A Randomized Controlled Trial of Clinical Hypnosis as an Opioid-Sparing Adjunct Treatment for Pain Relief in Adults Undergoing Major Oncologic Surgery.

Clinical hypnosis is an effective strategy for managing acute pain in the surgical setting. However, the opioid sparing effects of clinical hypnosis are not as well understood. This pre-registered (NCT03730350) randomized, controlled trial (RCT) examined the impact of clinical hypnosis, pre- and post-surgery, on opioid consumption during hospitalization as well as on measures of pain intensity, pain interference, depressed mood, anxiety, sleep, and pain catastrophizing. Participants (M = 57.6 years; SD = 10.9) awaiting oncologic surgery were randomized to treatment-as-usual (n = 47) or hypnosis (n = 45). Intent-to-treat analyses were conducted using linear mixed effects modeling. A significant Group × Time interaction, F(6, 323.34) = 3.32, p = 0.003, indicated an opioid sparing effect of clinical hypnosis during the acute postoperative period. Hypnosis also protected against increases in pain catastrophizing at one-week after surgery, F (1, 75.26) = 4.04, p = 0.048. A perioperative clinical hypnosis intervention had a sparing effect on opioid consumption in-hospital after major oncologic surgery. These findings extend the efficacy of clinical hypnosis as an adjunct tool for perioperative pain management.

Presurgical distress about bodily sensations predicts chronic postsurgical pain intensity and disability 6 months after cardiothoracic surgery.

ABSTRACT: Chronic postsurgical pain (CPSP) and disability after cardiothoracic surgery are highly prevalent and difficult to treat. Researchers have explored a variety of presurgical risk factors for CPSP and disability after cardiothoracic surgery, including one study that examined distress from bodily sensations. The current prospective, longitudinal study sought to extend previous research by investigating presurgical distress about bodily sensations as a risk factor for CPSP and disability after cardiothoracic surgery while controlling for several other potential psychosocial predictors. Participants included 543 adults undergoing nonemergency cardiac or thoracic surgery who were followed over 6 months postsurgically. Before surgery, participants completed demographic, clinical, and psychological questionnaires. Six months after surgery, participants reported the intensity of CPSP on a 0 to 10 numeric rating scale and pain disability, measured by the Pain Disability Index. Multinomial logistic regression analyses were conducted to evaluate the degree to which presurgical measures predicted pain outcomes 6 months after surgery. The results showed that CPSP intensity was significantly predicted by age and presurgical scores on the Symptom Checklist-90-Revised Somatization subscale (Nagelkerke R2 = 0.27, P < 0.001), whereas chronic pain disability was only predicted by presurgical Symptom Checklist-90-Revised Somatization scores (Nagelkerke R2 = 0.29, P < 0.001). These findings demonstrate that presurgical distress over bodily sensations predicts greater chronic pain intensity and disability 6 months after cardiothoracic surgery and suggest that presurgical treatment to diminish such distress may prevent or minimize CPSP intensity and disability.

The Prospective Prognostic Value of Biopsychosocial Indices of Sensitivity to Physical Activity Among People With Back Pain.

OBJECTIVES: Many people living with musculoskeletal pain conditions experience a range of negative biopsychosocial responses to physical activity, referred to as increased sensitivity to physical activity (SPA), that may undermine successful rehabilitation. This exploratory study aims to provide the first prospective analysis of the potential prognostic value of 3 biopsychosocial indices of SPA in relation to rehabilitation outcomes. This study also aimed to shed light on the cross-sectional interrelationships between these 3 biopsychosocial indices of SPA. MATERIALS AND METHODS: Adults with back pain were evaluated upon starting physical therapy and then again 3 months later. The initial testing session consisted of self-reported pain-related questionnaires and assessment of activity-related changes in pressure pain thresholds (SPA-Sensory), pain intensity ratings (SPA-Pain), and situational catastrophizing (SPA-Psych). The 3-month follow-up consisted of self-reported disability and pain questionnaires. Correlational and hierarchical linear regression analyses were conducted. RESULTS: A total of 97 participants completed both the initial visit and 3-month follow-up. The SPA-Pain index and the SPA-Psych index were significantly intercorrelated, but neither were correlated with the SPA-Sensory index. The SPA-Sensory index was not correlated with outcomes. The SPA-Pain index was correlated only with cross-sectional disability and pain outcomes. The SPA-Psych index was the only SPA index significantly correlated with outcomes both cross-sectionally and at 3-month follow-up. After controlling for baseline pain/disability and pain catastrophizing, SPA-Psych was no longer a significant prognostic factor for pain, but remained a significant prognostic factor for disability at 3-month follow-up (ß=0.272, t=2.674, P=0.008, R2 Δ=5.60%). DISCUSSION: This study highlights the importance of conceptualizing and measuring SPA as a biopsychosocial (rather than unidimensional) construct and points toward the added prognostic value of this construct. Implications for future research and practice are discussed.

Identifying priorities and developing strategies for building capacity in amputation research in Canada.

