Real-time monitoring of cortical brain activity in response to acute pain using wide-area Ca2+ imaging

Previous human and rodent studies indicated that nociceptive stimuli activate many brain regions that is involved in the somatosensory and emotional sensation. Although these studies have identified several important brain regions involved in pain perception, it has been a challenge to observe neural activity directly and simultaneously in these multiple brain regions during pain perception. Using a transgenic mouse expressing G-CaMP7 in majority of astrocytes and a subpopulation of excitatory neurons, we recorded the brain activity in the mouse cerebral cortex during acute pain stimulation. Both of hind paw pinch and intraplantar administration of formalin caused strong transient increase of the fluorescence in several cortical regions, including primary somatosensory, motor and retrosplenial cortex. This increase of the fluorescence intensity was attenuated by the pretreatment with morphine. The present study provides important insight into the cortico-cortical network during pain perception.

Sex differences in pain catastrophizing and its relation to the transition from acute pain to chronic pain

BACKGROUND AND IMPORTANCE

Differences exist between sexes in pain and pain-related outcomes, such as development of chronic pain. Previous studies suggested a higher risk for pain chronification in female patients. Furthermore, pain catastrophizing is an important risk factor for chronification of pain. However, it is unclear whether sex differences in catastrophic thinking could explain the sex differences in pain chronification.

OBJECTIVES

The aim of this study was to examine sex differences in pain catastrophizing. Additionally, we investigated pain catastrophizing as a potential mediator of sex differences in the transition of acute to chronic pain.

DESIGN, SETTINGS AND PARTICIPANTS

Adults visiting one of the 15 participating emergency departments in the Netherlands with acute pain-related complaints. Subjects had to meet inclusion criteria and complete questionnaires about their health and pain.

OUTCOMES MEASURE AND ANALYSIS

The outcomes in this prospective cohort study were pain catastrophizing (short form pain catastrophizing) and pain chronification at 90 days (Numeric Rating Scale ≥ 1). Data was analysed using univariate and multivariable logistic regression models. Finally, stratified regression analyses were conducted to assess whether differences in pain catastrophizing accounted for observed differences in pain chronification between sexes.

MAIN RESULTS

In total 1,906 patients were included. Females catastrophized pain significantly more than males (p < 0.001). Multiple regression analyses suggested that pain catastrophizing is associated with pain chronification in both sexes.

CONCLUSIONS

This study reported differences between sexes in catastrophic cognitions in the development of chronic pain. This is possibly of clinical importance to identify high-risk patients and ensure an early intervention to prevent the transition from acute to chronic pain.

Pain Sensitivity and Acute Postoperative Pain in Patients Undergoing Abdominal Surgery: The Mediating Roles of Pain Self-Efficacy and Pain Catastrophizing

BACKGROUND

Inadequately managed postoperative pain remains a common issue. Examining factors like pain sensitivity, pain catastrophizing, and pain self-efficacy can help improve postoperative pain management. While these factors have been identified as potential predictors of acute postoperative pain, their effects have been inconsistent. Few studies have explored the interactions between these factors.

AIM

To investigate the influence of preoperative pain sensitivity, pain catastrophizing, and pain self-efficacy on acute postoperative pain in abdominal surgery patients and to determine the mediating roles of pain catastrophizing and pain self-efficacy in the relationship between pain sensitivity and acute postoperative pain, as per the gate control theory.

METHODS

A total of 246 patients were enrolled in this study. General information was collected before surgery, and the Pain Sensitivity Questionnaire (PSQ), Pain Catastrophizing Scale (PCS), and Pain Self-Efficacy Questionnaire (PSEQ) were administered. After surgery, patients' average pain scores over the 24 hours were reported using the Numerical Rating Scale (NRS). Correlation analyses and a structural equation model were used to examine the relationships among these variables.

RESULTS

NRS scores over 3 during the 24 hours post-surgery were reported by 21.54% of patients. Postoperative acute pain was found to be associated with pain sensitivity (rs = 0.463, p < .001), pain catastrophizing (rs = 0.328, p < .001), and pain self-efficacy (rs = -0.558, p < .001). A direct effect on postoperative acute pain was exerted by pain sensitivity (effect = 0.250, p = .001), along with indirect effects through: (A) pain catastrophizing (effect = 0.028, p = .001); (B) pain self-efficacy (effect = 0.132, p = .001); and (C) the chain mediation of pain self-efficacy and pain catastrophizing (effect = 0.021, p = .008).

CONCLUSIONS

The severity of postoperative acute pain can be predicted by pain self-efficacy and pain catastrophizing, and the connection between moderate pain sensitivity and postoperative acute pain severity is mediated by them. Therefore, intervention programs aimed at boosting pain self-efficacy and reducing pain catastrophizing can enhance postoperative pain outcomes for abdominal surgery patients.

Acute pain impairs retention of locomotor learning

Despite abundant evidence that pain alters movement performance, considerably less is known about the potential effects of pain on motor learning. Some of the brain regions involved in pain processing are also responsible for specific aspects of motor learning, indicating that the two functions have the potential to interact, yet it is unclear if they do. In experiment 1, we compared the acquisition and retention of a novel locomotor pattern in young, healthy individuals randomized to either experience pain via capsaicin and heat applied to the lower leg during learning or no stimulus. On day 1, participants learned a new asymmetric walking pattern using distorted visual feedback, a paradigm known to involve mostly explicit re-aiming processes. Retention was tested 24 h later. Although there were no differences in day 1 acquisition between groups, individuals who experienced pain on day 1 demonstrated reduced retention on day 2. Furthermore, the degree of forgetting between days correlated with pain ratings during learning. In experiment 2, we examined the effects of a heat stimulus alone, which served as a control for (nonpainful) cutaneous stimulation, and found no effects on either acquisition or retention of learning. Thus, pain experienced during explicit, strategic locomotor learning interferes with motor memory consolidation processes and does so most likely through a pain mechanism and not an effect of distraction. These findings have important implications for understanding basic motor learning processes and for clinical rehabilitation, in which painful conditions are often treated through motor learning-based interventions.NEW & NOTEWORTHY Pain is a highly prevalent and burdensome experience that rehabilitation practitioners often treat using motor learning-based interventions. Here, we showed that experimental acute pain, but not a heat stimulus, during locomotor learning impaired 24-h retention of the newly learned walking pattern. The degree of retention loss was related to the perceived pain level during learning. These findings suggest important links between pain and motor learning that have significant implications for clinical rehabilitation.

[Control center team in interdisciplinary multimodal pain therapy]

The topic of this article is the team in interdisciplinary multimodal pain therapy (IMPT) in the context of the development of the team concept. The starting points are historical developments, both social and scientific. After World War II numerous war victims continued to suffer from persistent pain. On the part of medicine, the consequences were the failure of the usual procedures for acute pain and the resulting helplessness. Both the concept of pain as a symptom of physical injury and also the previous treatment options were no longer adequate. Very early on an interdisciplinary approach to pain management was organized. This involved the communication of experts from various disciplines with very different competencies and opinions. Various medical disciplines and psychotherapy were the core subjects. Crucial for functioning teams is an effective cooperation and interaction. Related organizational issues, conflicts, peculiarities, and possibilities for solutions are presented. In the meantime, IMPT as a procedure has become a regular service provided in health care.

Morphological changes of the limbic system associated with acute and chronic low-back pain: A UK biobank imaging study

BACKGROUND

Low back pain (LBP) is a major public health issue that influences physical and emotional factors integral to the limbic system. This study aims to investigate the association between LBP and brain morphometry alterations as the duration of LBP increases (acute vs. chronic).

METHODS

We used the UK Biobank data to investigate the morphological features of the limbic system in acute LBP (N = 115), chronic LBP (N = 243) and controls (N = 358), and tried to replicate our findings with an independent dataset composed of 45 acute LBP participants evaluated at different timepoints throughout 1 year from the OpenPain database.

RESULTS

We found that in comparison with chronic LBP and pain-free controls, acute LBP was associated with increased volumes of the nucleus accumbens, amygdala, hippocampus, and thalamus, and increased grey matter volumes in the hippocampus and posterior cingulate gyrus. In the replication cohort, we found non-significantly larger hippocampus and thalamus volumes in the 3-month visit (acute LBP) compared to the 1-year visit (chronic LBP), with similar effect sizes as the UK Biobank dataset.

CONCLUSIONS

Our results suggest that acute LBP is associated with dramatic morphometric increases in the limbic system and mesolimbic pathway, which may reflect an active brain response and self-regulation in the early stage of LBP.

SIGNIFICANCE

Our study suggests that LBP in the acute phase is associated with the brain morphometric changes (increase) in some limbic areas, indicating that the acute phase of LBP may represent a crucial stage of self-regulation and active response to the disease's onset.

