Caged Zn2+ Photolysis in Zebrafish Whole Brains Reveals Subsecond Modulation of Dopamine Uptake.

Free, ionic zinc (Zn2+) modulates neurotransmitter dynamics in the brain. However, the sub-s effects of transient concentration changes of Zn2+ on neurotransmitter release and uptake are not well understood. To address this lack of knowledge, we have combined the photolysis of the novel caged Zn2+ compound [Zn(DPAdeCageOMe)]+ with fast scan cyclic voltammetry (FSCV) at carbon fiber microelectrodes in live, whole brain preparations from zebrafish (Danio rerio). After treating the brain with [Zn(DPAdeCageOMe)]+, Zn2+ was released by application of light that was gated through a computer-controlled shutter synchronized with the FSCV measurements and delivered through a 1 mm fiber optic cable. We systematically optimized the photocage concentration and light application parameters, including the total duration and light-to-electrical stimulation delay time. While sub-s Zn2+ application with this method inhibited DA reuptake, assessed by the first-order rate constant (k) and half-life (t1/2), it had no effect on the electrically stimulated DA overflow ([DA]STIM). Increasing the photocage concentration and light duration progressively inhibited uptake, with maximal effects occurring at 100 µM and 800 ms, respectively. Furthermore, uptake was inhibited 200 ms after Zn2+ photorelease, but no measurable effect occurred after 800 ms. We expect that application of this method to the zebrafish whole brain and other preparations will help expand the current knowledge of how Zn2+ affects neurotransmitter release/uptake in select neurological disease states.

The clinical and radiographic degenerative spondylolisthesis classification and its predictive value.

INTRODUCTION: The clinical and radiographic degenerative spondylolisthesis (CARDS) classification is a new classification that has been introduced for degenerative spondylolisthesis (DS). It has four categories. Our study aimed to analyse the functional and radiographic outcome following DS surgery based on the preoperative CARDS classification. METHODS: A retrospective study of the prospectively collected Australian Spine Registry database was performed. Data on demographics, patient reported outcome measures including the Oswestry Disability Index (ODI) and EQ-5D-3 L scores, and changes in radiographic measurements were analysed. Based on the preoperative findings all x-rays were classified applying the CARDS classification. RESULTS: Between 2018 and 2021 a total of 54-patients were identified as having had surgery for DS at L4/5. The mean age was 65.3 ± 11.3years and females were predominantly affected (61%). Most cases were of CARDS type C (46%), followed by type B (29%). CARDS type A and D were observed in 18% and 6% respectively. Preoperatively, the L4/5 lordosis was 19.8 ± 6.3° and lumbar lordosis 43.9 ± 12.8°. Postoperatively the L4/5 lordosis alignment changed significantly to 23.5 ± 8.8° (p < 0.05). Preoperatively, the CARDS classification was 34.8 ± 17.4 (type A), 40.5 ± 11.0 (type B), 43.8 ± 12.9 and 50.0 ± 14.4 for type D (Pearson-coefficient 0.284, p = 0.041). Postoperatively this changed to 22.7 ± 16.1, 28.7 ± 21.2, 12.5 ± 13.1, and 6.5 ± 2.1 respectively. Similar improvements were observed for the EQ-5D-3 L. CONCLUSION: This study shows that the CARDS classification correlates with preoperative functional scores as well as helping to predict response to surgery. CARDS will likely assist in operative planning and prognostication. LEVEL OF EVIDENCE: III, therapeutic and prognostic study.

Effects of a liquefied petroleum gas stove intervention on stillbirth, congenital anomalies and neonatal mortality: A multi-country household air pollution intervention network trial.

