predictors was assessed preoperatively by medical history, patient-reported questionnaire, functional testing, and quantitative sensory testing in 248 patients undergoing TKA, and subsequently examined for their predictive capacity.

RESULTS

The majority of patients had mild or no pain at 6 months, and minimal pain-related impairment, but approximately 30% reported pain intensity ratings of 3/10 or higher. Reporting greater pain severity and dysfunction at 6 months post-TKA was predicted by higher preoperative levels of negative affect, prior pain history, opioid use, and disrupted sleep. Interestingly, lower levels of resilience-related "positive" psychosocial characteristics (i.e., lower agreeableness, lower social support) were among the strongest, most consistent predictors of poor outcomes in multivariable linear regression models. Maladaptive profiles of pain modulation (e.g., elevated temporal summation of pain), while not robust unique predictors, interacted with psychosocial risk factors such that the TKA patients with the most pain and dysfunction exhibited lower resilience and enhanced temporal summation of pain.

CONCLUSIONS

This study underscores the importance of considering psychosocial (particularly positively-oriented resilience variables) and sensory profiles, as well as their interaction, in understanding post-surgical pain trajectories.

Clinical Characteristics of Noncancer-Related Upper Back Pain on Initiation of Palliative Care in Patients with Incurable Cancer

Background: Cancer patients experience various types of pain unrelated to their malignancy. However, no previous study has reported the prevalence of noncancer-related pain among patients with incurable cancer.

Objective: We aimed to investigate the frequency of noncancer-related upper back pain, the type of noncancer disease, and pain intensity among patients.

Design: This is a multicenter cross-sectional survey.

Setting/Subjects: Subjects were patients with incurable cancer who underwent initiation of palliative care at two university hospitals in Japan.

Measurements: Data for patient characteristics were recorded, and the upper back pain intensity, duration, analgesic use, and opioid drug use with dose were determined. Appropriate statistical tests were also performed.

Results: Among the 103 patients with upper back pain, 20 (19.4%) had cancer-related pain, 28 (27.2%) had both cancer- and noncancer-related pain, and 53 (51.5%) had only noncancer-related pain. Myofascial pain was suspected in the 72 (88.9%) participants with noncancer-related pain. The median pain numerical rating scale score was four in the cancer-related pain group and seven in the other two groups (p = 0.005).

Conclusions: A high proportion of outpatients with incurable cancer undergoing palliative care initiation had noncancer-related upper back pain. Severe pain at the initiation of palliative care in patients with incurable cancer may include noncancer-related pain. Trial Registration: UMIN000038371. Registered December 1, 2019.

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.

Perception of music and its cultural elements on acute post-mastectomy pain management among Nigerian women: an exploratory qualitative study

PURPOSE

This study aimed to explore the cultural elements of music in relation to pain management among women who have undergone mastectomy.

METHOD

An exploratory qualitative study with in-depth interviews. Using the purposive sampling technique, 20 participants were recruited for the study. The interviews were conducted face to face at the surgical out-patient clinic and female surgical ward. Data collection continued until data saturation was reached. The inductive approach was used to analyse the data, and the concepts were organised into themes. The consolidated criteria for reporting qualitative research guidelines (COREQ) were used to report this study.

RESULTS

The participants were between 28 and 83 years old and mostly diagnosed with stage III breast cancer. Three main themes emerged from the data analysis, including pain experienced after mastectomy, culture and music, and the perception of music for postoperative pain management after mastectomy.

CONCLUSION

In this study, the knowledge of participants and the utilisation of music for pain management remains inadequate, but the participants perceived that music could be useful for pain control after mastectomy when the language and religion of the patient and the meaningfulness of the music were considered when introducing and selecting the music. This study will help open and extend the conversation about the utilisation and cultural elements of music that can be used clinically for pain management after mastectomy.

Pain Control After Mastectomy in Transgender Patients: Ultrasound-guided Pectoral Nerve Block II Versus Conventional Intercostal Nerve Block: A Randomized Clinical Trial

Background

Mastectomy is sometimes performed in transgender patients, which may damage the regional nerves such as the pectoral and intercostobrachial nerves, leading to postoperative pain. An ultrasound-guided nerve block can be used to track and block the nerves properly.

Objectives

This study aimed to compare the ultrasound-guided type-II pectoral nerve block with the blind (conventional) intercostal nerve block (ICNB) for pain control after breast tissue reconstruction surgery in transgender patients.

Methods

In the present single-blind randomized clinical trial, 47 patients were randomly divided into two groups: (A) Ultrasound-guided type-II pectoral nerve block (n = 23) and (B) blind intercostal nerve block (n = 24). After nerve block in both groups, pain intensity at 3, 6, 12, and 24 hours after surgery, upper limb paresthesia, frequency of nausea and vomiting, shortness of breath, hematoma, and the length of hospital stay were assessed.

