Anxiety sensitivity and pain: generalisability across noxious stimuli

Weak Relationships Between Psychological Factors and Experimental Pain Outcomes in Pain-Free Individuals: An Aggregate Analysis of 8 Studies

Although psychological factors such as anxiety, depression, and pain catastrophizing are known to influence pain outcomes in chronic pain populations, there are mixed results regarding whether they influence experimental pain outcomes in pain-free individuals. The objectives of this study were to determine the associations between psychological factors and experimental pain outcomes in pain-free adolescents and adults. Relationships between anxiety, depression, and pain catastrophizing and experimental pain outcomes across 8 different studies (total N = 595) were examined in different populations of pain-free adult and adolescent participants. Analyses were conducted with and without controlling for sex, age, and race. Studies were analyzed separately and as part of an aggregate analysis. Individual study analyses resulted in 136 regression models. Of these, only 8 models revealed a significant association between psychological factors and pain outcomes. The significant results were small and likely due to Type 1 error. Controlling for demographic factors had minimal effect on the results. The aggregate analyses revealed weak relationships between anxiety and pressure pain threshold (Fisher's z = -.10 [-.19, -.01]), anxiety and cold pain intensity ratings (Fisher's z = .18 [.04, .32]), and pain catastrophizing and pressure pain threshold (Fisher's z = -.14 [-.26, -.02]). Sample size calculations based on the aggregate analyses indicated that several hundred participants would be required to detect true relationships between these psychological factors and pain measures. The overall negative findings suggest that in pain-free individuals, anxiety, depression, and pain catastrophizing are not meaningfully related to experimental pain outcomes. PERSPECTIVE: Psychological variables have been shown to predict pain outcomes in chronic pain populations but these relationships may not generalize to pain-free populations. An analysis of 595 pain-free individuals across 8 studies in our lab revealed that anxiety, depression, and pain catastrophizing were not meaningfully related to experimental pain outcomes.

A developmental framework for understanding the influence of sex and gender on health: Pediatric pain as an exemplar

Sex differences are a robust finding in many areas of adult health, including cardiovascular disease, psychiatric disorders, and chronic pain. However, many sex differences are not consistently observed until after the onset of puberty. This has led to the hypothesis that hormones are primary contributors to sex differences in health outcomes, largely ignoring the relative contributions of early developmental influences, emerging psychosocial factors, gender, and the interaction between these variables. In this paper, we argue that a comprehensive understanding of sex and gender contributions to health outcomes should start as early as conception and take an iterative biopsychosocial-developmental perspective that considers intersecting social positions. We present a conceptual framework, informed by a review of the literature in basic, clinical, and social science that captures how critical developmental stages for both sex and gender can affect children's health and longer-term outcomes. The literature on pediatric chronic pain is used as a worked example of how the framework can be applied to understanding different chronic conditions.

Comparison between pupillometry and numeric pain rating scale for pain assessments in communicating adult patients in the emergency department

OBJECTIVE

The adequate assessment of pain in the emergency department (ED) can be challenging. Two dynamic pupillary measures used in conscious subjects after a surgical procedure were previously shown to correlate to the magnitude of ongoing pain. The objective of this study was to test the ability of dynamic measures derived from pupillometry to evaluate pain intensity in conscious adult patients admitted to the ED.

METHODS

This prospective, interventional, single-centre study was performed between August 2021 and January 2022 (NCT05019898). An assessment of self-reported pain intensity was performed on ED admission by the triage nurse using a numeric rating scale (NRS). This was followed by two dynamic measures derived from pupillometry that were previously correlated with pain perception: the pupillary unrest under ambient light (PUAL) and the pupillary light reflex (PLR).

RESULTS

Among the 313 analysed patients, the median age was 41 years, and 52% were women. No correlation was found between self-reported pain ratings and PUAL (r = 0.007) or PLR (baseline diameter r = -0.048; decrease r = 0.024; latency r = 0.019; slope = -0.051). Similarly, the pupillometry measures could not discriminate patients with moderate to severe pain (defined as NRS ≥4).

CONCLUSIONS

Pupillometry does not appear to be an effective tool to evaluate pain in the ED environment. Indeed, too many factors influencing the sympathetic system-and thus the dynamic pupillary measures-are not controllable in the ED.

SIGNIFICANCE

Pupillometry does not appear to be an effective tool to evaluate pain in the ED environment. There are several possible explanations for these negative results. The factors influencing the sympathetic system-and thus the PD fluctuations-are controllable in the postoperative period but not in the ED (e.g. full bladder, hypothermia). In addition, numerous psychological phenomena can impact pupillometry measurements such as emotional reactions or cognitive tasks. These phenomena are particularly difficult to control in the ED environment.

The contribution of subliminal perceptions, dietary habits, and psychological traits to the perception of oral tingling and burning sensations

The tingling evoked by Sichuan pepper and the burning elicited by chili pepper constitutes the typical flavor of Sichuan cuisine and is a component of leisure food. Although factors affecting the burning sensation have extensively been studied, few studies have examined the factors of individual sensitivity, personality traits, and dietary habits that contribute to the perception of oral tingling sensation, which hinders the formulation of tingling products and the development of new products. In contrast, many studies have examined the factors influencing the burning sensation. In this web-based survey, 68 participants disclosed their dietary habits, liking for tingling and hot foods, and psychological traits. Individual sensitivity to the tingling and burning sensation produced by a range of Sichuan pepper oleoresin and capsaicin solutions was determined using rated differences from control, generalized labeled magnitude scale method and ranking test. The consistency score indicated the accuracy of individual ranking results while also providing an indirect response to the sensitivity of the participant to supra-threshold for burning or tingling. Individual ratings for medium Sichuan pepper oleoresin concentrations significantly correlated with the just noticeable difference (p < 0.01), and ratings for medium and high capsaicin concentrations correlated significantly with 6-n-propylthiouracil ratings (p < 0.01). Notably, the power exponent of burning was significantly correlated with the burning recognition threshold (p < 0.01), and the power exponent of tingling and burning were significantly correlated (r = 0.340, p < 0.05). There was a negative correlation between supra-threshold tingling and burning sensation perceptions and life satisfaction ratings. Further, intensity ratings for oral tingling and burning sensation did not always correspond with individual sensitivity indicators (e.g., recognition threshold, 6-n-propylthiouracil, just noticeable difference, and consistency score). Thus, this study provides new insight into establishing a sensory selection method for chemesthetic sensation panelists and theoretical guidelines for formulation design and in-depth analysis of popular tingling dishes and foods.