Household air pollution (HAP) from cooking with solid fuels used during pregnancy has been associated with adverse pregnancy outcomes. The Household Air Pollution Intervention Network (HAPIN) trial was a randomized controlled trial that assessed the impact of a liquefied petroleum gas (LPG) stove and fuel intervention on health in Guatemala, India, Peru, and Rwanda. Here we investigated the effects of the LPG stove and fuel intervention on stillbirth, congenital anomalies and neonatal mortality and characterized exposure-response relationships between personal exposures to fine particulate matter (PM2.5), black carbon (BC) and carbon monoxide (CO) and these outcomes. Pregnant women (18 to <35 years of age; gestation confirmed by ultrasound at 9 to <20 weeks) were randomly assigned to intervention or control arms. We monitored these fetal and neonatal outcomes and personal exposure to PM2.5, BC and CO three times during pregnancy, we conducted intention-to-treat (ITT) and exposure-response (E-R) analyses to determine if the HAPIN intervention and corresponding HAP exposure was associated with the risk of fetal/neonatal outcomes. A total of 3200 women (mean age 25.4 ± 4.4 years, mean gestational age at randomization 15.4 ± 3.1 weeks) were included in this analysis. Relative risks for stillbirth, congenital anomaly and neonatal mortality were 0.99 (0.60, 1.66), 0.92 (95 % CI 0.52, 1.61), and 0.99 (0.54, 1.85), respectively, among women in the intervention arm compared to controls in an ITT analysis. Higher mean personal exposures to PM2.5, CO and BC during pregnancy were associated with a higher, but statistically non-significant, incidence of adverse outcomes. The LPG stove and fuel intervention did not reduce the risk of these outcomes nor did we find evidence supporting an association between personal exposures to HAP and stillbirth, congenital anomalies and neonatal mortality.

Improving the precision of shock resuscitation by predicting fluid responsiveness with machine learning and arterial blood pressure waveform data.

Fluid bolus therapy (FBT) is fundamental to the management of circulatory shock in critical care but balancing the benefits and toxicities of FBT has proven challenging in individual patients. Improved predictors of the hemodynamic response to a fluid bolus, commonly referred to as a fluid challenge, are needed to limit non-beneficial fluid administration and to enable automated clinical decision support and patient-specific precision critical care management. In this study we retrospectively analyzed data from 394 fluid boluses from 58 pigs subjected to either hemorrhagic or distributive shock. All animals had continuous blood pressure and cardiac output monitored throughout the study. Using this data, we developed a machine learning (ML) model to predict the hemodynamic response to a fluid challenge using only arterial blood pressure waveform data as the input. A Random Forest binary classifier referred to as the ML fluid responsiveness algorithm (MLFRA) was trained to detect fluid responsiveness (FR), defined as a ≥ 15% change in cardiac stroke volume after a fluid challenge. We then compared its performance to pulse pressure variation, a commonly used metric of FR. Model performance was assessed using the area under the receiver operating characteristic curve (AUROC), confusion matrix metrics, and calibration curves plotting predicted probabilities against observed outcomes. Across multiple train/test splits and feature selection methods designed to assess performance in the setting of small sample size conditions typical of large animal experiments, the MLFRA achieved an average AUROC, recall (sensitivity), specificity, and precision of 0.82, 0.86, 0.62. and 0.76, respectively. In the same datasets, pulse pressure variation had an AUROC, recall, specificity, and precision of 0.73, 0.91, 0.49, and 0.71, respectively. The MLFRA was generally well-calibrated across its range of predicted probabilities and appeared to perform equally well across physiologic conditions. These results suggest that ML, using only inputs from arterial blood pressure monitoring, may substantially improve the accuracy of predicting FR compared to the use of pulse pressure variation. If generalizable, these methods may enable more effective, automated precision management of critically ill patients with circulatory shock.

Liquefied Petroleum Gas or Biomass Cooking and Severe Infant Pneumonia.

