Chemical crystallography by serial femtosecond X-ray diffraction.

Inorganic-organic hybrid materials represent a large share of newly reported structures, owing to their simple synthetic routes and customizable properties1. This proliferation has led to a characterization bottleneck: many hybrid materials are obligate microcrystals with low symmetry and severe radiation sensitivity, interfering with the standard techniques of single-crystal X-ray diffraction2,3 and electron microdiffraction4-11. Here we demonstrate small-molecule serial femtosecond X-ray crystallography (smSFX) for the determination of material crystal structures from microcrystals. We subjected microcrystalline suspensions to X-ray free-electron laser radiation12,13 and obtained thousands of randomly oriented diffraction patterns. We determined unit cells by aggregating spot-finding results into high-resolution powder diffractograms. After indexing the sparse serial patterns by a graph theory approach14, the resulting datasets can be solved and refined using standard tools for single-crystal diffraction data15-17. We describe the ab initio structure solutions of mithrene (AgSePh)18-20, thiorene (AgSPh) and tethrene (AgTePh), of which the latter two were previously unknown structures. In thiorene, we identify a geometric change in the silver-silver bonding network that is linked to its divergent optoelectronic properties20. We demonstrate that smSFX can be applied as a general technique for structure determination of beam-sensitive microcrystalline materials at near-ambient temperature and pressure.

Evidence-Based Guidelines for Prehospital Airway Management: Methods and Resources Document.

INTRODUCTION: Emergency airway management is a common and critical task EMS clinicians perform in the prehospital setting. A new set of evidence-based guidelines (EBG) was developed to assist in prehospital airway management decision-making. We aim to describe the methods used to develop these EBGs. METHODS: The EBG development process leveraged the four key questions from a prior systematic review conducted by the Agency for Healthcare Research and Quality (AHRQ) to develop 22 different population, intervention, comparison, and outcome (PICO) questions. Evidence was evaluated using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework and tabulated into the summary of findings tables. The technical expert panel then used a rigorous systematic method to generate evidence to decision tables, including leveraging the PanelVoice function of GRADEpro. This process involved a review of the summary of findings tables, asynchronous member judging, and online facilitated panel discussions to generate final consensus-based recommendations. RESULTS: The panel completed the described work product from September 2022 to April 2023. A total of 17 summary of findings tables and 16 evidence to decision tables were generated through this process. For these recommendations, the overall certainty in evidence was "very low" or "low," data for decisions on cost-effectiveness and equity were lacking, and feasibility was rated well across all categories. Based on the evidence, 16 "conditional recommendations" were made, with six PICO questions lacking sufficient evidence to generate recommendations. CONCLUSION: The EBGs for prehospital airway management were developed by leveraging validated techniques, including the GRADE methodology and a rigorous systematic approach to consensus building to identify treatment recommendations. This process allowed the mitigation of many virtual and electronic communication confounders while managing several PICO questions to be evaluated consistently. Recognizing the increased need for rigorous evidence evaluation and recommendation development, this approach allows for transparency in the development processes and may inform future guideline development.

Complementary and Alternative Medicine: Consumers' Experience With Food Therapy in Traditional Chinese Medicine in Hong Kong.

Context: The trend of people using complementary and alternative medicine (CAM) has been increasing globally. To enact policies and regulations that promote the safe use of CAM, a detailed investigation is needed into people's knowledge, practices, and beliefs related to CAM. Food therapy has long been regarded as an important part of traditional Chinese medicine (TCM), a type of CAM. Objective: This study intended to empirically examine the public's knowledge about TCM food therapy, including the sources of that knowledge, actual practices, and the public's beliefs about the therapy. Design: The research team designed a questionnaire to test the public's understanding of food properties as designated in TCM food therapy and to identify the public's sources of knowledge and experience in using food therapy. Setting: The study took place at the College of Professional and Continuing Education, the Hong Kong Polytechnic University, and the University of Hong Kong in Hong Kong, China. Participants: Participants were 447 Chinese students participating in postsecondary or tertiary education at the two higher education institutions mentioned above. Outcome Measures: The survey's quantitative questions examined respondents' prior TCM knowledge, sources of knowledge, and food therapy experience compared to their ability to correctly categorize 24 foods. The survey's qualitative questions examined the general practice of food therapy and the cultural beliefs underlying the food therapy strategies that participants used. Results: The study showed that: (1) having prior and partial knowledge of food properties (P = .000); (2) seeking information from the internet (P = .000), television (P = .0473) and friends (P = .0181); and (3) having used food therapy for chronic conditions (P = .0034) significantly improved participants ability to correctly categorize foods as to their food therapy characteristics. Conclusions: Participants relied less on traditional medical sources such as parents and health professionals but more on the internet, which may have empowered them through wider access to information. The study has further contributed to the study of Complementary and Alternative Medicine (CAM) by highlighting the role of cultural practices and beliefs in TCM food therapy.

