The RAPID Consortium: A Platform for Clinical and Translational Pituitary Tumor Research

Objectives  Pituitary tumor treatment is hampered by the relative rarity of the disease, absence of a multicenter collaborative platform, and limited translational-clinical research partnerships. Prior studies offer limited insight into the formation of a multicenter consortium. Design  The authors describe the establishment of a multicenter research initiative, Registry of Adenomas of the Pituitary and Related Disorders (RAPID), to encourage quality improvement and research, promote scholarship, and apply innovative solutions in outcomes research. Methods  The challenges encountered during the formation of other research registries were reviewed with those lessons applied to the development of RAPID. Setting/Participants  RAPID was formed by 11 academic U.S. pituitary centers. Results  A Steering Committee, bylaws, data coordination center, and leadership team have been established. Clinical modules with standardized data fields for nonfunctioning adenoma, prolactinoma, acromegaly, Cushing's disease, craniopharyngioma, and Rathke's cleft cyst were created using a Health Insurance Portability and Accountability Act-compliant cloud-based platform. Currently, RAPID has received institutional review board approval at all centers, compiled retrospective data and agreements from most centers, and begun prospective data collection at one site. Existing institutional databases are being mapped to one central repository. Conclusion  The RAPID consortium has laid the foundation for a multicenter collaboration to facilitate pituitary tumor and surgical research. We sought to share our experiences so that other groups also contemplating this approach may benefit. Future studies may include outcomes benchmarking, clinically annotated biobank tissue, multicenter outcomes studies, prospective intervention studies, translational research, and health economics studies focused on value-based care questions.

Clinical Implications of Pituitary Adenomas Exhibiting Dual Transcription Factor Staining: A Case Series of 27 Patients

OBJECTIVE

According to the 2017 World Health Organization classification of neuro-endocrine tumors, pituitary adenomas (PAs) are classified according to immunoexpression of the pituitary-specific transcription factors (TFs). A small subset of PAs exhibit multiple TF staining on immunohistochemistry and we present a series of 27 pathologically-confirmed cases of dual TF staining PAs (dsTF-PAs), and report clinically relevant implications.

METHODS

A retrospective chart review of a multi-institutional database of patients with PAs surgically resected between 2008-2021 was performed. PAs expressing immunopositivity 2+ TFs. Patient demographics, neuro-imaging characteristics, histopathologic findings, and clinical data were collected.

RESULTS

Twenty-seven patients had pathologically verified dsTF-PAs, of whom 17 were female (63%), with ages ranging from 20-84 years. Twenty-three (85.2%) patients harbored functional PAs, with acromegaly being the most common functional subtype (86.4%). The most common combination of TFs within a single tumor was PIT-1/SF-1 (85.2%). Six PAs exhibited Knosp cavernous sinus invasion grades of 3 or 4 and the Ki-67 labeling index was ≥3% in 6 patients (24.0%) and all stained for PIT-1/SF-1. Hormonal remission was achieved in 78% of functional dsTF-PAs. No PAs showed evidence of recurrence or progression over the mean follow-up period of 28.5 months.

CONCLUSIONS

PAs exhibiting dsTF-PAs represent a small but clinically relevant diagnostic subset of PAs according to the 2021 World Health Organization criteria, as a majority are GH-producing. Precise classification using TF staining plays a key role in understanding the biology of these tumors. Favorable outcomes can be achieved in this subset of PAs with evolving TF classification.

Improving heart rate monitoring in the obese with time-of-flight photoplethysmography (TOF-PPG): a quantitative analysis of source-detector-distance effect

Commercial photoplethysmography (PPG) sensors rely on the measurement of continuous-wave diffuse reflection signals (CW-DRS) to monitor heart rate. Using Monte Carlo modeling of light propagation in skin, we quantitatively evaluate the dependence of continuous-wave photoplethysmography (CW-PPG) in commercial wearables on source-detector distance (SDD). Specifically, when SDD increases from 0.5 mm to 3.3 mm, CW-PPG signal increases by roughly 846% for non-obese (NOB) skin and roughly 683% for morbidly obese (MOB) skin. Ultimately, we introduce the concept of time-of-flight PPG (TOF-PPG) which can significantly improve heart rate signals. Our model shows that the optimized TOF-PPG improves heart rate monitoring experiences by roughly 47.9% in NOB and 93.2% in MOB when SDD = 3.3 mm is at green light. Moving forward, these results will provide a valuable source for hypothesis generation in the scientific community to improve heart rate monitoring.

Characteristics of Emergency Medicine Residency Programs With Unfilled Positions in the 2023 Match

STUDY OBJECTIVE

The unprecedented number of unfilled emergency medicine post-graduate year 1 (PGY-1) residency positions in the 2023 National Resident Matching Program shocked the emergency medicine community. This study investigates the association between emergency medicine program characteristics and the likelihood of unfilled positions in the 2023 Match.

METHODS

This cross-sectional, observational study examined 2023 National Resident Matching Program data, focusing on program type, length, location, size, proximity to other programs, previous American Osteopathic Association (AOA) accreditation, first accreditation year, and emergency department ownership structure. We constructed a generalized linear mixed model with a logistic linking function to determine predictors of unfilled positions.

RESULTS

A total of 554 of 3,010 (18.4%) PGY-1 positions at 131 of 276 (47%) emergency medicine programs went unfilled in the 2023 Match. In our model, predictors included having unfilled positions in the 2022 Match (odds ratio [OR] 48.14, 95% confidence interval [CI] 21.04 to 110.15), smaller program size (less than 8 residents, OR 18.39, 95% CI 3.90 to 86.66; 8 to 10 residents, OR 6.29, 95% CI 1.50 to 26.28; 11 to 13 residents, OR 5.88, 95% CI 1.55 to 22.32), located in the Mid Atlantic (OR 14.03, 95% CI 2.56 to 77.04) area, prior AOA accreditation (OR 10.13, 95% CI 2.82 to 36.36), located in the East North Central (OR 6.94, 95% CI 1.25 to 38.47) area, and corporate ownership structure (OR 3.21, 95% CI 1.06 to 9.72).

CONCLUSION

Our study identified 6 characteristics associated with unfilled emergency medicine residency positions in the 2023 Match. These findings may be used to guide student advising and inform decisions by residency programs, hospitals, and national organizations to address the complexities of residency recruitment and implications for the emergency medicine workforce.