Results

Patients who received the ultrasound-guided type-II pectoral nerve block had a greater reduction in pain intensity (24 h after surgery), opioid use (24 h after surgery), nausea, vomiting, and hospital stay than those who received ICNB, whereas the recovery time did not differ between the study groups.

Conclusions

The pectoral nerve block under ultrasound guidance, compared to the intercostal nerve block, in transgender patients can reduce the required dosage of opioids within 24 hours, pain intensity within 24 hours after surgery, the incidence of postoperative nausea, and vomiting, and the hospital stay of patients.

Validity and reliability of the Spanish fear-avoidance components scale in breast cancer survivors

OBJECTIVE

The aim of this study was to carry out a psychometric analysis of the Fear-Avoidance Components Scale (FACS-Sp) in Spanish breast cancer survivors (BCS).

METHODS

A validation study was carried out in 154 BCS. Participants were recruited from the service of Medical Oncology of the University Clinical Hospital Virgen de la Victoria, in Málaga (Spain). A psychometric analysis of internal consistency, internal structure and convergent validity of the FACS-Sp was performed. Cronbach's alpha was calculated for internal consistency. Exploratory Factor Analysis was used to determine the internal structure of the FACS-Sp. Convergent validity with the Tampa Scale of Kinesiophobia (TSK) and the Pain Catastrophizing Scale (PCS) was determined using the Pearson correlation coefficient.

RESULTS

The internal consistency was high (McDonald's ω = 0.91). The Exploratory Factor Analysis yielded one factor explaining the 40.80% of total variance. Convergent validity with the TSK and the PCS was demonstrated.

CONCLUSIONS

The FACS-Sp has demonstrated to be a valid and reliable measure for assessing pain-related fear avoidance in BCS based on internal consistency, structural validity and convergent validity. Further studies that analyse other measurement properties in different Spanish cancer populations are needed.

Effects of non-pharmacological interventions on preoperative anxiety and postoperative pain in patients undergoing breast cancer surgery: A systematic review

BACKGROUND

Poorly managed preoperative anxiety and pain were reported to slow the postoperative recovery of breast cancer patients. Thus, proactive management using non-pharmacological interventions becomes essential for decreasing opioid or anxiolytics consumption, anxiety level, pain intensity, postoperative complications and improving patients' haemodynamics and satisfaction with care.

PURPOSE

To identify, analyse and synthesise the effects of non-pharmacological interventions on preoperative anxiety and acute postoperative pain in women undergoing breast cancer surgery.

METHOD

For this systematic review, 12 databases including Ovid Nursing, PsycInfo, British Nursing Index, CINAHL, Cochrane Library were searched to identify relevant studies. A total of 6,012 articles were identified from the search, six RCTs and one quasi-experimental study that met the inclusion criteria were included after eligibility screening. Narrative synthesis was used to analyse data extracted from the included articles. The review adhered to the PRISMA guideline.

RESULTS

Twelve outcomes were measured in the included studies, including preoperative anxiety, and acute postoperative pain. Music, massage, aromatherapy and acupuncture were the interventions delivered. Music had a small-to-large effect size and aromatherapy had a small effect size on reducing preoperative anxiety. Also, music had a large effect size whilst acupuncture had a medium effect size on minimising postoperative pain in women undergoing breast cancer surgery.

CONCLUSION

Music, aromatherapy and acupuncture appeared to be effective for reducing preoperative anxiety and postoperative pain in women undergoing breast cancer surgery. However, the small number of studies available for each intervention prevents conclusive statements about which the most effective method.

IMPLICATION FOR CLINICAL PRACTICE

A nursing care pathway that standardises the use of non-pharmacological interventions for the management of both preoperative anxiety and postoperative pain in breast cancer surgery patients should be developed.

Contemplating or Acting? Which Immersive Modes Should Be Favored in Virtual Reality During Physiotherapy for Breast Cancer Rehabilitation

Background

Even though virtual reality (VR) is more and more considered for its power of distraction in different medical contexts, the optimal conditions for its use still have to be determined in order to design interfaces adapted to therapeutic support in oncology.

Objective

The objective of this study was to examine the benefits of VR using two immersion methods (i.e., one participatory, one contemplative) and comparing them with each other in a population of women with breast cancer who have undergone breast surgery, during scar massage sessions.

Methods

In a physiotherapy center, each patient participated in four experimental conditions in a random order: two sessions used virtual immersion (i.e., one participatory and one contemplative), one session proposed musical listening and the fourth one was a standard session care. The impact of the level of patient involvement in the virtual world was apprehended through the evaluation of the feeling of presence; the estimation of elapsed time of the physiotherapy sessions and particular attention was paid to the evaluation of patient emotional state.