BACKGROUND: Exposure to household air pollution is a risk factor for severe pneumonia. The effect of replacing biomass cookstoves with liquefied petroleum gas (LPG) cookstoves on the incidence of severe infant pneumonia is uncertain. METHODS: We conducted a randomized, controlled trial involving pregnant women 18 to 34 years of age and between 9 to less than 20 weeks' gestation in India, Guatemala, Peru, and Rwanda from May 2018 through September 2021. The women were assigned to cook with unvented LPG stoves and fuel (intervention group) or to continue cooking with biomass fuel (control group). In each trial group, we monitored adherence to the use of the assigned cookstove and measured 24-hour personal exposure to fine particulate matter (particles with an aerodynamic diameter of ≤2.5 µm [PM2.5]) in the women and their offspring. The trial had four primary outcomes; the primary outcome for which data are presented in the current report was severe pneumonia in the first year of life, as identified through facility surveillance or on verbal autopsy. RESULTS: Among 3200 pregnant women who had undergone randomization, 3195 remained eligible and gave birth to 3061 infants (1536 in the intervention group and 1525 in the control group). High uptake of the intervention led to a reduction in personal exposure to PM2.5 among the children, with a median exposure of 24.2 µg per cubic meter (interquartile range, 17.8 to 36.4) in the intervention group and 66.0 µg per cubic meter (interquartile range, 35.2 to 132.0) in the control group. A total of 175 episodes of severe pneumonia were identified during the first year of life, with an incidence of 5.67 cases per 100 child-years (95% confidence interval [CI], 4.55 to 7.07) in the intervention group and 6.06 cases per 100 child-years (95% CI, 4.81 to 7.62) in the control group (incidence rate ratio, 0.96; 98.75% CI, 0.64 to 1.44; P = 0.81). No severe adverse events were reported to be associated with the intervention, as determined by the trial investigators. CONCLUSIONS: The incidence of severe pneumonia among infants did not differ significantly between those whose mothers were assigned to cook with LPG stoves and fuel and those whose mothers were assigned to continue cooking with biomass stoves. (Funded by the National Institutes of Health and the Bill and Melinda Gates Foundation; HAPIN ClinicalTrials.gov number, NCT02944682.).

Return to sports following discectomy: does a consensus exist?

INTRODUCTION: In the USA, lumbar discectomy is one of the most commonly performed spinal procedures. As certain sports are considered to be major risk factors for disc herniation, the question remains as to when highly active patients should return to their previous level of activity. This study aimed to analyze spine surgeons' opinions on when patients may return to activities following discectomy as well as their underlying rationale for their decision. METHODS: A questionnaire was designed by five different fellowship-trained spine surgeons for the 168 members of the Spine Society of Australia. Questions on the surgeons experience, decision making, preferred surgical technique, the postoperative rehabilitation and the response to patient expectations were included. RESULTS: In total, 83.9% of surgeons discuss the postoperative level of activity with their patients. Sport is considered as an important contributor for good functional outcome by 71.0% of surgeons. Surgeons recommend avoiding, often permanently, weightlifting (35.7%) of the time, rugby (21.4%), horseback riding (17.9%) as well as martial arts (14.3%) postoperatively even with previous training. The return to high levels of activity is considered as a major risk factor for disc herniation recurrence by 25.8% of surgeons. Return to high level of activity is typically recommended after 3 months by 48.4% of surgeons. CONCLUSION: So far no consensus on the rehabilitation protocol and return to level of activity exists. Recommendations depend on personal experience as well as the individuals' training, and typically, a period of avoidance of sport for up to 3 months is recommended. LEVEL OF EVIDENCE: Level III, therapeutic and prognostic study.

The effects of age on dyspnea and respiratory mechanical and neural responses to exercise in healthy men.

The respiratory muscle pressure generation and inspiratory and expiratory neuromuscular recruitment patterns in younger and older men were compared during exercise, alongside descriptors of dyspnea. Healthy younger (n = 8, 28 ± 5 years) and older (n = 8, 68 ± 4 years) men completed a maximal incremental cycling test. Esophageal, gastric (Pga ) and transdiaphragmatic pressures, and electromyography (EMG) of the crural diaphragm were measured using a micro-transducer and EMG catheter. EMG of the parasternal intercostals, sternocleidomastoids, and rectus abdominis were measured using skin surface electrodes. After the exercise test, participants completed a questionnaire to evaluate descriptors of dyspnea. Pga at end-expiration, Pga expiratory tidal swings, and the gastric pressure-time product (PTPga ) at absolute and relative minute ventilation were higher (p < 0.05) for older compared to younger men. There were no differences in EMG responses between older and younger men. Younger men were more likely to report shallow breathing (p = 0.005) than older men. Our findings showed younger and older men had similar respiratory neuromuscular activation patterns and reported different dyspnea descriptors, and that older men had greater expiratory muscle pressure generation during exercise. Greater expiratory muscle pressures in older men may be due to compensatory mechanisms designed to offset increasing airway resistance due to aging. These results may have implications for exercise-induced expiratory muscle fatigue in older men.

