Characterization of the structure, vascularity, and stem/progenitor cell populations in porcine Achilles tendon (PAT).

This study aimed to characterize porcine Achilles tendon (PAT) in terms of its structural components, vascularity, and resident tendon cells. We found that PAT is composed of a paratenon sheath, a core of fascicles, and an endotenon/interfascicular matrix (IFM) that encases the fascicle bundles. We analyzed each of these three tendon components structurally using tissue sections and by isolating cells from each component and analyzing in vitro. Many blood vessel-like tissues were present in the paratenon and IFM but not in fascicles, and the vessels in the paratenon and IFM appeared to be inter-connected. Cells isolated from the paratenon and IFM displayed characteristics of vascular stem/progenitor cells expressing the markers CD105, CD31, with α-smooth muscle actin (α-SMA) localized surrounding blood vessels. The isolated cells from paratenon and IFM also harbored abundant stem/progenitor cells as evidenced by their ability to form colonies and express stem cell markers including CD73 and CD146. Furthermore, we demonstrate that both paratenon and IFM-isolated cells were capable of undergoing multi-differentiation. In addition, both paratenon and IFM cells expressed elastin, osteocalcin, tubulin polymerization promoting protein (TPPP), and collagen IV, whereas fascicle cells expressed none of these markers, except collagen I. The neurotransmitter substance P (SP) was also found in the paratenon and IFM-localized surrounding blood vessels. The findings of this study will help us to better understand the vascular and cellular mechanisms of tendon homeostasis, injury, healing, and regeneration.

Synthesis of non-nucleoside anti-viral cyclopropylcarboxacyl hydrazones and initial anti-HSV-1 structure-activity relationship studies.

The synthesis of a lead anti-viral cyclopropyl carboxy acyl hydrazone 4F17 (5) and three sequential arrays of structural analogues along with the initial assessment and optimization of the antiviral pharmacophore against the herpes simplex virus type 1 (HSV-1) are reported.

Discovery of potent antiviral (HSV-1) quinazolinones and initial structure-activity relationship studies.

The discovery of antiviral activity of 2,3-disubstituted quinazolinones, prepared by a one-pot, three-component condensation of isatoic anhydride with amines and aldehydes, against Herpes Simplex Virus (HSV)-1 is reported. Sequential iterative synthesis/antiviral assessment allowed structure-activity relationship (SAR) generation revealing synergistic structural features required for potent anti-HSV-1 activity. The most potent derivatives show greater efficacy than acyclovir against acute HSV-1 infections in neurons and minimal toxicity to the host.

Preoperative Predictors of 30-Day Mortality and Prolonged Length of Stay after Above-Knee Amputation.

BACKGROUND: The above-knee amputation (AKA) is an operation of last resort with high postoperative morbidity and mortality. This study identifies preoperative risk factors predictive of both 30-day mortality and extended length of stay (LOS) in AKA patients. METHODS: Two hundred ninety-five AKA patients from 2004 to 2013 from a single institution were retrospectively reviewed using a deidentified electronic medical record. Rationally selected factors potentially influencing 30-day mortality and LOS were chosen, including demographics, etiologies, vascular surgical history, lifestyle factors, comorbidities, and laboratory values. Variables trending with one of the end points on bivariate analysis (P ≤ 0.10) were entered into multivariate forward stepwise regression models to determine independence as a risk factor (P ≤ 0.05). Subgroup analysis of AKA patients without a traumatic, burn, or malignant etiology was similarly conducted. RESULTS: Within the 295 patient cohort, 60% of the patients were male, 18% were African American, mean age was 58 years and mean body mass index was 28 kg/m(2). The 30-day mortality rate was 9%, and mean postoperative LOS of discharged patients was 9.3 days. Upon logistic regression, thrombocytopenia (platelet count < 250 × 10(6)/mL, P < 0.001, odds ratio 6.1) and preoperative septic shock (P = 0.02, odds ratio 5.1) were identified as independent risk factors for 30-day mortality. Upon linear regression, burn etiology (P < 0.001, B = 15.8 days), leukocytosis (white blood cell count > 12 × 10(6)/mL, P < 0.001, B = 6.2 days), and guillotine amputation (P < 0.001, B = 7.6 days) were independently associated with prolonged LOS. Excluding patients with AKAs due to trauma, burn, or malignancy, only thrombocytopenia (platelet count < 250 × 10(6)/mL, P < 0.001, odds ratio 10.2) and leukocytosis (white blood cell count > 12 × 10(6)/mL, P = 0.01, B = 5.2 days) were independent risk factors for in-hospital mortality and prolonged LOS, respectively. CONCLUSIONS: Preoperative septic shock and thrombocytopenia are independent risk factors for 30-day mortality after AKA, while burn etiology, leukocytosis, and guillotine amputation contribute to prolonged LOS. Awareness of these risk factors may help enhance both preoperative decision making and expectations of the hospital admission.