BACKGROUND: Compared to other patient population groups, the field of amputation research in Canada lacks cohesion largely due to limited funding sources, lack of connection among research scientists, and loose ties among geographically dispersed healthcare centres, research institutes and advocacy groups. As a result, advances in clinical care are hampered and ultimately negatively influence outcomes of persons living with limb loss. OBJECTIVE: To stimulate a national strategy on advancing amputation research in Canada, a consensus-workshop was organized with an expert panel of stakeholders to identify key research priorities and potential strategies to build researcher and funding capacity in the field. METHODS: A modified Delphi approach was used to gain consensus on identifying and selecting an initial set of priorities for building research capacity in the field of amputation. This included an anonymous pre-meeting survey (N = 31 respondents) followed by an in-person consensus-workshop meeting that hosted 38 stakeholders (researchers, physiatrists, surgeons, prosthetists, occupational and physical therapists, community advocates, and people with limb loss). RESULTS: The top three identified research priorities were: (1) developing a national dataset; (2) obtaining health economic data to illustrate the burden of amputation to the healthcare system and to patients; and (3) improving strategies related to outcome measurement in patients with limb loss (e.g. identifying, validating, and/or developing outcome measures). Strategies for moving these priorities into action were also developed. CONCLUSIONS: The consensus-workshop provided an initial roadmap for limb loss research in Canada, and the event served as an important catalyst for stakeholders to initiate collaborations for moving identified priorities into action. Given the increasing number of people undergoing an amputation, there needs to be a stronger Canadian collaborative approach to generate the necessary research to enhance evidence-based clinical care and policy decision-making.IMPLICATIONS FOR REHABILITATIONLimb loss is a growing concern across North America, with lower-extremity amputations occurring due to complications arising from diabetes being a major cause.To advance knowledge about limb loss and to improve clinical care for this population, stronger connections are needed across the continuum of care (acute, rehabilitation, community) and across sectors (clinical, advocacy, industry and research).There are new surgical techniques, technologies, and rehabilitation approaches being explored to improve the health, mobility and community participation of people with limb loss, but further research evidence is needed to demonstrate efficacy and to better integrate them into standard clinical care.

A Cumulative Impact of Psychological and Sensitization Risk Factors on Pain-Related Outcomes.

OBJECTIVE: Risk constructs based on psychological risk factors (eg, pain catastrophizing, PC) and sensitization risk factors (eg, pressure pain threshold, PPT) are important in research and clinical practice. Most research looks at individual constructs but does not consider how different constructs might interact within the same individual. An evaluation of the cumulative impact of psychological and sensitization risk factors on pain-related outcomes may help guide us in the risk assessment of patients with pain conditions. The aim of this study is to evaluate the cumulative impact of these psychological (PC) and sensitization (PPT) risk factors on pain-related outcomes (activity avoidance, pain severity, and disability) considering covariates. METHODS: We included 109 participants (70.60% women; mean ± SD age 53.6 ± 12.3 years) with chronic musculoskeletal pain for data analysis, who completed all measures of this study. Participants completed a single testing session that included measures of risk factors (PC and PPT) and pain-related outcomes (self-reported avoidance, functional avoidance, disability, and pain severity). Subgroups were constructed by dichotomizing of PC and PPT scores, resulting in four groups: (1) low catastrophizing and low sensitivity (N = 26), (2) high catastrophizing and low sensitivity (N = 27), (3) low catastrophizing and high sensitivity (N = 25), and (4) high catastrophizing and high sensitivity (N = 31). RESULTS: One-way analysis of variance (ANOVA) revealed significant group differences (P < 0.05, η2  = 0.08 to 0.14) in all outcomes of this study (except functional avoidance), and post hoc analysis indicated the significant differences are between group 1 and 4. A cumulative impact is reflected by large effect sizes between group 1 and 4 (d = 0.8 to 1). The group 2 and 3 (one risk dimension groups: either high-PC or high-PPT) represent 47% of the total participants. CONCLUSIONS: The study suggests both higher level of PC and pressure sensitivity have a cumulative impact on risk screening for pain-related outcomes, considering gender in functional avoidance (task-related outcome). A clinical presentation with high-PC (one dimension of risk) is not associated with high-PPT (another dimension of risk). This finding has important clinical and theoretical implications.

Chronic pain produces hypervigilance to predator odor in mice.

The adaptive significance of acute pain (to withdraw from tissue-damaging or potentially tissue-damaging external stimuli, and to enhance the salience of the stimulus resulting in escape and avoidance learning) and tonic pain (to enforce recuperation by punishing movement) are well-accepted [1]. Pain researchers, however, generally assert that chronic pain has no adaptive significance, representing instead a pathophysiological state. This belief was recently challenged by the observation [2] that nociceptive sensitization caused by a chronic pain-producing injury reduced predation risk in squid (Doryteuthis pealeii). In that study, injury to an arm (removal of the tip with a scalpel) 6 hours prior led to increased targeting by black sea bass, resulting in decreased survival of the squid in a 30-minute trial featuring free interaction between predator and prey. The surprising finding was that anesthesia during surgery, preventing the chronic nociceptor sensitization associated with such injuries, led to even lower probability of survival. That is, the likely presence of pain increased apparent fitness, and the authors concluded that the chronic pain state and its associated nociceptive sensitization represented an adaptive function. Pain-induced defensive behaviors affecting fitness have also been reported in crustaceans (Gammarus fossarum) [3]. It is, however, currently unknown whether this may also be true in any other species, including in Mammalia.