Guided Approach to Implant Placement, Immediate Provisionalization, and Definitive Restoration: A Case Letter.

Replacement of missing teeth is becoming more prevalent, currently with more than 700,000 dental implants being placed every year. Patients seek out dental treatment with the expectations of having procedures performed in the least number of time/visits, for as inexpensive as possible, and at the highest quality. As this continues, clinicians can adapt with changing times and adopt the newer advancements in digital dentistry. This case letter aims to provide readers with insight to integration of digital workflows to optimize patient and clinician outcomes with single tooth implant therapy.

A thematic analysis of higher education students' perceptions of online learning in Hong Kong under COVID-19: Challenges, strategies and support.

Under the sudden outbreak of COVID-19 worldwide, students were forced to switch from face-to-face to online learning. This study reports the experience of Hong Kong students in higher education concerning the challenges they faced, the strategies they used and the support they needed in their online learning during the period. An online questionnaire was used to invite students to answer open-ended questions about these three aspects. 145 students from two higher education institutions completed the questionnaire and their comments were coded using thematic analysis. The study has discovered that socio-economic factors may have presented difficulties to students' online learning concerning their study environment and access to equipment. Students were emotionally distressed by online learning, particularly by the quality of feedback and clarity of course arrangement, so support for these aspects should be given. Self-regulated learning strategies were found to have been deployed by students to facilitate their learning, in which the use of time management apps and lecture videos highlights the increasing importance of technology to self study. These socio-economic, technological and emotional factors will be further discussed and corresponding suggestions will be made to help teachers and university policy makers examine the conditions that can help improve and promote online learning for higher education students under COVID-19.

Orthomageddon: A retrospective cohort study of weather-dependent variations in emergency department volume in a Canadian city.

INTRODUCTION: Unique weather patterns can dramatically increase the number of emergency department (ED) visits due to falls on snow or ice compared to winter averages. They can create "Orthomageddon" incidences; days when the number of orthopedic injuries dramatically exceeds average. The study objective was to identify weather-dependent differences in demographics, length-of-stay (LOS) predictors, and volume for fall-injury presenting to the ED. The authors placed emphasis on Chinook or Foehn phenomenon (rapid freeze-thaw cycles) common east of the Rocky Mountains. METHOD: Patients with extremity and hip fractures from fall on snow or ice were identified from the Calgary Zone Alberta Health Services ED database from November 1st 2013 to March 31st 2018 (n = 3894). High-volume dates were the 90th percentile of all dates by volume (n = 76). This equated to all dates with >10 fall-injuries. The authors compared post-Chinook, night-freezing, high-volume, and regular winter conditions. Meteorological data was collected from the Environment Canada weather station at the Calgary International Airport. RESULTS: The authors identified 588 post-Chinook, and 1149 night-freezing presenters. Weather was strongly predictive of ED fall-injury volume. Night-freezing events (above-freezing temperatures prior to 1800 hours the preceding day, followed by freezing temperatures prior to 0600 hours the following day) correlated with elevated fall-injury volume (OR, 6.84; 95% CI, 5.88, 7.97) as were recent Chinook events (OR, 2.19; 95% CI, 1.84, 2.62). CONCLUSION: Weather, particularly nighttime conditions, are highly predictive of winter, fall-related ED volume. This may inform future population-level alerts for dates of elevated fall risk and ED staffing patterns.