Spinal fractures in fused spines: nonoperative treatment is a reliable alternative.

INTRODUCTION: Spinal fractures in fused spines such as in ankylosing spondylitis or DISH are typically of type B or C fractures where operative treatment is recommended. The mortality rate in non-operatively treated patients is reported to be 51%. The purpose of this study was to investigate the mortality rate, complication rate and demographics of patients following non-operatively treatment in fused spine injuries. METHODS: Between 2019 and 2021, a retrospective study was conducted including all patients who presented to our trauma center with a spinal fracture of a fused spine. Radiology and patient charts were analyzed for fracture pattern, complications, neurological deficit, comorbidities, and mortality rate. RESULTS: A total of 49 patients were found at a mean age was 79.8 ± 10.9 years and primarily males were affected in 65.3%. All fractures were of type B and the thoracic spine was involved in 85.7%. The mean follow-up was 6.3 ± 8.2 months and fusion was obtained in all patients. No neurological deficit was observed in any. A total of 13 patients died at a mean age of 86.5 ± 10.0 years after 157.1 ± 158.1 days. 6 patients (10.2%) deceased within the first 6 weeks at a mean age of 91.8 ± 3.8 years. One patient each suffered from heart failure, an acute delirium, end stage colon cancer and subdural hemorrhage. CONCLUSION: This study shows that the mortality rate in the first 6 weeks following a fracture in a fused spine is 10.2% for patients above the age of 90 years. Therefore, non-operative treatment should be taken into consideration as the mortality rate in other studies may be overestimated. LEVEL OF EVIDENCE: III, retrospective study.

Birefringent Glass-Engraved Tilted Pillar Metasurfaces for High Power Laser Applications.

Birefringent materials-which are highly needed in high power laser systems-may be limited in usage due to the laser-induced damage threshold of traditional birefringent materials. This work reports here on all-glass metasurfaces, fabricated by angled etching through sacrificial metal nanoparticle (NP) etching masks, for generation of effective birefringence in the formed layer. As a result, a fused silica metasurface, monolithic to the underlying substrate, is demonstrated to exhibit a birefringence of 6.57° under 375 nm illumination. Full-wave analysis shows a good agreement with the measurement and presents potential paths forward to increasing the effective metasurface birefringence. This is the first demonstration, to the best of knowledge, of an etching technique to obtain the resulting tilted pillar-like nanofeatures. The anisotropy of the metasurface nanoelements along the two window in-plane major axes presents different effective paths for the two polarizations and thus generates birefringence in a nonbirefringent material. Additionally, the imparted anisotropy lends itself to manipulation of physical properties of the surface as well, with metasurface feature orientation suppressing water flow along one principal axis and giving rise to water flow steering capabilities.

Distinguishing science from pseudoscience in commercial respiratory interventions: an evidence-based guide for health and exercise professionals.

Respiratory function has become a global health priority. Not only is chronic respiratory disease a leading cause of worldwide morbidity and mortality, but the COVID-19 pandemic has heightened attention on respiratory health and the means of enhancing it. Subsequently, and inevitably, the respiratory system has become a target of the multi-trillion-dollar health and wellness industry. Numerous commercial, respiratory-related interventions are now coupled to therapeutic and/or ergogenic claims that vary in their plausibility: from the reasonable to the absurd. Moreover, legitimate and illegitimate claims are often conflated in a wellness space that lacks regulation. The abundance of interventions, the range of potential therapeutic targets in the respiratory system, and the wealth of research that varies in quality, all confound the ability for health and exercise professionals to make informed risk-to-benefit assessments with their patients and clients. This review focuses on numerous commercial interventions that purport to improve respiratory health, including nasal dilators, nasal breathing, and systematized breathing interventions (such as pursed-lips breathing), respiratory muscle training, canned oxygen, nutritional supplements, and inhaled L-menthol. For each intervention we describe the premise, examine the plausibility, and systematically contrast commercial claims against the published literature. The overarching aim is to assist health and exercise professionals to distinguish science from pseudoscience and make pragmatic and safe risk-to-benefit decisions.