The unique face of comorbid anxiety and depression: increased interoceptive fearfulness and reactivity

Anxiety and depression commonly co-occur, yet the underlying brain and behavioral processes are poorly understood. Here we examined the hypothesis that individuals with comorbid anxiety and depression would show increased fearful reactivity to an aversive interoceptive perturbation relative to depressed-only individuals. One-hundred and eighty anxious and/or depressed participants from the Tulsa 1000 study completed multi-level behavioral or functional magnetic resonance imaging assessments of interoception and nociception including breath-hold and cold-pressor challenges, and heartbeat perception and interoceptive attention tasks. One-hundred and four individuals with comorbid depression and anxiety disorders (Dep+Anx) were propensity matched with 52 individuals with depression-only (Dep). Data were analyzed using mixed-effects linear regression. The Dep+Anx group showed significantly greater self-reported fear of suffocation during breath holding (Wilcoxon r = 0.23) and reduced cold pain tolerance (R ² = 0.027) signified by hand removal during immersion. However, these groups did not differ with respect to neutrally-valenced behavioral indices of heartbeat perception or neural indices of interoceptive attention. Individuals with comorbid depression and anxiety, vs. those with only depression, show increased respiratory fearfulness and nociceptive reactivity during perturbations of these signals, whilst showing similar interoceptive awareness in the absence of perturbation. Our findings suggest that individuals with comorbid anxiety and depression process aversive interoceptive and nociceptive signals differently than those with depression alone, providing support for a process model of increased threat sensitivity and hyperarousal in anxious depression.

Comparing the Effects of Thought Suppression and Focused Distraction on Pain-Related Attentional Biases in Men and Women

Increasing attentional focus away from pain can affect pain experience, suggesting that cognitive strategies that move attentional allocation may be a moderator of pain. In a pre-post-design, the present study examined the effects of 2 cognitive strategies used in pain contexts, thought suppression and focused distraction, on subsequent pain-related attention. Thought suppression was hypothesized to increase pain-related attention, whereas focused distraction was expected to reduce it. Influences of both anxiety and sex were also considered, as secondary questions. 139 (86 women, 53 men) healthy, pain-free participants were randomly assigned to use either thought suppression or focused distraction during a mild cold pressor test (CPT). Pain-related attention was examined using a dot-probe and an attentional blink task, pre-and post-CPT. Questionnaires about relevant cognitive and emotional aspects, demographics, and pain were completed. Results showed no difference in the effect of the 2 pain inhibition strategies on pain-related attention. The hypothesized rebound effect in thought suppression on pain-related attention did not emerge. However, thought suppression showed a short-term benefit in comparison to focused distraction regarding reported pain and perceived threat during the cold pressor test. Few sex differences were found. Thus, the cognitive strategies affected pain outcomes, but did not influence pain-related attention. PERSPECTIVE: Cognitive strategies could help with pain through changing attention allocation. In this study, the effects of the 2 cognitive strategies thought suppression and focused distraction on pain-related attention in men and women were examined. Elucidating mechanisms that lie behind pain strategies that focus on changing attention may help improve treatments.

Triad Multisystem Phenotype with High-risk for Developing Temporomandibular Disorders- Characteristics and Potential Pathophysiology Results from the OPPERA Dataset

ABSTRACT

A multisystem phenotype with the Triad of bodily pain, psychological distress, and sleep disturbance was found to have high risk for developing initial onset of painful temporomandibular disorders (TMDs) in the multicenter Orofacial Pain: Prospective Evaluation and Risk Assessment (OPPERA) dataset. In this study, we systemically examined phenotypic characteristics and explored potential pathophysiology in quantitative sensory testing (QST) and autonomic nervous system (ANS) domains in this multisystem Triad phenotype. Secondary analysis was performed on 1199 non-Triad and 154 Triad TMD-free OPPERA enrollees at baseline. Results indicate that prior to developing TMDs, the Triad phenotype demonstrated both orofacial and systemic signs and symptoms that can only be captured through multisystem assessment. In addition, we found significantly lower resting heart rate variability and higher resting heart rate in the Triad phenotype as compared to the non-Triad group. However, pain sensitivity measured by QST was not different between groups. These findings highlight the importance of whole-person multisystem assessment at the stage prior to developing complex pain conditions such as TMDs, and suggest that, in addition to a "tissue damage monitor", pain should be considered in a broader context, such as a component within a "distress monitoring system" at the whole-person level when multisystem issues co-present. Therefore, the presence or absence of multisystem issues may carry critical information when searching for disease mechanisms and developing mechanism-based intervention and prevention strategies for TMDs and related pain conditions. Cardiovascular autonomic function should be further researched when multisystem issues co-present prior to developing TMDs.

Psychiatric Comorbidity and Emotional Dysregulation in Chronic Tension-Type Headache: A Case-Control Study

Background: Chronic tension-type headache (CTTH) is frequently associated with a psychiatric comorbidity of depression and anxiety. Most studies focus their attention on this association, and only few link CTTH with psycho-affective emotional regulation disorders. Objective: To evaluate the association of CTTH with anxiety, depression, positive and negative affectivity, and emotional management in CTTH patients with neither a previous diagnosis of psychiatric disorder nor use of psychoactive drugs or abuse of analgesics. Design: Case-control study. Methods: Validated scores for state and trait anxiety, depression, positive and negative state and trait affect, cognitive reappraisal, and expressive suppression were assessed in 40 subjects with CTTH and 40 healthy subjects. Associations between CTTH and psychological status were assessed through linear multivariate regression models. Results: CTTH was associated with higher scores for depression (Beta = 5.46, 95% CI: 1.04–9.88), state and trait anxiety (Beta = 12.77, 95% CI: 4.99–20.56 and Beta = 8.79, 95% CI: 2.29–15.30, respectively), and negative state affect (Beta = 5.26, 95% CI: 0.88–9.64). Conclusions: CTTH is directly associated with depression, anxiety, and negative affectivity signs despite the absence of a previously diagnosed psychiatric disorder or psychopharmacological intake. The recognition of these comorbid and psycho-affective disorders is essential to adapt the emotional management of these patients for better control.

Temperament and character dimensions differ in chronic post-surgical neuropathic pain and cold pressure pain

OBJECTIVES

Psychobiological temperament and cognitive-evaluative character link to coping with chronic pain. The aim was to study possible independent role of temperament and character dimensions both in chronic and experimental pain in chronic post-surgical pain patients. This is a substudy of a previously published larger cohort of patients with intercostobrachial nerve injury after breast cancer surgery.

METHODS

We recruited 241 women who had been treated for breast cancer 4-9 years before. They had a surgeon-verified intercostobrachial nerve injury with or without chronic post-surgical neuropathic pain (CPSNP). The patients filled in the Temperament and Character Inventory (TCI), Pain Catastrophizing Scale (PCS), Hospital Anxiety and Depression Scale (HADS), and Brief Pain Inventory (BPI), and underwent the cold pressor test (CPT).

RESULTS

201 (83%) patients reported chronic pain and 135 (56%) met the criteria for CPSNP. Patients with CPSNP showed higher levels of Harm Avoidance (HA) temperament than non-CPSNP patients, which was associated with lower cold pain tolerance and greater increase of pain intensity during CPT. HA subscales Fear of Uncertainty and Fatigability contributed to a stronger pain experience. For character dimensions, CPSNP patients reported higher levels of Self-Transcendence (ST) and lower levels of Self-Directedness (SD) and Cooperativeness (CO) than non-CPSNP patients. Cold pain tolerance, intensity, or unpleasantness did not associate with character dimensions.