Accuracy and precision of 3D-printed implant surgical guides with different implant systems: An in vitro study.

STATEMENT OF PROBLEM: Implant guided surgery systems promise implant placement accuracy and precision beyond straightforward nonguided surgery. Recently introduced in-office stereolithography systems allow clinicians to produce implant surgical guides themselves. However, different implant designs and osteotomy preparation protocols may produce accuracy and precision differences among the different implant systems. PURPOSE: The purpose of this in vitro study was to measure the accuracy and precision of 3 implant systems, Tapered Internal implant system (BioHorizons) (BH), NobelReplace Conical (Nobel Biocare) (NB), and Tapered Screw-Vent (Zimmer Biomet) (ZB) when in-office fabricated surgical guides were used. MATERIAL AND METHODS: A cone beam computed tomography (CBCT) data set of an unidentified patient missing a maxillary right central incisor and intraoral scans of the same patient were used as a model. A software program (3Shape Implant Studio) was used to plan the implant treatment with the 3 implant systems. Three implant surgical guides were fabricated by using a 3D printer (Form 2), and 30 casts were printed. A total of 10 implants for each system were placed in the dental casts by using the manufacturer's recommended guided surgery protocols. After implant placement, postoperative CBCT images were made. The CBCT cast and implant images were superimposed onto the treatment-planning image. The implant positions, mesiodistal, labiopalatal, and vertical, as well as implant angulations were measured in the labiolingual and mesiodistal planes. The displacements from the planning in each dimension were recorded. ANOVA with the Tukey adjusted post hoc pairwise comparisons were used to examine the accuracy and precision of the 3 implant systems (α=.05). RESULTS: The overall implant displacements were -0.02 ±0.13 mm mesially (M), 0.07 ±0.14 mm distally (D), 0.43 ±0.57 mm labially (L), and 1.26 ±0.80 mm palatally (P); 1.20 ±3.01 mm vertically in the mesiodistal dimension (VMD); 0.69 ±2.03 mm vertically in the labiopalatal dimension (VLP); 1.69 ±1.02 degrees in mesiodistal angulation (AMD); and 1.56 ±0.92 degrees in labiopalatal angulation (ALP). Statistically significant differences (ANOVA) were found in M (P=.026), P (P=.001), VMD (P=.009), AMD (P=.001), and ALP (P=.001). ZB showed the most displacements in the M and vertical dimensions and the least displacements in the P angulation (P<.05), suggesting statistically significant differences among the M, VMD, VLP, AMD, and ALP. NB had the most M variation. ZB had the least P deviation. NB had the fewest vertical dimension variations but the most angulation variations. CONCLUSIONS: Dimensional and angulation displacements of guided implant systems by in-office 3D-printed fabrication were within clinically acceptable limits: <0.1 mm in M-D, 0.5 to 1 mm in L-P, and 1 to 2 degrees in angulation. However, the vertical displacement can be as much as 2 to 3 mm. Different implant guided surgery systems have strengths and weaknesses as revealed in the dimensional and angulation implant displacements.

Tarnishing Silver Metal into Mithrene.

Silver metal exposed to the atmosphere corrodes and becomes tarnished as a result of oxidation and precipitation of the metal as an insoluble salt. Tarnish has so poor a reputation that the word itself connotes corruption and disrespectability; however, tarnishing is a facile synthetic approach for preparing thin metal-sulfide films on silver or copper metal that might be exploited to prepare more elaborate materials with desirable optoelectronic properties. In this work, we prepare luminescent semiconducting thin films of mithrene, a metal-organic chalcogenolate assembly, by replacing the tarnish-causing atmospheric sulfur source with diphenyl diselenide. Mithrene, or silver benzeneselenolate [AgSePh]∞, is a crystalline solid that contains both an organic supramolecular phase and a two-dimensional inorganic coordination polymer phase. This compound gradually accumulates as the sole product of silver metal corrosion. The chemical reaction is carried out on metallic silver thin films and yields crystalline films with thicknesses ranging from 5 to 100 nm. We use the large-area films (>6 cm2) afforded by this method to measure the optical properties of this compound. The mild-temperature, wafer-scale processing of hybrid chalcogenolate thin films may prove useful in the application of hybrid organic-inorganic materials in semiconductor devices and hierarchical architectures.