A Novel Tool for Assessment of Emergency Medicine Resident Skill in Determining Diagnosis and Management for Emergent Electrocardiograms: A Multicenter Study.

BACKGROUND: Reading emergent electrocardiograms (ECGs) is one of the emergency physician's most crucial tasks, yet no well-validated tool exists to measure resident competence in this skill. OBJECTIVES: To assess validity of a novel tool measuring emergency medicine resident competency for interpreting, and responding to, critical ECGs. In addition, we aim to observe trends in this skill for resident physicians at different levels of training. METHODS: This is a multi-center, prospective study of postgraduate year (PGY) 1-4 residents at five emergency medicine (EM) residency programs in the United States. An assessment tool was created that asks the physician to identify either the ECG diagnosis or the best immediate management. RESULTS: One hundred thirteen EM residents from five EM residency programs submitted completed assessment surveys, including 43 PGY-1s, 33 PGY-2s, and 37 PGY-3/4s. PGY-3/4s averaged 74.6% correct (95% confidence interval [CI] 70.9-78.4) and performed significantly better than PGY-1s, who averaged 63.2% correct (95% CI 58.0-68.3). PGY-2s averaged 69.0% (95% CI 62.2-73.7). Year-to-year differences were more pronounced in management than in diagnosis. CONCLUSIONS: Residency training in EM seems to be associated with improved ability to interpret "critical" ECGs as measured by our assessment tool. This lends validity evidence for the tool by correlating with a previously observed association between residency training and improved ECG interpretation. Resident skill in ECG interpretation remains less than ideal. Creation of this sort of tool may allow programs to assess resident performance as well as evaluate interventions designed to improve competency.

Faculty Prediction of In-Training Examination Scores of Emergency Medicine Residents: A Multicenter Study.

BACKGROUND: The Emergency Medicine In-Training Examination (EMITE) is one of the few validated instruments for medical knowledge assessment of emergency medicine (EM) residents. The EMITE is administered only once annually, with results available just 2 months before the end of the academic year. An earlier predictor of EMITE scores would be helpful for educators to institute timely remediation plans. A previous single-site study found that only 69% of faculty predictions of EMITE scores were accurate. OBJECTIVE: The goal of this article was to measure the accuracy with which EM faculty at five residency programs could predict EMITE scores for resident physicians. METHODS: We asked EM faculty at five different residency programs to predict the 2014 EMITE scores for all their respective resident physicians. The primary outcome was prediction accuracy, defined as the proportion of predictions within 6% of the actual scores. The secondary outcome was prediction precision, defined as the mean deviation of predictions from the actual scores. We assessed faculty background variables for correlation with the two outcomes. RESULTS: One hundred and eleven faculty participated in the study (response rate 68.9%). Mean prediction accuracy for all faculty was 60.0%. Mean prediction precision was 6.3%. Participants were slightly more accurate at predicting scores of noninterns compared to interns. No faculty background variable correlated with the primary or secondary outcomes. Eight participants predicted scores with high accuracy (>80%). CONCLUSIONS: In this multicenter study, EM faculty possessed only moderate accuracy at predicting resident EMITE scores. A very small subset of faculty members is highly accurate.

Spontaneous lingual abscess in an immunocompromised patient.