Results

Our study showed an increase in positive emotions (i.e., joy and happiness) and a decrease in anxiety regardless which support methods were offered. Participatory VR created a feeling of more intense spatial presence.

Conclusion

Our results highlight the importance of the context in which VR should be offered. The presence of the practitioner and his interactions with the patient can provide a context just as favorable in reducing anxiety as the emotional regulation tools used (VR, music). The use of technological tools should be favored when the practitioner is unavailable during the treatment phase or, even, in order to reduce the monotonous nature of repetitive therapeutic sessions.

Effect of perioperative pain neuroscience education in patients with post-mastectomy persistent pain: a retrospective, propensity score-matched study

PURPOSE

Central sensitization (CS)-related symptoms and pain catastrophizing contribute to persistent post-mastectomy pain (PPMP). Pain neuroscience education (PNE) is effective in reducing CS-related symptoms and pain catastrophizing in patients with chronic pain. However, to date, no intervention study of PNE has been conducted to patients with PPMP. This study was aimed to examine whether PNE is more effective than biomedical education (BME) for PPMP.

METHODS

In this retrospective case-control study, 118 patients were included. We intervened different patients at different times as follows: (1) a BME group (n = 58) of patients who received BME combined with physiotherapy and (2) a PNE group (n = 60) of patients who received PNE combined with physiotherapy. One year after surgery, we assessed pain intensity and interference (brief pain inventory [BPI]), CS-related symptoms (central sensitization inventory [CSI]), and pain catastrophizing (pain catastrophizing scale [PCS]). Propensity score matching was used to reduce or minimize selection bias and confounding biases and to make the number of cases in both groups match 1:1.

RESULTS

Propensity score matching generated the BME group (n = 51) and the PNE group (n = 51). The BPI score, CSI score, and PCS score were statistically significantly lower in the PNE group than in the BME group (all, p < 0.05). The effect sizes for the BPI intensity (r = 0.31) were moderate.

CONCLUSIONS

PNE resulted in a better outcome of pain management with less functional disability and CS-related symptoms compared to BME after breast surgery.

"Making Peace with Our Bodies": A Qualitative Analysis of Breast Cancer Survivors' Experiences with Qigong Mind-Body Exercise

Objectives: Breast cancer treatment leaves breast cancer survivors (BCS) with an array of lasting side effects, including persistent postsurgical pain (PPSP). In this study, we explored the perceptions of BCS with PPSP as they learned Qigong mind-body exercise (QMBE), a multimodal practice rooted in Traditional Chinese Medicine. Methods: Participants included 18 female BCS treated for stage 0-III breast cancer and experiencing PPSP. Participants were taught QMBE over 12 weeks. Semi-structured interviews were conducted before and after the intervention. Results: BCS disclosed a disconnect between mind and body that emerged during treatment. They perceived QMBE as moving meditation, which enabled them to reconnect mind and body, lessen their pain, and make peace with their bodies. Conclusion: These women's experiences both inform the promise of integrating QMBE and related mind-body exercise into PPSP clinical practice guidelines and suggest new areas of research regarding the role of multimodal interventions for holistic healing in BCS.

Prediction of Persistent Pain Severity and Impact 12 Months After Breast Surgery Using Comprehensive Preoperative Assessment of Biopsychosocial Pain Modulators

BACKGROUND

Persistent post-mastectomy pain (PPMP) is a significant negative outcome occurring after breast surgery, and understanding which individual women are most at risk is essential to targeting of preventive efforts. The biopsychosocial model of pain suggests that factors from many domains may importantly modulate pain processing and predict the progression to pain persistence.

METHODS

This prospective longitudinal observational cohort study used detailed and comprehensive psychosocial and psychophysical assessment to characterize individual pain-processing phenotypes in 259 women preoperatively. Pain severity and functional impact then were longitudinally assessed using both validated surgery-specific and general pain questionnaires to survey patients who underwent lumpectomy, mastectomy, or mastectomy with reconstruction in the first postsurgical year. An agnostic, multivariable modeling strategy identified consistent predictors of several pain outcomes at 12 months.

RESULTS

The preoperative characteristics most consistently associated with PPMP outcomes were preexisting surgical area pain, less education, increased somatization, and baseline sleep disturbance, with axillary dissection emerging as the only consistent surgical variable to predict worse pain. Greater pain catastrophizing, negative affect, younger age, higher body mass index (BMI), and chemotherapy also were independently predictive of pain impact, but not severity. Sensory disturbance in the surgical area was predicted by a slightly different subset of factors, including higher preoperative temporal summation of pain.