Bilateral Corticomotor Reorganization and Symptom Development in Response to Acute Unilateral Hamstring Pain: A Randomized, Controlled Study

Accumulating evidence demonstrates that pain induces adaptations in the corticomotor representations of affected muscles. However, previous work has primarily investigated the upper limb, with few studies examining corticomotor reorganization in response to lower limb pain. This is important to consider, given the significant functional, anatomical, and neurophysiological differences between upper and lower limb musculature. Previous work has also focused on unilateral corticomotor changes in response to muscle pain, despite an abundance of literature demonstrating that unilateral pain conditions are commonly associated with bilateral motor dysfunction. For the first time, this study investigated the effect of unilateral acute hamstring pain on bilateral corticomotor organization using transcranial magnetic stimulation (TMS) mapping. Corticomotor outcomes (TMS maps), pain, mechanical sensitivity (pressure pain thresholds), and function (maximal voluntary contractions) were recorded from 28 healthy participants at baseline. An injection of pain-inducing hypertonic (n = 14) or pain-free isotonic (n = 14) saline was then administered to the right hamstring muscle, and pain ratings were collected every 30 seconds until pain resolution. Follow-up measures were taken immediately following pain resolution and at 25, 50, and 75 minutes post-pain resolution. Unilateral acute hamstring pain induced bilateral symptom development and changes in corticomotor reorganization. Two patterns of reorganization were observed-corticomotor facilitation and corticomotor depression. Corticomotor facilitation was associated with increased mechanical sensitivity and decreased function bilaterally (all P < .05). These effects persisted for at least 75 minutes after pain resolution. PERSPECTIVE: These findings suggest that individual patterns of corticomotor reorganization may contribute to ongoing functional deficits of either limb following acute unilateral lower limb pain. Further research is required to assess these adaptations and the possible long-term implications for rehabilitation and reinjury risk in cohorts with acute hamstring injury.

The crucial role of locus coeruleus noradrenergic neurons in the interaction between acute sleep disturbance and headache

BACKGROUND

Both epidemiological and clinical studies have indicated that headache and sleep disturbances share a complex relationship. Although headache and sleep share common neurophysiological and anatomical foundations, the mechanism underlying their interaction remains poorly understood. The structures of the diencephalon and brainstem, particularly the locus coeruleus (LC), are the primary sites where the sleep and headache pathways intersect. To better understand the intricate nature of the relationship between headache and sleep, our study focused on investigating the role and function of noradrenergic neurons in the LC during acute headache and acute sleep disturbance.

METHOD

To explore the relationship between acute headache and acute sleep disturbance, we primarily employed nitroglycerin (NTG)-induced migraine-like headache and acute sleep deprivation (ASD) models. Initially, we conducted experiments to confirm that ASD enhances headache and that acute headache can lead to acute sleep disturbance. Subsequently, we examined the separate roles of the LC in sleep and headache. We observed the effects of drug-induced activation and inhibition and chemogenetic manipulation of LC noradrenergic neurons on ASD-induced headache facilitation and acute headache-related sleep disturbance. This approach enabled us to demonstrate the bidirectional function of LC noradrenergic neurons.

RESULTS

Our findings indicate that ASD facilitated the development of NTG-induced migraine-like headache, while acute headache affected sleep quality. Furthermore, activating the LC reduced the headache threshold and increased sleep latency, whereas inhibiting the LC had the opposite effect. Additional investigations demonstrated that activating LC noradrenergic neurons further intensified pain facilitation from ASD, while inhibiting these neurons reduced this pain facilitation. Moreover, activating LC noradrenergic neurons exacerbated the impact of acute headache on sleep quality, while inhibiting them alleviated this influence.

CONCLUSION

The LC serves as a significant anatomical and functional region in the interaction between acute sleep disturbance and acute headache. The involvement of LC noradrenergic neurons is pivotal in facilitating headache triggered by ASD and influencing the effects of headache on sleep quality.

Wunderlich syndrome in a patient with pyelonephritis

An elderly female patient with left pyelonephritis developed worsening left flank pain, hypotension and a drop in haemoglobin (Hb) from 97 g/L to 67g/L on the third day of her admission. There was no recent trauma, history of coagulopathy or risk factors for renal malignancy or vascular disease.A contrasted CT scan of the kidneys revealed a 3.8 cm left renal subcapsular haematoma with no active contrast extravasation. Her atraumatic subcapsular haematoma fulfils two out of three clinical features of Lenk's triad (acute flank pain, hypovolaemic shock), suggestive of Wunderlich syndrome. Urine and blood cultures grew Klebsiella pneumoniae and she was managed conservatively with culture-directed antibiotics, fluids and blood products.Wunderlich syndrome is a rare complication of pyelonephritis and should be considered in patients with pyelonephritis who develop acute severe flank pain, Hb drop and haemodynamic instability. Appropriate medical and surgical therapies need to be instituted early to ensure good outcomes.

The effectiveness of cupping therapy on low back pain: A systematic review and meta-analysis of randomized control trials

OBJECTIVES

This study aims to investigate the effectiveness of cupping therapy on low back pain (LBP).

METHODS

Medline, Embase, Scopus and WANFANG databases were searched for relevant cupping RCTs on low back pain articles up to 2023. A complementary search was manually made on 27 September for update screening. Full-text English and Chinese articles on all ethnic adults with LBP of cupping management were included in this study. Studies looking at acute low back pain only were excluded. Two independent reviewers screened and extracted data, with any disagreement resolved through consensus by a third reviewer. The methodological quality of the included studies was evaluated independently by two reviewers using an adapted tool. Change-from-baseline outcomes were treated as continuous variables and calculated according to the Cochrane Handbook. Data were extracted and pooled into the meta-analysis by Review Manager software (version 5.4, Nordic Cochrane Centre).

RESULTS

Eleven trials involving 921 participants were included. Five studies were assessed as being at low risk of bias, and six studies were of acceptable quality. High-quality evidence demonstrated cupping significantly improves pain at 2-8 weeks endpoint intervention (d=1.09, 95% CI: [0.35-1.83], p = 0.004). There was no continuous pain improvement observed at one month (d=0.11, 95% CI: [-1.02-1.23], p = 0.85) and 3-6 months (d=0.39, 95% CI: [-0.09-0.87], p = 0.11). Dry cupping did not improve pain (d=1.06, 95% CI: [-0.34, 2.45], p = 0.14) compared with wet cupping (d=1.5, 95% CI: [0.39-2.6], p = 0.008) at the endpoint intervention. There was no evidence indicating the association between pain reduction and different types of cupping (p = 0.2). Moderate- to low-quality evidence showed that cupping did not reduce chronic low back pain (d=0.74, 95% CI: [-0.67-2.15], p = 0.30) and non-specific chronic low back pain (d=0.27, 95% CI: [-1.69-2.24], p = 0.78) at the endpoint intervention. Cupping on acupoints showed a significant improvement in pain (d=1.29, 95% CI: [0.63-1.94], p < 0.01) compared with the lower back area (d=0.35, 95% CI: [-0.29-0.99], p = 0.29). A potential association between pain reduction and different cupping locations (p = 0.05) was found. Meta-analysis showed a significant effect on pain improvement compared to medication therapy (n = 8; d=1.8 [95% CI: 1.22 - 2.39], p < 0.001) and usual care (n = 5; d=1.07 [95% CI: 0.21- 1.93], p = 0.01). Two studies demonstrated that cupping significantly mediated sensory and emotional pain immediately, after 24 h, and 2 weeks post-intervention (d= 5.49, 95% CI [4.13-6.84], p < 0.001). Moderate evidence suggested that cupping improved disability at the 1-6 months follow-up (d=0.67, 95% CI: [0.06-1.28], p = 0.03). There was no immediate effect observed at the 2-8 weeks endpoint (d=0.40, 95% CI: [-0.51-1.30], p = 0.39). A high degree of heterogeneity was noted in the subgroup analysis (I2 >50%).

CONCLUSION

High- to moderate-quality evidence indicates that cupping significantly improves pain and disability. The effectiveness of cupping for LBP varies based on treatment durations, cupping types, treatment locations, and LBP classifications. Cupping demonstrated a superior and sustained effect on pain reduction compared with medication and usual care. The notable heterogeneity among studies raises concerns about the certainty of these findings. Further research should be designed with a standardized cupping manipulation that specifies treatment sessions, frequency, cupping types, and treatment locations. The actual therapeutic effects of cupping could be confirmed by using objective pain assessments. Studies with at least six- to twelve-month follow-ups are needed to investigate the long-term efficacy of cupping in managing LBP.

TRIAL REGISTRATION

This systematic review was initially registered on PROSPERO with registration code: CRD42021271245 on 08 September 2021.

A comparison of the effects of thoracolumbar interfascial plane (TLIP) block and erector spinae plane (ESP) block in postoperative acute pain in spinal surgery

PURPOSE

Spinal surgeries are a very painful procedure. New regional techniques for postoperative pain management are being considered. The present study aimed to evaluate the hypothesis that the ultrasound-guided erector spinae plane (ESP) block would lead to lower opioid consumption compared to the thoracolumbar interfascial plane (TLIP) block after lumbar disk surgery. The study's primary objective was to compare postoperative total opioid consumption, and the secondary objective was to assess postoperative pain scores.