Spatiotemporal Imaging of Zinc Ions in Zebrafish Live Brain Tissue Enabled by Fluorescent Bionanoprobes.

The zebrafish is a powerful model organism to study the mechanisms governing transition metal ions within whole brain tissue. Zinc is one of the most abundant metal ions in the brain, playing a critical pathophysiological role in neurodegenerative diseases. The homeostasis of free, ionic zinc (Zn2+) is a key intersection point in many of these diseases, including Alzheimer's disease and Parkinson's disease. A Zn2+ imbalance can eventuate several disturbances that may lead to the development of neurodegenerative changes. Therefore, compact, reliable approaches that allow the optical detection of Zn2+ across the whole brain would contribute to our current understanding of the mechanisms that underlie neurological disease pathology. We developed an engineered fluorescence protein-based nanoprobe that can spatially and temporally resolve Zn2+ in living zebrafish brain tissue. The self-assembled engineered fluorescence protein on gold nanoparticles was shown to be confined to defined locations within the brain tissue, enabling site specific studies, compared to fluorescent protein-based molecular tools, which diffuse throughout the brain tissue. Two-photon excitation microscopy confirmed the physical and photometrical stability of these nanoprobes in living zebrafish (Danio rerio) brain tissue, while the addition of Zn2+ quenched the nanoprobe fluorescence. Combining orthogonal sensing methods with our engineered nanoprobes will enable the study of imbalances in homeostatic Zn2+ regulation. The proposed bionanoprobe system offers a versatile platform to couple metal ion specific linkers and contribute to the understanding of neurological diseases.

Comorbidity data collection across different spine registries: an evidence map.

INTRODUCTION: Comorbidities are significant patient factors that contribute to outcomes after surgery. There is highly variable collection of this information across the literature. To help guide the systematic collection of best practice data, the Australian Spine Registry conducted an evidence map to investigate (i) what comorbidities are collected by spine registries, (ii) how they are collected and (iii) the compliance and completeness in collecting comorbidity data. METHOD: A literature search was performed to identify published studies of adult spine registry data reporting comorbidities. In addition, targeted questionnaires were sent to existing global spine registries to identify the maximum number of relevant results to build the evidence map. RESULTS: Thirty-six full-text studies met the inclusion criteria. There was substantial variation in the reporting of comorbidity data; 55% of studies reported comorbidity collection, but only 25% reported the data collection method and 20% reported use of a comorbidity index. The variation in the literature was confirmed with responses from 50% of the invited registries (7/14). Of seven, three use a recognised comorbidity index and the extent and methods of comorbidity collection varied by registry. CONCLUSION: This evidence map identified variations in the methodology, data points and reporting of comorbidity collection in studies using spine registry data, with no consistent approach. A standardised set of comorbidities and data collection methods would encourage collaboration and data comparisons between patient cohorts and could facilitate improved patient outcomes following spine surgery by allowing data comparisons and predictive modelling of risk factors.

Retrospective analysis of nurse-administered fall assessment scales in the Epilepsy Monitoring Unit.