Acute lingual abscess is a rare yet life-threatening clinical entity. Lingual abscess must be appropriately diagnosed and treated in the emergency department to avoid acute airway compromise. A 68-year-old woman on immunomodulatory medication for rheumatoid arthritis presented to the emergency department with left facial pain and swelling. An anterior lingual abscess was diagnosed on computed tomographic scan. The most common cause of lingual abscess is direct trauma, although immunocompromised state is a predisposing risk factor. Intravenous antibiotics are the primary treatment modality, with consideration given to adjunctive surgical drainage. We present this case to increase awareness surrounding this diagnosis among emergency physicians. Spontaneous lingual abscess should be considered in immunocompromised patients who present to the emergency department with tongue pain and edema even in the absence of lingual trauma.

Long-term mortality associated with acute kidney injury in children following congenital cardiac surgery.

OBJECTIVE: Children undergoing congenital cardiac surgery (CCS) are at increased risk for acute kidney injury (AKI) due to a number of factors. Recent evidence suggests AKI may influence mortality beyond the immediate postoperative period and hospitalization. We sought to determine the association between renal failure and longer-term mortality in children following CCS. METHODS: Our Study population included all patients that underwent cardiac surgery at our institution during a period of 3 years from 2004 through 2006. The primary definition of acute renal injury was based on pRIFLE using estimated creatinine clearance (pRIFLE eCCL). RESULTS: Predictors of mortality. Age, single ventricle status, and renal failure as defined by pRIFLE stage F were associated with mortality. The hazard ratio for a patient with renal failure as defined by pRIFLE stage F was 3.82 (CI 1.89-7.75). Predictors of AKI as defined by pRIFLE. Duration of cardiopulmonary bypass (CPB) and age were the only variables associated with pRIFLE by univariate analysis. However, in the ordinal or survival model, age was the only variable associated with renal failure as defined by pRIFLE. As patient age increases from 0.30 to 3.5 years, the risks of having renal injury (pRIFLE stage I) or failure (pRIFLE stage F) decreases (OR 0.44, CI 0.21-0.94). CONCLUSION: Mortality risk following CCS is increased in younger patients and those experiencing postoperative renal failure as defined by pRIFLE for a period of time that extends well beyond the immediate postoperative period and the time of hospitalization.

Home-Based Transcranial Direct Current Stimulation in Primary Progressive Aphasia: A Pilot Study.

BACKGROUND: This study aims to determine (a) if home-based anodal transcranial direct current stimulation (a-tDCS) delivered to the left supramarginal gyrus (SMG) coupled with verbal short-term memory/working memory (vSTM/WM) treatment ("RAM", short for "Repeat After Me") is more effective than sham-tDCS in improving vSTM/WM in patients with primary progressive aphasia (PPA), and (b) whether tDCS effects generalize to other language and cognitive abilities. METHODS: Seven PPA participants received home-based a-tDCS and sham-tDCS coupled with RAM treatment in separate conditions in a double-blind design. The treatment task required participants to repeat word spans comprising semantically and phonologically unrelated words in the same and reverse order. The evaluation of treatment effects was carried out using the same tasks as in the treatment but with different items (near-transfer effects) and tasks that were not directly related to the treatment (far-transfer effects). RESULTS: A-tDCS showed (a) a significant effect in improving vSTM abilities, measured by word span backward, and (b) a generalization of this effect to other language abilities, namely, spelling (both real words and pseudowords) and learning (retention and delayed recall). CONCLUSIONS: These preliminary results indicate that vSTM/WM intervention can improve performance in trained vSTM/WM tasks in patients with PPA, especially when augmented with home-based tDCS over the left SMG.

Perceptions of the current and future emergency medicine workforce.

