Non-Destructive Testing for Documenting Properties of Structural Concrete for Reuse in New Buildings: A Review.

Reuse in new buildings of structural concrete components from demolitions holds the potential for avoiding the use of raw materials to produce new components, including cement for new castings. Reuse rates are high in the circular economy; however, reusing structural components requires documentation of the properties to equate the safety of using reused and new components. Yet, there is no structured or recognized way to perform the documentation. This paper discusses a framework for the documentation requirements for structural concrete, stating the need for documenting the mechanical properties, concrete heterogeneity, and corrosion status of the reinforcement. The possibility is explored for documenting the required properties while the components are in the donor building by use of non-destructive test (NDT) methods. Such use of NDT methods is new. A comprehensive literature survey on the indirect literature, where NDT methods are used to demonstrate similar concrete properties though related to other purposes, is conducted. The overall conclusion is that the use of NDT methods has the potential to document the requested properties before reuse. The next steps towards implementation of NDT for documenting the properties of structural concrete components for reuse involve research in combined NDT methods and the development of AI systems for data interpretation.

High-frequency electrical stimulation increases cortical excitability and mechanical sensitivity in a chronic large animal model.

ABSTRACT: Translational models of the sensitized pain system are needed to progress the understanding of involved mechanisms. In this study, long-term potentiation was used to develop a mechanism-based large-animal pain model. Event-related potentials to electrical stimulation of the ulnar nerve were recorded by intracranial recordings in pigs, 3 weeks before, immediately before and after, and 3 weeks after peripheral high-frequency stimulation (HFS) applied to the ulnar nerve in the right forelimb (7 pigs) or in control animals (5 pigs). Event-related potential recordings and peripheral HFS were done during anesthesia. Two weeks before and after the HFS, behavioral responses reflecting mechanical and thermal sensitivity were collected using brush, noxious limb-mounted pressure algometer, and noxious laser stimuli. The HFS intervention limb was progressively sensitized to noxious mechanical stimulation in week 1 and 2 compared with baseline (P = 0.045) and the control group (P < 0.034) but not significantly to laser or brush stimulation. The first negative (N1) peak of the event-related potential was increased 30 minutes after HFS compared with before (P < 0.05). The N1 peak was also larger compared with control pigs 20 to 40 minutes after HFS (P < 0.031) but not significantly increased 3 weeks after. The relative increase in N1 30 minutes after HFS and the degree of mechanical hyperalgesia 2 weeks post-HFS was correlated (P < 0.033). These results show for the first time that the pig HFS model resembles the human HFS model closely where the profile of sensitization is comparable. Interestingly, the degree of sensitization was associated with the cortical signs of hyperexcitability at HFS induction.

Cross-sectional experimental assessment of pain modulation as part of multidimensional profiling of people with cervicogenic headache: protocol for a feasibility study.

BACKGROUND: An endogenous pain modulation profile, reflecting antinociceptive and pronociceptive mechanisms, may help to direct management by targeting the involved pain mechanism. For individuals with cervicogenic headache (CeH), the characteristics of such profiles were never investigated. However, the individual nature of experiencing pain demands profiling within a multidimensional framework including psychosocial lifestyle characteristics. The objective of the current protocol is to assess the pain modulation profile, which includes psychosocial lifestyle characteristics among people with CeH. METHODS AND ANALYSIS: A protocol is described to map pain modulation profiles in people with CeH. A cross-sectional non-randomised experimental design will be used to assess feasibility of mapping these profiles. The pain modulation profile is composed based on results on the Depression, Anxiety, Stress Scale, Pittsburgh Sleep Quality Index, Headache Impact Test and on responses to temporal summation of pain (pinprick), conditioned pain modulation and widespread hyperalgesia (mechanical pressure pain threshold and cuff algometry). Primary analyses will report results relating to outcomes on feasibility. Secondary analyses will involve an analysis of proportions (%) of the different psychosocial lifestyle profiles and pain profiles. ETHICS AND DISSEMINATION: Ethical approval was granted by the Ethics Committee Research UZ/KU Leuven (Registration number B3222024001434) on 30 May 2024. Results will be published in peer-reviewed journals, at scientific conferences and, through press releases. Protocol V.3. protocol date: 3 June 2024.