INTRODUCTION: Inpatient falls within the Epilepsy Monitoring Unit (EMU) are a common, and potentially preventable adverse event contributing to morbidity for patients living with epilepsy. Accurate fall risk screening is important to identify and efficiently allocate proper safety measures to high-risk patients, especially in EMUs with limited resources. We sought to compare existing screening tools for the ability to predict falls in the EMU. METHODS: This is a retrospective, single-center, case-controlled, comparative analysis of 7 nurse-administered fall risk assessment tools (NAFRAT) of patients admitted to the Vanderbilt University Medical Center (VUMC) EMU. Analysis of categorical data was compared using chi-square analysis while quantitative distributions were compared using student's t-test. RESULTS: A total of 56 patient records (28 falls and 28 controls) were included in the analysis. Epilepsy Monitoring Unit falls were most common within the first 3 days of admission (p = .0094). Pre-admission documentation of falls was a strong predictor of falls within the EMU (p < .0001). Epilepsy Monitoring Unit falls were associated with documented falls after EMU discharge (p = .011). The John Hopkins fall risk assessment tool (JHFRAT) accurately stratified fall risk in the fall group compared to the control (p = .008), however, none of the 7 NAFRATs demonstrated significant categorical differences among the epilepsy subgroups. There was a significant difference in the distribution of quantitative scores, higher in the fall group according to the Morse Fall Scale (MFS) (p = 0.012), JHFRAT (p = 0.003), Schmid Fall Risk Assessment Scale (p = 0.029) and Hester-Davis Scale (p = 0.049). The modified Conley (p = 0.03) and Morse scale (p = 0.025) demonstrated differences in the distribution of quantitative scores in the epilepsy subgroups. CONCLUSION: The findings of this study demonstrate variable accuracy of NAFRATs in assessing fall risk among patients admitted to the EMU, particularly among patients with epilepsy. The findings underscore the need for a validated, EMU-specific, fall assessment tool that accurately stratifies fall risk and inform efficient use of patient-specific fall prevention resources and protocols.

Blood Loss Following Open Posterior Spinal Fusion in Fractures: Cannulated vs. Solid Pedicle Screws.

We aim to delineate whether there is increased blood loss with the use of cannulated pedicle screws compared to solid pedicle screws in patients undergoing posterior spinal fusion. A single-centre retrospective case-control study was undertaken on patients undergoing PSF for spinal fractures. Cannulated screw fixation was compared with solid screw fixation. Intraoperative blood loss was estimated using pre and postoperative haemoglobin levels, recorded estimated blood loss and cell saver reports. Anticoagulation, blood product administration, operative time and number of levels fused were assessed. A total of 64 cases, 32 in each cohort, were included in the analysis. Overall mean haemoglobin reduction from pre- to post-operative was 2.82 ± 1.85 g/L per screw inserted in the cannulated group, compared to a haemoglobin decrease of 2.81 ± 1.521 g/L per screw inserted in the solid screw group (p = 0.971). Total estimated intraoperative blood loss was 616.3 + 355.4 mL in the cannulated group, compared to 713.6 + 473.5 mL in the solid screw group (p = 0.456). Patients with preoperative thrombocytopenia had a transfusion rate of 0.5 ± 0.71 units/patient compared to 0.04 ± 0.19 units/patient in patients with normal platelet levels (p < 0.005). The differences in blood loss observed between cannulated and solid pedicle screws are non-significant overall. The largest predictor for need of transfusion was pre-operative thrombocytopenia, regardless of the type of screw used.

Subacute Posttraumatic Ascending Myelopathy: Case Report and Systematic Review of the Literature.

STUDY DESIGN: Case report and literature review. OBJECTION: Aim of this study was to summarize the current evidence base behind subacute posttraumatic ascending myelopathy (SPAM) including the epidemiology, presentation, diagnosis, prognosis, and etiology. SUMMARY OF BACKGROUND DATA: SPAM is a rare, potentially fatal disorder which is not attributable to ongoing mechanical instability, syrinx formation, or iatrogenic causes. METHODS: A systematic literature search on SPAM was performed on Medline, Ovid, Cochrane, Embase, and PubMed databases between 1969 and 2021. Cases were reviewed and the findings summarized. Further evidence was reviewed to support the hypothesis that disruption of cerebrospinal fluid (CSF) circulation is the underlying etiology of the condition. RESULTS: It is estimated to occur in 0.4%-0.7% of spinal cord injuries and may have a mortality of up to 10%. The most likely etiology disruption of CSF circulation leading to further damage to the spinal cord presumably through pressure mediated effects such as a reduction in cellular perfusion. CONCLUSION: There is effectively no treatment of this condition, however, with interest developing in monitoring of CSF pressures during spinal cord injury this may help confirm the etiology, and allow the suggestion of therapies such as drains or expansion duraplasty to reduce spinal cord pressures. LEVEL OF EVIDENCE: Level II-case report and systematic review.