CONCLUSIONS

Psychobiological temperament, but not character, is independently from other psychological factors associated with primary pain processing in an experimental pain setting. Patients with and without CPSNP showed different profiles on both temperament and character dimensions suggesting a combination of heightened emotional vulnerability and lowered personality adaptability in CPSNP patients. Character dimensions associated with clinical but not experimental pain.

ETHICAL COMMITTEE NUMBER

The study protocol was approved by the Ethics Committee of the Helsinki and Uusimaa Hospital District (reference number: 149/13/03/00/14).

TRIAL REGISTRY NUMBER

The study is registered in ClinicalTrials.gov (NCT02487524).

AMAZONE: prevention of persistent pain after breast cancer treatment by online cognitive behavioral therapy-study protocol of a randomized controlled multicenter trial

Background

Surviving breast cancer does not necessarily mean complete recovery to a premorbid state of health. Among the multiple psychological and somatic symptoms that reduce the quality of life of breast cancer survivors, persistent pain after breast cancer treatment (PPBCT) with a prevalence of 15–65% is probably the most invalidating. Once chronic, PPBCT is difficult to treat and requires an individualized multidisciplinary approach. In the past decades, several somatic and psychological risk factors for PPBCT have been identified. Studies aiming to prevent PPBCT by reducing perioperative pain intensity have not yet shown a significant reduction of PPBCT prevalence. Only few studies have been performed to modify psychological distress around breast cancer surgery. The AMAZONE study aims to investigate the effect of online cognitive behavioral therapy (e-CBT) on the prevalence of PPBCT.

Methods

The AMAZONE study is a multicenter randomized controlled trial, with an additional control arm. Patients (n=138) scheduled for unilateral breast cancer surgery scoring high for surgical or cancer-related fears, general anxiety or pain catastrophizing are randomized to receive either five sessions of e-CBT or online education consisting of information about surgery and a healthy lifestyle (EDU). The first session is scheduled before surgery. In addition to the online sessions, patients have three online appointments with a psychotherapist. Patients with low anxiety or catastrophizing scores (n=322) receive treatment as usual (TAU, additional control arm).

Primary endpoint is PPBCT prevalence 6 months after surgery.

Secondary endpoints are PPBCT intensity, the intensity of acute postoperative pain during the first week after surgery, cessation of postoperative opioid use, PPBCT prevalence at 12 months, pain interference, the sensitivity of the nociceptive and non-nociceptive somatosensory system as measured by quantitative sensory testing (QST), the efficiency of endogenous pain modulation assessed by conditioned pain modulation (CPM) and quality of life, anxiety, depression, catastrophizing, and fear of recurrence until 12 months post-surgery.

Discussion

With perioperative e-CBT targeting preoperative anxiety and pain catastrophizing, we expect to reduce the prevalence and intensity of PPBCT. By means of QST and CPM, we aim to unravel underlying pathophysiological mechanisms. The online application facilitates accessibility and feasibility in a for breast cancer patients emotionally and physically burdened time period.

Trial registration

NTR NL9132, registered December 16 2020.

Anxiety sensitivity and Pain Experience: a prospective investigation among World Trade Center Responders

Chronic pain is a significant public health problem and is exacerbated by stress. The World Trade Center (WTC) Disaster represents a unique stressor, and responders to the WTC disaster are at increased risk for pain and other health complaints. Therefore, there is a significant need to identify vulnerability factors for exacerbated pain experience among this high-risk population. Anxiety sensitivity (AS), defined as fear of anxiety-related sensations, is one such vulnerability factor associated with pain intensity and disability. Yet, no work has tested the predictive effects of AS on pain, limiting conclusions regarding the predictive utility and direction of associations. Therefore, the current study examined the prospective associations of AS, pain intensity, and pain interference among 452 (M_age = 55.22, SD = 8.73, 89.4% male) responders to the WTC disaster completing a 2-week daily diary study. Using multi-level modeling, AS total score was positively associated with both pain intensity and pain interference, and that AS cognitive concerns, but not social or physical concerns, were associated with increased pain. These results highlight the importance of AS as a predictor of pain complaints among WTC responders and provide initial empirical evidence to support AS as a clinical target for treating pain complaints among WTC responders.

Symptoms of anxiety but not depression before start of taxane-based chemotherapy are associated with peripheral neuropathy: a multicenter study in women with breast cancer

Background

Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect of chemotherapy, especially after taxane-based therapy. This study aimed to examine the relationship between symptoms of anxiety and depression before the start of taxane-based chemotherapy and the development of CIPN in women with breast cancer.

Methods

In this prospective study, women with breast cancer receiving taxane-based (neo)adjuvant chemotherapy were recruited from four hospitals in the Netherlands. Patients completed questionnaires assessing anxiety and depressive symptoms before treatment and CIPN before treatment (T0), 6 weeks after start of treatment (T1), after the last cycle of chemotherapy (T2), and 6 months after the end of treatment (T3). Mixed model analyses were used to investigate whether medium/high levels of anxiety or depression at baseline are associated with the level of CIPN during and after treatment.

Results

Among the 61 participating women, 14 (23%) reported medium/high levels of anxiety and 29 (47.5%) reported medium/high levels of depressive symptoms at baseline. The group of women with medium/high baseline levels of anxiety showed a significantly higher increase in CIPN during and after chemotherapy than women with low baseline levels of anxiety (p < .001). No relationship between depressive symptoms at baseline and the development of CIPN was found.

Conclusion

This study showed that baseline medium to high levels of anxiety but not depressive symptoms impacted the development of CIPN during and in the 6 months after treatment.

Chronic Pain Personification Following Child Abuse: The Imprinted Experience of Child Abuse in Later Chronic Pain

Child abuse has been shown to increase the risk for chronic pain. The illness personification theory implies that individuals tend to ascribe humanlike characteristics to chronic pain, and that this personification is embedded in the way they cope with their chronic condition. Recent findings demonstrate that individuals who experienced interpersonal violence tend to personify chronic pain in a way that resonates with past abusive experience. Although findings prevail to the link between trauma and the experience of the body, the personification of chronic pain among individuals who experienced child abuse has not been examined before. This article includes two studies that tested whether child abuse is implicated in abusive chronic pain personification in a young adult female sample (Study 1) and among females who experienced child abuse (Study 2). In both studies, self-report measures of child abuse, posttraumatic stress (PTS) symptoms, complex posttraumatic symptoms (disturbances of self-organization [DSO]), and abusive chronic pain personification were administered. Structural equation modeling was utilized to assess the hypotheses. The findings of the two studies showed a significant association between child abuse and pain personification. Whereas PTS symptoms did not mediate this link (Study 1), DSO symptoms mediated this association (Study 2). The findings of these studies support the understanding that the experience of interpersonal violence is engraved in the experience of the body, as reflected in abusive chronic pain personification. Disturbances in self-organization seem to underlie this process, thus pertaining to the link between the experience of the body, self, and interpersonal trauma.