METHODS

Sixty-eight patients who underwent elective lumbar disk surgery were randomly assigned to either the ESP block group or the TLIP block group. The current pain status of the patients in both the ESP and TLIP block groups was assessed using the Numerical Rating Scale (NRS) at specific time intervals (30 min, 1, 6, 12 and 24 h) during the postoperative period. The number of times patients administered a bolus dose of patient-controlled analgesia, (PCA) within the first 24 h was recorded.

RESULTS

In the ESP group, the total opioid consumption in terms of morphine equivalents was found to be significantly lower (ESP group: 7.7 ± 7.0; TLIP group: 13.0 ± 10.1; p < 0.05). The NRS scores were similar between the groups at 30 min, 1, 6, and 12 h, but at 24 h, they were significantly lower in the ESP group. Moreover, the groups had no significant difference regarding observed side effects.

CONCLUSION

This study demonstrated the analgesic efficacy of both techniques, revealing that the ESP block provides more effective analgesia in patients undergoing lumbar disk surgery.

Managing chronic pain after breast cancer treatments: are web-based interventions the future?

PURPOSE OF THE REVIEW

Chronic post-treatment pain in breast cancer affects a high proportion of patients. Symptom burden and financial costs are increasingly impacting patients and healthcare systems because of improved treatments and survival rates. Supporting long-term breast cancer symptoms using novel methodology has been examined, yet few have explored the opportunity to utilise these interventions for prevention. This review aims to explore the need for, range of, and effectiveness of such interventions.

RECENT FINDINGS

Three papers describe risk factors for chronic pain, with six recent papers describing the use of interventions for acute pain in the surgical setting. The evidence for the effectiveness of these interventions to improve pain management in this setting is limited but tentatively positive. The results have to take into account the variation between systems and limited testing.

SUMMARY

Multiple types of intervention emerged and appear well accepted by patients. Most assessed short-term impact and did not evaluate for reduction in chronic pain. Such interventions require rigorous effectiveness testing to meet the growing needs of post-treatment pain in breast cancer. A detailed understanding of components of web-based interventions and their individual impact on acute pain and chronic pain is needed within future optimisation trials. Their effectiveness as preventative tools are yet to be decided.

Effect of acupressure applied to L4 point on the severity of fistula needle pain in patients: A randomised control trial

BACKGROUND

Patients usually feel pain when a needle is inserted into the fistula. This acute pain can be relieved by acupressure, which is a nonpharmacological application method.

OBJECTIVE

This study was designed to explore the effect of acupressure application to the Hegu point on the severity of acute pain caused by fistula needle insertion in patients with antecubital arteriovenous fistula.

DESIGN

It is a randomised control study.

PARTICIPANTS

The study was conducted with 32 intervention and 32 control patients, recruited from a dialysis centre of a foundation university in Turkey between October 2021 and January 2022.

MEASUREMENTS

Acupressure was applied 3 min before needle placement in the fistula area of the patients in the experimental group.

RESULT

While there was no decrease in the severity of acute pain during fistula needle insertion in the patients in the control group, there was a significant decrease in the mean acute pain severity scores experienced by the patients in the experimental group, whose Hegu point acupressure was applied.

CONCLUSION

The results of this study support the effectiveness of Hegu point acupressure as an effective and low-cost way to reduce the acute pain of needle insertion put on dialysis patients with a fistula. In addition, the results provide a practical reference for acute pain management for dialysis nurses.

Low-Intensity Focused Ultrasound to the Human Dorsal Anterior Cingulate Attenuates Acute Pain Perception and Autonomic Responses

The dorsal anterior cingulate cortex (dACC) is a critical brain area for pain and autonomic processing, making it a promising noninvasive therapeutic target. We leverage the high spatial resolution and deep focal lengths of low-intensity focused ultrasound (LIFU) to noninvasively modulate the dACC for effects on behavioral and cardiac autonomic responses using transient heat pain stimuli. A N = 16 healthy human volunteers (6 M/10 F) received transient contact heat pain during either LIFU to the dACC or Sham stimulation. Continuous electroencephalogram (EEG), electrocardiogram (ECG), and electrodermal response (EDR) were recorded. Outcome measures included pain ratings, heart rate variability, EDR response, blood pressure, and the amplitude of the contact heat-evoked potential (CHEP).LIFU reduced pain ratings by 1.09 ± 0.20 points relative to Sham. LIFU increased heart rate variability indexed by the standard deviation of normal sinus beats (SDNN), low-frequency (LF) power, and the low-frequency/high-frequency (LF/HF) ratio. There were no effects on the blood pressure or EDR. LIFU resulted in a 38.1% reduction in the P2 CHEP amplitude. Results demonstrate LIFU to the dACC reduces pain and alters autonomic responses to acute heat pain stimuli. This has implications for the causal understanding of human pain and autonomic processing in the dACC and potential future therapeutic options for pain relief and modulation of homeostatic signals.

Interpretation bias and the transition from acute to chronic pain

ABSTRACT

Most theories of pain emphasize cognitive factors in the development of chronicity, but they have rarely been studied in the context of the transition from acute to chronic pain. The aim of the present study was to assess the role of interpretation bias, pain anxiety, and pain avoidance in acute and chronic pain and the transition from acute to chronic pain. Study 1 recruited a sample of N = 85 adults with chronic pain. Study 2 recruited a sample of N = 254 adults with acute pain and followed them up 3 months later. Both studies assessed interpretation bias with the word association task, as well as measuring pain-related anxiety, pain avoidance, pain severity, and pain interference. In study 2, pain outcomes at 3 months were also assessed. Across both acute and chronic pain samples, interpretation bias was associated with pain interference, but not pain severity. Path analysis mediation models for study 2 showed that interpretation bias was associated with increased pain anxiety, which predicted both pain severity and pain interference 3 months later. Pain anxiety was also associated with pain avoidance, but pain avoidance did not predict pain outcomes. This research provides further insight into the transition from acute to chronic pain, suggesting that interpretation bias in acute pain may play a role in pain-related anxiety that drives pain interference, thus maintaining chronic pain. These findings hold promise for further research into potential large-scale preventative interventions targeting interpretation bias and pain anxiety in acute pain.

Effectiveness of dexmedetomidine during surgery under general anaesthesia on patient-centred outcomes: a systematic review and Bayesian meta-analysis protocol

INTRODUCTION

Dexmedetomidine is a promising pharmaceutical strategy to minimise opioid use during surgery. Despite its growing use, it is uncertain whether dexmedetomidine can improve patient-centred outcomes such as quality of recovery and pain.

METHODS AND ANALYSIS

We will conduct a systematic review and meta-analysis following the recommendations of the Cochrane Handbook for Systematic Reviews. We will search MEDLINE, Embase, CENTRAL, Web of Science and CINAHL approximately in October 2023. We will include randomised controlled trials evaluating the impact of systemic intraoperative dexmedetomidine on patient-centred outcomes. Patient-centred outcome definition will be based on the consensus definition established by the Standardised Endpoints in Perioperative Medicine initiative (StEP-COMPAC). Our primary outcome will be the quality of recovery after surgery. Our secondary outcomes will be patient well-being, function, health-related quality of life, life impact, multidimensional assessment of postoperative acute pain, chronic pain, persistent postoperative opioid use, opioid-related adverse events, hospital length of stay and adverse events. Two reviewers will independently screen and identify trials and extract data. We will evaluate the risk of bias of trials using the Cochrane Risk of Bias Tool (RoB 2.0). We will synthesise data using a random effects Bayesian model framework, estimating the probability of achieving a benefit and its clinical significance. We will assess statistical heterogeneity with the tau-squared and explore sources of heterogeneity with meta-regression. We have involved patient partners, clinicians, methodologists, and key partner organisations in the development of this protocol, and we plan to continue this collaboration throughout all phases of this systematic review.

ETHICS AND DISSEMINATION

Our systematic review does not require research ethics approval. It will help inform current clinical practice guidelines and guide development of future randomised controlled trials. The results will be disseminated in open-access peer-reviewed journals, presented at conferences and shared among collaborators and networks.

PROSPERO REGISTRATION NUMBER

CRD42023439896.

Music for pain relief of minor procedures in term neonates

BACKGROUND

Music for neonatal pain has not been exclusively studied in term neonates in a well-designed trial compared to the standard of care. This study aims to assess the effectiveness of music intervention as an adjuvant in relieving acute pain in term newborns undergoing minor painful procedures.

METHODS

This randomized, controlled, blinded trial included any term neonate undergoing heel prick. Both control and intervention groups received oral sucrose 2 min before heel prick. Intervention group was exposed to 'Bedtime Mozart' lullaby recorded music via bedside speakers. Pain was measured using Neonatal Infant Pain Scale (NIPS) at 1-min intervals. Investigators were blinded using noise-canceling headphones that played random music.

RESULTS

A total of 100 neonates were enrolled. Mean gestational age was 39.2 weeks, and mean duration of the procedure was 113 s. Music group was found to have significantly lower pain scores [OR = 0.42 (0.31, 0.56), p < 0.001]. Baseline NIPS scores were similar across groups and there was no interaction effect between groups and time. When NIPS were categorized as pain and no pain, there continued to be statistically significant lower NIPS scores in the music group (p < 0.001).