Exercise-induced bronchoconstriction in university field hockey athletes: Prevalence, sex differences, and associations with dyspnea symptoms.

Introduction: Exercise-induced bronchoconstriction (EIB) is a prevalent condition in athletes. EIB screening studies identify many athletes with undiagnosed EIB. Moreover, there is a poor relationship between EIB and dyspnea symptoms recalled from memory. Purpose: This study investigated: (I) the prevalence of EIB in British university field hockey athletes; (II) the effect of sex and diagnostic criteria on EIB prevalence; and (III) the association between EIB and contemporaneous dyspnea symptoms. Methods: 52 field hockey athletes (age: 20 ± 2 years; height: 173 ± 9 cm; body mass: 72 ± 10 kg; male = 31; female = 22) completed a eucapnic voluntary hyperpnea (EVH) test with multi-dimensional dyspnea scores measured 3-10 mins post-EVH. A test was deemed positive (EIB+) if a fall index (FI) ≥10% in FEV1 occurred at two consecutive time points post-test (FIATS). Two further criteria were used to assess the effect of diagnostic criteria on prevalence: FI≥10%, determined by a pre-to-post-EVH fall in FEV1 of ≥10% at any single time-point; and FI≥10%-NORM calculated as FI≥10% but with the fall in FEV1 normalized to the mean ventilation achieved during EVH. Results: EIB prevalence was 19% and greater in males (30%) than females (5%). In EIB+ athletes, 66% did not have a previous diagnosis of EIB or asthma and were untreated. Prevalence was significantly influenced by diagnostic criteria (P = 0.002) ranging from 19% (FIATS) to 38% (FI≥10%-NORM). Dyspnea symptoms were higher in EIB+ athletes (P ≤ 0.031), produced significant area under the curve for receive operator characteristics (AUC ≥ 0.778, P ≤ 0.011) and had high negative prediction values (≥96%). Conclusion: Overall, 19% of university field hockey athletes had EIB, and most were previously undiagnosed and untreated. EVH test diagnostic criteria significantly influences prevalence rates, thus future studies should adopt the ATS criteria (FIATS). Contemporaneous dyspnea symptoms were associated with bronchoconstriction and had high negative prediction values. Therefore, contemporaneous dyspnea scores may provide a useful tool in excluding a diagnosis of EIB.

Cervical immobilization in trauma patients: soft collars better than rigid collars? A systematic review and meta-analysis.

INTRODUCTION: Rigid cervical spine following trauma immobilization is recommended to reduce neurological disability and provide spinal stability. Soft collars have been proposed as a good alternative because of the complications related to rigid collars. The purpose of this study was to perform a systematic review on soft and rigid collars in the prehospital management of cervical trauma. METHOD: A systematic review was performed following the PRISMA guidelines. Search terms were (immobilization) AND (collar) AND ((neck) OR (cervical)) to evaluate the range of motion (ROM) and evidence of clinical outcome for soft and rigid collars. RESULTS: A total of 18 studies met eligibility criteria including 2 clinical studies and 16 articles investigating the range of motion (ROM). Four hundred and ninety-six patients at a mean age of 32.5 years (SD 16.8) were included. Measurements were performed in a seated position in twelve studies. Eight articles reported the ROM without a collar, 7 with a soft collar, and 15 with a rigid collar. There was no significant difference in flexion/extension, bending and rotation following immobilization with soft collars compared to no collar. Rigid collars provided significantly higher stability compared to no collar (p < 0.005) and to soft collars in flexion/extension and rotation movements (p < 0.05). The retrospective clinical studies showed no significant differences in secondary spinal cord injuries for soft collar (0.5%) and for rigid collar (1.1%). One study, comparing immobilization without a collar compared to that with a rigid collar, found a significant difference in neurologic deficiency and supraclavicular nerve lesion. CONCLUSION: Although rigid collars provide significant higher stability to no collar and to soft collars in flexion/ extension and rotation movements, clinical studies could not confirm a difference in neurological outcome. LEVEL OF EVIDENCE: II, Systematic Review.