CONCLUSIONS

This comprehensive approach assessing consistent predictors of pain severity, functional impact, and sensory disturbance may inform personalized prevention of PPMP and also may allow stratification and enrichment in future preventive studies of women at higher risk of this outcome, including pharmacologic and behavioral interventions and regional anesthesia.

The role of regional anaesthesia and multimodal analgesia in the prevention of chronic postoperative pain: a narrative review

Effective prevention of chronic postoperative pain is an important clinical goal, informed by a growing body of studies. Peri-operative regional anaesthesia remains one of the most important tools in the multimodal analgesic toolbox, blocking injury-induced activation and sensitisation of both the peripheral and central nervous system. We review the definition and taxonomy of chronic postoperative pain, its mechanistic basis and the most recent evidence for the preventative potential of multimodal analgesia, with a special focus on regional anaesthesia. While regional anaesthesia targets several important aspects of the mechanistic pathway leading to chronic postoperative pain, evidence for its efficacy is still mixed, possibly owing to the heterogeneity of risk profiles within the surgical patient, but also to variation in techniques and medications reported in the literature.

Patient phenotyping in clinical trials of chronic pain treatments: IMMPACT recommendations

There is tremendous interpatient variability in the response to analgesic therapy (even for efficacious treatments), which can be the source of great frustration in clinical practice. This has led to calls for “precision medicine” or personalized pain therapeutics (ie, empirically based algorithms that determine the optimal treatments, or treatment combinations, for individual patients) that would presumably improve both the clinical care of patients with pain and the success rates for putative analgesic drugs in phase 2 and 3 clinical trials. However, before implementing this approach, the characteristics of individual patients or subgroups of patients that increase or decrease the response to a specific treatment need to be identified. The challenge is to identify the measurable phenotypic characteristics of patients that are most predictive of individual variation in analgesic treatment outcomes, and the measurement tools that are best suited to evaluate these characteristics. In this article, we present evidence on the most promising of these phenotypic characteristics for use in future research, including psychosocial factors, symptom characteristics, sleep patterns, responses to noxious stimulation, endogenous pain-modulatory processes, and response to pharmacologic challenge. We provide evidence-based recommendations for core phenotyping domains and recommend measures of each domain.

Pain Neuroscience Education in cancer survivors with persistent pain: A pilot study

PURPOSE

To describe the Pilot Study: Pain Neuroscience Education in Cancer Survivors and describe the innovative educational component of Pain Neuroscience Education (PNE).

DESIGN

Quasi experimental design.

METHOD

The PNE program, encompassing a one-on-one education session and an information leaflet was given to 30 cancer survivors. At baseline and two weeks after the PNE, participants were asked to fill out following outcome measures; pain intensity, pain catastrophizing, and HRQoL.

FINDINGS

Following PNE, a significant decrease on pain intensity (p = 0.001), on the SF-36 subscale pain (p = 0.003) and for the following PCS subscales: Helplessness (p < 0.001), Rumination (p = 0.002) and Total score (p < 0.001) was found compared to baseline.

CONCLUSIONS

Although the current results need to be verified in a larger randomized, controlled trial, preliminary evidence shows a decrease in pain intensity and pain catastrophizing following PNE in cancer survivors with persistent pain.

Risk Factors for Increased Postoperative Pain and Recommended Orderset for Postoperative Analgesic Usage

An interdisciplinary pain team was established at our institution to explore options for improving pain control in patients undergoing orthopedic surgery by identifying traits that put a patient at increased risk for inadequate pain control postoperatively.

Botulinum Neurotoxins and Cancer-A Review of the Literature

Botulinum neurotoxins (BoNT) possess an analgesic effect through several mechanisms including an inhibition of acetylcholine release from the neuromuscular junction as well as an inhibition of specific pain transmitters and mediators. Animal studies have shown that a peripheral injection of BoNTs impairs the release of major pain transmitters such as substance P, calcitonin gene related peptide (CGRP) and glutamate from peripheral nerve endings as well as peripheral and central neurons (dorsal root ganglia and spinal cord). These effects lead to pain relief via the reduction of peripheral and central sensitization both of which reflect important mechanisms of pain chronicity. This review provides updated information about the effect of botulinum toxin injection on local pain caused by cancer, painful muscle spasms from a remote cancer, and pain at the site of cancer surgery and radiation. The data from the literature suggests that the local injection of BoNTs improves muscle spasms caused by cancerous mass lesions and alleviates the post-operative neuropathic pain at the site of surgery and radiation. It also helps repair the parotid damage (fistula, sialocele) caused by facial surgery and radiation and improves post-parotidectomy gustatory hyperhidrosis. The limited literature that suggests adding botulinum toxins to cell culture slows/halts the growth of certain cancer cells is also reviewed and discussed.