Subpectineal obturator nerve block reduces opioid consumption after hip arthroscopy: a triple-blind, randomized, placebo-controlled trial.

BACKGROUND: Hip arthroscopy causes severe pain during the first few hours in the postoperative care unit. This is probably due to the intraoperative stretching of the hip joint capsule. Pain relief requires high doses of opioids which may prolong recovery and may cause opioid-related adverse events.The majority of hip joint capsule nociceptors are located anteriorly. The obturator nerve innervates the anteromedial part of the hip joint capsule. We hypothesized that a subpectineal obturator nerve block using 15 ml bupivacaine 5 mg/mL with added epinephrine 5 µg/mL would reduce the opioid consumption after hip arthroscopy. METHODS: 40 ambulatory hip arthroscopy patients were enrolled in this randomized, triple-blind controlled trial. All patients were allocated to a preoperative active or placebo subpectineal obturator nerve block. The primary outcome was opioid consumption for the first 3 hours in the postanesthesia care unit. Secondary outcomes were pain, nausea, and hip adductor strength. RESULTS: 34 patients were analyzed for the primary outcome. The mean intravenous morphine equivalent consumption in the subpectineal obturator nerve block group was 11.9 mg vs 19.7 mg in the placebo group (p<0.001). The hip adductor strength was significantly reduced in the active group. No other intergroup differences were observed regarding the secondary outcomes. CONCLUSION: We found a significant reduction in the opioid consumption for patients receiving an active subpectineal obturator nerve block. The postoperative intravenous morphine equivalent reduction the first painful 3 hours was reduced by 40% for patients receiving a subpectineal obturator nerve block in this randomized, triple-blind trial. TRIAL REGISTRATION NUMBER: EudraCT database 2021-006575-42.

The Anterior Branch of the Medial Femoral Cutaneous Nerve Innervates Cutaneous and Deep Surgical Incisions in Total Knee Arthroplasty.

Background/Objectives: The intermediate femoral cutaneous nerve (IFCN), the saphenous nerve, and the medial femoral cutaneous nerve (MFCN) innervate the skin of the anteromedial knee region. However, it is unknown whether the MFCN has a deeper innervation. This would be relevant for total knee arthroplasty (TKA) that intersects deeper anteromedial genicular tissue layers. Primary aim: to investigate deeper innervation of the anterior and posterior MFCN branches (MFCN-A and MFCN-P). Secondary aim: to investigate MFCN innervation of the skin covering the anteromedial knee area and medial parapatellar arthrotomy used for TKA. Methods: This study consists of (1) a dissection study and (2) unpublished data and post hoc analysis from a randomized controlled double-blinded volunteer trial (EudraCT number: 2020-004942-12). All volunteers received bilateral active IFCN blocks (nerve block round 1) and saphenous nerve blocks (nerve block round 2). In nerve block round 3, all volunteers were allocated to a selective MFCN-A block. Results: (1) The MFCN-A consistently innervated deeper structures in the anteromedial knee region in all dissected specimens. No deep innervation from the MFCN-P was observed. (2) Sixteen out of nineteen volunteers had an unanesthetized skin gap in the anteromedial knee area and eleven out of the nineteen volunteers had an unanesthetized gap on the skin covering the medial parapatellar arthrotomy before the active MFCN-A block. The anteromedial knee area and medial parapatellar arthrotomy was completely anesthetized after the MFCN-A block in 75% and 82% of cases, respectively. Conclusions: The MFCN-A shows consistent deep innervation in the anteromedial knee region and the area of MFCN-A innervation overlaps the skin area covering the medial parapatellar arthrotomy. Further trials are mandated to investigate whether an MFCN-A block translates into a clinical effect on postoperative pain after total knee arthroplasty or can be used for diagnosis and interventional pain management for chronic neuropathic pain due to damage to the MFCN-A during surgery.

High efficacy treatment of murine Pseudomonas aeruginosa catheter-associated urinary tract infections using the c-di-GMP modulating anti-biofilm compound Disperazol in combination with ciprofloxacin.