Objective: The objectives of the study were to assess emergency medicine (EM) physician perceptions of the EM job market 2 years after "The Emergency Medicine Physician Workforce: Projections for 2030" was published in Annals of Emergency Medicine and to examine how the workforce report may have influenced perceptions about job prospects. Methods: A cross-sectional survey was conducted in 2022 of EM residents, fellows, and attendings at 21 practice sites. Main outcomes were perceptions of the likelihood of currently finding any job, currently finding a desirable job, and confidence in the future EM job market. Results: Note that 831 of 1938 physicians (42.9%) responded. A total of 92.4% reported a high likelihood of finding any job currently, 49.8% reported a high likelihood of finding a desirable job currently, and 44.4% reported future confidence. Workforce report familiarity was associated with greater likelihood of finding a desirable job. Fellows were least confident in the future. Residents with desired Midwest location were twice as confident in the future job market; those with desired West location were less confident. Attendings 20 or more years post-training were more than twice as likely to report a high likelihood of finding a desirable job and almost twice as likely to report future confidence. Attendings in leadership were nearly three times as likely to report high a likelihood of finding a desirable job and future confidence. Conclusion: EM trainees and attendings have favorable perceptions of the current job market but are less confident in future prospects. As the projected surplus of EM physicians appears to have had an impact, updated projections are needed for more accurate assessments of the future of the specialty.

Alterations in visible light exposure modulate platelet function and regulate thrombus formation.

BACKGROUND: Variations in light exposure are associated with changes in inflammation and coagulation. The impact of light spectra on venous (VT) and arterial thrombosis is largely unexplored. OBJECTIVES: To investigate the impact of altering light spectrum on platelet function in thrombosis. METHODS: Wild type (WT) C57BL/6J mice were exposed to ambient (micewhite, 400lux), blue (miceblue, 442nm, 1,400lux), or red light (micered, 617nm, 1,400lux) with 12:12 hour light:dark cycle for 72 hours. After 72 hours of light exposure, platelet aggregation, activation, transcriptomic, and metabolomic changes were measured. The ability of released products of platelet activation to induce thrombosis-generating NET formation was quantified. Subsequent thrombosis was measured using murine models of VT and stroke. To translate our findings to human patients, light filtering cataract patients were evaluated over an 8-year period for rate of VTE with multivariable logistic regression clustered by hospital. RESULTS: Exposure to long wavelength red light resulted in reduced platelet aggregation and activation. RNA-seq analysis demonstrated no significant transcriptomic changes between micered and micewhite. However, there were global metabolomic changes in platelets from micered compared to micewhite. Releasate from activated platelets resulted in reduced NET formation. Micered also had reduced VT weight and brain infarct size following stroke. On subgroup analysis of cataract patients, patients with a history of cancer have lower lifetime risk of VTE after implantation with lenses that filter low wavelength light. CONCLUSIONS: Light therapy may be a promising approach to thrombus prophylaxis by specifically targeting the intersection between innate immune function and coagulation.

Direct comparison of 20-hour IV, 36-hour oral, and 72-hour oral acetylcysteine for treatment of acute acetaminophen poisoning.

There is no general consensus among clinicians on the superior route or duration of treatment with N-acetylcysteine (NAC) for acute acetaminophen (APAP) poisoning, and head-to-head studies comparing intravenous (IV) and oral NAC have not been done. Recent 20-hour IV NAC protocol failures in the United States prompted some to question its safety. Our objective was to determine if treatment with the 20-hour IV NAC protocol results in clinical outcomes different from the longer 36-hour oral or 72-hour oral NAC protocols in cases of acute APAP poisoning. We performed a retrospective analysis of all consecutive cases of acute APAP overdose where NAC treatment was initiated within 8 hours of ingestion between January 1, 2002, and December 31, 2007. Outcomes were survival, transplant, and death; secondary outcomes were based on King's College Criteria; interrater reliability was calculated with a kappa score. Out of 4642 cases of APAP overdose, 795 met study inclusion criteria: 213 were treated with 20-hour IV protocol, 213 with the 36-hour oral protocol, and 369 with the 72-hour oral protocol. The mean age in these groups was 25 years [95% confidence interval (CI): 22-26], 26 years (95%CI: 23-29), and 27 years (95%CI: 25-28), respectively. The mean 4-hour APAP concentration was 199 µg/mL (95%CI: 188-211), 174 µg/mL (95%CI: 164-184), and 205 µg/mL (95%CI: 195-216), respectively. No cases of transplant or death occurred, and secondary outcomes were rare. When administered within 8 hours of acute APAP poisoning, the 20-hour IV treatment protocol was as effective as the longer 36-hour oral and 72-hour oral treatment protocols. Further study is needed to determine outcome differences between IV and oral NAC when treatment is initiated >8 hours after overdose or in cases of coingestion with other drugs.