AAAPT Diagnostic Criteria for Acute Pain Following Breast Surgery

Acute pain after breast surgery decreases the quality of life of cancer survivors. Previous studies using a variety of definitions and methods report prevalence rates between 10% and 80%, which suggests the need for a comprehensive framework that can be used to guide assessment of acute pain and pain-related outcomes after breast surgery. A multidisciplinary task force with clinical and research expertise performed a focused review and synthesis and applied the 5 dimensional framework of the AAAPT (Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks [ACTTION], American Academy of Pain Medicine [AAPM], American Pain Society [APS] Pain Taxonomy) to acute pain after breast surgery. Application of the AAAPT taxonomy yielded the following: 1) Core Criteria: Location, timing, severity, and impact of breast surgery pain were defined; 2) Common Features: Character and expected trajectories were established in relevant surgical subgroups, and common pain assessment tools for acute breast surgery pain identified; 3) Modulating Factors: Biological, psychological, and social factors that modulate interindividual variability were delineated; 4) Impact/Functional Consequences: Domains of impact were outlined and defined; 5) Neurobiologic Mechanisms: Putative mechanisms were specified ranging from nerve injury, inflammation, peripheral and central sensitization, to affective and social processing of pain. PERSPECTIVE: The AAAPT provides a framework to define and guide improved assessment of acute pain after breast surgery, which will enhance generalizability of results across studies and facilitate meta-analyses and studies of interindividual variation, and underlying mechanism. It will allow researchers and clinicians to better compare between treatments, across institutions, and with other types of acute pain.

Development of a Simple Preoperative Risk Score for Persistent Pain After Breast Cancer Surgery: A Prospective Observational Cohort Study

OBJECTIVES

Persistent postoperative pain is reported by 30% to 50% of patients following breast cancer surgery. Studies testing preventive measures, however, have so far failed to produce consistent positive results. If preventive measures could be targeted to a subgroup of patients at high risk of persistent pain, positive results would be more likely. Our aim was to develop a simple risk score predicting persistent pain after breast cancer surgery.

MATERIALS AND METHODS

In a prospective observational cohort study, we tested the predictive ability of a 4 simple items score for persistent pain in 200 patients scheduled for breast cancer surgery. A multivariable logistic regression model was created for the outcome of clinically important pain at 4 months.

RESULTS

On the basis of literature review and univariable analysis of our data, 4 parameters were selected: preoperative pain at the surgical site, history of depression, age below 50 years and expected pain of high intensity (>6/10). Points for the score are based on the coefficients of the logistic regression model. A total score ≥2 points/5 predicts a risk of developing clinically important pain at 4 months >30%, with an area under the curve-receiver operating characteristic of 0.81.

DISCUSSION

We studied known risk factors for persistent pain in patients scheduled for breast cancer surgery and constructed a preoperative risk score simple enough to select high-risk patients in future prevention studies.

Caesarean delivery: Bringing more than just a bundle of joy

Background: Chronic postsurgical pain (CPSP) is a potential complication of all surgical procedures, including caesarean delivery (CD). Psychological factors such as anxiety and depression with negative coping strategies are known to increase the risk of the development of CPSP.

Aim: This short review will appraise some additional features that are unique to CD and assess the interplay between them and persisting pain.

Methods: This is a narrative review with a focus on describing relevant features associated with the development of CPSP after CD.

Results: Hormone changes, postpartum depression, breastfeeding, and sleep disturbance each may affect the mother’s pain in the short and long term. Together they have the potential to negatively impact the mother–infant bond.

Conclusions: In the weeks after delivery, pain, depression, and poor sleep negatively impact the mother’s quality of life and her ability to care for, and bond with, her baby. This represents a critical time for the emotional, social, and behavioral development of the infant. Far-reaching benefits for the whole family may be realized by the early identification and management of persisting postoperative pain and postpartum depression.

Sex differences in negative affect and postoperative pain in patients undergoing total knee arthroplasty

Background

Knee osteoarthritis (OA) is among the most common and disabling persistent pain conditions, with increasing prevalence in the developed world, and affects women to a greater degree than men. In the USA, the growth of knee OA has been paralleled by an increase in rates of total knee arthroplasty (TKA), a surgical treatment option for late-stage knee OA. While TKA outcomes are generally good, postoperative trajectories of pain vary widely, with some patients reporting a complete absence of pain, but with a significant minority reporting worsening pain. Biopsychosocial factors, including anxiety and depression, are known to contribute importantly to the experience of joint pain, with women reporting a higher degree of negative affective symptoms.

Methods

This study investigated sex differences in TKA outcomes in age-matched groups of men and women at two academic medical centers. Pain and physical function were assessed in 100 patients (50 men and 50 women) during the perioperative period (preoperative visit—6 weeks postsurgical). The association of preoperative negative affect (anxiety and depression scores) to postoperative pain and function was evaluated, with specific attention to sex differences in this relationship.