CONCLUSION

Recorded music, in addition to sucrose, is efficacious in reducing pain, encouraging its use in term neonates.

IMPACT

Recorded music effectively reduces pain induced by minor procedures in term neonates. Clinical studies have shown that live and recorded music induces changes in vital signs and pain scores in the NICU's predominantly preterm population. Most of these studies were also conducted in the white ethnic population. Our study objectively proves reduction in pain scores by using recorded music in a randomized, controlled, blinded study of predominantly non-white, term neonates. Recorded music is effective in reducing acute pain in term neonates and can be widely used even in low-resource nurseries.

Pain trajectories after bilateral orthotopic lung transplantation surgery performed via a clamshell incision

INTRODUCTION

The nature, intensity, and progression of acute pain after bilateral orthotopic lung transplantation (BOLT) performed via a clamshell incision has not been well investigated. We aimed to describe acute pain after clamshell incisions using pain trajectories for the study cohort, in addition to stratifying patients into separate pain trajectory groups and investigating their association with donor and recipient perioperative variables.

METHODS

After obtaining IRB approval, we retrospectively included all patients ≥18 years old who underwent primary BOLT via clamshell incision at a single center between January 1, 2017, and June 30, 2022. We modeled the overall pain trajectory using pain scores collected over the first seven postoperative days and identified separate pain trajectory classes via latent class analysis.

RESULTS

Three hundred one adult patients were included in the final analysis. Three separate pain trajectory groups were identified, with most patients (72.8%) belonging to a well-controlled, stable pain trajectory. Uncontrolled pain was either observed in the early postoperative period (10%), or in the late postoperative period (17.3%). Late postoperative peaking trajectory patients were younger (p = .008), and sicker with a higher lung allocation score (p = .005), receiving preoperative mechanical ventilation (p < .001), or VV-ECMO support (p < .001).

CONCLUSION

Despite the extensive nature of a clamshell incision, most pain trajectories in BOLT patients had a well-controlled stable pain profile. The benign nature of pain profiles in our patient population may be attributed to the routine institutional practice of early thoracic epidural analgesia for BOLT patients unless contraindicated.

A Case of Doxycycline-Induced Pancreatitis

INTRODUCTION

Acute pancreatitis is a common cause of hospitalizations in the United States, causing approximately 230 000 to 275 000 annual admissions We present the case of a patient with acute pancreatitis likely due to doxycycline.

CASE PRESENTATION

A 64-year-old male was admitted after developing acute epigastric pain radiating to his back, a lipase of 6611 (units/L), and a computed tomography scan showing moderate peripancreatic inflammation. He had no recent alcohol use, his gallbladder was surgically absent, and he had no gallbladder pathology on evaluation; however, he had been started on doxycycline 10 days prior. While hospitalized, he was treated with pain medications, fluids, and antibiotics for aspiration pneumonia. His acute symptoms resolved, except for minor intermittent abdominal pain 2 months after discharge.

DISCUSSION

Doxycycline-induced pancreatitis has been reported within 3 to 17 days of medication initiation. Given the temporal correlation and lack of other inciting etiologies, we determined the most likely etiology was doxycycline.

CONCLUSIONS

Further study is needed to understand the pathophysiology and incidence of doxycycline-induced pancreatitis.

A secondary analysis: the impact of pre-existing chronic pain among patients with cancer presenting to the emergency department with acute pain

PURPOSE

Patients with cancer may experience pain from cancer itself or its treatment. Additionally, chronic pain (CP) predating a patient's cancer diagnosis may make the etiology of pain less clear and the management of pain more complex. In this brief report, we investigated differences in biopsychosocial characteristics, pain severity, and opioid consumption, comparing groups of cancer patients with and without a history of CP who presented to the emergency department (ED) with a complaint of cancer-related pain.

METHODS

This secondary analysis of a prospective cohort study included patients with cancer who presented to the ED with a complaint of pain (≥ 4/10). Sociodemographic, clinical, psychological, and pain characteristics were assessed in the ED and subsequent hospitalization. Mann-Whitney U-, T-, and Chi-square tests were used to compare differences between patients with and without pre-existing CP before cancer.

RESULTS

Patients with pre-existing CP had lower income (p = 0.21) and less formal education (p = 0.25) and were more likely to have a diagnosis of depression or substance use disorder (p < 0.01). Patients with pre-existing CP reported significantly greater pain severity in the ED and during hospitalization compared to those without pre-existing CP (p < 0.05), despite receiving greater amounts of opioid analgesics (p = 0.036).

CONCLUSION

Identifying a history of pre-existing CP during intake may help identify patients with cancer with difficult to manage pain, who may particularly benefit from multimodal interventions and supportive care. In addition, referral of these patients for the management of co-occurring pain disorders may help decrease the usage of the ED for undertreated pain.

Effect of ultrasound-guided continuous erector spinae plane block on postoperative pain and inflammatory response in patients undergoing modified radical mastectomy for breast cancer: study protocol for a randomised controlled trial

BACKGROUND

A single injection of local anaesthetic (LA) in the erector spinae plane block (ESPB) can reduce pain after modified radical mastectomy (MRM) surgery, but the duration of analgesia is affected by the duration of the LA. The aim of this study is to investigate the effect of continuous ESPB on acute and chronic pain and inflammatory response after MRM surgery.

METHODS

In this prospective, randomised, controlled trial, we will recruit 160 patients, aged 18-80 years, scheduled for elective MRM surgery under general anaesthesia. They will be randomly assigned to two groups: a continuous ESPB group (group E) and a sham block group (group C). Both groups of patients will have a nerve block (group C pretended to puncture) and an indwelling catheter fixed prior to surgery. Electronic pumps containing LA are shielded. The primary outcome is the total consumption of analgesic agents. The secondary outcomes include the levels of inflammation-related cytokines; the occurrence of chronic pain (post-mastectomy pain syndrome, PMPS); static and dynamic pain scores at 2, 6, 12, 24 and 48 h postoperatively; and post-operative and post-puncture adverse reactions.

DISCUSSION

Analgesia after MRM surgery is important and chronic pain can develop when acute pain is prolonged, but the analgesic effect of a nerve block with a single injection of LA is limited by the duration of drug action. The aim of this trial is to investigate whether continuous ESPB can reduce acute pain after MRM surgery and reduce the incidence of chronic pain (PMPS), with fewer postoperative analgesic drug-related complications and less inflammatory response. Continuous ESPB and up to 12 months of follow-up are two innovations of this trial.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ( https://www.chictr.org.cn/ ) ChiCTR2200061935. Registered on 11 July 2022. This trial is a prospective registry with the following registry names: Effect of ultrasound-guided continuous erector spinae plane block on postoperative pain and inflammatory response in patients undergoing modified radical mastectomy for breast cancer.

Ketamine Compared With Morphine for Out-of-Hospital Analgesia for Patients With Traumatic Pain: A Randomized Clinical Trial

Importance

Pain is a common out-of-hospital symptom among patients, and opioids are often prescribed. Research suggests that overprescribing for acute traumatic pain is still prevalent, even when limits restricting opioid prescriptions have been implemented. Ketamine hydrochloride is an alternative to opioids in adults with out-of-hospital traumatic pain.

Objective

To assess the noninferiority of intravenous ketamine compared with intravenous morphine sulfate to provide pain relief in adults with out-of-hospital traumatic pain.

Design, Setting, and Participants

The Intravenous Subdissociative-Dose Ketamine Versus Morphine for Prehospital Analgesia (KETAMORPH) study was a multicenter, single-blind, noninferiority randomized clinical trial comparing ketamine hydrochloride (20 mg, followed by 10 mg every 5 minutes) with morphine sulfate (2 or 3 mg every 5 minutes) in adult patients with out-of-hospital trauma and a verbal pain score equal to or greater than 5. Enrollment occurred from November 23, 2017, to November 26, 2022, in 11 French out-of-hospital emergency medical units.

Interventions

Patients were randomly assigned to ketamine (n = 128) or morphine (n = 123).

Main Outcomes and Measures

The primary outcome was the between-group difference in mean change in verbal rating scale pain scores measured from the time before administration of the study drug to 30 minutes later. A noninferiority margin of 1.3 was chosen.

Results

A total of 251 patients were randomized (median age, 51 [IQR, 34-69] years; 111 women [44.9%] and 140 men [55.1%] among the 247 with data available) and were included in the intention-to-treat population. The mean pain score change was -3.7 (95% CI, -4.2 to -3.2) in the ketamine group compared with -3.8 (95% CI, -4.2 to -3.4) in the morphine group. The difference in mean pain score change was 0.1 (95% CI, -0.7 to 0.9) points. There were no clinically meaningful differences for vital signs between the 2 groups. The intravenous morphine group had 19 of 113 (16.8% [95% CI, 10.4%-25.0%]) adverse effects reported (most commonly nausea [12 of 113 (10.6%)]) compared with 49 of 120 (40.8% [95% CI, 32.0%-49.6%]) in the ketamine group (most commonly emergence phenomenon [24 of 120 (20.0%)]). No adverse events required intervention.

