Pain Expectations Research Articles

Influence of instructions and expectations in pain perception on pupil diameter and the cognitive assessment of pain

ObjectiveThe purpose of this study was to analyze the influence of pain and no pain expectation on pupil diameter and the cognitive assessment of pain using pupillometry and the visual analog scale (VAS). MethodsThis was an experimental cross-sectional study in which painful stimulation of the muscle masseter was produced by palpation with an algometer in a sample of 30 healthy participants. Before the painful stimulation, pain expectation and no pain expectation situations were induced by employing instructional videos. Cognitive and physiological pain responses were measured by the VAS and by pupillometry. Visual analog scale score was assessed at the end of each experimental condition, and pupillometry measurements were recorded at different moments of the experimental process (events). ResultsThe pain score and larger pupil diameter for all events (except, as expected, for the initial baseline), were statistically significant for the pain expectation condition compared with the no pain expectation. ConclusionWithin the conditions of this study, pain expectation modulated both cognitive assessment of pain (VAS) and pupil diameter. These findings suggest that pupil diameter may be a useful and complementary tool with the VAS for pain assessment. Furthermore, the findings support models postulating that emotion and cognition are important aspects involved in pain perception, which is in line with the recent International Association for the Study of Pain definition of pain.

Attention and nocebo hyperalgesia: Testing a novel virtual reality attention bias modification paradigm

Nocebo effects in pain (nocebo hyperalgesia) have received significant attention recently, with negative expectancies and anxiety proposed to be explanatory factors. While both expectancy and anxiety can bias attention, attention has been rarely explored as a potential mechanism involved in nocebo hyperalgesia. The present study aimed to explore whether attention bias modification (ABM) using an immersive, ecologically valid VR paradigm successfully induced attention biases (AB) and subsequently influenced nocebo hyperalgesia. One-hundred and two healthy participants were randomised in a 2 (AB training: towards vs. away from pain) x 2 (nocebo condition: nocebo vs. control) design. Pain-related AB was successfully changed by the VR paradigm as measured by reaction time and gaze, with moderate to large effects. Participants then completed either a nocebo instruction and conditioning procedure (nocebo paradigm) or a matched control procedure. The primary outcome was self-reported pain intensity. Secondary outcomes were attention bias and self-reports of expectancy, anticipatory anxiety, and state anxiety. The nocebo paradigm induced significantly greater pain expectancy, anticipatory anxiety and pain intensity during the test phase for the nocebo group compared to control. Pain expectancy also fully mediated the effect of the nocebo group on nocebo hyperalgesia and anticipatory anxiety in separate models. ABM did not, however, affect nocebo hyperalgesia or pain expectancy, casting doubt on the potential for ABM to inoculate against nocebo hyperalgesia. Unexpected effects of ABM were observed for state anxiety and anticipatory anxiety, whereby training away from pain exacerbated each, which necessitates further exploration. PerspectiveThis article tests the efficacy of a novel attention bias modification paradigm, designed in virtual reality, for inducing pain-related biases, and whether these biases exacerbate or inoculate against nocebo hyperalgesia. While pain-related biases were successfully induced, there was no relationship with the strength of induced nocebo hyperalgesia.

Alpha transcranial alternating current stimulation modulates pain anticipation and perception in a context-dependent manner.

Pain perception is closely tied to the brain's anticipatory processes, particularly involving the suppression of sensorimotor α-oscillations, which reflect the system's readiness for incoming pain. Higher sensorimotor α-oscillation levels are correlated with lower pain sensitivity. Alpha transcranial alternating current stimulation (α-tACS) can enhance these oscillations, potentially reducing pain perception, with effects that may be sustained and influenced by the certainty of pain expectations. Hence, this study investigated the immediate and sustained effects of α-tACS on pain anticipation and perception, focusing on how these effects are shaped by the certainty of expectations. In a double-blind, sham-controlled design, 80 healthy participants underwent a 20-minute session of real or sham α-tACS over the right sensorimotor region. Behavioral and neural responses related to pain anticipation and perception were recorded before, immediately after, and 30 minutes poststimulation under both certain and uncertain conditions. Compared with sham stimulation, real α-tACS disrupted the habituation of laser-evoked potentials (N2-P2 complex), particularly under certain expectations, with effects persisting 30 minutes poststimulation. In anticipatory brain oscillations, real α-tACS enhanced somatosensory α1-oscillations and increased midfrontal θ-oscillations in conditions of certainty, with θ-oscillation modulation showing sustained effects. Mediation analysis revealed that α-tACS reduced pain reactivity by enhancing somatosensory α1-oscillations but increased pain reactivity through the enhancement of midfrontal θ-oscillations, with the latter effect being more pronounced. These findings suggest that while α-tACS may provide pain relief through somatosensory α-oscillation augmentation, its stronger and longer-lasting impact on midfrontal θ-oscillations could lead to hyperalgesia, particularly in the context of certain pain expectations.