Pituitary adenoma or neuroendocrine tumour: the need for an integrated prognostic classification

In the 2022 fifth edition of the WHO Classification of Endocrine Tumours and of Central Nervous System Tumours, pituitary adenomas are reclassified as neuroendocrine tumours (NETs). This change confers an oncology label to neoplasms that are overwhelmingly benign. A comprehensive clinical classification schema is required to guide prognosis, therapy and outcomes for all patients with pituitary adenomas. Pituitary adenomas and NETs exhibit some morphological and ultrastructural similarities. However, unlike NETs, pituitary adenomas are highly prevalent, yet indolent and rarely become malignant. This Perspective presents the outcomes of an interdisciplinary international workshop that addressed the merit and clinical implications of the classification change of pituitary adenoma to NET. Many non-histological factors provide mechanistic insight and influence the prognosis and treatment of pituitary adenoma. We recommend the development of a comprehensive classification that integrates clinical, genetic, biochemical, radiological, pathological and molecular information for all anterior pituitary neoplasms.

Targeting the Tyrosine Kinase 2 (TYK2) Pseudokinase Domain: Discovery of the Selective TYK2 Inhibitor ABBV-712

Tyrosine kinase 2 (TYK2) is a nonreceptor tyrosine kinase that belongs to the JAK family also comprising JAK1, JAK2, and JAK3. TYK2 is an attractive target for various autoimmune diseases as it regulates signal transduction downstream of IL-23 and IL-12 receptors. Selective TYK2 inhibition offers a differentiated clinical profile compared to currently approved JAK inhibitors. However, selectivity for TYK2 versus other JAK family members has been difficult to achieve with small molecules that inhibit the catalytically active kinase domain. Successful targeting of the TYK2 pseudokinase domain as a strategy to achieve isoform selectivity was recently exemplified with deucravacitinib. Described herein is the optimization of selective TYK2 inhibitors targeting the pseudokinase domain, resulting in the discovery of the clinical candidate ABBV-712 (21).

Needs Assessment of Non-core Content for Podcasts in Emergency Medicine

Study objective The purpose of this study was to assess the use of podcasts among emergency medicine (EM) students, residents, and attending physicians for non-core content. Methods A survey was administered to medical students interested in emergency medicine, current residents of emergency medicine, and attending physicians to determine which podcasts, if any, they listen to and how often. The purpose of listening to these podcasts was also evaluated and determined it was to learn the non-core content of the specialty. The survey was administered online via multiple platforms including Google Forms (Google, Inc., Mountain View, CA), email, and Twitter (San Francisco, CA). The survey was also distributed via messaging application and word of mouth. Results There were 52 responses that were received on the survey. Of the respondents, 73.1% (N = 38) stated that they do listen to medical podcasts. Of these listeners, 21.2% (N = 11) stated that they listen to them once a year, 15.4% (N = 8) once a month, 11.5% (N = 6) once every two weeks, 19.2% (N = 10) weekly, 11.5% (N = 6) 1-2 days per week, 5.8% (N = 3) 3-4 days per week, 5.8% (N = 3) 5-6 days per week, and 9.6% (N = 5) daily. Based on the 52 responses received, 30.8% (N = 16) stated that they listen to them as a supplement to other sources of foundational content, 25% (N = 13) for general interest, 28.8% (N = 15) for entertainment, 7.7% (N = 4) as a primary resource to learn foundational content in their specialty, and 7.7% (N = 4) other. Based on the data metrics, 51.9% (N = 27) stated that 1-5 of the medical podcasts they listen to discuss the practice of emergency medicine, 44.2% (N = 23) stated that none do, and 3.8% (N = 2) stated that more than 10 do. The list of emergency medicine podcasts being listened to are as follows: EMplify, EM:RAP, EM Over Easy, EM Clerkship, Core EM, EM Basic, EMA, EM Cases, Internet Book of Critical Care, Pharm So Hard, EMCRIT, EM Board Bombs, PEM Rules, and REBEL CAST. When asked how important medical podcasts are for learning within the specialty, 44.2% (N = 23) reported not important, 26.9% (N = 14) reported somewhat important, and 28.8% (N = 15) reported very important. When asked how important medical podcasts are for learning outside the specialty, 40% (N = 20) reported not important, 48% (N = 24) reported somewhat important, and 12% (N = 6) stated very important. When asked if their program includes medical education podcasts as part of their curriculum, 18.4% (N = 9) responded yes, while 81.6% (N = 40) responded no. When asked if they believe medical education podcasts should be included as part of their curriculum, 52% (N = 26) stated yes, while 48% (N = 24) stated no. Conclusion Based on the results of the survey, roughly three-quarters of the surveyees listen to medical podcasts. Of the respondents, 38.5% (N = 20) stated that they listen to these podcasts as some form of supplement to learning content (7.7% (N = 4) primary and 30.8% (N = 16) supplementary), which explains the rising availability of the number of podcasts related to emergency medicine. Of the respondents stating that medical podcasts should be included in their curriculum, 52% (N = 26) signifies the importance of quality learning that these medical podcasts provide to their listeners.

Assessment of the MAGIC recommendations in context of evolving evidence based on the use of PICC in ICU

The goal of the 2015 Michigan Appropriateness Guide for Intravenous Catheters (MAGIC) was to define indications and appropriate practices for peripherally inserted central catheters (PICC) use; however, MAGIC recommendations virtually reduced the use of PICC in hospital settings, including critical care. The aim of this review is to present an assessment of the MAGIC guidelines, considering contemporary evidence to date. The validity of the MAGIC recommendations and their applicability to current practice are called into question given important concerns with the methodology for their development (e.g. high volume of clinical scenarios for evaluation) and the supporting evidence used. There is a considerable amount of contemporary evidence not considered in MAGIC that reports on evolving practices, techniques, and technologies targeted to reduce complications associated with central venous access devices (CVADs). Recent evidence dictates that CVADs are necessary in the intensive care unit (ICU), and that PICCs are a safe, reliable, and appropriate type of central lines, which cannot be replaced in several ICU situations. In light of evolving evidence and practice, as well as the methodological concerns identified, the MAGIC guidelines should be revisited. It is also recommended to create a clinical assessment tool that identifies potential uses of specific CVADs, based on patient needs. The choice of the CVAD should be based on unique clinical considerations and current scientific evidence, not on fears informed by antiquated data.