Conclusions and Relevance

In the KETAMORPH study of patients with out-of-hospital traumatic pain, the use of intravenous ketamine compared with morphine showed noninferiority for pain reduction. In the ongoing opioid crisis, ketamine administered alone is an alternative to opioids in adults with out-of-hospital traumatic pain.

Trial Registration

ClinicalTrials.gov Identifier: NCT03236805.

Long-Acting Drug Delivery Technologies for Meloxicam as a Pain Medicine

Meloxicam, a selective COX-2 inhibitor, has demonstrated clinical effectiveness in managing inflammation and acute pain. Although available in oral and parenteral formulations such as capsule, tablet, suspension, and solution, frequent administration is necessary to maintain therapeutic efficacy, which can increase adverse effects and patient non-compliance. To address these issues, several sustained drug delivery strategies such as oral, transdermal, transmucosal, injectable, and implantable drug delivery systems have been developed for meloxicam. These sustained drug delivery strategies have the potential to improve the therapeutic efficacy and safety profile of meloxicam, thereby reducing the frequency of dosing and associated gastrointestinal side effects. The choice of drug delivery system will depend on the desired release profile, the target site of inflammation, and the mode of administration. Overall, meloxicam sustained delivery systems offer better patient compliance, and reduce the side effects, thereby improving the clinical applications of this drug. Herein, we discuss in detail different strategies for sustained delivery of meloxicam.

A novel manual therapy approach for managing acute interscapular pain following median sternotomy for open cardiac surgery: A clinical comparative analysis

INTRODUCTION

Acute interscapular pain is a frequent postoperative complication observed in patients who have undergone median sternotomy. This study aimed to assess a novel approach to manual therapy utilizing the Regional Interdependence (RI) concept for managing interscapular pain in post-sternotomy patients.

MATERIALS AND METHODS

In an observational study, a cohort of 60 consecutively admitted patients undergoing median sternotomy was enrolled. Data collection involved standardized clinical evaluations conducted at specific time points: prior to manual treatment (T0), following five manual treatments (T5), and at post-treatment days 10 (T10) and 30 (T30). The Experimental Group (EG) received manual treatment based on the RI concept, performed in a seated position to accommodate individual clinical conditions and surgical wound considerations. The Control Group (CG) received simulated treatment involving identical exercises to the EG but lacking the physiological or biomechanical stimulation.

RESULTS

Among the initial 60 patients, 36 met the inclusion criteria, while 24 were excluded due to one or more exclusion criteria. Treatment outcomes revealed a statistically significant improvement in the EG compared to the CG, not only in terms of pain reduction but also in functional recovery and consequent disability reduction.

DISCUSSION

The RI concept emerges as a potentially valuable therapeutic approach for addressing interscapular dysfunction, particularly in highly complex post-sternotomy patients. This study highlights the clinical relevance of the RI concept in the management of interscapular pain and highlights its potential utility in improving patient outcomes in the challenging context of sternotomy surgery.

Pain Scales: What Are They and What Do They Mean

PURPOSE OF REVIEW

It is essential to have validated and reliable pain measurement tools that cover a wide range of areas and are tailored to individual patients to ensure effective pain management. The main objective of this review is to provide comprehensive information on commonly used pain scales and questionnaires, including their usefulness, intended purpose, applicability to different patient populations, and associated advantages and disadvantages.

RECENT FINDINGS

Acute pain questionnaires typically focus on measuring the severity of pain and the extent of relief achieved through interventions. Chronic pain questionnaires evaluate additional aspects such as pain-related functional limitations, psychological distress, and psychological well-being. The selection of an appropriate pain scale depends on the specific assessment objectives. Additionally, each pain scale has its strengths and limitations. Understanding the differences among these pain scales is essential for selecting the most appropriate tool tailored to individual patient needs in different settings.

CONCLUSION

Medical professionals encounter challenges in accurately assessing pain. Physicians must be familiar with the different pain scales and their applicability to specific patient population.

Could generative artificial intelligence replace fieldwork in pain research?

BACKGROUND

Generative artificial intelligence (AI) models offer potential assistance in pain research data acquisition, yet concerns persist regarding data accuracy and reliability. In a comparative study, we evaluated open generative AI models' capacity to acquire data on acute pain in rock climbers comparable to field research.

METHODS

Fifty-two rock climbers (33 m/19 f; age 29.0 [24.0-35.75] years) were asked to report pain location and intensity during a single climbing session. Five generative pretrained transformer models were tasked with responses to the same questions.

RESULTS

Climbers identified the back of the forearm (19.2%) and toes (17.3%) as primary pain sites, with reported median pain intensity at 4 [3-5] and median maximum pain intensity at 7 [5-8]. Conversely, AI models yielded divergent findings, indicating fingers, hands, shoulders, legs, and feet as primary pain localizations with average and maximum pain intensity ranging from 3 to 4.4 and 5 to 10, respectively. Only two AI models provided references that were untraceable in PubMed and Google searches.

CONCLUSION

Our findings reveal that, currently, open generative AI models cannot match the quality of field-collected data on acute pain in rock climbers. Moreover, the models generated nonexistent references, raising concerns about their reliability.

The other COVID-19 survivors: Timing, duration, and health impact of post-acute sequelae of SARS-CoV-2 infection

AIMS AND OBJECTIVES

To determine the frequency, timing, and duration of post-acute sequelae of SARS-CoV-2 infection (PASC) and their impact on health and function.

BACKGROUND

Post-acute sequelae of SARS-CoV-2 infection is an emerging major public health problem that is poorly understood and has no current treatment or cure. PASC is a new syndrome that has yet to be fully clinically characterised.

DESIGN

Descriptive cross-sectional survey (n = 5163) was conducted from online COVID-19 survivor support groups who reported symptoms for more than 21 days following SARS-CoV-2 infection.

METHODS

Participants reported background demographics and the date and method of their covid diagnosis, as well as all symptoms experienced since onset of covid in terms of the symptom start date, duration, and Likert scales measuring three symptom-specific health impacts: pain and discomfort, work impairment, and social impairment. Descriptive statistics and measures of central tendencies were computed for participant demographics and symptom data.

RESULTS

Participants reported experiencing a mean of 21 symptoms (range 1-93); fatigue (79.0%), headache (55.3%), shortness of breath (55.3%) and difficulty concentrating (53.6%) were the most common. Symptoms often remitted and relapsed for extended periods of time (duration M = 112 days), longest lasting symptoms included the inability to exercise (M = 106.5 days), fatigue (M = 101.7 days) and difficulty concentrating, associated with memory impairment (M = 101.1 days). Participants reported extreme pressure at the base of the head, syncope, sharp or sudden chest pain, and "brain pressure" among the most distressing and impacting daily life.

CONCLUSIONS

Post-acute sequelae of SARS-CoV-2 infection can be characterised by a wide range of symptoms, many of which cause moderate-to-severe distress and can hinder survivors' overall well-being.

RELEVANCE TO CLINICAL PRACTICE

This study advances our understanding of the symptoms of PASC and their health impacts.

Child appraisals of injustice in the context of acute and chronic pain: An interpretative phenomenological analysis

BACKGROUND

Recent research has found child pain-related injustice appraisals to be associated with adverse pain-related outcomes. However, this evidence is mainly based on research using a measure developed for adults in the context of accident-related injuries, which may not translate to paediatric pain populations. Research on the phenomenology of child pain-related injustice appraisals is lacking. This study aimed to examine the phenomenology of pain-related injustice appraisals among both pain-free children and children living with chronic pain, to compare and contrast their experiences.

METHODS

Two focus groups were held with pain-free children (n = 16), and three focus groups were held with paediatric chronic pain patients attending a rehabilitation centre (n = 15) in Belgium. Interpretative phenomenological analysis was applied.

RESULTS

Two injustice-related themes were generated from the focus groups with pain-free children: (1) 'Someone else is at fault' and (2) 'I am in pain and he is not'. Two injustice-related themes were generated from the focus groups with paediatric chronic pain patients: (1) 'People don't see my pain' and (2) 'I am missing out because of my pain'.

CONCLUSIONS

This study offers the first exploration of the phenomenology of child pain-related injustice appraisals in both pain-free children and paediatric pain patients. Findings highlight the interpersonal nature of lived injustice experiences caused by chronic pain, which is not fully captured by existing child pain-related injustice measures. Findings further suggest that pain-related injustice notions may not be extrapolated from a chronic to an acute pain context.

SIGNIFICANCE

The current study offers the first exploration of the phenomenology of child pain-related injustice appraisals in both pain-free children and paediatric chronic pain patients. Findings highlight the interpersonal nature of injustice appraisals that are specific to the experience of chronic rather than acute pain. These appraisals are not fully captured by current child pain-related injustice measures.

Diagnostic profiles associated with long-term opioid therapy in active duty servicemembers

INTRODUCTION

Over-prescription of opioids has diminished in recent years; however, certain populations remain at high risk. There is a dearth of research evaluating prescription rates using specific multimorbidity patterns.

OBJECTIVE

To identify distinct clinical profiles associated with opioid prescription and evaluate their relative odds of receiving long-term opioid therapy.