The Effect of Different Education Methods Before Invasive Urodynamics on Patients’ Anxiety, Pain, Readiness and Satisfaction Levels: Randomized Controlled Clinical Trial

Urodynamic testing is an invasive procedure that causes pain and anxiety. Patient education is an evidence-based nursing intervention that relieves pain and anxiety and increases patient satisfaction. This study was carried out to compare the effects of different education methods utilized before a urodynamic testing procedure on patients' pain, anxiety, readiness for the procedure, and satisfaction. The study is a randomized controlled clinical trial. Participants (n = 80) were randomly assigned to four groups. While patients in the control group were provided with routine clinical information, patients in the intervention group were given education with brochures, videos, and brochure-supported videos. The research data were collected by using a Data Collection Form with items about participants' descriptive characteristics, the Visual Analog Scale, and the State Anxiety Inventory. It was determined that pain expectation before urodynamics and the severity of pain during urodynamics were lower in intervention groups than in the control group. Pain expectation before urodynamics was lower in the brochure-supported video education group than in the brochure education group. Anxiety levels were lower and satisfaction levels were higher in the video education and brochure-supported video education groups than in the control and brochure education groups. Of the methods utilized, it was determined that the most effective one was brochure-supported video education as it affected all parameters positively.

Rural-urban residence and life expectancies with and without pain

This paper analyzes rural-urban disparities in life expectancy with and without pain among upper-middle age and older adults. Data are from the nationally representative Health and Retirement Study, 2000–2018, N = 18,160, age 53+. Interpolated Markov Chain software, based on the multistate life tables, is used to calculate absolute and relative pain expectancies by age, sex, rural-suburban-urban residence and U.S. regions. Results show significant rural disadvantages versus those in urban and often suburban areas. Example: males at 55 in rural areas can expect to live 15.1 years, or 65.2 percent pain-free life, while those in suburban areas expect to live 1.7 more years, or 2.6 percentage points more, pain-free life and urban residents expect to live 2.4 more year, or 4.7 percentage points more. The rural disadvantage persists for females, with differences being a little less prominent. At very old age (85+), rural-urban differences diminish or reverse. Rural-urban pain disparities are most pronounced in the Northeast and South regions, and least in the Midwest and West. The findings highlight that rural-urban is an important dimension shaping the geography of pain. More research is needed to disentangle the mechanisms through which residential environments impact people's pain experiences.

Optimizing Safe Opioid Prescribing: A Paradigm Shift in Buprenorphine Management for Orthopaedic Surgery

The worsening opioid epidemic in the United States, exacerbated by the COVID-19 pandemic, necessitates innovative approaches to pain management. Buprenorphine, a long-acting opioid, has gained popularity due to its safety profile and accessibility. Orthopaedic surgeons, encountering an increasing number of patients on buprenorphine, face challenges in perioperative management. This article will update orthopaedic surgeons on new developments in the understanding of buprenorphine as a pain reliever and share evidence-based practice guidelines for buprenorphine management. For patients on buprenorphine for opioid use disorder or chronic pain, the updated recommendation is to continue their home dose of buprenorphine through the perioperative period. The patient’s buprenorphine prescriber should be contacted and notified of any impending surgery. The continuation of buprenorphine should be accompanied by a multimodal approach to analgesia, including a preoperative discussion about expectations of pain and pain control, regional anesthesia, standing acetaminophen, Nonsteroidal anti-inflammatory drugs when possible, gabapentinoids at night for patients under 65 years, cryotherapy, elevation, and early mobilization. Patients can also be prescribed short-acting, immediate-release opioids for breakthrough pain. Transdermal buprenorphine is emerging as an excellent option for the management of acute perioperative pain in both elective and nonelective orthopaedic patients. A single patch can provide a steady dose of pain medication for up to 1 week during the postoperative period. A patch delivery method can help combat patient nonadherence and ultimately provide better overall pain control. In the future, transdermal buprenorphine patches could be applied in virtually all fracture surgery, spinal surgery, total joint arthroplasty, ligament reconstructions with bony drilling, etc. As the stigma surrounding buprenorphine decreases, further opportunities for perioperative use may develop.