Prevalence and predictors of chronic postsurgical pain after colorectal surgery: A prospective study

AIM

The aim was to investigate the incidence, characteristics and the potential predictors of chronic postsurgical pain (CPSP) after colorectal surgery.

METHOD

Patients who underwent colorectal surgery at our institution from July 2014 to December 2016 were prospectively enrolled in this study. Perioperative potential demographic, clinical and psychological predictors for CPSP were collected. The follow-up visits were conducted through telephone interviews at 3 and 6 months postoperatively. The interview questionnaire comprised items regarding pain intensity, frequency, site, analgesic administration and impact on activities of daily living.

RESULTS

A total of 624 patients completed the 6-month follow-up and were included in the analysis. CPSP was reported by 32.1% of these patients at 3 months and 21.8% at 6 months after colorectal surgery. The pain interfered with several activities of daily living in a considerable proportion of CPSP cases. At 3 months, the identified predictors of CPSP were young age, preoperative abdominal pain and pain elsewhere, preoperative anxiety and depression, longer duration of surgery, and high pain intensity on movement within 24 h after surgery. Predictors of CPSP at 6 months were young age, preoperative abdominal pain, preoperative anxiety, longer duration of surgery, and high pain intensity on movement within 24 h after surgery.

CONCLUSION

Chronic pain after colorectal surgery is a common complication associated with young age, preoperative abdominal pain and pain elsewhere, preoperative anxiety and depression, longer duration of surgery, and high pain intensity on movement within 24 h after surgery.

Reducing the prevalence of low-back pain by reducing the prevalence of psychological distress: Evidence from a natural experiment and implications for health care providers

OBJECTIVE

To determine whether exogenously reduced psychological distress reduces reported low-back pain (LBP) and is associated with reduced medical visits for LBP.

DATA SOURCES

National Health Interview Survey, National Ambulatory Medical Care Survey, National Hospital Ambulatory Medical Care Survey, 1998-2004.

STUDY DESIGN

We estimate a fuzzy regression discontinuity model in which a discontinuity in the prevalence of psychological distress is identified by exogenous national events. We examine whether this discontinuity induced a corresponding discontinuity in the prevalence of LBP. We additionally estimate a regression discontinuity model to determine associated changes in medical visits with LBP as the primary complaint.

PRINCIPAL FINDINGS

The prevalence of LBP was discontinuously reduced by one-fifth due to the exogenous national discontinuous reduction in psychological distress. This discontinuity in LBP cannot be explained by discontinuities in employment, insurance, injuries/poisoning, general health status, or other factors. We find an associated three-fifth discontinuous reduction in medical visits with LBP as the primary complaint.

CONCLUSIONS

On a monthly basis, 2.1 million (P < .01) adults ceased to suffer LBP due to the national reduction in psychological distress, and associated medical visits with LBP as the primary complaint declined by 685 000 (P < .01).

Guidelines for Perioperative Care in Cytoreductive Surgery (CRS) with or without hyperthermic IntraPEritoneal chemotherapy (HIPEC): Enhanced recovery after surgery (ERAS®) Society Recommendations - Part I: Preoperative and intraoperative management

BACKGROUND

Enhanced recovery after surgery (ERAS) pathways have been shown to considerably reduce complications, length of stay and costs after most of surgical procedures by standardised application of best evidence-based perioperative care. The aim was to elaborate dedicated recommendations for cytoreductive surgery (CRS) ± hyperthermic intraperitoneal chemotherapy (HIPEC) in a two-part series of guidelines based on expert consensus. The present part I of the guidelines highlights preoperative and intraoperative management.

METHODS

The core group assembled a multidisciplinary panel of 24 experts involved in peritoneal surface malignancy surgery representing the fields of general surgery (n = 12), gynaecological surgery (n = 6), and anaesthesia (n = 6). Experts systematically reviewed and summarized the available evidence on 72 identified perioperative care items, following the GRADE (grading of recommendations, assessment, development, evaluation) system. Final consensus (defined as ≥50%, or ≥70% of weak/strong recommendations combined) was reached by a standardised 2-round Delphi process, regarding the strength of recommendations.

RESULTS

Response rates were 100% for both Delphi rounds. Quality of evidence was evaluated high, moderate low and very low, for 15 (21%), 26 (36%), 29 (40%) and 2 items, respectively. Consensus was reached for 71/72(98.6%) items. Strong recommendations were defined for 37 items, No consensus could be reached regarding the preemptive use of fresh frozen plasma.

CONCLUSION

The present ERAS recommendations for CRS±HIPEC are based on a standardised expert consensus process providing clinicians with valuable guidance. There is an urgent need to produce high quality studies for CRS±HIPEC and to prospectively evaluate recommendations in clinical practice.

"My own flesh and blood": The implications of child maltreatment for the orientation towards the body among dyads of mothers and daughters

BACKGROUND

Orientation to bodily signals reflects the ways in which individuals interpret their bodily sensations. Such orientation is formed within early interpersonal context. Findings reveal that trauma may result in catastrophic and fearful orientation towards bodily signals. However, not much is known regarding the link between trauma and orientation towards the body as manifested within a family intergenerational context.

OBJECTIVE

This study examines the link between child maltreatment, complex posttraumatic stress symptoms (CPTS symptoms), and a posttraumatic orientation to bodily signals among dyads of mothers and their young adult daughters.

PARTICIPANTS AND SETTING

194 mother-daughter dyads (mothers' mean age = 56, SD = 6.3; daughters' mean age = 26, SD = 3.03) completed self-reported questionnaires, assessing child maltreatment (CTQ), CPTS symptoms (ITQ), and orientation to bodily signals (pain catastrophizing, anxiety sensitivity-physical, body vigilance).

RESULTS

Orientation to bodily signals was associated with child maltreatment, through the mediation of CPTS symptoms among mothers (indirect effects between 0.13-0.28; p > 0.021) and daughters (indirect effects between 0.21-0.11; p > 0.032). Mothers' child maltreatment was associated with daughters' child maltreatment (effect = 0.35; p < 0.001), and mothers' orientation to bodily signals was associated with daughters' orientation (effects between 0.19-0.27; p < 0.016). Daughters' orientation to bodily signals was partially associated with mothers' child maltreatment through mothers' CPTS symptoms and orientation to body (indirect effect = 0.064; p = 0.023).

CONCLUSIONS

Child maltreatment is implicated in posttraumatic orientation towards bodily signals. Such secondary processes may be intergenerationally transmitted.

Age does not affect sex effect of conditioned pain modulation of pressure and thermal pain across 2 conditioning stimuli

Introduction:

Conditioned pain modulation (CPM) is a laboratory test resulting in pain inhibition through activation of descending inhibitory mechanisms. Older adults consistently demonstrate reduced CPM compared with younger samples; however, studies of sex differences in younger cohorts have shown mixed results.

Objectives:

This study tested for sex differences in CPM within samples of younger and older adults.