Competing Roles of Crystallization and Degradation of a Metal-Organic Chalcogenolate Assembly under Biphasic Solvothermal Conditions.

Metal-organic chalcogenolate assemblies have attracted recent interest as ensemble nanomaterials that contain one- or two-dimensional inorganic nanostructures in a periodic array with supramolecular isolation provided by an associated organic ligand lattice. Biphasic immiscible synthesis at liquid-liquid interfaces is a convenient way to grow crystalline d10 metal-organic chalcogenolate assemblies. However, there has been little systematic study of the role of temperature on the nucleation, growth, and stability of hybrid chalcogenolates during biphasic synthesis. Silver benzeneselenolate, a robustly blue-luminescent, lamellar metal-organic chalcogenolate assembly, was crystallized at biphasic immiscible liquid-liquid interfaces under solvothermal conditions. A positive correlation between temperature and nucleation density was observed, and the luminescence was conserved in all examples of the crystalline phase. Applying solvothermal conditions to the biphasic synthesis generally increased the lateral dimensions of the crystals and strongly favored the crystalline phase of the compound. Although thin, well-formed crystals were observed within 1 h for interfacial reactions performed at high temperatures, degradation was observed in long duration growths resulting in aggregated silver metal. A study of the thermal stability of the material via thermogravimetric analysis revealed that the decomposition is likely a redox reaction reverting the compound to silver metal and diphenyl diselenide. In situ analysis of this degradation was performed by grazing-incidence wide-angle X-ray scattering, which confirmed that the decomposition occurs in a single step with no preceding changes to the structure of the material. This work demonstrates that biphasic solvothermal methods are amenable to the synthesis of hybrid metal-organic chalcogenolate assemblies and that temperature can be used to control product morphology and lateral crystal growth at the immiscible interface.

In Vivo Tooth-Supported Implant Surgical Guides Fabricated With Desktop Stereolithographic Printers: Fully Guided Surgery Is More Accurate Than Partially Guided Surgery.

PURPOSE: Desktop stereolithographic printers combined with intraoral scanning and implant planning software promise precise and cost-effective guided implant surgery. The purpose of the present study was to determine the overall range of accuracy of tooth-supported guided implant surgery using desktop printed stereolithographic guides. MATERIALS AND METHODS: A cross-sectional study comparing fully and partially guided implant surgery was conducted. Preoperative cone beam computed tomography (CBCT) and intraoral scans were used to plan the implant sites. Surgical guides were then fabricated using a desktop stereolithographic 3-dimensional printer. Postoperative CBCT was used to evaluate the accuracy of placement. Deviations from the planned positions were used as the primary outcome variables. The planning software used, implant systems, and anterior/posterior positions were the secondary outcome variables. The differences between the planned and actual implant positions in the mesial, distal, buccal, and lingual dimensions and buccolingual angulations were determined, and the accuracy was compared statistically using the 1-tail F-test (P = .01), box plots, and 95% confidence intervals for the mean. RESULTS: Sixteen partially edentulous patients requiring placement of 31 implants were included in the present study. The implant deviations from the planned positions for mesial, distal, buccal, and lingual dimensions and buccolingual angulations with the fully guided protocol (n = 20) were 0.17 ± 0.78 mm, 0.44 ± 0.78 mm, 0.23 ± 1.08 mm, -0.22 ± 1.44 mm, and -0.32° ± 2.36°, respectively. The corresponding implant deviations for the partially guided protocol (n = 11) were 0.33 ± 1.38 mm, -0.03 ± 1.59 mm, 0.62 ± 1.15 mm, -0.27 ± 1.61 mm, and 0.59° ± 6.83°. The difference between the variances for fully and partially guided surgery for the distal and angulation dimensions was statistically significant (P = .006 and P < .001, respectively). No statistically significant difference was found between the software programs. Anterior implants had less variation in deviation than posterior implants. CONCLUSIONS: Fully guided implant surgery is more accurate than partially guided implant surgery. Implant positional deviation is influenced by implant location but not implant systems or software. If possible, clinicians should use guided surgery protocols that allow placement of implants through a surgical guide.