Some considerations on the dependence to numerical schemes of Lagrangian radionuclide transport models for the aquatic environment

Lagrangian models present several advantages over Eulerian models to simulate the transport of radionuclides in the aquatic environment in emergency situations. A radionuclide release is simulated as a number of particles whose trajectories are calculated along time and thus these models do not require a spatial discretization (although it is always required in time). In this paper we investigate the dependence of a Lagrangian model output with the grid spacing which is used to calculate concentrations from the final distribution of particles, with the number of particles in the simulation and with the interpolation schemes which are required because of the discrete nature of the water circulation data used to feed the model. Also, a Lagrangian model may describe the exchanges of radionuclides between phases (liquid and solid), which is done in terms of transition probabilities. The dependence of these probabilities with time step is analyzed as well. It was found that the optimum grid size used to calculate concentrations should be carefully checked, and that temporal interpolation is more significant than spatial interpolation to obtain a more accurate solution. A method to estimate the number of particles required to have a certain accuracy level is proposed. Finally, it was found that for low sediment concentrations and small radionuclide k_d, exact equations for the transition probabilities should be used; and that phase transitions introduce a stability condition as in Eulerian models.

Metabolic cost of osmoregulation by the gastro-intestinal tract in marine teleost fish

Introduction: Although dozens of studies have attempted to determine the metabolic cost of osmoregulation, mainly by comparing standard metabolic rates (SMR) in fish acclimated to different salinities, consensus is still lacking. Methods: In the present study, using the Gulf toadfish, Opsanus beta, we aimed to determine the metabolic cost of esophageal and intestinal osmoregulatory processes by estimating ATP consumption from known ion transport rates and pathways and comparing these estimates with measurements on isolated tissues. Further, we performed whole animal respirometry on fish acclimated to 9, 34 and 60 ppt. Results and Discussion: Our theoretical estimates of esophageal and intestinal osmoregulatory costs were in close agreement with direct measurements on isolated tissues and suggest that osmoregulation by these tissues amounts to ∼2.5% of SMR. This value agrees well with an earlier attempt to estimate osmoregulation cost from ion transport rates and combined with published measurements of gill osmoregulatory costs suggests that whole animal costs of osmoregulation in marine teleosts is ∼7.5% of SMR. As in many previous studies, our whole animal measurements were variable between fish and did not seem suited to determine osmoregulatory costs. While the esophagus showed constant metabolic rate regardless of acclimation salinity, the intestine of fish acclimated to higher salinities showed elevated metabolic rates. The esophagus and the intestine had 2.1 and 3.2-fold higher metabolic rates than corresponding whole animal mass specific rates, respectively. The intestinal tissue displays at least four different Cl- uptake pathways of which the Na+:Cl-:2 K+ (NKCC) pathway accounts for 95% of the Cl- uptake and is the most energy efficient. The remaining pathways are via apical anion exchange and seem to primarily serve luminal alkalinization and the formation of intestinal CaCO3 which is essential for water absorption.

Emergency provider preference for powered intraosseous devices and satisfaction with features improving safety, reliability, and ease-of-use

BACKGROUND

Powered intraosseous (IO) systems are valuable devices for emergent situations, with limited data on user preferences. A simulation/survey-based study was conducted among emergency medical service (EMS) providers to evaluate attitudes toward general powered IO system features to measure preferences/satisfaction for the most-commonly used and a novel powered IO system (with a passive safety needle, battery life indicator, and snap-securement/dressing).

RESEARCH DESIGN AND METHODS

Forty-two EMS providers completed a simulated activity using both powered IO systems and a 30-item questionnaire, including multiple choice, free-text, ranking, and Likert-like questions. Ranking scores were reported using a scale of 0 (least important/satisfactory) to 100 (most important/satisfactory). Statistical significances were evaluated via Wilcoxon signed-rank sum test.

RESULTS

Providers indicated driver performance (mean score ± SD; 77.8 ± 27.5) and IO needle safety mechanism (63.1 ± 27.9) as the most important features. Participants reported significantly higher (p < 0.001) satisfaction with the novel IO system overall, and its needle safety, battery life indicator, securement/dressing, and ease-of-use. Powered driver performance satisfaction was similar and favorable for the novel (88.1 ± 18.2) and traditional (87.1 ± 15.3) systems.

CONCLUSIONS

These findings highlight the value of clinician/user input and demonstrate EMS providers are more satisfied with a powered IO system featuring design elements intended to enhance safety and ease-of-use.

RF01 | PMON168 Hedgehog-Induced Somatostatin Receptor Expression is Inhibited by the Activation of the Glucocorticoid Receptor Signaling Pathway in Human Pituitary Adenoma Organoids

Background

Cushing's disease (CD) is an endocrine disorder caused by an ACTH-secreting pituitary adenoma that is associated with increased morbidity and mortality. Because somatostatin inhibits pituitary ACTH secretion, the somatostatin receptor subtypes (SSTR) 2 and 5 have been targets of medical therapies for CD. The SSTR5 is most consistently and strongly expressed in corticotroph pituitary tumors but the SSTR dynamics in CD during treatment and responses to cortisol level changes are far from being understood. Studies in adult stomach demonstrated that the Hedgehog (Hh) signaling pathway is critical for the regulation of somatostatin and SSTR signaling. While Hh signaling is known to be essential during the embryonic development of the pituitary and in the adult gland, the mechanism by which Hh signaling regulates SSTR expression in CD is unknown.

Hypothesis

Activation of glucocorticoid receptor (NR3C1, GR) results in the inhibition of Hh transcription factor GLI1 leading to reduced SSTR expression.

Methods

We developed a human pituitary adenoma organoid model (hPITOiPSC) from induced pluripotent stem cells treated with the glucocorticoid receptor (GR) antagonist mifepristone, and co-treated them with or without SSTR agonists pasireotide or octreotide. In a separate series of experiments, the role of Hh transcription factor GLI1 was identified using hPITOiPSC treated with mifepristone with or without GANT61 (GLI inhibitor) or ketoconazole (Smoothened, SMO inhibitor). CRISPR-Cas9 gene editing of hPITOiPSC pituitary organoids were used to model the development of pituitary corticotroph adenomas in the presence of BRAF, USP48 and USP8 mutations. Human pituitary adenoma tissue harvested fresh during pituitary surgery was used to generate pituitary corticotroph subtype adenoma organoids (hPITOs). Dose responses using standard of care drugs were performed using the hPITOs.

Results

1) At baseline SSTR2 was abundantly expressed within hPITOiPSC. Mifepristone induced significant increases in ACTH secretion and POMC expression that correlated with induced SSTR2 and 5. Mifepristone-induced SSTR2 and 5 expression was significantly inhibited in the presence of GANT61, whereas SMO inhibitor ketoconazole had a minimal effect on mifepristone-induced SSTR2/5, POMC expression and ACTH secretion. Dexamethasone alone significantly inhibited both GLI1 and SSTR2 and 5. 2) While pituitary organoids that were differentiated from control iPSCs (iPSCCtrl) expressed all major hormone-producing cell lineages, there was a significant increase in ACTH expression with loss of PIT1, GH, FSH, LH and PRL in iPCSs expressing mutated BRAF, USP48 and USP8. Organoids expressing a mutation in BRAF had significantly higher SSTR2 expression levels compared to controls. 3) HPITOs generated from pituitary adenomas of CD patients showed differential organoid responses to pasireotide, mifepristone, and ketoconazole.