Methods:

Participants were 67 younger adults (mean age = 25.4 years) and 50 older adults (66.4 years). Study conditioning paradigms were the cold-pressor test and contact heat pain administered in separate sessions. Pressure pain threshold and ramping suprathreshold heat were the test stimuli across three time points after presentation of the conditioning stimuli (CS).

Results:

Significant inhibition was observed during both testing sessions. The hypothesis for sex differences across both age cohorts was supported only for ∆PPTh. However, sex differences did not reach significance for either paradigm using ascending suprathreshold heat as the test stimuli. The overall trend was that younger males experienced the strongest CPM and older females the weakest. From a methodological perspective, duration differences were seen in CPM, with inhibition decaying more quickly for PPTh than for suprathreshold heat pain. Furthermore, there were no differences in inhibition induced by cold-pressor test and contact heat pain as CS.

Conclusion:

Sex differences were similar across both age cohorts with males experiencing greater inhibition than females. Cross-sectional associations were also demonstrated between CPM inhibition and measures of recent pain, further supporting CPM as an experimental model with clinical utility.

Potential role of pharmacogenomics testing in the setting of enhanced recovery pathways after surgery

In 2001, a group of European academic surgeons created the Enhanced Recovery After Surgery (ERAS) study group and established the first official ERAS protocol. One of the most significant challenges during ERAS implementation is variability of drugs used throughout the perioperative period. Pharmacogenomic testing (blood or saliva) results (obtained within approximately 48 hrs) provide guidelines on how to prescribe the optimal drug with the optimal dosage to each patient based on an individual's unique genetic profile. Pharmacogenomic testing of various methods of multimodal analgesia is an essential element of ERAS protocols spanning the entire perioperative period to ultimately optimize postoperative pain control. The key goal for anesthetic management in ERAS protocols is to facilitate rapid emergence by using the shortest acting agents available, thus accelerating recovery and reducing length of stay, hospital expenses, and postoperative complications. Postoperative nausea and vomiting (PONV) is an additional challenge that should be overcome to ensure an enhanced recovery and shorter length of stay with the use of antiemetics. Postoperative ileus (POI) can result in longer hospital stay with increasing susceptibility to associated morbidities along with an increase in associated hospitalization costs. Genetics-guided pharmacotherapy and its impact on clinical outcomes should be thoroughly studied for better understanding and managing drug administration in the settings of ERAS.

The impact of anxiety on chronic musculoskeletal pain and the role of astrocyte activation

Supplemental Digital Content is Available in the Text.

Anxiety predicts onset of knee pain and drives greater osteoarthritis pain in humans. Our validated preclinical model identifies supraspinal astrocytosis as a potential mechanism.

Anxiety and depression are associated with increased pain responses in chronic pain states. The extent to which anxiety drives chronic pain, or vice versa, remains an important question that has implications for analgesic treatment strategies. Here, the effect of existing anxiety on future osteoarthritis (OA) pain was investigated, and potential mechanisms were studied in an animal model. Pressure pain detection thresholds, anxiety, and depression were assessed in people with (n = 130) or without (n = 100) painful knee OA. Separately, knee pain and anxiety scores were also measured twice over 12 months in 4730 individuals recruited from the general population. A preclinical investigation of a model of OA pain in normo-anxiety Sprague-Dawley (SD) and high-anxiety Wistar Kyoto (WKY) rats assessed underlying neurobiological mechanisms. Higher anxiety, independently from depression, was associated with significantly lower pressure pain detection thresholds at sites local to (P < 0.01) and distant from (P < 0.05) the painful knee in patients with OA. Separately, high anxiety scores predicted increased risk of knee pain onset in 3274 originally pain-free people over the 1-year period (odds ratio = 1.71; 95% confidence interval = 1.25-2.34, P < 0.00083). Similarly, WKY rats developed significantly lower ipsilateral and contralateral hind paw withdrawal thresholds in the monosodium iodoacetate model of OA pain, compared with SD rats (P = 0.0005). Linear regressions revealed that baseline anxiety-like behaviour was predictive of lowered paw withdrawal thresholds in WKY rats, mirroring the human data. This augmented pain phenotype was significantly associated with increased glial fibrillary acidic protein immunofluorescence in pain-associated brain regions, identifying supraspinal astrocyte activation as a significant mechanism underlying anxiety-augmented pain behaviour.

Effects of preoperative mental distress versus surgical modality, arthroplasty, or fusion on long-term outcome in patients with cervical radiculopathy

OBJECTIVE

Several efforts have been made to investigate the long-term efficacy of artificial disc replacement surgery compared with that of fusion after decompression for the treatment of cervical degenerative disc disease and radiculopathy. However, research on the impact of mental distress on surgical treatment outcome has been sparse. The aim of the authors was to investigate the potential predictive value of preoperative risk factors in determining long-term outcome.

METHODS

A total of 153 patients (mean age 47 years) with single- or double-level cervical degenerative disc disease and radiculopathy were randomly assigned to undergo either anterior cervical discectomy and fusion (n = 70) or artificial disc replacement (n = 83). The primary outcome was the Neck Disability Index (NDI) score, a patient-reported function score that ranges from 0% to 100%; higher scores indicate greater disability. Preoperative variables such as sex, age, smoking status, employment status, having a strenuous job, neck pain duration, arm pain duration, amount of regular exercise, Hospital Anxiety and Depression Scale (HADS) score, NDI score, whether surgery was performed on 1 or 2 levels, and allocated treatment were analyzed in multiple linear regression models with the 5-year NDI score as the outcome.

RESULTS

A total of 47 (31%) patients had either a HADS anxiety or HADS depression score of 10 points or higher. High values on the preoperative HADS were a negative predictor of outcome (p = 0.009). Treatment allocation had no effect on 5-year NDI scores (p = 0.32).

CONCLUSIONS

Preoperative mental distress measured with the HADS affects long-term outcome in surgically treated patients with cervical radiculopathy.

Enhanced Recovery After Surgery Protocols in Major Urologic Surgery

The purpose of the review

The analysis of the components of enhanced recovery after surgery (ERAS) protocols in urologic surgery.

Recent findings

ERAS protocols has been studied for over 20 years in different surgical procedures, mostly in colorectal surgery. The concept of improving patient care and reducing postoperative complications was also applied to major urologic surgery and especially procedure of radical cystectomy. This procedure is technically challenging, due to a major surgical resection and high postoperative complication rate that may reach 65%. Several clinical pathways were introduced to improve perioperative course and reduce the length of hospital stay. These protocols differ from ERAS modalities in other surgeries. The reasons for this are longer operative time, increased risk of perioperative transfusion and infection, and urinary diversion achieved using transposed intestinal segments. Previous studies in this area analyzed the need for mechanical bowel preparation, postoperative nasogastric tube decompression, as well as the duration of urinary drainage. Furthermore, the attention has also been drawn to perioperative fluid optimization, pain management, and bowel function.

Summary

Notwithstanding partial resemblance between the pathways in major urologic surgery and other pelvic surgeries, there are still scarce guidelines for ERAS protocols in urology, which is why further studies should assess the importance of preoperative medical optimization, implementation of thoracic epidural anesthesia and analgesia, and perioperative nutritional management.