Preoperative Expectations of Women Undergoing Breast Reconstruction Surgery.

The study investigated the expectations of patients undergoing immediate breast reconstruction after mastectomy, considering factors such as the cause for mastectomy (cancer versus prophylactic due BRCA1 or BRCA2 gene mutations), age, marital status, and education. The study had a cross-sectional design. Eligible patients at Oslo University Hospital received a link to the BREAST-Q Expectations questionnaire, which they filled out before surgery from 2019 to 2022. One hundred forty-six patients completed the questionnaire (79.8% response rate). The mean age was 46.6 years, and the majority (95.1%) were undergoing reconstruction with implants. Most patients (86.9%) wanted to be involved in the decision-making. The highest expectation was for breast appearance and the lowest for sensation after surgery. Patients not diagnosed with cancer (n = 27) before surgery expected significantly more pain after surgery compared with patients diagnosed with cancer (P = 0.016). Patients 40 years or younger had higher expectation of pain after surgery than patients 41 years or older, 73.2 versus 54.2, P < 0.001, respectively. After 10 years, 26.7% of the patients expected that further reconstruction procedures might be necessary. Our study's results regarding patient's expectations with breast reconstruction, as assessed using the BREAST-Q Expectations module, align with previous research in terms of overall trends. However, our study provides a more nuanced understanding by exploring variations within different patient subgroups. These differences emphasize the need for personalized preoperative counseling and support to align patient's expectations with realistic outcomes.

The proteus effect on human pain perception through avatar muscularity and gender factors

The Proteus effect, which occurs when using an avatar in virtual reality, influences user behavior, changes attitudes, and improves physical performance. Here, we show that human pain perception can be alleviated by the Proteus effect. To investigate the pain alleviation effect of using an avatar in a virtual environment, we conducted two experiments using a head-mounted display and a thermal pain stimulator to induce acute pain. The first experiment involved 20 adult participants, while the second experiment involved 44 adult participants. Experimental results show that participants reported significantly lower pain scores (15.982% reduction), as measured by the Pain Assessment Scale (PAS), when using a muscular avatar than when using a normal avatar. The experiments also revealed several significant gender factors. For example, participants reported significantly lower pain scores when using a gender-congruent avatar. In addition, the use of a muscular avatar was particularly effective for male participants. In contrast, female participants consistently reported lower pain scores when using the avatar regardless of its body type (muscular/normal). To further our understanding, we also measured participants’ gender-related pain stereotypes using the Gender Role Expectations of Pain (GREP) questionnaire, as well as participants’ sense of embodiment. The results of these questionnaires are consistent with the results of the PAS, suggesting possible relationships between stereotypes and the Proteus effect on pain perception, and between the degree of immersion in an avatar and the user’s perception of pain.

Pain reflects the informational value of nociceptive inputs.

Pain perception and its modulation are fundamental to human learning and adaptive behavior. This study investigated the hypothesis that pain perception is tied to pain's learning function. Thirty-one participants performed a threat conditioning task where certain cues were associated with a possibility of receiving a painful electric shock. The cues that signaled potential pain or safety were regularly changed, requiring participants to continually establish new associations. Using computational models, we quantified participants' pain expectations and prediction errors throughout the task and assessed their relationship with pain perception and electrophysiological responses. Our findings suggest that subjective pain perception increases with prediction error, that is, when pain was unexpected. Prediction errors were also related to physiological nociceptive responses, including the amplitude of nociceptive flexion reflex and electroencephalography markers of cortical nociceptive processing (N1-P2-evoked potential and gamma-band power). In addition, higher pain expectations were related to increased late event-related potential responses and alpha/beta decreases in amplitude during cue presentation. These results further strengthen the idea of a crucial link between pain and learning and suggest that understanding the influence of learning mechanisms in pain modulation could help us understand when and why pain perception is modulated in health and disease.