Conclusion

Within pituitary adenomas, the SSTR is a transcriptional target of Gli1, and this response is blocked by the activation of the GR. These data form the basis of combination therapy for CD with mifepristone and pasireotide.

Presentation: Saturday, June 11, 2022 1:37 p.m. - 1:42 p.m., Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

Fragment Optimization of Reversible Binding to the Switch II Pocket on KRAS Leads to a Potent, In Vivo Active KRASG12C Inhibitor

Activating mutations in KRAS are the most frequent oncogenic alterations in cancer. The oncogenic hotspot position 12, located at the lip of the switch II pocket, offers a covalent attachment point for KRAS^G12C inhibitors. To date, KRAS^G12C inhibitors have been discovered by first covalently binding to the cysteine at position 12 and then optimizing pocket binding. We report on the discovery of the in vivo active KRAS^G12C inhibitor BI-0474 using a different approach, in which small molecules that bind reversibly to the switch II pocket were identified and then optimized for non-covalent binding using structure-based design. Finally, the Michael acceptor containing warhead was attached. Our approach offers not only an alternative approach to discovering KRAS^G12C inhibitors but also provides a starting point for the discovery of inhibitors against other oncogenic KRAS mutants.

Twisting Ovaries: Three Cases of Ovarian Torsion

Ovarian torsion is a medical emergency that should be considered for every female presenting with abdominal pain. This series consists of three cases of females of varying ages presenting with abdominal pain who were all ultimately diagnosed with ovarian torsion. It highlights the variability in presentation, physical examination, and other factors related to the diagnosis.

Pediatric Emergency Medicine Podcasts: Current Status

Background: Podcasting has become a primary delivery model for medical content among various specialties. Although this model is still growing, it has become an essential tool for many learners, educators, and institutions. Because of this rapid growth, there is an unknown availability of podcasts for each specialty.

Objectives: This paper aimed to evaluate the podcasts currently available in the subspecialty of pediatric emergency medicine (PEM).

Methods: The investigators sought to evaluate the prevalence of PEM podcasts from the end-user's (medical students, residents, etc.) perspective. This was completed by performing a simple internet search using the term “podcasts in pediatric emergency medicine.” Using Google Search, the first 50 results were analyzed.

Results: For PEM, there were only eight podcasts found, five of which were active.

Conclusion: PEM podcasts in comparison to other specialties are currently underrepresented and lacking in this important resource. The authors call on PEM physicians, educators, and organizations to consider creating content in this educational space.

Development of a gamma ray dose rate calculation and mapping tool for Lagrangian marine nuclear emergency response models

This paper presents the development and testing of a gamma radiation dose rate calculation model for the marine environment, and evaluates the potential use for such a model in both short term nuclear emergency response management and emergency response planning. This is believed to be the first implementation of a full field gamma radiation mapping model (including air attenuation and buildup) to be incorporated within a Lagrangian marine dispersion model. Calculated surface gamma ray dose rates for nine generic release scenarios are presented and used to undertake an emergency countermeasure optioneering assessment.

A narrative review of historic and current approaches for patients with difficult venous access: considerations for the emergency department

INTRODUCTION

Timely placement of vascular access devices is critical during emergent clinical situations; however, challenges in peripheral access can be a common occurrence. Historically, emergency teams have used various approaches to gain peripheral vascular access in situations where traditional means were not feasible; these options have included peripheral venous cutdown, ultrasound-guided peripheral intravenous catheters (PIVs), longer PIVs, central catheters, and intraosseous devices. Each of these options have associated strengths and limitations depending on the clinical situation.

AREAS COVERED

This narrative review reports on the burden of difficult venous access situations and discusses the evidence, and strengths and limitations of vascular access options to help address this challenge. Although first puncture success rates can be high when using alternative methods, significant challenges can include increased procedure time and greater risk of complications. The Easy-Internal Jugular (Easy-IJ) technique is a newer alternative option for patients with difficult venous access that is demonstrated to be safe and effective in emergency care.

EXPERT OPINION

Moving forward, additional clinical studies are required to fully characterize the outcomes associated with the Easy-IJ technique and guidewire-assisted intravenous catheters, as well as to inform guideline development for more comprehensive recommendations on managing challenging or difficult peripheral access situations.

Physician preferences associated with powered intraosseous access systems: Safety features, reliability, and ease of use

Objective

This study evaluated physician preferences and values related to the most commonly used (traditional) powered intraosseous (IO) system and a novel powered IO system featuring a passive safety needle, battery life indicator, and snap‐securement/skin attachment.

Methods

Emergency physicians participated in an IO simulation using both the traditional and novel IO systems. Participants completed a 27‐item postsimulation questionnaire to state their preferences toward each IO system and values related to the novel IO system features using a multiple choice, 11‐point value ranking scale (0 = no value, 10 = extremely valuable) and free‐text answer questions.

Results

Among the 22 study participants, 90.9% (95% confidence interval [CI]: 70.8%, 98.9%) preferred the novel IO system; top reasons for this preference were the novel IO system's passive safety needle and snap‐securement/skin attachment. Participants who preferred the traditional IO system (9.1%) noted its ease of use and familiarity. Many physicians preferred the novel IO system's needle (81.8%; 95% CI: 59.7%, 94.8%), powered driver (77.3%; 95% CI: 54.6%, 92.2%), and snap‐securement/skin attachment (100%; 95% CI: 84.6%, 100%) compared with the traditional IO system. Safety and ease of use were the most common preference explanations. Of the participants, 100% provided a value score ≥7 for the novel IO system's passive safety needle (mean score, 9.45), whereas fewer participants (59.1%) gave a value score ≥7 for the multilight battery life indicator (mean score, 6.68).

Conclusion

This study demonstrates that emergency physicians prefer and value a novel IO system with features that enhance safety and ease of use. These results provide insight into important factors related to IO systems for emergency physicians.

Provider Perspective on Being Recorded During Emergency Medicine Discharge Conversations

Objective: Despite the possible benefits of provider-recorded visit summaries for patient use, the utilization of such recordings has yet to be adopted as standard care in most specialities. The objective of this study was to investigate the perspectives of emergency department (ED) providers regarding the utilization of audio or video recordings during ED patient encounters, particularly during discharge conversations.