Long wavelength light exposure reduces systemic inflammation coagulopathy, and acute organ injury following polytrauma in mice.

BACKGROUND: Evidence suggests that variation in light exposure strongly influences the dynamic of inflammation, coagulation, and the immune system. Polytrauma induces systemic inflammation that can lead to end-organ injury. Here, we hypothesize that alterations in light exposure influence post-trauma inflammation, coagulopathy, and end-organ injury. METHODS: Study Type: Original Research Article. Level of Evidence: Basic Science (Level IV).C57BL/6 mice underwent a validated polytrauma and hemorrhage model performed following 72 hours of exposure to red (617 nm, 1,700lux), blue (321 nm, 1,700lux), and fluorescent white light (300lux) (n = 6-8/group). The animals were sacrificed at 6 h post-trauma. Plasma samples were evaluated and compared for pro-inflammatory cytokine expression levels, coagulation parameters, markers of liver and renal injury, and histological changes (Carstairs staining). One-way ANOVA statistical tests were applied to compare study groups. RESULTS: Pre-exposure to long-wavelength red light significantly reduced the inflammatory response at 6 hours post-polytrauma compared to blue and ambient light, as evidenced by decreased levels of IL-6, MCP-1 (both p < 0.001), liver injury markers (ALT, p < 0.05), and kidney injury markers (cystatin C, p < 0.01). Additionally, Carstairs staining of organ tissues revealed milder histological changes in the red light-exposed group, indicating reduced end-organ damage. Furthermore, PT was significantly lower (p < 0.001) and fibrinogen levels were better maintained (p < 0.01) in the red light-exposed mice compared to those exposed to blue and ambient light. CONCLUSION: Prophylactic light exposure can be optimized to reduce systemic inflammation, coagulopathy and minimize acute organ injury following polytrauma. Understanding the mechanisms by which light exposure attenuates inflammation may provide a novel strategy to reducing trauma related morbidity.

The more things change the more they stay the same: Factors influencing emergency medicine residency selection in the virtual era.

Background: Interviews for emergency medicine (EM) residency positions largely transitioned to a virtual-only format in 2020-2021. The impact of virtual interview factors on applicants' rank of programs is unknown. Objective: We sought to assess the impact of modifiable factors in virtual interviews on applicants' rank of EM residency programs. Methods: We conducted a cross-sectional mixed-methods survey of students applying to at least one of seven study authors' EM residency programs in the United States during the 2020-2021 application cycle. The survey was developed using an interactive Delphi process and piloted prior to implementation. The survey was administered from May to June 2021 with up to four email reminders. Quantitative analysis included descriptive statistics. Three authors performed a thematic qualitative analysis of free-text responses. Results: A total of 664 of 2281 (29.1%) students completed the survey, including 335 (50.5%) male, 316 (47.7%) female, and six (0.9%) nonbinary. A total of 143 (21.6%) respondents identified as underrepresented in medicine and 84 (12.7%) identified as LGBTQIA+. Respondents participated in a median of 14 interviews and ranked a median of 14 programs. Most respondents (335, 50.6%) preferred a choice of in-person or virtual, while 183 (27.6%) preferred all in-person, and 144 (21.8%) preferred all virtual. The program website and interview social were the most important factors influencing respondent ranking. Qualitative analysis revealed several positive aspects of virtual interviews including logistical ease and comfort. Negative aspects include technical issues, perceived interview hoarding, and barriers to applicant assessment and performance. Demonstrated effort by the program, effective information delivery, communication of resident culture, and a well-implemented interview day positively influenced respondents' rank of programs. Conclusions: This study identified characteristics of the virtual interview format that impact applicants' rank of programs. These results can inform future recruitment practices.

MACROPHAGE SWITCHING: POLARIZATION AND MOBILIZATION AFTER TRAUMA.