Do Implant Surgical Guides Allow an Adequate Zone of Keratinized Tissue for Flapless Surgery?

PURPOSE: A major advantage of guided implant surgery using 3-dimensionally printed guides is the ability to perform accurate flapless surgery. A drawback of a flapless technique is the inability to manipulate soft tissue to ensure sufficient gingiva around the implant. The purpose of this study was to determine how often flapless surgery using surgical guides results in less than 2 mm of keratinized tissue surrounding the implant. MATERIALS AND METHODS: This retrospective analysis included 27 maxillary and 27 mandibular implant sites that underwent treatment planning for implant-guided surgery using 3Shape Implant Studio (3Shape, Copenhagen, Denmark). Intraoral scan images were used to measure the width of the keratinized tissue on the buccal aspect of each implant site in both arches and the lingual aspect in the mandibular arch. Three examiners measured the amount of buccal and lingual keratinized tissue in millimeters at each implant site. Analysis of variance (P < .05) and correlation coefficients were used to determine statistically significant differences in keratinized tissue among sites. RESULTS: No statistically significant difference was found either between the widths of buccal keratinized tissue in the maxillary anterior (4.06 ± 1.42 mm) and posterior (4.93 ± 2.54 mm) areas (P = .293) or between the amounts of buccal and lingual keratinized tissue in the mandible (P = .995). The keratinized tissue width in the maxillary buccal area was significantly different (4.48 ± 2.04 mm) from that in the mandibular posterior buccal (1.98 ± 1.41 mm) and lingual (1.98 ± 1.23 mm) areas (P < .001). Over 77% of maxillary implant sites had greater than 3 mm of gingiva, and just over 20% had sufficient gingiva in the mandible. CONCLUSIONS: Adequate keratinized tissue was found in most of the planned maxillary implant sites, whereas most of the mandibular posterior implant sites had inadequate keratinized tissue. Therefore, elevation of a flap to preserve and reposition existing keratinized tissue around implants should be considered when planning to use tooth-borne surgical guides in the posterior mandible.

The clinical significance of aldosterone synthase deficiency: report of a novel mutation in the CYP11B2 gene.

BACKGROUND: Aldosterone synthase (CYP11B2) deficiency is a rare autosomal recessive disorder, usually presenting with severe salt-wasting in infancy or stress-induced hyperkalaemia and postural hypotension in adulthood. Neonatal screening for congenital adrenal hyperplasia, another cause of salt wasting, using 17-hydroxyprogesterone measurement would fail to detect aldosterone synthase deficiency, a diagnosis which may be missed until the patient presents with salt-wasting crisis. Due to this potential life-threatening risk, comprehensive hormonal investigation followed by genetic confirmation for suspected patients would facilitate clinical management of the patient and assessment of the genetic implication in their offspring. CASE PRESENTATION: We describe a 33-year old Chinese man who presented in infancy with life-threatening hyponatraemia and failure to thrive, but remained asymptomatic on fludrocortisone since. Chromosomal analysis confirmed a normal male karyotype of 46, XY. Plasma steroid profile showed high plasma renin activity, low aldosterone level, and elevated 18-hydroxycorticosterone, compatible with type 2 aldosterone synthase deficiency. The patient was heterozygous for a novel CYP11B2 mutation: c.977C > A (p.Thr326Lys) in exon 3. He also carried a heterozygous mutation c.523_525delAAG (p.Lys175del) in exon 6, a known pathogenic mutation causing aldosterone synthase deficiency. Sequencing of CYP11B2 in his parents demonstrated that the mother was heterozygous for c.977C > A, and the father was heterozygous for c.523_525delAAG. CONCLUSION: Although a rare cause of hyperreninaemic hypoaldosteronism, aldosterone synthase deficiency should be suspected and the diagnosis sought in patients who present with life-threatening salt-wasting in infancy, as it has a good long-term prognosis when adequate fludrocortisone replacement is instituted. To our knowledge, this is the first Chinese patient in which the molecular basis of aldosterone synthase deficiency has been identified.