Results

Overall, women reported more baseline pain-related physical dysfunction (although not higher baseline pain scores), as well as higher acute postoperative pain scores during the 2 weeks following TKA than their male counterparts. By 6 weeks postoperatively, sex differences in reported pain were no longer evident. Interestingly, although women reported higher preoperative levels of emotional distress than men, preoperative anxiety and depression scores were better predictors of severe postoperative pain among men than women, throughout the postoperative test period.

Conclusions

This study underlines the importance of considering sex and psychosocial factors, as well as their interaction, in understanding postsurgical pain trajectories.

Local anesthetics and regional anesthesia versus conventional analgesia for preventing persistent postoperative pain in adults and children: A Cochrane systematic review and meta-analysis update

BACKGROUND

Regional anesthesia may mitigate the risk of persistent postoperative pain (PPP). This Cochrane review, published originally in 2012, was updated in 2017.

METHODS

We updated our search of Cochrane CENTRAL, PubMed, EMBASE and CINAHL to December 2017. Only RCTs investigating local anesthetics (by any route) or regional anesthesia versus any combination of systemic (opioid or non-opioid) analgesia in adults or children, reporting any pain outcomes beyond three months were included. Data were extracted independently by at least two authors, who also appraised methodological quality with Cochrane 'Risk of bias' assessment and pooled data in surgical subgroups. We pooled studies across different follow-up intervals. As summary statistic, we reported the odds ratio (OR) with 95% confidence intervals and calculated the number needed to benefit (NNTB). We considered classical, Bayesian alternatives to our evidence synthesis. We explored heterogeneity and methodological bias.

RESULTS

40 new and seven ongoing studies, identified in this update, brought the total included RCTs to 63. We were only able to synthesize data from 39 studies enrolling 3027 participants in a balanced design. Evidence synthesis favored regional anesthesia for thoracotomy (OR 0.52 [0.32 to 0.84], moderate-quality evidence), breast cancer surgery (OR 0.43 [0.28 to 0.68], low-quality evidence), and cesarean section (OR 0.46, [0.28 to 0.78], moderate-quality evidence). Evidence synthesis favored continuous infusion of local anesthetic after breast cancer surgery (OR 0.24 [0.08 to 0.69], moderate-quality evidence), but was inconclusive after iliac crest bone graft harvesting (OR 0.20, [0.04 to 1.09], low-quality evidence).

CONCLUSIONS

Regional anesthesia reduces the risk of PPP. Small study size, performance, null, and attrition bias considerably weakened our conclusions. We cannot extrapolate to other interventions or to children.

Chronic pain after bilateral thoracotomy in lung transplant patients

Background and aims

The relative contribution of patient-related factors and intraoperative nerve damage for the development of chronic pain after surgery is unclear. This study aimed to examine chronic pain after bilateral thoracotomy. We hypothesized, that individual patient-related risk factors would be important resulting in an intraindividual uniformity of pain and hyperphenomena between the two sides of the thorax.

Methods

Twenty patients who had undergone lung transplantation via bilateral thoracotomy 6–12 months previously were included from the Danish Lung Transplant program, Rigshospitalet, Denmark, from October 2016 to August 2017. All patients answered questionnaires about pain in and around the scar, completed the Neuropathic Pain Symptom Inventory, and underwent bedside examination for hyperphenomena (brush- and cold-evoked allodynia, pinprick hyperalgesia) and pinprick hypoalgesia.

Results

Nine patients reported spontaneous pain bilaterally, five patients had pain on one side only, and six patients had no pain. Hyperphenomena were present on both sides of the thorax in 13 patients, on one side in four patients, and three patients had no hyperphenomena. The intraindividual uniformity of pain (p=0.029) and hyperphenomena (p=0.011) between the two sides of the thorax suggests that patient-related factors play an important role in the development of chronic pain.

Conclusions

The results of the present study provide support for the hypothesis of an individual predisposition for the development of chronic pain after thoracotomy.

Implications

Patient-related risk factors contribute to the development of chronic pain after thoracotomy. This result most likely can be transferred to chronic pain after other surgical procedures and therefore help us understand risk factors for chronic pain after surgery.

Evaluating psychosocial contributions to chronic pain outcomes

The biopsychosocial model of pain dominates the scientific community's understanding of chronic pain. Indeed, the biopsychosocial approach describes pain and disability as a multidimensional, dynamic integration among physiological, psychological, and social factors that reciprocally influence one another. In this article, we review two categories of studies that evaluate the contributions of psychosocial factors to the experience of chronic pain. First, we consider general psychosocial variables including distress, trauma, and interpersonal factors. Additionally, we discuss pain-specific psychosocial variables including catastrophizing, expectations, and pain-related coping. Together, we present a diverse array of psychological, social, and contextual factors and highlight the need to consider their roles in the development, maintenance, and treatment of chronic pain conditions.