ABSTRACT: Introduction: Trauma alters the immune response in numerous ways, affecting both the innate and adaptive responses. Macrophages play an important role in inflammation and wound healing following injury. We hypothesize that macrophages mobilize from the circulation to the site of injury and secondary sites after trauma, with a transition from proinflammatory (M1) shortly after trauma to anti-inflammatory (M2) at later time points. Methods: C57Bl6 mice (n = 6/group) underwent a polytrauma model using cardiac puncture/hemorrhage, pseudofemoral fracture, and liver crush injury. The animals were killed at several time points: uninjured, 24 h, and 7 days. Peripheral blood mononuclear cells, spleen, liver nonparenchymal cells, and lung were harvested, processed, and stained for flow cytometry. Macrophages were identified as CD68 + ; M1 macrophages were identified as iNOS + ; M2 macrophages as arginase 1 + . Results: We saw a slight presence of M1 macrophages at baseline in peripheral blood mononuclear cells (6.6%), with no significant change at 24 h and 7 days after polytrauma. In contrast, the spleen has a larger population of M1 macrophages at baseline (27.7%), with levels decreasing at 24 h and 7 days after trauma (20.6% and 12.6%, respectively). A similar trend is seen in the lung where at baseline 14.9% of CD68 + macrophages are M1, with subsequent continual decrease reaching 8.7% at 24 h and 4.4% at 7 days after polytrauma. M1 macrophages in the liver represent 14.3% of CD68 + population in the liver nonparenchymal cells at baseline. This percentage increases to 20.8% after trauma and decreases at 7 days after polytrauma (13.4%). There are few M2 macrophages in circulating peripheral blood mononuclear cells and in spleen at baseline and after trauma. The percentage of M2 macrophages in the lungs remains constant after trauma (7.2% at 24 h and 9.2% at 7 days). In contrast, a large proportion of M2 macrophages are seen in the liver at baseline (36.0%). This percentage trends upward and reaches 45.6% acutely after trauma and drops to 21.4% at 7 days. The phenotypic changes in macrophages seen in the lungs did not correlate with a functional change in the ability of the macrophages to perform oxidative burst, with an increase from 2.0% at baseline to 22.1% at 7 days after polytrauma ( P = 0.0258). Conclusion: Macrophage phenotypic changes after polytrauma are noted, especially with a decrease in the lung M1 phenotype and a short-term increase in the M2 phenotype in the liver. However, macrophage function as measured by oxidative burst increased over the time course of trauma, which may signify a change in subset polarization after injury not captured by the typical macrophage phenotypes.

The introduction of public access defibrillation to a university community: the University of Virginia public access defibrillation program.

The use of the automatic external defibrillator (AED) can significantly reduce the time to defibrillation in patients with sudden cardiac death. This early defibrillation via the AED can also improve patient outcome, including survival and neurologic status among survivors. We undertook the addition of a public access defibrillation program at a large mid-Atlantic university. In our design of the system, we found little useful information to guide us in the development and construction our system. This article is a review of the process of public access defibrillation AED system development such that other medical and academic leaders at similar institutions can more easily develop such systems.

Bilateral Central Retinal Vein Occlusion as a First Presentation of Multiple Myeloma: A Case Report.

INTRODUCTION: Acute presentation of multiple myeloma in the emergency department (ED) is an uncommon yet life-threatening clinical entity. CASE REPORT: A 42-year-old male presented to the ED with severe generalized fatigue and vision changes most notable in his left eye. Bilateral central retinal vein occlusion (CRVO) was diagnosed on dilated fundus exam in the ED. CONCLUSION: The most common cause of CRVO in adults over age 50 is vascular disease, but in younger adults, conditions of systemic inflammation or hyperviscosity must be considered. Diagnosis of CRVO requires emergent ophthalmology consultation and further treatment with phototherapy, steroids, and potentially anti-vascular endothelial growth factor. Ultimately, patients require hematology/oncology and ongoing management of acute hyperviscosity syndrome. We present this case to increase awareness surrounding this diagnosis among emergency physicians. Multiple myeloma should be considered in young patients who present to the ED with bilateral CRVO, acute renal failure, and symptomatic anemia.

Effects of Brief Mental Skills Training on Emergency Medicine Residents' Stress Response During a Simulated Resuscitation: A Prospective Randomized Trial.