Harnessing Next-Generation Sequencing as a Timely and Accurate Second-Tier Screening Test for Newborn Screening of Inborn Errors of Metabolism.

In this study, we evaluated the implementation of a second-tier genetic screening test using an amplicon-based next-generation sequencing (NGS) panel in our laboratory during the period of 1 September 2021 to 31 August 2022 for the newborn screening (NBS) of six conditions for inborn errors of metabolism: citrullinemia type II (MIM #605814), systemic primary carnitine deficiency (MIM #212140), glutaric acidemia type I (MIM #231670), beta-ketothiolase deficiency (#203750), holocarboxylase synthetase deficiency (MIM #253270) and 3-hydroxy-3-methylglutaryl-CoA lyase deficiency (MIM # 246450). The custom-designed NGS panel can detect sequence variants in the relevant genes and also specifically screen for the presence of the hotspot variant IVS16ins3kb of SLC25A13 by the copy number variant calling algorithm. Genetic second-tier tests were performed for 1.8% of a total of 22,883 NBS samples. The false positive rate for these six conditions after the NGS second-tier test was only 0.017%, and two cases of citrullinemia type II would have been missed as false negatives if only biochemical first-tier testing was performed. The confirmed true positive cases were citrullinemia type II (n = 2) and systemic primary carnitine deficiency (n = 1). The false positives were later confirmed to be carrier of citrullinemia type II (n = 2), carrier of glutaric acidemia type I (n = 1) and carrier of systemic primary carnitine deficiency (n = 1). There were no false negatives reported. The incorporation of a second-tier genetic screening test by NGS greatly enhanced our program's performance with 5-working days turn-around time maintained as before. In addition, early genetic information is available at the time of recall to facilitate better clinical management and genetic counseling.

Expanded Newborn Screening for Inborn Errors of Metabolism in Hong Kong: Results and Outcome of a 7 Year Journey.

Newborn screening (NBS) is an important public health program that aims to identify pre-symptomatic healthy babies that will develop significant disease if left undiagnosed and untreated. The number of conditions being screened globally is expanding rapidly in parallel with advances in technology, diagnosis, and treatment availability for these conditions. In Hong Kong, NBS for inborn errors of metabolism (NBSIEM) began as a pilot program in October 2015 and was implemented to all birthing hospitals within the public healthcare system in phases, with completion in October 2020. The number of conditions screened for increased from 21 to 24 in April 2016 and then to 26 in October 2019. The overall recruitment rate of the NBS program was 99.5%. In the period between October 2015 and December 2022, 125,688 newborns were screened and 295 were referred back for abnormal results. The recall rate was reduced from 0.26% to 0.12% after the implementation of second-tier testing. An inherited metabolic disorder (IMD) was eventually confirmed in 47 infants, making the prevalence of IMD in Hong Kong 1 in 2674. At the time of the NBS result, 78.7% of the newborns with IMD were asymptomatic. There were two deaths reported: one newborn with methylmalonic acidemia cobalamin B type (MMACblB) died after the initial crisis and another case of carnitine palmitoyltransferase II deficiency (CPTII) died at 18 months of age after metabolic decompensation. The most common IMD noted were disorders of fatty acid oxidation metabolism (40%, 19 cases), closely followed by disorders of amino acid metabolism (38%, 18 cases), with carnitine uptake defect (19.1%, 9 cases) and citrullinemia type II (17%, 8 cases) being the two most common IMD picked up by the NBSIEM in Hong Kong. Out of the all the IMDs identified, 19.1% belonged to diverse ethnic groups. False negative cases were reported for citrullinemia type II and congenital adrenal hyperplasia during this period.

Tranexamic acid in emergency medicine. An overview of reviews.