Anesthesia and fast-track in video-assisted thoracic surgery (VATS): from evidence to practice

In thoracic surgery, the introduction of video-assisted thoracoscopic techniques has allowed the development of fast-track protocols, with shorter hospital lengths of stay and improved outcomes. The perioperative management needs to be optimized accordingly, with the goal of reducing postoperative complications and speeding recovery times. Premedication performed in the operative room should be wisely administered because often linked to late discharge from the post-anesthesia care unit (PACU). Inhalatory anesthesia, when possible, should be preferred based on protective effects on postoperative lung inflammation. Deep neuromuscular blockade should be pursued and carefully monitored, and an appropriate reversal administered before extubation. Management of one-lung ventilation (OLV) needs to be optimized to prevent not only intraoperative hypoxemia but also postoperative acute lung injury (ALI): protective ventilation strategies are therefore to be implemented. Locoregional techniques should be favored over intravenous analgesia: the thoracic epidural, the paravertebral block (PVB), the intercostal nerve block (ICNB), and the serratus anterior plane block (SAPB) are thoroughly reviewed and the most common dosages are reported. Fluid therapy needs to be administered critically, to avoid both overload and cardiovascular compromisation. All these practices are analyzed singularly with the aid of the most recent evidences aimed at the best patient care. Finally, a few notes on some of the latest trends in research are presented, such as non-intubated video-assisted thoracoscopic surgery (VATS) and intravenous lidocaine.

Anxiety sensitivity moderates the painful effects of feeling burdensome to others

Perceived burdensomeness (PB), the perception of being a burden to others, is associated with pain and physical symptoms. Anxiety sensitivity (AS), the fear of arousal-related sensations, arising from beliefs that the sensations may have adverse personal consequences (physical, cognitive, and social), may increase risk for pain responding, particularly in anxiety-provoking (e.g. socially threatening) contexts. Accordingly, individuals high in AS may have a stronger pain response when experiencing PB than those low in AS. Undergraduate participants (n = 262) completed the Anxiety Sensitivity Index (ASI-3), and then were randomly assigned to re-live an experience when they were either burdensome to others (burdensome condition) or contributed equally to a group (control condition). Both social and physical self-reported pain were assessed post-manipulation. Those high in AS reported significantly higher pain ratings in the burdensome condition than the control condition; for those low in AS, pain did not change across conditions. In particular, being fearful of the physical repercussions of anxiety (AS physical concerns) while also feeling burdensome to others was associated with greater physical pain. AS may exacerbate the already painful effects of feeling burdensome to others, and may have important implications for the development of future suicide- and pain-related interventions.

New Therapeutic Targets for Osteoarthritis Pain

Osteoarthritis (OA), the most common form of arthritis, causes pain and disability, as well as emotional distress. While total joint replacement is one of the most effective treatments available for improving the quality of life in people with severe OA, it is not suitable for all patients and all joints. Current pharmacological analgesics have limited efficacy, and their use is often restricted by adverse events. Medications that might reduce pain by slowing or preventing structural disease remain elusive. Our increasing understanding of the complex mechanisms that underlie OA pain offers a wide range of potential new treatment targets. New drugs for OA pain might come from repurposing those developed for other conditions, as well as novel compounds targeting pain mechanisms specific to the joint. Here we discuss the mechanisms of OA pain and its therapeutic implications. We explore evolving treatment modalities, including combination treatment. We review recent research and patents pointing to future OA therapies. We discuss the potential for biomarkers to facilitate drug development and targeting.

The association between preoperative mental distress and patient-reported outcome measures in patients treated surgically for cervical radiculopathy

BACKGROUND CONTEXT

Previous research indicates that there might exist a link between the experience of pain and mental distress. Pain can possibly trigger anxiety and chronic pain, as well as also depression. On the other hand, anxiety and depression might also be risk factors for painful conditions and more pronounced subsequent disability and thus, the pathways may be bidirectional. Expanded knowledge of how different factors affect pain and function may help surgeons in preoperative decision-making.

PURPOSE

The aim of this study was to evaluate the impact of potential preoperative risk factors with special reference to mental distress.

STUDY DESIGN/SETTING

This is a prospective outcome study in a cohort from a multicenter randomized controlled trial comparing anterior cervical decompression and fusion with disc replacement.

PATIENT SAMPLE

The sample included 151 patients with cervical radiculopathy planned for surgery.

OUTCOME MEASURES

Surgical outcome was evaluated with Neck Disability Index (NDI), health related quality-of-life with European Quality of Life-5 Dimensions, and pain with visual analogue scale for arm and neck. Mental distress was preoperatively measured with the Hospital Anxiety and Depression (HAD) scale.

METHODS

Preoperative data regarding possible risk factors for poor outcome were analyzed in multiple linear regression models with postoperative NDI and change of NDI as dependent factors. Patients with high preoperative levels of anxiety or depression (H-HAD), indicating mental distress, were compared with patients scoring low/moderate levels (L-HAD) regarding patient-reported outcome measures (PROMs) preoperatively and at 1- and 2-year follow-up.

RESULTS

Outcome data were available for 136 patients at the 2-year follow-up. No statistically significant difference in any outcome data could be demonstrated between the two surgical treatment groups. Mental distress was the variable most strongly associated with NDI at 2 years in the regression analysis. There were 42 patients classified as H-HAD and 94 as L-HAD. The average improvement in NDI was 16.9 in the H-HAD group and 26.3 in the L-HAD group, p=.02. The H-HAD patients showed a tendency for poorer baseline data and worse outcome overall in all PROMs at follow-up at both 1 and 2 years.

CONCLUSIONS

Preoperative mental distress measured with HAD was associated with worse outcome overall. More research is needed to investigate whether patients with mental distress may achieve better results if other treatments are offered, either as non-surgical treatment alone or as an adjunct to surgery.

Analgesic Effects of Alcohol: A Systematic Review and Meta-Analysis of Controlled Experimental Studies in Healthy Participants

Despite the long-standing belief in the analgesic properties of alcohol, experimental studies have produced mixed results. This meta-analysis aimed to clarify whether alcohol produces a decrease in experimentally-induced pain and to determine the magnitude of any such effect. PubMed, PsycINFO, and Embase databases were searched from inception until April 21, 2016 for controlled studies examining the effect of quantified dosages of alcohol on pain response to noxious stimulation. Eighteen studies involving 404 participants were identified providing alcohol versus no-alcohol comparisons for 13 tests of pain threshold (n = 212) and 9 tests of pain intensity ratings (n = 192). Random effects meta-analysis of standardized mean difference (SMD) provided robust support for analgesic effects of alcohol. A mean blood alcohol content (BAC) of approximately .08% (3-4 standard drinks) produced a small elevation of pain threshold (SMD [95% CI] = .35 [.17-.54], P = .002), and a moderate to large reduction in pain intensity ratings (SMD [95% CI] = .64 [.37-.91], P < .0001), or equivalently, a mean reduction of 1.25 points on a 0- to 10-point pain rating scale. Furthermore, increasing BAC resulted in increasing analgesia, with each .02% BAC increment producing an increase of SMD = .11 for pain threshold and SMD = .20 for reduced pain intensity. Some evidence of publication bias emerged, but statistical correction methods suggested minimal impact on effect size. Taken together, findings suggest that alcohol is an effective analgesic that delivers clinically-relevant reductions in ratings of pain intensity, which could explain alcohol misuse in those with persistent pain despite its potential consequences for long-term health. Further research is needed to corroborate these findings for clinical pain states.