Persistent urinary tract infections (UTIs) in hospitalized patients constitute an important medical problem. It is estimated that 75% of nosocomial UTIs are associated with urinary tract catheters with P. aeruginosa being a species that forms biofilms on these catheters. These infections are highly resistant to standard-of-care antibiotics, and the effects of the host immune defenses, which allows for development of persistent infections. With antibiotics losing their efficacy, new treatment options against resilient infections, such as catheter-associated urinary tract infections (CAUTIs), are critically needed. Central to our anti-biofilm approach is the manipulation of the c-di-GMP signaling pathway in P. aeruginosa to switch bacteria from the protective biofilm to the unprotected planktonic mode of life. We recently identified a compound (H6-335-P1), that stimulates the c-di-GMP degrading activity of the P. aeruginosa BifA protein which plummets the intracellular c-di-GMP content and induces dispersal of P. aeruginosa biofilm bacteria into the planktonic state. In the present study, we formulated H6-335-P1 as a hydrochloride salt (Disperazol), which is water-soluble and facilitates delivery via injection or oral administration. Disperazol can work as a monotherapy, but we observed a 100-fold improvement in efficacy when treating murine P. aeruginosa CAUTIs with a Disperazol/ciprofloxacin combination. Biologically active Disperazol reached the bladder 30 min after oral administration. Our study provides proof of concept that Disperazol can be used in combination with a relevant antibiotic for effective treatment of CAUTIs.

Porcine Model of Cerebral Ischemic Stroke Utilizing Intracortical Recordings for the Continuous Monitoring of the Ischemic Area.

PURPOSE: Our aim was to use intracortical recording to enable the tracking of ischemic infarct development over the first few critical hours of ischemia with a high time resolution in pigs. We employed electrophysiological measurements to obtain quick feedback on neural function, which might be useful for screening, e.g., for the optimal dosage and timing of agents prior to further pre-clinical evaluation. METHODS: Micro-electrode arrays containing 16 (animal 1) or 32 electrodes (animal 2-7) were implanted in the primary somatosensory cortex of seven female pigs, and continuous electrical stimulation was applied at 0.2 Hz to a cuff electrode implanted on the ulnar nerve. Ischemic stroke was induced after 30 min of baseline recording by injection of endothelin-1 onto the cortex adjacent to the micro-electrode array. Evoked responses were extracted over a moving window of 180 s and averaged across channels as a measure of cortical excitability. RESULTS: Across the animals, the cortical excitability was significantly reduced in all seven 30 min segments following endothelin-1 injection, as compared to the 30 min preceding this intervention. This difference was not explained by changes in the anesthesia, ventilation, end-tidal CO2, mean blood pressure, heart rate, blood oxygenation, or core temperature, which all remained stable throughout the experiment. CONCLUSIONS: The animal model may assist in maturing neuroprotective approaches by testing them in an accessible model of resemblance to human neural and cardiovascular physiology and body size. This would constitute an intermediate step for translating positive results from rodent studies into human application, by more efficiently enabling effective optimization prior to chronic pre-clinical studies in large animals.

Facilitation of Early and Middle Latency SEP after tDCS of M1: No Evidence of Primary Somatosensory Homeostatic Plasticity.

Homeostatic plasticity is a mechanism that stabilizes cortical excitability within a physiological range. Most homeostatic plasticity protocols have primed and tested the homeostatic response of the primary motor cortex (M1). This study investigated if a homeostatic response could be recorded from the primary sensory cortex (S1) after inducing homeostatic plasticity in M1. In 31 healthy participants, homeostatic plasticity was induced over M1 with a priming and testing block of transcranial direct current stimulation (tDCS) in two different sessions (anodal and cathodal). S1 excitability was assessed by early (N20, P25) and middle-latency (N33-P45) somatosensory evoked potentials (SEP) extracted from 4 electrodes (CP5, CP3, P5, P3). Baseline and post-measures (post-priming, 0-min, 10-min, and 20-min after homeostatic induction) were taken. Anodal M1 homeostatic plasticity induction significantly facilitated the N20-P25, P45 peak, and N33-P45 early SEP components up to 20-min post-induction, without any indication of a homeostatic response (i.e., reduced SEP). Cathodal homeostatic induction did not induce any significant effect on early or middle latency SEPs. M1 homeostatic plasticity induction by anodal stimulation protocol to the primary motor cortex did not induce a homeostatic response in SEPs.

Evoked oscillatory cortical activity during acute pain: Probing brain in pain by transcranial magnetic stimulation combined with electroencephalogram.