AAPT Diagnostic Criteria for Peripheral Neuropathic Pain: Focal and Segmental Disorders

Peripheral neuropathic pain is among the most prevalent types of neuropathic pain. No comprehensive peripheral neuropathic pain classification system that incorporates contemporary clinical, diagnostic, biological, and psychological information exists. To address this need, this article covers the taxonomy for 4 focal or segmental peripheral neuropathic pain disorders, as part of the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) public-private partnership and the American Pain Society (APS) collaborative to develop a standardized, evidence-based taxonomy initiative: the ACTTION-APS Pain Taxonomy (AAPT). The disorders-postherpetic neuralgia, persistent posttraumatic neuropathic pain, complex regional pain disorder, and trigeminal neuralgia-were selected because of their clinical and clinical research relevance. The multidimensional features of the taxonomy are suitable for clinical trials and can also facilitate hypothesis-driven case-control and cohort epidemiologic studies. PERSPECTIVE: The AAPT peripheral neuropathic pain taxonomy subdivides the peripheral neuropathic pain disorders into those that are generalized and symmetric and those that are focal or segmental and asymmetric. In this article, we cover the focal and segmental disorders: postherpetic neuralgia, persistent posttraumatic neuropathic pain, complex regional pain disorder, and trigeminal neuralgia. The taxonomy is evidence-based and multidimensional, with the following dimensions: 1) core diagnostic criteria; 2) common features; 3) common medical and psychiatric comorbidities; 4) neurobiological, psychosocial, and functional consequences; and 5) putative neurobiological and psychosocial mechanisms, risk factors, and protective factors.

Preoperative Psychosocial and Psychophysical Phenotypes as Predictors of Acute Pain Outcomes After Breast Surgery

The severity and impact of acute pain after breast surgery varies markedly among individuals, underlining the importance of comprehensively identifying specific risk factors, including psychosocial and psychophysical traits. In this prospective observational study, women (n = 234) undergoing breast-conserving surgery, mastectomy, or mastectomy with reconstruction completed a brief bedside quantitative sensory testing battery, along with measures of psychosocial characteristics. Postoperative pain severity, impact, and opioid use at 2 weeks were assessed using Brief Pain Inventory and procedure-specific breast cancer pain questionnaires. Moderate-severe average pain (>3/10) was reported by 29% of patients at 2 weeks. Regression analysis of pain outcomes revealed that pain severity was independently predicted by axillary dissection, pre-surgical pain, temporal summation of pain (TSP), (-)positive affect, and behavioral coping style. Pain impact was predicted by age, education, axillary dissection, reconstruction, but also by negative affect and depression scores. Lastly, opioid use was predicted by age, education, axillary dissection, reconstruction, TSP, and reinterpreting coping style. Our findings suggest that, individuals with certain phenotypic characteristics, including high TSP and negative affect, may be at greater risk of significant pain and continued opioid use at 2 weeks after surgery, independent of known surgical risk factors. PERSPECTIVE: We measured differences in the psychosocial and psychophysical processing of pain amongst patients before breast surgery using simple validated questionnaires and brief quantitative sensory testing. Independent of younger age and procedural extent (axillary surgery and reconstruction), affect and greater temporal summation of pain predicted acute postoperative pain and opioid use.

Systematic review of genetic polymorphisms associated with psychoneurological symptoms in breast cancer survivors

PURPOSE

Psychoneurological (PN) symptoms, such as anxiety, cognitive impairment, depression, fatigue, sleep disturbances, and pain, are highly prevalent in breast cancer patients undergoing cancer treatment. Emerging evidence suggests that genetic polymorphisms may contribute to differential symptom susceptibility. We aimed to systematically review associations between genetic polymorphisms and PN symptoms during or after cancer treatment for early-stage breast cancer.

METHODS

Twenty-six eligible articles published until October 2017 were identified in PubMed, PsycINFO, Web of Science, and additional records. Information on study characteristics, genetic polymorphisms, and PN symptoms was extracted. Study quality was evaluated by the STrengthening the REporting of Genetic Association (STREGA) guideline. Genes included in the analysis were categorized by biological pathways based on the Reactome database.

RESULTS

A total of 54 single nucleotide polymorphisms and haplotypes that are significantly associated with PN symptoms were identified; half of them were associated with increased severity of PN symptoms, while the other half contributed to the decrease of PN symptoms. Pain has the known highest number of associated genetic polymorphisms reported, followed by fatigue, cognitive impairment, depressive symptoms, sleep disturbances, and anxiety. The majority of genetic polymorphisms were involved in immune system and neuronal system pathways. Most studies were unsuccessful in meeting the STREGA guideline, which requires transparent reporting of methods and results.