DESIGN

Retrospective analysis of the complete military electronic health record. We assessed demographics and 26 physiological, psychological, and pain conditions present during initial opioid prescription. Latent class analysis (LCA) identified unique clinical profiles using diagnostic data. Logistic regression measured the odds of these classes receiving long-term opioid therapy.

SETTING

All electronic health data under the TRICARE network.

PARTICIPANTS

All servicemembers on active duty during fiscal years 2016 through 2019 who filled at least one opioid prescription.

MAIN OUTCOME MEASURES

Number and qualitative characteristics of LCA classes; odds ratios (ORs) from logistic regression. We hypothesized that LCA classes characterized by high-risk contraindications would have significantly higher odds of long-term opioid therapy.

RESULTS

A total of N = 714,446 active duty servicemembers were prescribed an opioid during the study window, with 12,940 (1.8%) receiving long-term opioid therapy. LCA identified five classes: Relatively Healthy (82%); Musculoskeletal Acute Pain and Substance Use Disorders (6%); High Pain, Low Mental Health Burden (9%); Low Pain, High Mental Health Burden (2%), and Multisystem Multimorbid (1%). Logistic regression found that, compared to the Relatively Healthy reference, the Multisystem Multimorbid class, characterized by multiple opioid contraindications, had the highest odds of receiving long-term opioid therapy (OR = 9.24; p < .001; 95% confidence interval [CI]: 8.56, 9.98).

CONCLUSION

Analyses demonstrated that classes with greater multimorbidity at the time of prescription, particularly co-occurring psychiatric and pain disorders, had higher likelihood of long-term opioid therapy. Overall, this study helps identify patients most at risk for long-term opioid therapy and has implications for health care policy and patient care.

Nociception related biomolecules in the adult human saliva: A scoping review with additional quantitative focus on cortisol

Nociception related salivary biomolecules can be useful patients who are not able to self-report pain. We present the existing evidence on this topic using the PRISMA-ScR guidelines and a more focused analysis of cortisol change after cold pain induction using the direction of effect analysis combined with risk of bias analysis using ROBINS-I. Five data bases were searched systematically for articles on adults with acute pain secondary to disease, injury, or experimentally induced pain. Forty three articles met the inclusion criteria for the general review and 11 of these were included in the cortisol-cold pain analysis. Salivary melatonin, kallikreins, pro-inflammatory cytokines, soluable TNF-α receptor II, secretory IgA, testosterone, salivary α-amylase (sAA) and, most commonly, cortisol have been studied in relation to acute pain. There is greatest information about cortisol and sAA which both rise after cold pain when compared with other modalities. Where participants have been subjected to both pain and stress, stress is consistently a more reliable predictor of salivary biomarker change than pain. There remain considerable challenges in identifying biomarkers that can be used in clinical practice to guide the measurement of nociception and treatment of pain. Standardization of methodology and researchers' greater awareness of the factors that affect salivary biomolecule concentrations are needed to improve our understanding of this field towards creating a clinically relevant body of evidence.

Peripheral Neuroinflammation and Pain: How Acute Pain Becomes Chronic

The number of individuals suffering from severe chronic pain and its social and financial impact is staggering. Without significant advances in our understanding of how acute pain becomes chronic, effective treatments will remain out of reach. This mini review will briefly summarize how critical signaling pathways initiated during the early phases of peripheral nervous system inflammation/ neuroinflammation establish long-term modifications of sensory neuronal function. Together with the recruitment of non-neuronal cellular elements, nociceptive transduction is transformed into a pathophysiologic state sustaining chronic peripheral sensitization and pain. Inflammatory mediators, such as nerve growth factor (NGF), can lower activation thresholds of sensory neurons through posttranslational modification of the pain-transducing ion channels transient-receptor potential TRPV1 and TRPA1. Performing a dual role, NGF also drives increased expression of TRPV1 in sensory neurons through the recruitment of transcription factor Sp4. More broadly, Sp4 appears to modulate a nociceptive transcriptome including TRPA1 and other genes encoding components of pain transduction. Together, these findings suggest a model where acute pain evoked by peripheral injury-induced inflammation becomes persistent through repeated cycles of TRP channel modification, Sp4-dependent overexpression of TRP channels and ongoing production of inflammatory mediators.

Responsiveness of multiple patient-reported outcome measures for acute postsurgical pain: primary results from the international multi-centre PROMPT NIT-1 study

BACKGROUND

Postsurgical outcome measures are crucial to define the efficacy of perioperative pain management; however, it is unclear which are most appropriate. We conducted a prospective study aiming to assess sensitivity-to-change of patient-reported outcome measures assessing the core outcome set of domains pain intensity (at rest/during activity), physical function, adverse events, and self-efficacy.

METHODS

Patient-reported outcome measures were assessed preoperatively, on day 1 (d1), d3, and d7 after four surgical procedures (total knee replacement, breast surgery, endometriosis-related surgery, and sternotomy). Primary outcomes were sensitivity-to-change of patient-reported outcome measures analysed by correlating their changes (d1-d3) with patients' global impression of change and patients' specific impression of change items as anchor criteria. Secondary outcomes included identification of baseline and patient characteristic variables explaining variance in change for each of the scales and descriptive analysis of various patient-reported outcome measures from different domains and after different surgeries.

RESULTS

Of 3322 patients included (18 hospitals, 10 countries), data from 2661 patients were analysed. All patient-reported outcome measures improved on average over time; the median calculated sensitivity-to-change for all patient-reported outcome measures (overall surgeries) was 0.22 (range: 0.07-0.31, scale: 0-10); all changes were independent of baseline data or patient characteristics and similar between different procedures.

CONCLUSIONS

Pain-related patient-reported outcome measures have low to moderate sensitivity-to-change; those showing higher sensitivity-to-change from the same domain should be considered for inclusion in a core outcome set of patient-reported outcome measures to assess the effectiveness and efficacy of perioperative pain management.

Chiropractic spinal manipulative therapy for acute neck pain: A 4-arm clinical placebo randomized controlled trial. A prospective study protocol

INTRODUCTION

Neck pain poses enormous individual and societal costs worldwide. Spinal manipulative therapy and Non-Steroidal Anti-Inflammatory Drug treatment are frequently used despite a lack of compelling efficacy data. This protocol describes a multicentre 4-arm, clinical placebo randomized controlled trial (RCT), investigating the efficacy of chiropractic spinal manipulative therapy (CSMT) versus sham CSMT, ibuprofen, and placebo medicine for acute neck pain. This superiority study will employ parallel groups, featuring a 1:1:1:1 allocation ratio.

MATERIAL AND METHODS

We will randomize 320 participants equally into four groups: CSMT, sham CSMT, ibuprofen, or placebo medicine. CSMT groups are single-blinded, while the medicine groups are double-blinded. Data will be collected at baseline (Day 0), during treatment and post-treatment. The primary endpoint will assess the difference in mean pain intensity from Day 0 to Day 14 on a numeric rating scale 0-10; the CSMT group is compared to sham CSMT, ibuprofen, and placebo medicine groups, respectively. Secondary endpoints will assess mean pain intensity and mean duration at different time points, and adverse events, blinding success, and treatment satisfaction, including comparison between ibuprofen and placebo medicine. Power calculation is based on a mean neck pain rating of 5 at Day 0, with standard deviation of 1 in all groups. Mean pain reduction at Day 14 is expected to be 60% in the CSMT group, 40% in sham CSMT and ibuprofen groups, and 20% in the placebo medicine group. A linear mixed model will compare the mean values for groups with corresponding 95% confidence intervals. P values below 0.017 will be considered statistically significant. All analyses will be conducted blinded from group allocation.

DISCUSSION

This RCT aims towards the highest research standards possible for manual-therapy RCTs owing to its two placebo arms. If CSMT and/or ibuprofen proves to be effective, it will provide evidence-based support for CSMT and/or ibuprofen for acute neck pain.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT05374057. EU Clinical Trials Register: EudraCT number: 2021-005483-21.

Fully automated deep learning models with smartphone applicability for prediction of pain using the Feline Grimace Scale

This study used deep neural networks and machine learning models to predict facial landmark positions and pain scores using the Feline Grimace Scale© (FGS). A total of 3447 face images of cats were annotated with 37 landmarks. Convolutional neural networks (CNN) were trained and selected according to size, prediction time, predictive performance (normalized root mean squared error, NRMSE) and suitability for smartphone technology. Geometric descriptors (n = 35) were computed. XGBoost models were trained and selected according to predictive performance (accuracy; mean square error, MSE). For prediction of facial landmarks, the best CNN model had NRMSE of 16.76% (ShuffleNetV2). For prediction of FGS scores, the best XGBoost model had accuracy of 95.5% and MSE of 0.0096. Models showed excellent predictive performance and accuracy to discriminate painful and non-painful cats. This technology can now be used for the development of an automated, smartphone application for acute pain assessment in cats.

Gastrointestinal symptoms, diagnostic evaluations, and abdominal pathology in children with sickle cell disease

BACKGROUND

Children with sickle cell disease (SCD) frequently present with acute pain. The abdomen, a common site of acute SCD-related pain, may be present in a variety of gastrointestinal (GI) pathologies. Limited data exist on prevalence and workup of abdominal pain in patients with SCD during acute pain events.