Recent advances in understanding and managing phantom limb pain.

Post-amputation phantom limb pain (PLP) is highly prevalent and very difficult to treat. The high-prevalence, high-pain intensity levels, and decreased quality of life associated with PLP compel us to explore novel avenues to prevent, manage, and reverse this chronic pain condition. This narrative review focuses on recent advances in the treatment of PLP and reviews evidence of mechanism-based treatments from randomized controlled trials published over the past 5 years. We review recent evidence for the efficacy of targeted muscle reinnervation, repetitive transcranial magnetic stimulation, imaginal phantom limb exercises, mirror therapy, virtual and augmented reality, and eye movement desensitization and reprocessing therapy. The results indicate that not one of the above treatments is consistently better than a control condition. The challenge remains that there is little level 1 evidence of efficacy for PLP treatments and most treatment trials are underpowered (small sample sizes). The lack of efficacy likely speaks to the multiple mechanisms that contribute to PLP both between and within individuals who have sustained an amputation. Research approaches are called for to classify patients according to shared factors and evaluate treatment efficacy within classes. Subgroup analyses examining sex effects are recommended given the clear differences between males and females in pain mechanisms and outcomes. Use of novel data analytical approaches such as growth mixture modeling for multivariate latent classes may help to identify sub-clusters of patients with common outcome trajectories over time.

Comparing Novel and Existing Measures of Sensitivity to Physical Activity Among People With Chronic Musculoskeletal Pain: The Importance of Tailoring Activity to Pain.

OBJECTIVES: Increasing pain during physical activity is an important, but often poorly assessed, barrier to engaging in activity-based rehabilitation among people with chronic musculoskeletal pain. Preliminary work has addressed this problem by developing new clinical measures of sensitivity to physical activity (SPA). Indices of SPA are generated by evaluating how pain changes in relation to brief physical tasks. Three strategies have been identified for structuring SPA-related physical tasks (self-paced, standardized, and tailored). This cross-sectional study aimed to comparatively estimate the extent of the 3 SPA tasks' evoked pain responses, predictive value of pain severity and pain interference, and their underlying psychological and sensory constructs, among 116 adults with chronic musculoskeletal pain. MATERIALS AND METHODS: Testing included questionnaires, quantitative sensory testing, and the 3 SPA measures (self-paced, standardized, and tailored). The primary analysis estimated the predictive value of each SPA measure for pain severity and pain interference. Correlational analyses were first conducted between all variables of interest to determine what variables will be included in the hierarchical regression analysis, which in turn was conducted for each outcome. RESULTS: Analyses revealed that the tailored SPA index was most effective at evoking activity-related pain, was uniquely associated with temporal summation of pain, and was a unique predictor of pain and pain-related interference, even when controlling for established psychological and sensory risk factors. DISCUSSION: This study further emphasizes SPA as an important and unique attribute of the pain experience and reveals the added value of using a tailored approach to assess SPA.

Evaluating the novel added value of neurophysiological pain sensitivity within the fear-avoidance model of pain.

BACKGROUND: The fear-avoidance model (FAM) is a leading theoretical paradigm for explaining persistent pain following musculoskeletal injury. The model suggests that as injuries heal, pain-related outcomes are increasingly determined by psychological, rather than physiological factors. Increasing literature, however, suggests that neurophysiological processes related to pain sensitivity also play an important role in chronicity. To date, there has been limited research that has specifically explored the role of pain sensitivity within the FAM. This study addresses this gap by evaluating whether clinical measures of pain sensitivity help explain FAM-related outcomes, beyond model-relevant psychological predictors. METHODS: The study sample consisted of 80 adults with chronic and widespread musculoskeletal pain. Participants completed a single testing session that included measures of all of the major constructs of the FAM, including pain catastrophizing, pain-related fear, activity avoidance (self-report and functional measures), pain-related disability, depression and pain severity, as well as a battery of quantitative sensory testing that included measures of pressure pain threshold and temporal summation of mechanical pain across eight body sites. RESULTS: A series of hierarchical regression analyses revealed that after controlling for the psychological predictors of the FAM, indices of pain sensitivity significantly predicted 4 of the 5 FAM-related outcomes (p < 0.05). Depression was the only outcome not significantly predicted by pain sensitivity. Interestingly, measures of pain sensitivity, but not FAM psychological factors, predicted the functional measure of activity avoidance. CONCLUSIONS: These findings provide further evidence for the importance of neurophysiological factors within the FAM and have important clinical and theoretical implications. SIGNIFICANCE: This study provides evidence for the unique and added value of neurophysiological factors within the Fear Avoidance Model of pain and for the importance of integrating both sensory and psychological factors within both theoretical paradigms and clinical management strategies.