ARE WE MEETING PATIENTS’ EXPECTATIONS FOLLOWING REVISION TOTAL HIP ARTHROPLASTY?

The number of revision total hip arthroplasties (THA) is increasing. This procedure is associated with a higher complication rate than primary THA, and so it is important for patients to have realistic expectations. The aim of this systematic review was to gather and summarise the available evidence on patients’ expectations following revision THA.A literature search was conducted in PubMed, PsycINFO, Cochrane, Google Scholar and Web of Science from inception to December 2021. Methodological quality was assessed by two independent reviewers using the National Heart, Lung and Blood Institute (NIH) study quality assessment tool for observational cohort and cross-sectional studies.The search strategy generated 3132 references of which 4 articles met the inclusion criteria. Methodological quality scores ranged from 7–10. Patients have high expectations concerning future walking ability, pain and implant longevity. Implant longevity expectations vary according to the longevity of the primary implant. A significant positive correlation was found between fulfilled expectations of pain and walking ability and patient satisfaction (r = .46 – .47). Only one study assessed fulfilment of patient expectations. Great variability was seen in operationalisation and assessment of expectations.Patients undergoing revision THA appear to have high expectations with regards to future outcomes. Whilst results are promising, there is a paucity of high-quality data in this area. Further research is needed, which places emphasis on developing a sound theoretical framework for expectations, allowing for the consistent implementation of valid measurement tools.

The Role of Pain Expectations in the Development of Secondary Pinprick Hypersensitivity: Behavioral-Neurophysiological Evidence and the Role of Pain-Related Fear

Secondary mechanical hypersensitivity, a common symptom of neuropathic pain, reflects increased responsiveness of nociceptive pathways and can be induced temporarily in healthy volunteers using high-frequency electrical stimulation of the skin. Expectations modulate acute pain perception and fear of pain has been shown to attenuate and amplify the placebo and nocebo effects, respectively. However, the role of expectations and fear in the development of mechanical secondary hypersensitivity remains unclear. The modulatory role of fear and expectations in the development of mechanical secondary hypersensitivity remains so far mainly correlational. Here, we randomly assigned healthy participants (women) to a placebo, nocebo, or control group. In the experimental groups, participants’ expectations of pain were manipulated using verbal suggestions accompanied by an inert treatment. Fear of pain was evaluated both in terms of fear of pain and via questionnaires. Sensitivity to mechanical stimulation was assessed by self-reported pinprick ratings before and after high-frequency stimulation; pinprick-evoked potentials elicited by the stimulation were recorded. The placebo group developed the least mechanical secondary hypersensitivity (smaller proximal-distal spread), while the nocebo group developed the most, but only when outliers were excluded. Higher expectations of pain predicted a greater development of mechanical secondary hypersensitivity. Anticipatory pain-related fear only mediated the relationship between unpleasantness expectations and perceived pinprick unpleasantness. Dispositional fear of pain moderated the relationship between expectations and the perceived intensity and unpleasantness of pinpricks. No group differences were observed in pinprick-evoked potentials. We provide preliminary evidence that both expectations and fear impact the development of mechanical secondary hypersensitivity. PerspectiveExpectations of pain may influence the development of secondary mechanical hypersensitivity. This effect is moderated by dispositional fear of pain and partially mediated by situational fear of pain.

Pain Management in Outpatient Gynecologic Procedures: An Exploration of #Colposcopy on TikTok [ID 2683582