OBJECTIVES

Determine prevalence of GI symptoms, GI-specific evaluation and risks of hospitalization in children with SCD presenting to the emergency department (ED) or hospitalized with abdominal pain.

METHODS

Retrospective study of children less than 21 years presenting to the ED or hospitalized with pain in our center over 2 years. Descriptive statistics were used to report clinical characteristics, frequency of GI symptoms, workup by age (<5 vs. ≥5 years), and genotype (sickle cell anemia [SCA] vs. non-SCA). Logistic regression models were used to identify risks associated with hospitalization.

RESULTS

A total of 1279 encounters in 378 patients were analyzed; 23% (n = 291) encounters were associated with abdominal pain. More abdominal pain-associated hospitalizations occurred in older children, SCA, children with lower mean hemoglobin (8.7 ± 1.9 vs. 9.6 ± 1.6 g/dL, p < .001) and higher mean white blood cell (WBC) count (14.9 ± 6.6 vs. 13.2 ± 5.3 × 103 /μL, p = .02). We identified that less than 50% of patients presenting to the ED with abdominal pain received a GI-specific evaluation.

CONCLUSION

Children with SCD frequently present with abdominal pain and other GI symptoms, with limited GI evaluations performed. GI-specific evaluation may increase diagnosis of GI pathologies, rule out GI pathologies, and contribute to the limited knowledge of the abdomen as a primary site of SCD pain.

Testing Similarity in Romantic Partners' COVID-19 Experiences at the Time of a Pain-Related Emergency Department Visit

BACKGROUND

Research has established associations between romantic partners' health-related behaviors, although links between partners' experiences of the COVID-19 pandemic at the time of an important medical event remain untested.

METHODS

The sample was drawn from an existing study of patients who received a new opioid prescription at an emergency department visit for acute pain. We assessed COVID-19 experiences of 97 patients and their romantic partners from April 2021 through June 2022.

RESULTS

Romantic partners reported similar ratings of COVID-19 impact and were likely to agree on their coping with the pandemic by engaging in more time on activities like puzzles or books, using marijuana, and drinking alcohol. Partners also demonstrated high concordance in their COVID-19 vaccination statuses.

CONCLUSIONS

These findings extend a robust literature showing romantic partners' concordance in a host of health-relevant behaviors to their COVID-19 experiences.

Chest Wall Injury Society recommendation for surgical stabilization of nonunited rib fractures to decrease pain, reduce opiate use, and improve patient reported outcomes in patients with rib fracture nonunion after trauma

BACKGROUND

Rib fractures are common injuries which can be associated with acute pain and chronic disability. While most rib fractures ultimately go on to achieve bony union, a subset of patients may go on to develop non-union. Management of these nonunited rib fractures can be challenging and variability in management exists.

METHODS

The Chest Wall Injury Society's Publication Committee convened to develop recommendations for use of surgical stabilization of nonunited rib fractures (SSNURF) to treat traumatic rib fracture nonunions. PubMed, Embase, and the Cochrane database were searched for pertinent studies. Using a process of iterative consensus, all committee members voted to accept or reject the recommendation.

RESULTS

No identified studies compared SSNURF to alternative therapy and the overall quality of the body of evidence was rated as low. Risk of bias was identified in all studies. Despite these limitations, there is lower-quality evidence suggesting that SSNURF may be beneficial for decreasing pain, reducing opiate use, and improving patient reported outcomes among patients with symptomatic rib nonunion. However, these benefits should be balanced against risk of symptomatic hardware failure and infection.

CONCLUSION

This guideline document summarizes the current CWIS recommendations regarding use of SSNURF for management of rib nonunion.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level IV.

Simplified assessment of castration-induced pain in pigs using lower complexity algorithms

Pigs are raised on a global scale for commercial or research purposes and often experience pain as a by product of management practices and procedures performed. Therefore, ensuring pain can be effectively identified and monitored in these settings is critical to ensure appropriate pig welfare. The Unesp-Botucatu Pig Composite Acute Pain Scale (UPAPS) was validated to diagnose pain in pre-weaned and weaned pigs using a combination of six behavioral items. To date, statistical weighting of supervised and unsupervised algorithms was not compared in ranking pain-altered behaviors in swine has not been performed. Therefore, the aim of this study was to verify if supervised and unsupervised algorithms with different levels of complexity can improve UPAPS pain diagnosis in pigs undergoing castration. The predictive capacity of the algorithms was evaluated by the area under the curve (AUC). Lower complexity algorithms containing fewer pain-altered behaviors had similar AUC (90.1-90.6) than algorithms containing five (89.18-91.24) and UPAPS (90.58). In conclusion, utilizing a short version of the UPAPS did not influence the predictive capacity of the scale, and therefore it may be easier to apply and be implemented consistently to monitor pain in commercial and experimental settings.

Antinociceptive effect of intermittent fasting via the orexin pathway on formalin-induced acute pain in mice

It has been suggested that stress responses induced by fasting have analgesic effects on nociception by elevating the levels of stress-related hormones, while there is limited understanding of pain control mechanisms. Here, we investigated whether acute or intermittent fasting alleviates formalin-induced pain in mice and whether spinal orexin A (OXA) plays a role in this process. 6, 12, or 24 h acute fasting (AF) and 12 or 24 h intermittent fasting (IF) decreased the second phase of pain after intraplantar formalin administration. There was no difference in walking time in the rota-rod test and distance traveld in the open field test in all groups. Plasma corticosterone level and immobility time in the forced swim test were increased after 12 h AF, but not after 12 h IF. 12 h AF and IF increased not only the activation of OXA neurons in the lateral hypothalamus but also the expression of OXA in the lateral hypothalamus and spinal cord. Blockade of spinal orexin 1 receptor with SB334867 restored formalin-induced pain and spinal c-Fos immunoreactivity that were decreased after 12 h IF. These results suggest that 12 h IF produces antinociceptive effects on formalin-induced pain not by corticosterone elevation but by OXA-mediated pathway.

Distinct Alterations in Central Pain Processing of Visceral and Somatic Pain in Quiescent Ulcerative Colitis Compared to Irritable Bowel Syndrome and Health

BACKGROUND AND AIMS

Despite relevance to pain chronicity, disease burden, and treatment, mechanisms of pain perception for different types of acute pain remain incompletely understood in patients with inflammatory bowel disease [IBD]. Building on experimental research across pain modalities, we herein addressed behavioural and neural correlates of visceral versus somatic pain processing in women with quiescent ulcerative colitis [UC] compared to irritable bowel syndrome [IBS] as a patient control group and healthy women [HC].

METHODS

Thresholds for visceral and somatic pain were assessed with rectal distensions and cutaneous thermal pain, respectively. Using functional magnetic resonance imaging, neural and behavioural responses to individually calibrated and intensity-matched painful stimuli from both modalities were compared.

RESULTS

Pain thresholds were comparable across groups, but visceral thresholds correlated with gastrointestinal symptom severity and chronic stress burden exclusively within UC. Upon experience of visceral and somatic pain, both control groups demonstrated enhanced visceral pain-induced neural activation and greater perceived pain intensity, whereas UC patients failed to differentiate between pain modalities at both behavioural and neural levels.

CONCLUSIONS

When confronted with acute pain from multiple bodily sites, UC patients' responses are distinctly altered. Their failure to prioritise pain arising from the viscera may reflect a lack of adaptive behavioural flexibility, possibly resulting from long-lasting central effects of repeated intestinal inflammatory insults persisting during remission. The role of psychological factors, particularly chronic stress, in visceral sensitivity and disease-specific alterations in the response to acute pain call for dedicated mechanistic research as a basis for tailoring interventions for intestinal and extraintestinal pain symptoms in IBD.

Better safe than sorry?-On the influence of learned safety on pain perception

The experience of threat was found to result-mostly-in increased pain, however it is still unclear whether the exact opposite, namely the feeling of safety may lead to a reduction of pain. To test this hypothesis, we conducted two between-subject experiments (N = 94; N = 87), investigating whether learned safety relative to a neutral control condition can reduce pain, while threat should lead to increased pain compared to a neutral condition. Therefore, participants first underwent either threat or safety conditioning, before entering an identical test phase, where the previously conditioned threat or safety cue and a newly introduced visual cue were presented simultaneously with heat pain stimuli. Methodological changes were performed in experiment 2 to prevent safety extinction and to facilitate conditioning in the first place: We included additional verbal instructions, increased the maximum length of the ISI and raised CS-US contingency in the threat group from 50% to 75%. In addition to pain ratings and ratings of the visual cues (threat, safety, arousal, valence, and contingency), in both experiments, we collected heart rate and skin conductance. Analysis of the cue ratings during acquisition indicate successful threat and safety induction, however results of the test phase, when also heat pain was administered, demonstrate rapid safety extinction in both experiments. Results suggest rather small modulation of subjective and physiological pain responses following threat or safety cues relative to the neutral condition. However, exploratory analysis revealed reduced pain ratings in later trials of the experiment in the safety group compared to the threat group in both studies, suggesting different temporal dynamics for threat and safety learning and extinction, respectively. Perspective: The present results demonstrate the challenge to maintain safety in the presence of acute pain and suggest more research on the interaction of affective learning mechanism and pain processing.