PERSPECTIVE

This meta-analysis provides robust evidence for the analgesic properties of alcohol, which could potentially contribute to alcohol misuse in pain patients. Strongest analgesia occurs for alcohol levels exceeding World Health Organization guidelines for low-risk drinking and suggests raising awareness of alternative, less harmful pain interventions to vulnerable patients may be beneficial.

Psychological and endocrine factors and pain after mastectomy

BACKGROUND

This prospective study was designed to examine the associations of demographic, clinical, psychological and neuroendocrine factors with acute and chronic post-operative pain following partial mastectomy.

METHODS

Sixty-four female patients scheduled for partial mastectomy were enrolled. Pre-operative anxiety/depression was assessed, using the Hospital Anxiety and Depression Scale (HADS). Pre-operative 24-h urinary cortisol levels were measured 2 days before surgery. Post-operative pain was examined using a visual analog scale (VAS) for acute pain on 0-2 post-operative day (POD), and a short-form McGill Pain Questionnaire for chronic pain at 6 months after surgery. In the last 29 subjects, post-operative 24-h urinary cortisol levels were also measured on 0 POD and were subjected to correlation analysis.

RESULTS

Multivariate logistic regression analysis revealed that lower pre-operative cortisol secretion and greater pre-operative anxiety were significantly associated with an increased risk of moderate to severe acute post-operative pain [Odds Ratio (95% Confidence Interval); 0.96 (0.92-0.98), and 1.24 (1.04-1.54)], and that patients with greater pre-operative anxiety and moderate to severe acute pain were more likely to develop chronic post-operative pain [OR (95% CI); 1.63 (1.23-2.40), and 5.07 (1.30-24.6)]. Correlational analysis demonstrated that the post-operative cortisol level was inversely correlated with pre-operative anxiety and the intensity of acute post-operative pain (r = -0.40, p < 0.05, and r = -0.50, p < 0.01), but not with the intensity of chronic pain.

CONCLUSIONS

This study confirms that pre-operative anxiety is associated with both acute and chronic post-operative pain after partial mastectomy. It also suggests that lower perioperative cortisol secretion might be associated with greater acute post-operative pain.

SIGNIFICANCE

Although the associations between psychological stress/stress hormone levels and chronic post-operative pain remain to be determined, pre-operative psychological stress and perioperative cortisol levels are correlated with acute post-operative pain.

Is Pain Perception Altered in People With Depression? A Systematic Review and Meta-Analysis of Experimental Pain Research

Although clinical studies suggest depressed patients may be more vulnerable to pain, experimental research is equivocal. This meta-analysis aimed to clarify whether depression is associated with altered pain perception in response to noxious stimulation and to identify factors that might influence this association. A search of major electronic databases was conducted to identify experimental studies investigating pain response in depressed participants versus healthy control participants using established pain outcome measures. Random effects meta-analysis of standardized mean differences was conducted on data from 32 studies (N = 1,317). For high-intensity noxious stimulation, overall pain tolerance was similar across depressed and control groups (Hedges g = .09, P = .71, studies = 10). For low-intensity stimulation, a small, but statistically significant higher mean sensory threshold (g = .35, P = .01, studies = 9) and pain threshold (g = .32, P = .02, studies = 25) was observed in depressed participants, suggesting diminished pain. However, considerable heterogeneity in the direction and magnitude of effects was observed, indicating a likely condition-specific effect of depression on pain. Subgroup analysis found that pain threshold/tolerance was increased in depression for exteroceptive (cutaneous) stimulation but decreased for interoceptive (ischemic) stimulation, but that substantial heterogeneity remained. Overall, results provide some support for altered pain processing in depression, but suggest this link is dependent upon modality and additional, unidentified factors.

PERSPECTIVE

This meta-analysis of experimental studies suggests potential effects of depression on pain perception are variable and likely to depend upon multiple factors. The contrasting pattern for ischemic versus other noxious stimuli suggests that stimulus modality is a key factor, which could help explain discrepancies across clinical and experimental findings.

New generalized poisson mixture model for bimodal count data with drug effect: An application to rodent brief-access taste aversion experiments

Pharmacodynamic (PD) count data can exhibit bimodality and nonequidispersion complicating the inclusion of drug effect. The purpose of this study was to explore four different mixture distribution models for bimodal count data by including both drug effect and distribution truncation. An example dataset, which exhibited bimodal pattern, was from rodent brief-access taste aversion (BATA) experiments to assess the bitterness of ascending concentrations of an aversive tasting drug. The two generalized Poisson mixture models performed the best and was flexible to explain both under and overdispersion. A sigmoid maximum effect (Emax ) model with logistic transformation was introduced to link the drug effect to the data partition within each distribution. Predicted density-histogram plot is suggested as a model evaluation tool due to its capability to directly compare the model predicted density with the histogram from raw data. The modeling approach presented here could form a useful strategy for modeling similar count data types.

Enhanced Recovery After Surgery (ERAS) for gastrointestinal surgery, part 2: consensus statement for anaesthesia practice

Background

The present interdisciplinary consensus review proposes clinical considerations and recommendations for anaesthetic practice in patients undergoing gastrointestinal surgery with an Enhanced Recovery after Surgery (ERAS) programme.

Methods

Studies were selected with particular attention being paid to meta‐analyses, randomized controlled trials and large prospective cohort studies. For each item of the perioperative treatment pathway, available English‐language literature was examined and reviewed. The group reached a consensus recommendation after critical appraisal of the literature.

Results

This consensus statement demonstrates that anaesthesiologists control several preoperative, intraoperative and postoperative ERAS elements. Further research is needed to verify the strength of these recommendations.

Conclusions

Based on the evidence available for each element of perioperative care pathways, the Enhanced Recovery After Surgery (ERAS ^®) Society presents a comprehensive consensus review, clinical considerations and recommendations for anaesthesia care in patients undergoing gastrointestinal surgery within an ERAS programme. This unified protocol facilitates involvement of anaesthesiologists in the implementation of the ERAS programmes and allows for comparison between centres and it eventually might facilitate the design of multi‐institutional prospective and adequately powered randomized trials.

Pain in older people with frailty

In this review we identified cohort and cross-sectional studies that assessed pain in community-dwelling older people (>65 years) reliably characterized as frail. Secondly, we considered biologically plausible mechanisms that may alter pain perception, or contribute to, or exacerbate pain in an older person with frailty. Thirdly, we considered specific implications of pain management for this group of people. From the limited data from the seven included studies, it would appear that the presence of pain is higher in older people with frailty compared with people characterized as pre-frail or not frail. Thus older people reporting pain are more likely to be frail. However, a lack of prospective data precludes inferences about the direction of the relationship: that is whether pain or frailty is the antecedent. Further research is needed to understand the direction of the relationship, and to identify appropriate pain management strategies for older people with frailty.