INTRODUCTION: TikTok, a rapidly expanding social platform, features content on painful outpatient gynecologic procedures like colposcopy. Although pain management strategies have been studied, mainstream perceptions of this procedure remain underresearched. This study aims to describe #colposcopy content on TikTok. METHODS: On August 30, 2023, the first 200 videos under #colposcopy on TikTok were collected for cross-sectional content analysis. Data were collected for author demographics, intent, tones, timing, and content themes. Educational videos were rated for quality and reliability utilizing the modified DISCERN scale. RESULTS: As of August 2023, #colposcopy on TikTok had 65.3 million views. 183 of the first 200 posts were eligible for inclusion. On average, each video received 21,754 likes, 623 comments, and 752 shares. The majority of creators (n=133; 72.7%) were White, 14 (7.7%) were Black, 6 (3.3%) were Asian, 6 (3.3%) were Hispanic/Latino, and 24 (13.1%) were unable to determine. 109 (59.6%) of the creators were patients sharing their experiences, and 26 (14.2%) were physicians or APPs intending to educate. 33 (18.0%) TikToks were educational, with a median DISCERN score of 2. Among 13 content categories, the category most observed was “pain and pain management” (n=117; 63.9%), with 81 (75.7%) creators describing the procedure as painful and 26 (25.5%) describing it as painless. Significant differences in content were also analyzed by author demographics, intent, tone, and timing. CONCLUSION: Colposcopy-related content on TikTok centers on patients’ pain experiences. Specifically, users of #colposcopy discussed the providers’ lack of pain management options. Opportunities exist to improve pain expectations and management strategies with patients.

Nocebo hyperalgesia and other expectancy-related factors in daily fibromyalgia pain: Combining experimental and electronic diary methods

ObjectiveExpectancies are known to shape pain experiences, but it remains unclear how different types of expectancies contribute to daily pain fluctuations in fibromyalgia. This combined experimental and diary study aims to provide insights into how experimentally-derived nocebo hyperalgesia and other, diary-derived, expectancy-related factors are associated with each other and with daily pain in fibromyalgia. MethodsForty-one female patients with fibromyalgia first participated in a lab procedure measuring nocebo hyperalgesia magnitude, then filled out an electronic diary 3 times a day over 3 weeks regarding the expectancy-related factors of pain expectancy, anxiety, optimism, and pain-catastrophizing thoughts, and current pain intensity. ResultsOur results indicate that experimentally-induced nocebo hyperalgesia was not significantly related to diary-assessed expectancy-related factors and did not predict daily fibromyalgia pain. Higher levels of the self-reported expectancy-related factors pain expectancy and pain catastrophizing, but not anxiety and optimism, predicted moment-to-moment pain increases in fibromyalgia, after controlling for current pain, moment-of-day and all other expectancy-related factors. ConclusionOur exploratory research findings indicate that self-reported expectancy-related factors, particularly pain expectancy and pain catastrophizing, are potentially more relevant for predicting daily pain experience than experimentally-induced nocebo hyperalgesia. Further translation of nocebo hyperalgesia is needed from experimental to Ecological Momentary Assessment research. Our findings imply that targeting the decrease in pain expectancy and catastrophizing thoughts e.g., via Cognitive Behavioral Therapy, have potential for improving daily pain levels in fibromyalgia.

Understanding oscillatory correlates of pain expectation

Understanding oscillatory correlates of pain expectation

An Updated Analysis of Body Contouring Malpractice Cases.

Body contouring procedures are commonly performed in the United States for patients seeking to sculpt specific areas of their bodies. The aim of this study was to provide an updated analysis of the factors that influence medical malpractice litigation surrounding body contouring surgery. The following terms were used to search the Westlaw Campus Legal research Database for cases with earliest documentation after January 2013: ("contouring" OR "abdominoplasty" OR "liposuction" OR "tummy tuck" OR "body lift" OR "thigh lift" OR "arm lift" OR "brachioplasty" OR "thighplasty" OR "lipectomy" OR "panniculectomy") AND "surgery" AND "medical malpractice." Cases were only included if there was a complaint of medical malpractice subsequent to a body contouring procedure, and details of the cases were provided. Information was collected on the location of the lawsuit, the earliest year of available case documentation, patient demographics, procedure(s) performed, alleged injury, specialty involvement, and verdicts. A total of 32 cases were included in the study. Most of the patients involved in the cases were women (n = 30, 93.8%) and alive (n = 28, 87.5%). New York state had the most cases (n = 7, 21.9%). Abdominoplasty (56.3%), liposuction (53.1%), and buttock augmentations (15.6%) were the most common procedures. Plastic surgeons were involved in 93.8% (n = 30) of the cases, and anesthesia, emergency medicine, dermatology, and oncology were also involved. Claims of malpractice most often discussed negligent technique (71.9%) and poor postoperative management (62.5%). Common postoperative complications were infection/sepsis (40.6%), scarring (31.3%), and emotional distress/prolonged pain (31.3%). One available ruling was in favor of the plaintiff. Although many of the cases in this analysis cited negligent technique, none were founded in their argument. Because involvement in these cases can place a burden on attending physicians, clear expectations of postoperative infections, scarring, and prolonged pain should be addressed during the informed consent process.