CONCLUSIONS

This review provides comprehensive evidence of genetic polymorphisms underlying PN symptoms, which may pave the way for the development of personalized therapeutics targeting these symptoms. More well-designed genome-wide association studies are required to validate and replicate these findings.

Preventive effect of oral magnesium in postmastectomy pain: protocol for a randomised, double-blind, controlled clinical trial

INTRODUCTION

Breast cancer affects 1 in 10 women worldwide, and mastectomy is a cause of chronic pain with neuropathic characteristics. N-methyl-D-aspartate receptor (NMDAR) antagonists such as ketamine, memantine, dextromethorphan or magnesium are used to treat refractory pain by blocking NMDAR. Oral memantine has been shown to prevent postmastectomy pain and cognitive impact and to maintain quality of life. Likewise, the present study is intended to assess the preventive effect of oral magnesium, administered ahead of mastectomy, on the development of neuropathic pain. As a physiological blocker of NMDAR, magnesium could be an interesting candidate to prevent postoperative pain and associated comorbidities, including cognitive and emotional disorders, multiple analgesic consumption and impaired quality of life.

METHODS AND ANALYSIS

A randomised double-blind controlled clinical trial (NCT03063931) will include 100 women with breast cancer undergoing mastectomy at the Oncology Hospital, Clermont-Ferrand, France. Magnesium (100 mg/day; n=50) or placebo (n=50) will be administered for 6 weeks, starting 2 weeks before surgery. Intensity of pain, cognitive and emotional function and quality of life will be assessed by questionnaires. The primary endpoint is pain intensity on a 0-10 numerical rating scale at 1 month postmastectomy. Data analysis will use mixed models; all tests will be two-tailed, with type-I error set at α=0.05.

ETHICS AND DISSEMINATION

The study protocol and informed consent form were approved in December 2016 by the French Research Ethics Committee (South East VI Committee). Results will be communicated in various congresses and published in international publications.

TRIAL REGISTRATION NUMBER

NCT03063931.

The experience of persistent pain and quality of life among women following treatment for breast cancer: An attachment perspective

OBJECTIVES

The aims of this study were to investigate associations between attachment and the presence of persistent pain in women following treatment for breast cancer and to investigate the relationship between attachment, pain, and quality of life (QOL) in women with persistent pain.

METHODS

Women (N = 335) previously diagnosed with primary non-metastatic breast cancer completed an online survey with measures of attachment, pain, QOL, demographics, and medical history. Variables were compared between women with (N = 128) and without (N = 207) persistent pain. For those reporting pain, regression analyses were conducted to investigate relationships between attachment, pain, and QOL.

RESULTS

Higher attachment anxiety, but not attachment avoidance, was related to the presence of persistent pain. Among women with persistent pain, associations between attachment anxiety and avoidance and greater pain intensity were lost when pain catastrophizing was considered in analysis. Significant associations between attachment and diminished QOL and perceived effectiveness of pain management were identified in multivariate analysis.

CONCLUSIONS

These findings extend the available literature regarding associations between pain and attachment insecurity. In women with pain after breast cancer treatment, attachment anxiety and avoidance were associated with negative pain and QOL outcomes. Further attention regarding the use of attachment-informed approaches in supporting women following breast cancer treatment is indicated.

C-reactive Protein Level on Postoperative Day One is Associated with Chronic Postsurgical Pain After Mastectomy

Background

C-reactive protein (CRP) is an acute phase reactant released in response to inflammation or tissue injury. Inflammation is one of the pathogenic factors related to transition from acute postsurgical pain (APSP) to chronic postsurgical pain (CPSP). Although several risk factors are reportedly associated with CPSP, the effects of CRP levels on CPSP have not been examined.

Objectives

The present study investigated the relationship between perioperative risk factors, including CRP levels on postoperative day one and CPSP, in patients undergoing mastectomy.

Methods

Preoperative anxiety and depression levels were evaluated in female patients undergoing mastectomy under general anesthesia, with or without peripheral nerve block. Patients with chronic preoperative pain and/or preoperative breast pain were excluded. The intensity of postoperative pain was prospectively examined one and six days, and three and twelve months after surgery using a numerical rating scale (NRS).

Results

The current researchers conducted univariate and multivariate linear regression analyses to explore risk factors for CPSP in 36 patients. Patient demographics, preoperative psychological states, and anesthetic managements showed no relationship with CPSP. On the other hand, pain intensity of APSP and CRP levels on postoperative day one was significantly associated with the pain intensity of CPSP.

Conclusions

Postoperative CRP level is likely to be associated with the development of CPSP after mastectomy.