Pain Sensitivity in Adolescent Males with Attention-Deficit/Hyperactivity Disorder: Testing for Associations with Conduct Disorder and Callous and Unemotional Traits

Background

Reduced processing and experience of aversive emotional cues is a common component of theories on the development and persistence of aggression and antisocial behaviour. Yet physical pain, arguably the most basic aversive cue, has attracted comparatively little attention.

Methods

This study measured pain sensitivity and physiological response to painful stimuli (skin conductance level, SCL) in adolescent boys with Attention-Deficit/Hyperactivity Disorder (ADHD; n = 183), who are at high risk for antisocial behaviour. We compared boys with ADHD with and without a comorbid diagnosis of Conduct Disorder (CD) on pain sensitivity, and examined patterns of association between pain measures, on the one hand, and problem severity and callous and unemotional (CU) traits, on the other.

Results

Boys with comorbid CD exhibited a higher pain threshold and tolerance than boys with ADHD alone, but the groups did not differ in physiology at the time the pain threshold and tolerance were reported. Regression analyses showed that ADHD problem severity positively predicted pain sensitivity, whereas levels of CU traits negatively predicted pain sensitivity.

Conclusions

These findings on physical pain processing extend evidence of impairments in aversive cue processing among those at risk of antisocial behaviour. The study highlights the importance of considering comorbidity and heterogeneity of disorders when developing interventions. The current findings could be used to identify subgroups within those with ADHD who might be less responsive to interventions that use corrective feedback to obtain behaviour change.

Pain perception and EEG dynamics: does hypnotizability account for the efficacy of the suggestions of analgesia?

We report novel findings concerning the role of hypnotizability, suggestions of analgesia and the activity of the Behavioral Inhibition/Activation System (BIS/BAS) in the modulation of the subjective experience of pain and of the associated EEG dynamics. The EEG of high (highs) and low hypnotizable participants (lows) who completed the BIS/BAS questionnaire was recorded during basal conditions, tonic nociceptive stimulation without (PAIN) and with suggestions for analgesia (AN). Participants scored the perceived pain intensity at the end of PAIN and AN. The EEG midline dynamics was characterized by indices indicating the signal predictability (Determinism) and complexity (Entropy) obtained through the Recurrence Quantification Analysis. The reduced pain intensity reported by highs during AN was partially accounted for by the activity of the Behavioral Activation System. The decreased midline cortical Determinism observed during nociceptive stimulation in both groups independently of suggestions remained significantly reduced only in lows after controlling for the activity of the Behavioral Activation System. Finally, controlling for the activity of the Behavioral Inhibition System abolished stimulation, suggestions and hypnotizability-related differences. Results indicate that the BIS/BAS activity may be more important than hypnotizability itself in pain modulation and in the associated EEG dynamics.

Trait Emotional Intelligence, Anxiety Sensitivity, and Experiential Avoidance in Stress Reactivity and Their Improvement Through Psychological Methods

Stress pervades daily society, often with deleterious consequences for those prone to react intensely to it. Intervention techniques to attenuate stress reactivity are thus paramount. With that goal in mind, researchers have sought to identify and alter malleable psychological dispositional variables that influence stress reactivity. Trait emotional intelligence (TEI), anxiety sensitivity (AS), and experiential avoidance (EA) are increasingly receiving attention in these research efforts. The self-reported emotional component of stress reactivity has been emphasized in investigations and is our focus. Specifically, this paper overviews the role of TEI, AS, and EA in self-reported stress responses. We also discuss empirically supported psychological methods to adjust suboptimal levels of these variables in normal populations. Both psycho-educational (information, skills) and mindfulness-based interventions (specific mindfulness therapies or components) are covered. Findings include that (1) TEI, AS, and EA are each correlated with the emotional component of stress reactivity to both naturalistic and lab-based stressors; (2) preliminary support currently exists for psycho-educational intervention of TEI and AS but is lacking for EA; (3) adequate evidence supports mindfulness-based interventions to target EA, with very limited but encouraging findings suggesting mindfulness methods improve TEI and AS; and (4) although more research is needed, stress management approaches based on mindfulness may well target all three of these psychological variables and thus appear particularly promising. Encouragingly, some methods to modify dispositional variables (e.g., a mindfulness-based format of guided self-help) are easily disseminated and potentially applicable to the general public.

Pain in 1,000 women treated for breast cancer: a prospective study of pain sensitivity and postoperative pain

BACKGROUND

This article describes the methods and results of the early part (experimental pain tests and postoperative analgesia) of a study that assesses genetic and other factors related to acute pain and persistent pain after treatment of breast cancer in a prospective cohort of 1,000 women.

METHODS

One thousand consenting patients were recruited to the study. Before surgery (breast resection or mastectomy with axillary surgery), the patients filled in questionnaires about health, life style, depression (Beck Depression Inventory), and anxiety (State-Trait Anxiety Inventory). They were also exposed to experimental tests measuring heat (43° and 48°C, 5 s) and cold (2-4°C) pain intensity and tolerance. Anesthesia was standardized with propofol and remifentanil, and postoperative analgesia was optimized with i.v. oxycodone.

RESULTS

The patients showed significant interindividual variation in heat and cold pain sensitivity and cold pain tolerance. There was a strong correlation between the experimental pain measures across the tests. Presence of chronic pain, the number of previous operations, and particularly state anxiety were related to increased pain sensitivity. Previous smoking correlated with decreased heat pain sensitivity. These factors explained 4-5% of the total variance in pain sensitivity in these tests. Oxycodone consumption during 20 h was significantly higher in patients who had axillary clearance. Oxycodone consumption had only a weak correlation with the experimental pain measures.

CONCLUSIONS

Contact heat and cold pressure tests identify variability in pain sensitivity which is modified by factors such as anxiety, chronic pain, previous surgery, and smoking. High levels of anxiety are connected to increased pain sensitivity in experimental and acute postoperative pain.

Neurobiology of stress-induced hyperalgesia

The intensity and severity of perceived pain does not correlate consistently with the degree of peripheral or central nervous system tissue damage or with the intensity of primary afferent or spinal nociceptive neurone activity. In this respect, the modulation of pain by emotion and context is now widely recognized. In particular, stress, fear and anxiety exert potent, but complex, modulatory influences on pain. Stress can either suppress pain (stress-induced analgesia) or exacerbate it (stress-induced hyperalgesia; SIH) depending on the nature, duration and intensity of the stressor. Herein, we review the methods and models used to study the phenomenon of SIH in rodents and humans and then present a detailed discussion of our current understanding of neural substrates and neurobiological mechanisms. The review provides perspectives and challenges for the current and future treatment of pain and the co-morbidity of pain with stress-related psychiatric disorders including anxiety and depression.