Exploring the association of gender role expectations of pain and measures of pain sensitization in people with knee osteoarthritis: A cross-sectional study

ObjectivesFirst, we explored the association between Gender Role Expectations of Pain (GREP), and psychophysical measures of sensitization in people with knee osteoarthritis (OA). Second, we explored whether the association differed by level of GREP items (high vs low scores). DesignWe conducted secondary analyses of a cohort study. Those who were (i) age of ≥ 40, English or French speaking, ii) diagnosed with knee OA using American College of Rheumatology criteria and iii) consulting with an orthopedic surgeon were included. GREP items pertaining to pain sensitivity and pain endurance of the typical man or woman were rated by males and females respectively. Psychophysical tests consisted of pressure pain thresholds (PPTs), Temporal Summation (TS), and Conditioned Pain Modulation (CPM). Multiple linear regression models for males and females were run with GREP scores (independent variables) and psychophysical tests (dependent variables). Next models stratified on the median split of GREP scores were run. Models were adjusted for age, BMI, pain catastrophizing, anxio-depressive symptoms, and radiographic severity. Results280 participants (57% females; age (SD): 63.9 (9.6) and BMI (SD): 31.3 (8.40)) were included. GREP pain sensitivity scores in males were associated with CPM values (β: 95% CI: 0.09 (0.01 to 0.17)). Males with low GREP pain sensitivity or pain endurance had very small to small positive associations with PPT and CPM values. ConclusionThis first exploration of gendered pain sensitivity and pain endurance by males and females has small and clinically unimportant associations with measures of pain sensitization requiring further validation.

A Study to Assess the effectiveness of Planned Teaching Program on Knowledge regarding Non Pharmacological Techniques for Pain Relief during Child Birth among Pregnant mothers in selected Community Area, Satna

Background: The experience of childbirth is a subjective and multidimensional issue and each woman passes through it in a different way. It is one of the most beautiful episodes in a mother’s life, associated with joy, happiness, and celebration. However, a delivery is also related to negative emotions: fear, anxiety, low sense of security, and the expectation of pain. Pain is both sensory and emotional. As a sensation, pain is interpreted by each individual is based on personal, cultural, and social experiences. Comfort measures that provide natural pain relief can be very effective during labor and childbirth. Birthing techniques such as hydrotherapy, hypno-birthing, patterned breathing, relaxation, and visualization can increase the production of endogenous endorphins that bind to receptors in the brain for pain relief. Objective: The present study aimed to assess the effectiveness of planned teaching program on knowledge regarding non pharmacological techniques for pain relief during child birth among pregnant mothers in selected community area, Satna. Methodology: Pre-experimental, one group pre-test post-test design was adopted for this study. 30 mothers were selected by using simple random sampling method for this study. A pre test was conducted by using structured knowledge questionnaire and on the same day the planned teaching program regarding non pharmacological techniques for pain relief during child birth was administered to them. After 7 days, post test was conducted with the same questionnaire for the same group of mothers to assess the effectiveness of planned teaching program. Result: The mean score in the post test is 22.8 and the mean score in the pre test is 9.8. The calculated value of t is 51.1 which is highly significant. The result confirms that the planned teaching program was effective significantly in improving the knowledge on non pharmacological techniques for pain relief during child birth among pregnant mothers.

Predictors for Failure to Respond to Erector Spinae Plane Block Following Minimally Invasive Transforaminal Lumbar Interbody Fusion.