Methods: This study utilized an eight-question survey pooling the opinions of various emergency medicine nurses, advanced practitioners, residents, and physicians within a local Ohio hospital system. Providers from multiple healthcare centers were studied. Study data were collected using an anonymous online survey database. 

Results: Fifty-seven providers were surveyed. Twenty (35%) agreed that patients had the right to record medical conversations, and 36 (63%) cited potential legal liability as their reason for hesitation. Twenty-five providers (43.9%) answered that no video or audio recordings should be provided at discharge. There was no significant difference in secondary outcomes comparing between demographic categories of age, sex, and practice facility type (p>0.05). 

Conclusion: Providers who responded to this survey did not feel comfortable being recorded during any portion of their patient encounter, even when providing discharge instructions. Our study showed that there is at least some hesitation on behalf of ED providers based on fear of legal retaliation or violation of HIPPA. However, more research in this area is necessary for recordings to become the standard of care during ED encounters. 

Cost-Effective Training Models in Point-of-Care Ultrasound for Medical Students in Emergency Medicine: An Evaluation of Current Resources

Background

Ultrasound is becoming more widely utilized in clinical practice; however, its effectiveness is limited by the operator’s skills. Simulation models are attractive options for developing skills because they allow inexperienced users to practice without the risk of endangering patients.

Objective

The purpose of this study was to identify commercially available and homemade ultrasound models to describe them in terms of materials, cost, and whether they are high- or low-fidelity for medical student education.

Methods

This is an investigational study on cost-effective ultrasound training methods for medical students. Our study was performed using search engines in Google, Google Scholar, and PubMed to search for models for the following five modalities: foreign body identification, intravenous (IV) injection training, abdominal ultrasound, ocular ultrasound, and ultrasound-guided lumbar puncture training.

Results

Most homemade models for foreign body identification, IV injection training, and ocular ultrasound could be created for less than $20. IV injection training models were the cheapest commercially available models. There are multiple commercially available options for abdominal ultrasound models, but no options were found for homemade construction. The construction cost for lumbar puncture models was larger due to the need to purchase an anatomically accurate set of lumbar vertebrae.

Conclusions

This study provides initial guidance and suggestions for ultrasound training models that are currently available. Ultrasound models that can be cheaply made or purchased increase accessibility for medical students to gain early exposure in a cost-effective and safe manner.

Low-Fidelity Canthotomy Model Use in Resident Education: The Learner's Perspective

Lateral canthotomy is a low incidence but high-risk procedure that is expected to be within the scope of practice for every emergency department physician. Due to the low incidence of this procedure, training residents may prove difficult and costly. The purpose of this study was to evaluate a synthetic, low-fidelity, low-cost, eye model to train and improve confidence in performing a lateral canthotomy. This is the first study that we know of that uses a 5 point Likert scale, two-sample t-test to assess the value of using such a model for lateral canthotomy training. Our results showed that using such a model for the training of lateral canthotomy did in fact improve the competence and confidence of performing this procedure.

Emergency Department "Bounce-Back" Rates as a Function of Emergency Medicine Training Year

Introduction: Since the 1990s, the emergency department (ED) unscheduled return visit (URV), or “bounce-back,” has been used as a quality of care measurement. During that time, resident training was also scrutinized and uncovered a need for closer resident supervision, especially of second-year residents. Over the years, bounce-backs have continued to be analyzed with vigor, but research on residency training and supervision has lagged with few studies concurrently investigating residency supervision and bounce-backs. Other literature on resident supervision suggests that with adequate attending supervision, resident performance is equivalent to attending performance. With that in mind, it was hypothesized that resident bounce-back rates will be equivalent to attending bounce-back rates, and there will be no change among residency years. The primary objective of this study was to determine the rate at which patients are seen as a bounce-back visit within 72 hours of their initial visit to a community hospital ED during the study time frame. The secondary aims were to evaluate if the ED bounce-back rate is impacted by training level (residents or attending) and to describe bounce-back patient characteristics, including primary complaint/disease, age, comorbidities and issues with compliance.

Methods: A retrospective chart review of 1000 charts was conducted from September 2015 to September 2017. Charts were randomly selected by the Quality & Patient Safety (QPS) team and, after applying inclusion/exclusion criteria, 732 charts were analysed. Inclusion criteria included age ≥ 18 years, patients treated by an Emergency Medicine (EM) resident during their initial visit and patients with a “discharge” disposition. Exclusion criteria included patients seen as a scheduled return visit (e.g., two-day return for blood pregnancy recheck, wound check, etc.). Demographics, initial visit variables, comorbidities and bounce-back data were collected based on electronic record query or chart review. Data was analysed using means, standard deviations, medians and ranges for continuous variables. Logistic regression modelling techniques were used to examine factors that affect whether the patient had a bounce-back visit.

Results: The rate of URVs within 72 hours of the patient's initial visit was 4.65%. PGY1 and PGY2's bounce-back rate was 3.8% and 3.6%, respectively, and PGY3 and PGY4's bounce-back rate was 5.7% and 5.6%, respectively (p-value=.63). There was no statistically significant change among residency years. Most bounce-back characteristics analysed including primary complaint, age, and comorbidities demonstrated no statistical significance in the increased rate of bounce-back except for patients with a history of tobacco abuse, alcohol abuse and chronic pain. Current smokers were 6.5 times more likely to bounce back than former smokers (odds ratio=6.485, 95% confidence interval = 2.089 to 20.133, p-value=0.0012) and those with chronic pain were 2.5 times more likely to bounce back than those without chronic pain (odds ratio=2.518, 95% confidence interval =1.029 to 6.164, p=0.0431).

Conclusion: EM residency training year does not increase the frequency of bounce-backs in a community hospital ED. Finally, patients with substance abuse and chronic pain were more likely to bounce back.

Podcasting in Medicine: The Current Content by Emergency Medicine Subspecialty

Background

Podcasts and their use in medical education, particularly emergency medicine (EM), are growing and becoming more popular. Many podcasts focus on EM, but the number of podcasts on each EM subspecialty remains unknown. Therefore, the goal of this study was to ascertain the number of podcasts available by EM subspecialty and collect the basic characteristics of each podcast.

Methods

We conducted a Google-based, investigational study of EM podcasts by subspecialty from July 2019 to January 2020. Search terms included “podcasts in ____”, where the EM subspecialties of Toxicology, Ultrasound, Wilderness Medicine, Emergency Medicine Services, Medical Education, and Simulation were inserted to identify podcasts.