Tranexamic acid (TXA) is a common haemorrhage control agent in both emergency department (ED) settings and intra-operatively. While efficacy and potential harms are well-studied, there are no overviews of reviews completed on TXA efficacy in the ED setting. We set out to provide an overview of systematic reviews on TXA efficacy in trauma, gastrointestinal bleeding, and subarachnoid haemorrhage in the ED setting, with outcomes including short and long-term mortality, thromboembolic (TE) events, and whether bleeding continued. Our review is guided by the PRIOR statement. We searched Pubmed, Medline, and EMBASE using broad search terms for systematic reviews, and calculated pooled relative-risk ratios using random and fixed-effects modelling from these studies. A risk-of-bias assessment was also completed for each review. We identified 13 systematic reviews for inclusion, with a variety of different outcomes. We identified improvements in 24-h mortality for trauma (RR 0.88, 95% CI 0.84-0.92) and gastrointestinal bleeds (RR 0.30, 95% CI 0.23-0.39), and decreased long-term gastrointestinal bleed mortality (RR 0.57, 95% CI 0.48-0.69). We also identified an increase in TE risk in gastrointestinal bleeding scenarios (RR 1.45, 95% CI 1.09-1.94), but no other clinical scenarios. TXA is effective in reducing mortality following trauma and gastrointestinal bleeds, however, there is limited evidence at this time to support TXA administration in the context of subarachnoid haemorrhage. TE risk is elevated when used in gastrointestinal bleeds. Selective use in high-risk patients may be warranted. TXA should strongly be considered in management in ED and prehospital settings.

Opioid-related emergency department visits and deaths after a harm-reduction intervention: a retrospective observational cohort time series analysis.

BACKGROUND: To date, there has been little research on the effect of safe consumption site and community-based naloxone programs on regional opioid-related emergency department visits and deaths. We sought to determine the impact of these interventions on regional opioid-related emergency department visit and death rates in the province of Alberta. METHODS: We used a retrospective observational design, via interrupted time series analysis, to assess municipal opioid-related emergency department visit volume and opioid-related deaths (defined by poisoning and opioid use disorder). We compared rates before and after program implementation in individual Alberta municipalities and province-wide after safe consumption site (March 2018 to October 2018) and community-based naloxone (January 2016) program implementation. RESULTS: A total of 24 107 emergency department visits and 2413 deaths were included in the study. After safe consumption site opening, we saw decreased opioid-related emergency department visits in Calgary (level change -22.7 [-20%] visits per month, 95% confidence interval [CI] -29.7 to -15.8) and Lethbridge (level change -8.8 [-50%] visits per month, 95% CI -11.7 to -5.9), and decreased deaths in Edmonton (level change -5.9 [-55%] deaths per month, 95% CI -8.9 to -2.9). We observed increased emergency department visits after community-based naloxone program implementation in urban Alberta (level change 38.9 [46%] visits, 95% CI 33.3 to 44.4). We also observed an increase in urban opioid-related deaths (level change 9.1 [40%] deaths, 95% CI 6.7 to 11.5). INTERPRETATION: The results of this study suggest differences exist between municipalities employing similar interventions. Our results also suggest contextual variation; for example, illicit drug supply toxicity may modify the ability of a community-based naloxone program to prevent opioid overdose without a thorough public health response.

Inter-screw index as a novel diagnostic indicator of tether breakage.

PURPOSE: Tether breakage is the most common complication of Vertebral Body Tethering (VBT) occurring in up to 52% of Adolescent Idiopathic Scoliosis (AIS) patients and risks continued progression and revision. Radiographical diagnosis of tether breakage is commonly defined by a 5° increase in inter-screw angle and associates breakage with loss of correction. However, the sensitivity of this method was 56% only, suggesting that tethers can break without an increase in angulation, which was supported by other studies. To our knowledge, current literature lacks a method merely focusing on the diagnosis of tether breakage radiographically that does not associate the breakages with loss of correction. METHODS: This was a retrospective review of prospectively collected data of AIS patients who underwent VBT. The "inter-screw index" is defined as the percentage increase in inter-screw distance since post-op, with ≥ 13% increase defined as tether breakage as suggested by our mechanical tests. CTs were reviewed to identify the breakages and compared with inter-screw angle and inter-screw index. RESULTS: 94 segments from 13 CTs were reviewed, and 15 tether breakages were identified. Use of inter-screw index correctly identified 14 breakages (93%), whereas ≥ 5° increase in inter-screw angle only identified 12 breakages (80%). CONCLUSION: Use of inter-screw index is proven to be more sensitive than inter-screw angle in identifying tether breakages. Therefore, we propose the use of inter-screw index to diagnose tether breakages radiographically. Tether breakages were not necessarily accompanied by a loss of segmental correction leading to an increase in inter-screw angle, especially after skeletal maturity. LEVEL OF EVIDENCE: Level 3.