Temporal dynamics of local cortical rhythms during acute pain remain largely unknown. The current study used a novel approach based on transcranial magnetic stimulation combined with electroencephalogram (TMS-EEG) to investigate evoked-oscillatory cortical activity during acute pain. Motor (M1) and dorsolateral prefrontal cortex (DLPFC) were probed by TMS, respectively, to record oscillatory power (event-related spectral perturbation and relative spectral power) and phase synchronization (inter-trial coherence) by 63 EEG channels during experimentally induced acute heat pain in 24 healthy participants. TMS-EEG was recorded before, during, and after noxious heat (acute pain condition) and non-noxious warm (Control condition), delivered in a randomized sequence. The main frequency bands (α, ß1, and ß2) of TMS-evoked potentials after M1 and DLPFC stimulation were recorded close to the TMS coil and remotely. Cold and heat pain thresholds were measured before TMS-EEG. Over M1, acute pain decreased α-band oscillatory power locally and α-band phase synchronization remotely in parietal-occipital clusters compared with non-noxious warm (all p < .05). The remote (parietal-occipital) decrease in α-band phase synchronization during acute pain correlated with the cold (p = .001) and heat pain thresholds (p = .023) and to local (M1) α-band oscillatory power decrease (p = .024). Over DLPFC, acute pain only decreased ß1-band power locally compared with non-noxious warm (p = .015). Thus, evoked-oscillatory cortical activity to M1 stimulation is reduced by acute pain in central and parietal-occipital regions and correlated with pain sensitivity, in contrast to DLPFC, which had only local effects. This finding expands the significance of α and ß band oscillations and may have relevance for pain therapies.

Ex-vivo systems for neuromodulation: A comparison of ex-vivo and in-vivo large animal nerve electrophysiology.

BACKGROUND: Little research exists on extending ex-vivo systems to large animal nerves, and to the best of our knowledge, there has yet to be a study comparing these against in-vivo data. This paper details the first ex-vivo system for large animal peripheral nerves to be compared with in-vivo results. NEW METHOD: Detailed ex-vivo and in-vivo closed-loop neuromodulation experiments were conducted on pig ulnar nerves. Temperatures from 20 °C to 37 °C were evaluated for the ex-vivo system. The data were analysed in the time and velocity domains, and a regression analysis established how evoked compound action potential amplitude and modal conduction velocity (CV) varied with temperature and time after explantation. MAIN RESULTS: Pig ulnar nerves were sustained ex-vivo up to 5 h post-explantation. CV distributions of ex-vivo and in-vivo data were compared, showing closer correspondence at 37 °C. Regression analysis results also demonstrated that modal CV and time since explantation were negatively correlated, whereas modal CV and temperature were positively correlated. COMPARISON WITH EXISTING METHODS: Previous ex-vivo systems were primarily aimed at small animal nerves, and we are not aware of an ex-vivo system to be directly compared with in-vivo data. This new approach provides a route to understand how ex-vivo systems for large animal nerves can be developed and compared with in-vivo data. CONCLUSION: The proposed ex-vivo system results were compared with those seen in-vivo, providing new insights into large animal nerve activity post-explantation. Such a system is crucial for complementing in-vivo experiments, maximising collected experimental data, and accelerating neural interface development.

Effects of pain on cortical homeostatic plasticity in humans: a systematic review.

Homeostatic plasticity (HP) is a negative feedback mechanism that prevents excessive facilitation or depression of cortical excitability (CE). Cortical HP responses in humans have been investigated by using 2 blocks of noninvasive brain stimulation with a no-stimulation block in between. A healthy HP response is characterized by reduced CE after 2 excitatory stimulation blocks and increased CE when using inhibitory stimulation. Conversely, impaired HP responses have been demonstrated in experimental and chronic pain conditions. Therefore, this systematic review aimed to provide an overview of the effect of pain on cortical HP in humans. Scopus, Embase, and PubMed were searched from inception until November 20, 2023. The included studies (1) compared experimental or clinical pain conditions with healthy controls, (2) induced HP using 2 blocks of stimulation with a no-stimulation interval, and (3) evaluated CE measures such as motor-evoked potentials. Four studies were included, consisting of 5 experiments and 146 participants, of whom 63 were patients with chronic pain and 48 were subjected to an experimental pain model. This systematic review found support for an HP impairment in pain compared with that in pain-free states, reflected by a lack of CE reduction after excitatory-excitatory HP induction over the primary motor cortex. Inhibitory-inhibitory HP induction did not produce a consistent HP response across studies, independent of pain or pain-free states. Standardization of HP induction protocols and outcome calculations is needed to ensure reproducibility and study comparison. Future HP studies may consider investigating sensory domains including nociception, which would further our understanding of abnormal HP regulation in pain conditions.