Results 

Emergency Medical Services (EMS) and Medical Education subspecialties have the most active podcasts. Toxicology and EMS have the most inactive podcasts, while Medical Education and Simulation were the only subspecialties found to not have any identified inactive podcasts.

Conclusions

The use of podcasts in EM has been increasing overall, but physicians in specific subspecialties, such as EMS and Medical Education, have access to a larger number of podcasts specific to their subspecialty than others. There is an opportunity for experts in Toxicology, Simulation, and Ultrasound to create podcast content.

The Impact of Advanced Cardiac Life Support Simulation Training on Medical Student Self-reported Outcomes

Introduction: Simulation has become a well-recognized and innovative tool in medical education. While there has been tremendous growth of simulation curricula at the level of graduate medical education, there have been few studies looking at simulation as a learning tool for undergraduate medical education. The goal of this study was to determine if high-fidelity simulation training impacts medical student perception of knowledge and confidence regarding comprehension and application of advanced cardiac life support (ACLS) algorithms.

Methods: This is a prospective observational survey study of third and fourth year medical students who participated in an ACLS simulation training during their emergency medicine rotation between January 2018 and October 2018. Cases covered several ACLS topics including unstable bradycardia, supraventricular tachycardia and ventricular tachycardia. After each session, students received a short survey to assess their simulation experience pertaining to knowledge and comfort levels with ACLS topics before and after the simulation experience.

Results: A total of 89 students were included in the study with 86.5% of those being fourth year students. There was a significant increase in both knowledge (pre-training 3.17 vs. 4.11 post-training, p<0.001) and comfort scores (pre-training 2.54 vs. 3.74 post-training, p<0.001) after the ACLS simulation training. Overall, 77.5% of students reported an increase in knowledge and 83.1% reported an increase in confidence after the training session. 

Conclusions: The study revealed a statistically significant increase in both perceived knowledge and comfort and confidence of medical students after high-fidelity simulation using ACLS scenarios.

Podcasting in Medicine: A Review of the Current Content by Specialty

Background

Podcasts and their use in medical education is growing and becoming more popular, all while not knowing what podcasts are available for each specialty.

Objectives

To ascertain the number of podcasts available by specialty and collect basic characteristics of each podcast. 

Methods

This was a Google-based, investigational study of medical podcasts by specialty undertaken by all authors from January to June 2019. Search terms included “podcasts in ____”, where various specialties were inserted to identify current podcasts.

Results

Over the course of a six month period, 19 specialties were investigated for podcasting content. Emergency medicine, internal medicine, and pediatrics had the most active podcasts. Obstetrics and gynecology, ophthalmology, and orthopedic surgery have the most inactive podcasts. Neurosurgery was the only specialty searched without any identifiable active podcasts.

Conclusions

While emergency medicine has a large number of podcasts, both active and available other specialties have less of a selection.

Administration of Naloxone by Prehospital Personnel: A Retrospective Analysis

Introduction

Patient-specific discrepancies in prehospital naloxone administration have been documented. As the opioid epidemic continues to evolve, further evaluation of prehospital naloxone administration practices is needed. The objective of this study was to compare patients who received prehospital naloxone and received an emergency department (ED) diagnosis of opioid overdose with patients who received prehospital naloxone and received an alternative ED diagnosis. 

Methods

This was a retrospective, multicenter chart review of patients who received naloxone by prehospital personnel for suspected opioid overdose between October 1, 2016, and October 31, 2017. Patients were excluded if age was less than 18 years, naloxone was administered by non-emergency medical service (EMS) personnel, not transported, or if prehospital records could not be linked with ED records. Demographic information and several prehospital clinical findings, including unresponsiveness, apnea, and miosis, were compared between patients diagnosed with opioid overdoses versus an alternative ED diagnosis. Descriptive statistics were utilized.

Results

A total of 837 patients had complete data available and were included in the analysis. Overall, 402 (48%) of patients received an ED diagnosis of opioid overdose, and 435 (52%) of patients received an alternative ED diagnosis. Patients in the alternative diagnosis group were older, had less known drug use, were more likely to be admitted, and had lower incidences of apnea, unresponsiveness, and miosis. In the opioid overdose group, there was a higher proportion of previous drug use, apnea, unresponsiveness, and miosis in the EMS setting, whereas there was a higher proportion of previous overdose, previous suicide attempts, and neurological deficits in the ED setting.

Conclusions

In this retrospective review evaluating patients who received prehospital naloxone, several demographic and clinical differences were noted between the two groups. Further elucidation of the safety and efficacy of prehospital naloxone in alternative diagnoses is needed.

Implementation of a Standardized Multimodal Postoperative Analgesia Protocol Improves Pain Control, Reduces Opioid Consumption, and Shortens Length of Hospital Stay After Posterior Lumbar Spinal Fusion

BACKGROUND

Multimodal analgesia regimens have been suggested to improve pain control and reduce opioid consumption after surgery.

OBJECTIVE

To institutionally implement an evidence-based quality improvement initiative to standardize and optimize pain treatment following neurosurgical procedures. Our goal was to objectively evaluate efficacy of this multimodal protocol.

METHODS

A retrospective cohort analysis of pain-related outcomes after posterior lumbar fusion procedures was performed. We compared patients treated in the 6 mo preceding (PRE) and 6 mo following (POST) protocol execution.

RESULTS

A total of 102 PRE and 118 POST patients were included. The cohorts were well-matched regarding sex, age, surgical duration, number of segments fused, preoperative opioid consumption, and baseline physical status (all P &gt; .05). Average patient-reported numerical rating scale pain scores significantly improved in the first 24 hr postoperatively (5.6 vs 4.5, P &lt; .001) and 24 to 72 hr postoperatively (4.7 vs 3.4, P &lt; .001), PRE vs POST, respectively. Maximum pain scores and time to achieving appropriate pain control also significantly improved during these same intervals (all P &lt; .05). A concomitant decrease in opioid consumption during the first 72 hr was seen (110 vs 71 morphine milligram equivalents, P = .02). There was an observed reduction in opioid-related adverse events per patient (1.31 vs 0.83, P &lt; .001) and hospital length of stay (4.6 vs 3.9 days, P = .03) after implementation of the protocol.

CONCLUSION

Implementation of an evidence-based, multimodal analgesia protocol improved postoperative outcomes, including pain scores, opioid consumption, and length of hospital stay, after posterior lumbar spinal fusion.