BACKGROUND: Acute stress impairs physician decision-making and clinical performance in resuscitations. Mental skills training, a component of the multistep, cognitive-behavioral technique of stress inoculation, modulates stress response in high-performance fields. OBJECTIVE: We assessed the effects of mental skills training on emergency medicine (EM) residents' stress response in simulated resuscitations as well as residents' perceptions of this intervention. METHODS: In this prospective, educational intervention trial, postgraduate year-2 EM residents in seven Chicago-area programs were randomly assigned to receive either stress inoculation training or not. One month prior to assessment, the intervention group received didactic training on the "Breathe, Talk, See, Focus" mental performance tool. A standardized, case-based simulation was used for assessment. We measured subjective stress response using the six-item short form of the Spielberger State-Trait Anxiety Inventory (STAI-6). Objective stress response was measured through heart rate (HR) and heart rate variability (HRV) monitoring. We measured subjects' perceptions of the training via survey. RESULTS: Of 92 eligible residents, 61 participated (25 intervention; 36 control). There were no significant differences in mean pre-/post-case STAI-6 scores (-1.7 intervention, 0.4 control; p = 0.38) or mean HRV (-3.8 milliseconds [ms] intervention, -3.8 ms control; p = 0.58). Post-assessment surveys indicated that residents found this training relevant and important. CONCLUSION: There was no difference in subjective or objective stress measures of EM resident stress response after a didactic, mental performance training session, although residents did value the training. More extensive or longitudinal stress inoculation curricula may provide benefit.

EFFECT OF IRRIGATION FLUID COMPOSITION ON HEMOSTASIS IN MOUSE BLEEDING MODELS.

ABSTRACT: Introduction: Intraoperative irrigation, usually with normal saline (NS), aids in bleeding identification and management. We investigated the effect of different irrigation fluids, with additives, on hemostasis using two bleeding models. Methods: C57BL/6 J mice were subjected to a tail bleed model or uncontrolled abdominal hemorrhage via liver laceration followed by abdominal cavity irrigation. We compared NS, lactated Ringer's (LR), and PlasmaLyte. We examined NS and LR at different temperatures. Normal saline or LR with calcium (Ca 2+ ) or tranexamic acid (TXA) was studied. Results: Compared with room temperature (RT), increasing the temperature of the irrigation fluid to 37°C and 42°C reduced tail vein bleeding times substantially in both NS and LR (all P < 0.001), with no significant differences between the two fluids. At RT, LR, but not PlasmaLyte, substantially reduced bleeding times in comparison to NS ( P < 0.0001). Liver injury blood loss was lower with LR ( P < 0.01). Normal saline supplemented with 2.7 mEq/L of Ca 2+ decreased bleeding time and blood loss volume ( P < 0.001 and P < 0.01, respectively) to similar levels as LR. Normal saline with 150 mg/mL of TXA markedly reduced bleeding time ( P < 0.0001), and NS with 62.5 mg/mL TXA decreased blood loss ( P < 0.01). Conclusion: Whereas Ca 2+ - and TXA-supplemented NS reduced bleeding, LR remained superior to all irrigation fluid compositions. As LR contains Ca 2+ , and Ca 2+ -supplemented NS mirrored LR in response, Ca 2+ presence in the irrigation fluid seems key to improving solution's hemostatic ability. Because warming the fluids normalized the choice of agents, the data also suggest that Ca 2+ -containing fluids such as LR may be more suitable for hemostasis when used at RT.

Large-event medicine--event characteristics impacting medical need.

Large events have been defined in many ways, from the vague description of a focused gathering of people to the more specific description of an event with at least 1,000 spectators and participants who are gathered at a specific location for a defined period of time. Regardless of the definition applied, the actual medical requirements vary considerably from one event to the next. The ability to predict these medical needs allows for the provision of adequate medical support. Many factors contribute to medical need at a large event, including event type, weather (particularly heat index), the presence of alcohol and / or illicit drugs, the number of participants, event duration, crowd demographics, and venue characteristics. This review will focus on the various features of large events such that the medical planner can better understand the challenge and provide adequate resource for patient care.