A study on the risk stratification for patients within 24 hours of admission for risk of hospital-acquired urinary tract infection using Bayesian network models.

Early identification of patients at risk of hospital-acquired urinary tract infections (HA-UTI) enables the initiation of timely targeted preventive and therapeutic strategies. Machine learning (ML) models have shown great potential for this purpose. However, existing ML models in infection control have demonstrated poor ability to support explainability, which challenges the interpretation of the result in clinical practice, limiting the adaption of the ML models into a daily clinical routine. In this study, we developed Bayesian Network (BN) models to enable explainable assessment within 24 h of admission for risk of HA-UTI. Our dataset contained 138,250 unique hospital admissions. We included data on admission details, demographics, lifestyle factors, comorbidities, vital parameters, laboratory results, and urinary catheter. Models developed from a reduced set of five features were characterized by transparency compared to models developed from a full set of 50 features. The expert-based clinical BN model over the reduced feature space showed the highest performance (area under the curve = 0.746) compared to the naïve- and tree-augmented-naïve BN models. Moreover, models developed from expert-based knowledge were characterized by enhanced explainability.

Assessment of Dementia in Minority Ethnic Groups in Scotland: Results of a Survey of Cognitive Specialists.

OBJECTIVE: Minority ethnic groups (MEGs) in Europe receive suboptimal dementia evaluation, yet related research in Scotland is lacking. This research examined the evaluation of dementia in MEGs in Scotland and compared it with previous research to highlight the changes in the clinical evaluation of dementia over the decade. DESIGN AND SETTING: A self-administered survey was created online and emailed to 14 Heads of the boards under the Scottish National Health Service and dementia-associated settings and organizations. RESULTS: Most surveyed centers (85.6%) received MEG referrals. Although 92.9% of the centers used professional translators when needed, 85.7% thought assessing dementia in MEGs was difficult, mostly due to the suitability of test instruments and rating scales and patients' linguistic abilities. Very few found their skills to be good in evaluating MEGs. There was no mention of specialized dementia services for MEGs. CONCLUSIONS: The lack of culturally appropriate instruments and specialized dementia services reveals that the services are not ready to meet the demand for evaluating patients from diverse cultural and language backgrounds. Inadequate clinical evaluation may lead to misdiagnoses. Therefore, although significant work has been carried out in the past few years, improvements must be continued to enhance the current practices and apply suitable evaluation methods for MEGs.

Impact of Chronic Pain on Use-Dependent Plasticity: Corticomotor Excitability and Motor Representation in Musicians With and Without Pain.

Long-term musical training induces adaptive changes in the functional representation of the motor cortex. It is unknown if the maladaptive plasticity associated with chronic pain, frequently affecting trained musicians, may alter the use-dependent plasticity in the motor cortex. This study investigated the interaction between adaptive and maladaptive plasticity in the motor pathways, in particular how chronic pain influences long-term use-dependent plasticity. Using transcranial magnetic stimulation (TMS), corticospinal excitability was assessed by measuring the amplitude of the motor-evoked potential (MEP), area of the motor map, volume, and center of gravity of the first dorsal interosseous muscle in 19 pain-free musicians, 17 upper limb/neck pain chronic pain musicians, and 19 pain-free non-musicians as controls. Motor map volume and MEP amplitude were smaller for both pain-free and chronic pain musicians compared to pain-free controls (P < 0.011). No significant differences were found between musicians with and without chronic pain. These findings confirm that long-term musical training can lead to focalized and specialized functional organization of the primary motor cortex. Moreover, the adaptive use-dependent plasticity acquired through fine-motor skill acquisition is not significantly compromised by the maladaptive plasticity typically associated with chronic pain, highlighting the potential of long-term sensorimotor training to counteract the effects of chronic pain in the motor system.