Gabapentin-induced Facial Myoclonus in the Setting of Acute on Chronic Kidney Disease

An 82-year-old male with chronic kidney disease presented to the emergency department with sudden onset of left sided facial myoclonus. Myoclonus is a rare, but known side effect of gabapentin; however, there does not appear to be documented cases of gabapentin-induced facial myoclonus described in the emergency medicine literature. This case discusses the emergency department evaluation and inpatient treatment of gabapentin-induced facial myoclonus in the setting of acute on chronic kidney disease. Though rare, side effects of gabapentin should remain on a broad differential diagnosis in patients taking the medication who present with myoclonus, especially in the setting of chronic kidney disease.

MON-440 Cyberknife Radiosurgery for Functional and Non-Functional Pituitary Adenomas: Long-Term Single-Center Experience

Background: In recent years, CyberKnife radiosurgery (CKRS) has become an accepted adjuvant treatment modality when surgery has failed to achieve biochemical control of functional pituitary adenomas or after subtotal removal of non-secretory and secretory adenomas. However, long-term experience and clinical follow-up is limited. We present a retrospective review of our institutional experience with CKRS in patients with functional and non-functional pituitary adenomas. Methods: Forty-eight patients (23M/25F, age range 24-83 years) with pituitary adenomas received CKRS. Median follow-up period was 50 months (range 1 to 123 months). Patients consisted of 31 with non-functioning adenomas, 10 with acromegaly, 5 with Cushing disease (CD) and 2 with prolactinomas. Changes in hormonal function and treatment complications were analyzed in each case. Results: The ranges of radiation doses administered and prescription isodose line were 2500-3500 cGy/5 fractions and 62-78%, respectively. Pituitary hormone secretion improved in all 17 functioning adenomas, with hormonal normalization observed in 11/17 (65%) patients over median of 14 months. In patients with nonfunctioning adenomas, 4/31 (13%) patients subsequently developed panhypopituitarism over a median duration of 16 months. Radiological data was available in 42 patients, and 11/42 (26%) patients had reduction in tumor size over median of 16.5 months, 4/42 (10%) patients had local tumor recurrence over median of 41.5 months, and 27/11 (64%) patients had stable and unchanged tumor size. Of those with local tumor recurrence, 1 patient that had CD was treated with a low dose of 2500 cGy of salvage radiation therapy, 1 patient had Crooke’s changes after a dose of 2500 cGy salvage surgery, and 2 patients had high MIB scores (> 10). Post-treatment complications included temporal radiation-induced changes (n=2), 6^th nerve palsy (n=1), and secondary malignancy (n=1). No patients developed visual field deficits. Five- and 7-year local progression free survival rates were 90% and 83%, respectively. Four patients died due to the following reasons: suicide, unknown reason, previously diagnosed testicular malignancy and infield neuroendocrine malignancy. Conclusion: We describe the long-term efficacy, safety and complication profile of CKRS in the treatment of functional and non-functional pituitary adenomas in our cohort of patients. Our data demonstrated that CKRS is a safe and effective adjunct for salvage therapy in patients with pituitary adenomas that have failed first-line therapy. In functioning pituitary adenomas, hormone hypersecretion improved in all patients, with the majority of patients achieving biochemical remission. Post-radiosurgery pituitary hormone deficiencies resulting in panhypopituitarism was observed in only a minority of patients. Overall, local tumor control and survival rates were relatively high.

SUN-459 Analysis of the Evolution of Postoperative Pituitary Resection Cavities Assessed by Magnetic Resonance Imaging and Implications Regarding Choice of Radiation Therapy Modality

Surgical resection is the standard initial therapy for patients with symptomatic non-prolactin secreting adenomas and other pituitary tumors (1). After surgical resection select patients will require adjuvant radiation therapy. There are a number of radiation modalities available for treatment. One factor that influences the choice of radiation modality is proximity of tumor to local critical anatomy, namely the optic chiasm (2). MRI is the modality of choice for evaluating pituitary tumors, postoperative resection cavities and the relationship between tumor and the optic chiasm (3). To study the expected evolution of postoperative pituitary resection cavities and the relationship between residual sellar tissue and the optic chiasm we retrospectively reviewed MRI’s of patients with surgically resected pituitary tumors obtained during the preoperative (PreO), immediate postoperative (IPO) (<72 h) and delayed postoperative (DPO) (>3 mo) phases. 91 patients (45 F, 46 M, mean age 50.9 yrs) with functional adenomas (26.4%), non-functional adenomas (46.2%), Rathke cleft cysts (9.9%), craniopharyngioma’s (3.3%) and other lesions (14.2%) were studied. PreO estimated tumor volume was 4.3 cc (0-28.7), craniocaudal (CC) dimension 17.2 mm (2-49), and distance between tumor and optic chiasm 2.0 mm (0-10). 9.9 % of patients had cavernous sinus invasion by imaging criteria. On IPO imaging 83.5 % of patients had gross total resection. Average IPO and DPO resection cavity estimated volumes were 3.3 cc (0.1-16.3) and 1.6 cc (0.0-8.7), respectively. Average % decrease in cavity volume from IPO to DPO scans was 51.5%. Average distance between residual sellar tissue and chiasm was 2.5 mm on IPO and 4.7 mm on DPO scans. The distance between tissue and chiasm on IPO and DPO scans was greater for tumors <10 mm vs >10mm (p=0.019). Percent change in CC dimension of resection cavities from IPO to DPO scans was higher for cavities without fat packing (63.2%) vs cavities with fat packing (52.1%) (p=0.025). Tumor histology, cavernous sinus invasion, degree of PreO chiasm mass effect, and presence of fluid or blood within the IPO cavity did not correlate with distance between tissue and chiasm on DPO scans. Conclusion: There is a significant reduction in cavity volume and increased distance between the chiasm and residual sellar tissue on DPO vs IPO scans. Evaluation for radiosurgery as a treatment option, which has less total and chiasm dose, may be an option after reviewing DPO scans. References: (1) Rim et al., Radiat Oncol J. 2011;29(3):156-63. (2) Minniti et al., Radiat Oncol. 2016;(11)135. (3) Patel et al., World Neurosurg. 2014;82(5):770-80.