App-Based Rehabilitation in Back Pain, a Systematic Review.

Smartphones and their associated applications are used frequently by patients and clinicians alike. Despite the technology being widely accessible, their use to aid in rehabilitation is yet to be adopted. The SARS CoV-2 pandemic has presented an opportunity to expedite their integration given the difficulty patients currently have in accessing healthcare. The aim of this study was to perform a systematic literature review on the use of smartphone rehabilitation applications compared to standard physiotherapy for back pain. We conducted a search of Medline/Pubmed and google databases using the search terms [APP] AND [[Orthopaedic] OR [Neurosurgery]], following the PRISMA guidelines. All prospective studies investigating rehabilitation applications for back pain or following spine surgery were included. A total of nine studies met the inclusion criteria which investigated 7636 patients, of which 92.4% were allocated to the interventional group (n = 7055/7636) with a follow up of 4 weeks to 6 months. All except one study reported on patients experiencing back pain on average for 19.6 ± 11.6 months. The VAS-pain score was presented in all studies without significance between the interventional and control group (p = 0.399 before and p = 0.277 after intervention). Only one research group found significantly higher improvement in PROMs for the application group, whereas the remaining showed similar results compared to the control group. Using application-based rehabilitation programs provides an easily accessible alternative or substitute to traditional physiotherapy for patients with back pain. Given that smartphones are so prevalent in activities in our daily lives, this will enhance and improve rehabilitation if patients are self-dedicated and compliant.

Liquefied Petroleum Gas or Biomass for Cooking and Effects on Birth Weight.

BACKGROUND: Exposure during pregnancy to household air pollution caused by the burning of solid biomass fuel is associated with adverse health outcomes, including low birth weight. Whether the replacement of a biomass cookstove with a liquefied petroleum gas (LPG) cookstove would result in an increase in birth weight is unclear. METHODS: We performed a randomized, controlled trial involving pregnant women (18 to <35 years of age and at 9 to <20 weeks' gestation as confirmed on ultrasonography) in Guatemala, India, Peru, and Rwanda. The women were assigned in a 1:1 ratio to use a free LPG cookstove and fuel (intervention group) or to continue using a biomass cookstove (control group). Birth weight, one of four prespecified primary outcomes, was the primary outcome for this report; data for the other three outcomes are not yet available. Birth weight was measured within 24 hours after birth. In addition, 24-hour personal exposures to fine particulate matter (particles with a diameter of ≤2.5 µm [PM2.5]), black carbon, and carbon monoxide were measured at baseline and twice during pregnancy. RESULTS: A total of 3200 women underwent randomization; 1593 were assigned to the intervention group, and 1607 to the control group. Uptake of the intervention was nearly complete, with traditional biomass cookstoves being used at a median rate of less than 1 day per month. After randomization, the median 24-hour personal exposure to fine particulate matter was 23.9 µg per cubic meter in the intervention group and 70.7 µg per cubic meter in the control group. Among 3061 live births, a valid birth weight was available for 94.9% of the infants born to women in the intervention group and for 92.7% of infants born to those in the control group. The mean (±SD) birth weight was 2921±474.3 g in the intervention group and 2898±467.9 g in the control group, for an adjusted mean difference of 19.6 g (95% confidence interval, -10.1 to 49.2). CONCLUSIONS: The birth weight of infants did not differ significantly between those born to women who used LPG cookstoves and those born to women who used biomass cookstoves. (Funded by the National Institutes of Health and the Bill and Melinda Gates Foundation; HAPIN ClinicalTrials.gov number, NCT02944682.).