Early mortality in children with cancer in Denmark and Sweden: The role of social background in a setting with universal healthcare.

Socioeconomic differences in overall survival from childhood cancer have been shown previously, but the underlying mechanisms remain unclear. We aimed to investigate if social inequalities were seen already for early mortality in settings with universal healthcare. From national registers, all children diagnosed with cancer at ages 0-19 years, during 1991-2014, in Sweden and Denmark, were identified, and information on parental social characteristics was collected. We estimated odds ratios (OR) and 95% confidence intervals (CI) of early mortality (death within 90 days after cancer diagnosis) by parental education, income, employment, cohabitation, and country of birth using logistic regression. For children with acute lymphoblastic leukaemia (ALL), clinical characteristics were obtained. Among 13,926 included children, 355 (2.5%) died within 90 days after diagnosis. Indications of higher early mortality were seen among the disadvantaged groups, with the most pronounced associations observed for maternal education (ORadj_Low_vs_High 1.65 [95% CI 1.22-2.23]) and income (ORadj_Q1(lowest)_vs_Q4(highest) 1.77 [1.25-2.49]). We found attenuated or null associations between social characteristics and later mortality (deaths occurring 1-5 years after cancer diagnosis). In children with ALL, the associations between social factors and early mortality remained unchanged when adjusting for potential mediation by clinical characteristics. In conclusion, this population-based cohort study indicated differences in early mortality after childhood cancer by social background, also in countries with universal healthcare. Social differences occurring this early in the disease course requires further investigation, also regarding the timing of diagnosis.

Morphology and morphometry of the ulnar nerve in the forelimb of pigs.

The knowledge of the morphology and morphometry of peripheral nerves is essential for developing neural interfaces and understanding nerve regeneration in basic and applied research. Currently, the most adopted animal model is the rat, even though recent studies have suggested that the neuroanatomy of large animal models is more comparable to humans. The present knowledge of the morphological structure of large animal models is limited; therefore, the present study aims to describe the morphological characteristics of the Ulnar Nerve (UN) in pigs. UN cross-sections were taken from seven Danish landrace pigs at three distinct locations: distal UN, proximal UN and at the dorsal cutaneous branch of the UN (DCBUN). The nerve diameter, fascicle diameter and number, number of fibres and fibre size were quantified. The UN diameter was larger in the proximal section compared to the distal segment and the DCBUN. The proximal branch also had a more significant number of fascicles (median: 15) than the distal (median: 10) and the DCBUN (median: 11) segments. Additionally, the mean fascicle diameter was smaller at the DCBUN (mean: 165 µm) than at the distal (mean: 197 µm) and proximal (mean: 199 µm) segments of the UN. Detailed knowledge of the microscopical structure of the UN in pigs is critical for further studies investigating neural interface designs and computational models of the peripheral nervous system.

Pain history and experimental pressure pain responses in adolescents: Results from a population-based birth cohort.

BACKGROUND: Sensitized pain mechanisms are often reported in musculoskeletal pain conditions, but population-based paediatric studies are lacking. We assessed whether adolescents with musculoskeletal pain history had evidence of increased responsiveness to experimental pressure stimuli. METHODS: Data were from 1496 adolescents of the Generation XXI birth cohort. Pain history was collected using the Luebeck Pain Questionnaire (self-reported at 13, parent-reported at 7 and 10 years). Two case definitions for musculoskeletal pain were considered: (1) cross-sectional-musculoskeletal pain lasting more than 3 months at age 13 and (2) longitudinal-musculoskeletal pain at age 13 with musculoskeletal pain reports at ages 7 and/or 10. Lower limb cuff pressure algometry was used to assess pain detection and tolerance thresholds, conditioned pain modulation effects (CPM, changes in thresholds in the presence on painful conditioning) and temporal summation of pain effects (TSP, changes in pain intensity to 10 phasic painful cuff stimulations). RESULTS: Adolescents with musculoskeletal pain at age 13 plus a history of pain in previous evaluations (longitudinal definition) had lower pain tolerance thresholds compared to the remaining sample (40.2 v. 49.0 kPa, p = 0.02), but showed no differences in pain detection threshold, CPM effect and TSP effect. Pain sensitivity, CPM effects and TSP effects were not significantly different when the current pain only case definition (cross-sectional) was used. CONCLUSIONS: Adolescents with current musculoskeletal pain who had a history of pain since childhood had lower tolerance to cuff stimulation. This may suggest long-standing musculoskeletal pain since childhood may contribute to sensitisation, rather than the presence of current pain only. SIGNIFICANCE: Repeated musculoskeletal pain up to age 13 years may contribute to higher pain sensitivity (particularly lowered pressure pain tolerance) in the general adolescent population. This does not seem to be the case when reported pain experiences are recent or when the outcomes are temporal pain summation or CPM. In this community-based paediatric sample, the vast majority showed no sign of altered pain processing, but a small fraction may reveal some pain sensitization at 13 years of age.