MON-439 Evaluation of Surgical Resection Goal and Its Relationship to the Extent of Resection and Patient Outcomes in 221 Patients following Transsphenoidal Surgery for Nonfunctioning Pituitary Adenomas: Data from the TRANSSPHER Study

Background: Prospective data of the influence of the neurosurgeon’s preoperative goal regarding the extent of tumor resection and patient outcomes are scarce in patients with pituitary adenomas who have undergone transsphenoidal pituitary surgery using modern gland-sparing surgical techniques. Objective: We analyze the relationship between surgical tumor removal goal and patient outcomes in a prospective multicenter study of patients with nonfunctioning pituitary adenomas (ClinicalTrials.gov NCT02357498). Methods: Centrally adjudicated extent of tumor resection (gross total resection [GTR] and subtotal resection [STR]) data were analyzed using standard univariate and multivariable analyses. Results: A total of 221 patients were treated with transsphenoidal surgery at 7 pituitary centers in the United States from February 2015 to June 2017. GTR was accomplished in 148 of 171 (86.5%) patients with planned GTR and 32 of 50 (64.0%) patients with planned STR (P = 0.001). Sensitivity, specificity, positive predictive value, and negative predictive values of GTR goal were 82.2%, 43.9%, 86.5%, and 36.0%, respectively. Knosp grade 0-2, first surgery, and being an experienced neurosurgeon were associated with neurosurgeons choosing GTR as the goal (P < 0.01). However, there was no association between surgical goal and the presence of pituitary hormone deficiencies 6 months after surgery (P = 0.31). There was a trend towards a higher rate of major neurological complications in the STR goal cohort (4/50 patients, 8.0%) compared to the GTR cohort (4/171, 2.3%) (p=0.079). Tumor Knosp grade (P = 0.004) and size (P = 0.001) were stronger predictors of GTR than was surgical goal (P = 0.014). The most common site of detecting residual tumor was the cavernous sinus (29 of 41 patients; 70.1%). Conclusion: This is the first prospective multi-center pituitary surgery study that examined surgical goal regarding extent of tumor resection and associated patient outcomes. We found that surgical goal is not a reliable predictor of actual tumor resection, and a more aggressive surgical goal does not correlate with pituitary gland dysfunction or major neurological complications 6 months after surgery. A better understanding of the ability of neurosurgeons to meet their expectations and of the factors associated with surgical result could improve prognostication and preoperative counseling of the extent of tumor resection, and postoperative functionality of pituitary hormone secretion.

Air of the Dog: Impending Respiratory Failure After a Dog Bite

Animal and human bites represent a significant health issue worldwide. However, penetrating neck trauma secondary to animal bites is a rare presentation. We present the case of a 32-year-old female with neck pain and difficulty breathing after suffering a dog bite to the neck. Bedside ultrasound and subsequent computed tomography (CT) showed findings consistent with subcutaneous emphysema. Due to rapidly progressing neck swelling and stridor, she required advanced airway management followed by emergent exploratory surgery. We present a case report on impending respiratory failure after a dog bite and review the management of penetrating neck trauma.

The Barrow Innovation Center: A Novel Program in Neurosurgery Resident Education and Medical Device Innovation

Medical innovation is the application of scientific knowledge and problem solving for the betterment of the human condition. Every great advancement in the field of neurosurgery can be traced back to a novel surgical procedure or technology that challenged existing standards of care. Considering the critical importance of innovation to the advancement of neurosurgery, and a surprising lack of formal training in innovation among residency programs, we sought to create a residency training program in neurosurgical innovation. Neurosurgery residents at the authors’ institution envisioned the creation of a program that contained all the necessary equipment, personnel, and information required to bring their ideas from theoretical concepts to functional devices implemented in a clinical setting. The Barrow Innovation Center was established as a result. The center currently comprises a rapid prototyping laboratory and several collaborative partnerships between neurosurgery residents, patent law students, and biomedical engineering students. The creation of this model was guided by an overarching mission to educate the next generation of neurosurgical innovators. With modest start-up capital and strong faculty and institutional support, the center has grown from a simple idea to a multistate, multidisciplinary collaboration in just 18 months; it has generated substantial intellectual property, educational opportunities, and a new business entity. We hope that by continuing to advance the Barrow Innovation Center and its core mission of innovation education, we will advance the field of neurosurgery by providing the next generation of surgeon-scientists with the skills, knowledge, and opportunity needed to revolutionize the field.

Antiferromagnetic Resonance and Terahertz Continuum in α-RuCl_{3}

We report measurements of optical absorption in the zigzag antiferromagnet α-RuCl_{3} as a function of temperature T, magnetic field B, and photon energy ℏω in the range ∼0.3-8.3 meV, using time-domain terahertz spectroscopy. Polarized measurements show that threefold rotational symmetry is broken in the honeycomb plane from 2 to 300 K. We find a sharp absorption peak at 2.56 meV upon cooling below the Néel temperature of 7 K at B=0 that we identify as the magnetic-dipole excitation of a zero-wave-vector magnon, or antiferromagnetic resonance (AFMR). With the application of B, the AFMR broadens and shifts to a lower frequency as long-range magnetic order is lost in a manner consistent with transitioning to a spin-disordered phase. From a direct, internally calibrated measurement of the AFMR spectral weight, we place an upper bound on the contribution to the dc susceptibility from a magnetic excitation continuum.

Validity and test-retest reliability of a novel simple back extensor muscle strength test

OBJECTIVES

To develop and determine convergent validity and reliability of a simple and inexpensive clinical test to quantify back extensor muscle strength.

METHODS

Two testing sessions were conducted, 7 days apart. Each session involved three trials of standing maximal isometric back extensor muscle strength using both the novel test and isokinetic dynamometry. Lumbar spine bone mineral density was examined by dual-energy X-ray absorptiometry. Validation was examined with Pearson correlations (r). Test-retest reliability was examined with intraclass correlation coefficients and limits of agreement. Pearson correlations and intraclass correlation coefficients are presented with corresponding 95% confidence intervals. Linear regression was used to examine the ability of peak back extensor muscle strength to predict indices of lumbar spine bone mineral density and strength.

RESULTS

A total of 52 healthy adults (26 men, 26 women) aged 46.4 ± 20.4 years were recruited from the community. A strong positive relationship was observed between peak back extensor strength from hand-held and isokinetic dynamometry (r = 0.824, p < 0.001). For the novel back extensor strength test, short- and long-term reliability was excellent (intraclass correlation coefficient = 0.983 (95% confidence interval, 0.971-0.990), p < 0.001 and intraclass correlation coefficient = 0.901 (95% confidence interval, 0.833-0.943), p < 0.001, respectively). Limits of agreement for short-term repeated back extensor strength measures with the novel back extensor strength protocol were -6.63 to 7.70 kg, with a mean bias of +0.71 kg. Back extensor strength predicted 11% of variance in lumbar spine bone mineral density (p < 0.05) and 9% of lumbar spine index of bone structural strength (p < 0.05).

CONCLUSION

Our novel hand-held dynamometer method to determine back extensor muscle strength is quick, relatively inexpensive, and reliable; demonstrates initial convergent validity in a healthy population; and is associated with bone mass at a clinically important site.