Retrospective review of prospectively collected data. To identify the risk factors associated with failure to respond to erector spinae plane (ESP) block following minimally invasive transforaminal lumbar interbody fusion (MI-TLIF). ESP block is an emerging opioid-sparing regional anesthetic that has been shown to reduce immediate postoperative pain and opioid demand following MI-TLIF-however, not all patients who receive ESP blocks perioperatively experience a reduction in immediate postoperative pain. This was a retrospective review of consecutive patients undergoing 1-level MI-TLIF who received ESP blocks by a single anesthesiologist perioperatively at a single institution. ESP blocks were administered in the OR following induction. Failure to respond to ESP block was defined as patients with a first numerical rating scale (NRS) score post-surgery of >5.7 (mean immediate postoperative NRS score of control cohort undergoing MI TLIF without ESP block). Multivariable logistic regressions were performed to identify predictors for failure to respond to ESP block. A total of 134 patients were included (mean age 60.6 years, 43.3% females). The median and interquartile range (IQR) first pain score post-surgery was 2.5 (0.0-7.5). Forty-nine (36.6%) of patients failed to respond to ESP block. In the multivariable regression analysis, several independent predictors for failure to respond to ESP block following MI TLIF were identified: female sex (OR 2.33, 95% CI 1.04-5.98, P=0.040), preoperative opioid use (OR 2.75, 95% CI 1.03- 7.30, P=0.043), anxiety requiring medication (OR 3.83, 95% CI 1.27-11.49, P=0.017), and hyperlipidemia (OR 3.15, 95% CI 1.31-7.55, P=0.010). Our study identified several predictors for failure to respond to ESP block following MI TLIF including female sex, preoperative opioid pain medication use, anxiety, and hyperlipidemia. These findings may help inform the approach to counseling patients on perioperative outcomes and pain expectations following MI-TLIF with ESP block. III.

Spatial summation of pain is associated with pain expectations: Results from a home-based paradigm.

The purpose of this study was to reproduce the previously observed spatial summation of pain effect (SSp) using non-laboratory procedures and commercial equipment. An additional aim was to explore the association between expectations and SSp. The Cold Pressor Task (CPT) was used to induce SSp. Healthy participants (N = 68) immersed their non-dominant hands (divided into 5 segments) into cold water (CPT). Two conditions were used 1) gradual hand immersion (ascending condition) and 2) gradual hand withdrawal (descending condition). Pain intensity was measured on a Visual Analogue Scale (VAS). Psychological factors, such as the participants' expectations of pain intensity were also measured on a VAS. Results showed significant SSp (χ2(4) = 116.90, p < 0.001), reproduced with non-laboratory equipment in a home-based set-up. Furthermore, two novel findings were observed: i) there was a significant correlation between expectations and perceived pain, indicating a link between pain expectations and SSp, ii) spatial summation increased with the increase in duration exposure to the noxious stimulus (Wald χ2(8) = 80.80, p < 0.001). This study suggests that SSp is associated with pain expectations and can be formed by a mixture of excitatory and inhibitory mechanisms potentially driven by temporal characteristics of neural excitation. Moreover, this study proposes a new feasible way to induce SSp using a home-based set-up.

Patient Expectations of Pain Versus Experienced Expectations of Pain Following Shoulder Injection

PurposeCorticosteroids, platelet-rich plasma, and hyaluronic acid injections to either the subacromial space (SAS) or the glenohumeral joint (GHJ) of the shoulder are commonly used for diagnostic and therapeutic purposes in outpatient settings. The first aim of this study was to determine whether the anticipated pain level differed significantly from the actual pain level experienced by patients who underwent shoulder injections. The second aim was to determine whether there was a significant difference in these pain levels between SAS and GHJ injections. The secondary goal was to investigate the correlation between patients’ demographic data, anxiety characteristics, and pain scores. DesignProspective clinical study. MethodsThis study involved patients who completed a three-part questionnaire prior as well as following an injections to the GHJ\\SAS. FindingsSixty-three patients (28 males; 35 females), mean age of 54.28 years (standard deviation 13.95, range 25 to 84) met the inclusion criteria. There was a significant difference between the anticipated and the experienced pain (visual analog score 6.03 vs 3.17, P < .001). Experienced pain of the GHJ injections (n = 34) was rated as being greater than that of the SAS injections (n = 29) with borderline significance (visual analog scale 3.79 vs 2.36; P = .05). Forty-five patients (71.42%) reported a decrease in at least one pain category between anticipated and experienced pain compared to an increase reported by two patients (3.17%). ConclusionsInjections to the GHJ and SAS were shown to be significantly less painful than anticipated by the patients. GHJ injections were perceived as more painful than SAS injections. Communicating this evidence-based reassuring information with patients prior to an injection may alleviate fear of the procedure, reduce the perception of pain, and ultimately improve compliance with the procedure.