Distal subsartorial compartment block of the saphenous nerve - A dissection study and a patient case series.

STUDY OBJECTIVE: A saphenous nerve block is an important tool for analgesia after foot and ankle surgery. The conventional midthigh approach to saphenous nerve block in the femoral triangle may impede ambulation by impairing quadriceps motor function. PRIMARY OBJECTIVE: Developing a selective saphenous nerve block targeting the nerve distal to its emergence from the adductor canal in the subsartorial compartment. DESIGN: This study consists of A) a dissection study and B) Data from a clinical case series. SETTING: A) Medical University of Innsbruck, Austria (dissection of 15 cadaver sides) and. B) Aarhus University Hospital, Denmark (5 patients). INTERVENTIONS: A) Five mL of methylene blue was injected into the subsartorial compartment distal to the intersection of the saphenous nerve and the tendon of the adductor magnus guided by ultrasound. B) Five patients undergoing major hindfoot and ankle surgery had a subsartorial compartment block with 10 mL of local anesthetic in addition to a popliteal sciatic nerve block. MEASUREMENT: A) The frequencies of staining the saphenous and medial vastus nerves. B) Assessment of postoperative pain by NRS score (0-10) and success rate of saphenous nerve block by presence of cutaneous anesthesia in the anteromedial lower leg, and motor impairment by ability to ambulate. MAIN RESULTS: A) The saphenous nerve was stained in 15/15 cadaver sides. A terminal branch of the medial vastus nerve was stained in 2/15 cadaver sides. B) All patients were fully able to ambulate without support. No patients had any post-surgical pain from the anteromedial aspect of the ankle and foot (NRS score 0). The success rate of saphenous nerve block was 100%. CONCLUSION: The saphenous nerve can be targeted in the subsartorial compartment distal to the intersection of the nerve and the tendon of the adductor magnus. The subsartorial compartment block provided efficient analgesia without quadriceps motor impairment.

Efficacy of iliopsoas plane block for patients undergoing hip arthroscopy: a prospective, triple-blind, randomized, placebo-controlled trial.

BACKGROUND: Intraoperative stretching of the hip joint capsule often generates severe pain during the first 3 hours after hip arthroscopy. The short-lived severe pain mandates high opioid consumption, which may result in adverse events and delay recovery. The femoral nerve nociceptors are located anteriorly in the hip joint capsule. A femoral nerve block reduces pain and opioid demand after hip arthroscopy. It impedes, however, ambulation and home discharge after outpatient surgery. The iliopsoas plane block selectively anesthetizes the femoral sensory nerve branches innervating the hip joint capsule without compromising ambulation. We aimed to assess reduction of opioid consumption after iliopsoas plane block during the short-lived painful postsurgical period of time after hip arthroscopy. METHODS: In a randomized, triple-blind trial, 50 patients scheduled for hip arthroscopy in general anesthesia were allocated to active or placebo iliopsoas plane block. The primary outcome was opioid consumption during the first three postoperative hours in the postanesthesia care unit. Secondary outcomes included pain, nausea, and ability to ambulate. RESULTS: Forty-nine patients were analyzed for the primary outcome. The mean 3-hour intravenous morphine equivalent consumption in the iliopsoas plane block group was 10.4 mg vs 23.8 mg in the placebo group (p<0.001). No intergroup differences were observed for the secondary outcomes during the postoperative follow-up. CONCLUSION: An iliopsoas plane block reduces opioid consumption after hip arthroscopy. The reduction of opioid consumption during the clinically relevant 3-hour postsurgical period of time was larger than 50% for active versus placebo iliopsoas plane block in this randomized, triple-blind trial.