Pericapsular nerve group (PENG) block for early pain management of elderly patients with hip fracture: a single-center double-blind randomized controlled trial

BACKGROUND

The pericapsular nerve group block (PENG) is a novel technique that blocks the articular branches of the hip joint. This study aimed to compare its effectiveness to a sham block in elderly patients with hip fractures.

METHOD

A randomized double-blind controlled trial was conducted in elderly patients with intertrochanteric and neck of femur fractures. Patients were randomized to receive either PENG block or a sham block. Postblock, systemic analgesia was titrated using a standardized protocol of acetaminophen, oral morphine or patient-controlled analgesia. The primary outcome was the dynamic pain score (Numerical Rating Scale 0-10) at 30 min postblock. Secondary outcomes included pain scores at multiple other time points and 24-hour opioid consumption.

RESULTS

60 patients were randomized and 57 completed the trial (PENG n=28, control n=29). Patients in PENG group had significantly lower dynamic pain scores at 30 min compared with control group (median (IQR) 3 (0.5-5) vs 5 (3-10), p<0.01). For the secondary outcomes, dynamic pain scores were lower in PENG group at 1 hour (median (IQR) 2 (1-3.25) vs 5 (3-8), p<0.01) and 3 hours postblock (median (IQR) 2 (0-5) vs 5 (2-8), p<0.05). Patients in PENG group had lower 24-hour opioid consumption (median (IQR) oral morphine equivalent dose 10 (0-15) vs 15 (10-30) mg, p<0.05).

CONCLUSION

PENG block provided effective analgesia for acute traumatic pain following hip fracture. Further studies are required to validate the superiority of PENG blocks over other regional techniques.

TRIAL REGISTRATION NUMBER

NCT04996979.

IUPHAR themed review: Opioid efficacy, bias, and selectivity

Drugs acting at the opioid receptor family are clinically used to treat chronic and acute pain, though they represent the second line of treatment behind GABA analogs, antidepressants and SSRI's. Within the opioid family mu and kappa opioid receptor are commonly targeted. However, activation of the mu opioid receptor has side effects of constipation, tolerance, dependence, euphoria, and respiratory depression; activation of the kappa opioid receptor leads to dysphoria and sedation. The side effects of mu opioid receptor activation have led to mu receptor drugs being widely abused with great overdose risk. For these reasons, newer safer opioid analgesics are in high demand. For many years a focus within the opioid field was finding drugs that activated the G protein pathway at mu opioid receptor, without activating the β-arrestin pathway, known as biased agonism. Recent advances have shown that this may not be the way forward to develop safer analgesics at mu opioid receptor, though there is still some promise at the kappa opioid receptor. Here we discuss recent novel approaches to develop safer opioid drugs including efficacy vs bias and fine-tuning receptor activation by targeting sub-pockets in the orthosteric site, we explore recent works on the structural basis of bias, and we put forward the suggestion that Gα subtype selectivity may be an exciting new area of interest.

The relationship between acute pain and other types of suffering in pre-hospital trauma victims: An observational study

BACKGROUND

Acute pain is an important complaint reported by trauma victims, however, the relationship between it and other types of discomfort, such as discomfort caused by cold, discomfort caused by immobilization, and psychological distress such as fear, anxiety, and sadness is limitedly studied and documented.

AIM

To assess the relationship between acute trauma pain and other types of suffering in pre-hospital trauma victims.

METHODS

This is a prospective multicentre cohort study conducted in Immediate Life Support Ambulances in Portugal. All adult trauma victims with a mechanism of blunt and penetrating injuries, falls, road accidents and explosions, were included.

RESULTS

605 trauma victims were included, mainly male, with a mean age of 53.4 years. Before the intervention of the rescue teams, 90.5 % of the victims reported some level of pain, 39.0 % reported discomfort caused by cold, while 15.7 % felt fear, 8.4 % sadness, 49.8 % anxiety and 4.5 % apathy. Victims with high discomfort caused by cold tend to have higher pain levels. Significantly higher pain intensity were observed in victims with fear and anxiety. Univariate and multivariate analysis indicates that immobilization is associated with increased pain levels.

CONCLUSIONS

There is a statistically significant relationship between acute trauma pain, anxiety, fear, cold and immobilization.

Effect of physical therapy timing on patient-reported outcomes for individuals with acute low back pain: A systematic review with meta analysis of randomized controlled trials

OBJECTIVE

The purpose of this systematic review with meta-analysis was to investigate the effect of early physical therapy (PT) for the management of acute low back pain (LBP) on patient-reported outcomes of pain and disability, compared to delayed PT or non-PT care.

LITERATURE SURVEY

Randomized controlled trials in three electronic databases (MEDLINE, CINAHL, Embase) were searched from inception to June 12, 2020, and updated on September 23, 2021.

METHODOLOGY

Eligible participants were individuals with acute low back pain. The intervention was early PT compared to delayed PT or non-PT care. Primary outcomes included the patient-reported outcomes of pain and disability. The following information was extracted from included articles: demographic data, sample size, selection criteria, PT interventions, and pain and disability outcomes. Data were extracted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Methodological quality was assessed using the Physiotherapy Evidence Database (PEDro) Scale. Random effects models were used for the meta-analysis.

SYNTHESIS

Seven of 391 articles met the eligibility criteria and were included in the meta-analysis. Random effects meta-analysis comparing early PT to non-PT care for acute LBP indicated a significant reduction in pain (standard mean difference [SMD] = 0.43, 95% confidence interval [CI]: -0.69 to -0.17) and disability (SMD = 0.36, 95% CI: -0.57 to -0.16) in the short term. Early PT compared to delayed PT did not result in improvement in short-term pain (SMD = -0.24, 95% CI: -0.52 to 0.04) or disability (SMD = 0.28, 95% CI: -0.56 to 0.01), or long-term pain (SMD = 0.21, 95% CI: -0.15 to 0.57) or disability (SMD = 0.14, 95% CI: -0.15 to 0.42).

CONCLUSIONS

This systematic review and meta-analysis suggest early PT versus non-PT care is associated with statistically significant reductions in short-term pain and disability (up to 6 weeks) with small effect sizes. The results indicate a nonsignificant trend favoring a small benefit of early PT over delayed PT for outcomes at short-term follow-up but no effect at long-term follow-up (6 months or greater).

ACR Appropriateness Criteria® Acute Onset Flank Pain-Suspicion of Stone Disease (Urolithiasis)

Noncontrast CT (NCCT) is the imaging study of choice for initial evaluation of patients with acute onset of flank pain and suspicion of stone disease without known prior stone disease. NCCT can reliably characterize the location and size of an offending ureteral calculus, identify complications, and diagnose alternative etiologies of abdominal pain. Although less sensitive in the detection of stones, ultrasound may have a role in evaluating for signs of obstruction. Radiography potentially has a role, although has been shown to be less sensitive than NCCT. For patients with known disease and recurrent symptoms of urolithiasis, NCCT remains the test of choice for evaluation. In pregnancy, given radiation concerns, ultrasound is recommended as the initial modality of choice with potential role for noncontrast MRI. In scenarios where stone disease suspected and initial NCCT is inconclusive, contrast-enhanced imaging, either with MRI or CT/CT urogram may be appropriate. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Rethinking headache as a global public health case model for reaching the SDG 3 HEALTH by 2030

The 2030 Agenda for Sustainable Development sets out, through 17 Sustainable Development Goals (SDGs), a path for the prosperity of people and the planet. SDG 3 in particular aims to ensure healthy lives and promote well-being for all at all ages and includes several targets to enhance health. This review presents a "headache-tailored" perspective on how to achieve SDG 3 by focusing on six specific actions: targeting chronic headaches; reducing the overuse of acute pain-relieving medications; promoting the education of healthcare professionals; granting access to medication in low- and middle-income countries (LMIC); implementing training and educational opportunities for healthcare professionals in low and middle income countries; building a global alliance against headache disorders. Addressing the burden of headache disorders directly impacts on populations' health, as well as on the possibility to improve the productivity of people aged below 50, women in particular. Our analysis pointed out several elements, and included: moving forward from frequency-based parameters to define headache severity; recognizing and managing comorbid diseases and risk factors; implementing a disease management multi-modal management model that incorporates pharmacological and non-pharmacological treatments; early recognizing and managing the overuse of acute pain-relieving medications; promoting undergraduate, postgraduate, and continuing medical education of healthcare professionals with specific training on headache; and promoting a culture that favors the recognition of headaches as diseases with a neurobiological basis, where this is not yet recognized. Making headache care more sustainable is an achievable objective, which will require multi-stakeholder collaborations across all sectors of society, both health-related and not health-related. Robust investments will be needed; however, considering the high prevalence of headache disorders and the associated disability, these investments will surely improve multiple health outcomes and lift development and well-being globally.