Between paradigms: Comparing experiences for adolescents treated at pediatric and adult trauma centres.

INTRODUCTION: Injured adolescents may be treated at pediatric trauma centres (PTCs) or adult trauma centres (ATCs). Patient and parent experiences are an integral component of high-quality health care and can influence patient clinical trajectory. Despite this knowledge, there is little research on differences between PTCs and ATCs with respect to patient and caregiver-reported experience. We sought to identify differences in patient and parent-reported experiences between the regional PTC and ATC using a recently developed Patient and Parent-Reported Experience Measure. METHODS: We prospectively enrolled patients (caregivers) aged 15-17 (inclusive), admitted to the local PTC and ATC for injury management (01/01/2020 - 31/05/2021) We provided a survey 8-weeks post-discharge to query acute care and follow-up experience. Patient and parent experiences were compared between the PTC and ATC using descriptive statistics, chi-square tests for categorical and independent t-tests for continuous variables. RESULTS: We identified 90 patients for inclusion (51 PTC, and 39 ATC). From this population, we had 77 surveys (32 patient and 35 caregiver) completed at the PTC, and 41 (20 patient and 21 caregiver) at the ATC. ATC patients tended to be more severely injured. We identified few differences in reported experience on the patient measure but identified lower ratings from caregivers of adolescents treated in ATCs for the domains of information and communication, follow-up care, and overall hospital scores. Patients and parents reported poorer family accommodation at the ATC. CONCLUSION: Patient experiences were similar between centres. However, caregivers report poorer experiences at the ATC in several domains. These differences are multifaceted, and may reflect differing patient volumes, effects of COVID-19, and healthcare paradigms. However, further work should target information and communication improvement in adult paradigms given its impact on other domains of care.

Robotic arm-assisted unicondylar knee arthroplasty resulted in superior radiological accuracy: a propensity score-matched analysis.

INTRODUCTION: Unicompartmental knee arthroplasty (UKA) is an effective surgical treatment for medial compartment arthritis of the knee, yet surgical outcomes are directly related to surgical execution. Robotic arm-assisted surgery aims to address these difficulties by allowing for detailed preoperative planning, real-time intraoperative assessment and haptic-controlled bone removal. This study aimed to compare the clinical and radiological outcomes between conventional manual mobile bearing and robot arm-assisted fixed bearing medial UKA in our local population. MATERIALS AND METHODS: This is a retrospective case-control study of 148 UKAs performed at an academic institution with a minimum of 1-year follow-up. 74 robotic arm-assisted UKAs were matched to 74 conventional UKAs via propensity score matching. Radiological outcomes included postoperative mechanical axis and individual component alignment. Clinical parameters included a range of motion, Knee Society knee score and functional assessment taken before, 6 and 12 months after the operation. RESULTS: Robot arm-assisted UKA produced a more neutral component coronal alignment in both femoral component (robotic -0.2 ± 2.8, manual 2.6 ± 2.3; P = 0.043) and tibial component (robotic -0.3 ± 4.0, manual 1.7 ± 5.3; P < 0.001). While the postoperative mechanical axis was comparable, robot arm-assisted UKA demonstrated a smaller posterior tibial slope (robotic 5.7 ± 2.7, manual 8.2 ± 3.3; P = 0.02). Clinical outcomes did not show any statistically significant differences. CONCLUSION: Compared with conventional UKA, robotic arm-assisted UKA demonstrated improved component alignment and comparable clinical outcomes. Improved radiological accuracy with robotic-arm assistance demonstrated promising early results.