Safety of treating acute pulmonary embolism at home: an individual patient data meta-analysis.

BACKGROUND AND AIMS: Home treatment is considered safe in acute pulmonary embolism (PE) patients selected by a validated triage tool (e.g. simplified PE severity index score or Hestia rule), but there is uncertainty regarding the applicability in underrepresented subgroups. The aim was to evaluate the safety of home treatment by performing an individual patient-level data meta-analysis. METHODS: Ten prospective cohort studies or randomized controlled trials were identified in a systematic search, totalling 2694 PE patients treated at home (discharged within 24 h) and identified by a predefined triage tool. The 14- and 30-day incidences of all-cause mortality and adverse events (combined endpoint of recurrent venous thromboembolism, major bleeding, and/or all-cause mortality) were evaluated. The relative risk (RR) for 14- and 30-day mortalities and adverse events is calculated in subgroups using a random effects model. RESULTS: The 14- and 30-day mortalities were 0.11% [95% confidence interval (CI) 0.0-0.24, I2 = 0) and 0.30% (95% CI 0.09-0.51, I2 = 0). The 14- and 30-day incidences of adverse events were 0.56% (95% CI 0.28-0.84, I2 = 0) and 1.2% (95% CI 0.79-1.6, I2 = 0). Cancer was associated with increased 30-day mortality [RR 4.9; 95% prediction interval (PI) 2.7-9.1; I2 = 0]. Pre-existing cardiopulmonary disease, abnormal troponin, and abnormal (N-terminal pro-)B-type natriuretic peptide [(NT-pro)BNP] at presentation were associated with an increased incidence of 14-day adverse events [RR 3.5 (95% PI 1.5-7.9, I2 = 0), 2.5 (95% PI 1.3-4.9, I2 = 0), and 3.9 (95% PI 1.6-9.8, I2 = 0), respectively], but not mortality. At 30 days, cancer, abnormal troponin, and abnormal (NT-pro)BNP were associated with an increased incidence of adverse events [RR 2.7 (95% PI 1.4-5.2, I2 = 0), 2.9 (95% PI 1.5-5.7, I2 = 0), and 3.3 (95% PI 1.6-7.1, I2 = 0), respectively]. CONCLUSIONS: The incidence of adverse events in home-treated PE patients, selected by a validated triage tool, was very low. Patients with cancer had a three- to five-fold higher incidence of adverse events and death. Patients with increased troponin or (NT-pro)BNP had a three-fold higher risk of adverse events, driven by recurrent venous thromboembolism and bleeding.

Pandemic phase-related racial and ethnic disparities in COVID-19 positivity and outcomes among patients presenting to emergency departments during the first two pandemic waves in the USA.

BACKGROUND: In many countries including the USA, the UK and Canada, the impact of COVID-19 on people of colour has been disproportionately high but examination of disparities in patients presenting to ED has been limited. We assessed racial and ethnic differences in COVID-19 positivity and outcomes in patients presenting to EDs in the USA, and the effect of the phase of the pandemic on these outcomes. METHODS: This is a retrospective cohort study of adult patients tested for COVID-19 during, or 14 days prior to, the index ED visit in 2020. Data were obtained from the National Registry of Suspected COVID-19 in Emergency Care network which has data from 155 EDs across 27 US states. Hierarchical models were used to account for clustering by hospital. The outcomes included COVID-19 diagnosis, hospitalisation at index visit, subsequent hospitalisation within 30 days and 30-day mortality. We further stratified the analysis by time period (early phase: March-June 2020; late phase: July-September 2020). RESULTS: Of the 26 111 adult patients, 38% were non-Hispanic White (NHW), 29% Black, 20% Hispanic/Latino, 3% Asian and 10% all others; half were female. The median age was 56 years (IQR 40-69), and 53% were diagnosed with COVID-19; of those, 59% were hospitalised at index visit. Of those discharged from ED, 47% had a subsequent hospitalisation in 30 days. Hispanic/Latino patients had twice (adjusted OR (aOR) 2.3; 95% CI 1.8 to 3.0) the odds of COVID-19 diagnosis than NHW patients, after adjusting for age, sex and comorbidities. Black, Asian and other minority groups also had higher odds of being diagnosed (compared with NHW patients). On stratification, this association was observed in both phases for Hispanic/Latino patients. Hispanic/Latino patients had lower odds of hospitalisation at index visit, but when stratified, this effect was only observed in early phase. Subsequent hospitalisation was more likely in Asian patients (aOR 3.1; 95% CI 1.1 to 8.7) in comparison with NHW patients. Subsequent ED visit was more likely in Blacks and Hispanic/Latino patients in late phase. CONCLUSION: We found significant differences in ED outcomes that are not explained by comorbidity burden. The gap decreased but persisted during the later phase in 2020.

Application of motor learning theory to teach the head impulse test to emergency medicine resident physicians.

Objectives: The objective was to develop an innovative method of training emergency medicine (EM) resident physicians to perform the head impulse test (HIT) component of the HINTS (head impulse test, nystagmus, test of skew) examination using video-oculography (VOG) device feedback. Methods: Using principles from motor learning theory and Ericsson's framework for expertise, we developed a training innovation utilizing VOG device feedback to teach the degree (10°-20°) and velocity (>100°/s) of head turn required for the HIT. We assessed the technical ability of participants to perform the HIT using the VOG device, without feedback, to count the number of successful HITs out of 20 attempts before, immediately after, and 2 weeks after the training innovation. Participants rated their confidence on a 1 to 5 Likert scale before and 2 weeks after training. Results: Most participants (11 of 14, 78%) were unable to perform even one successful HIT in 20 attempts before training despite brief verbal and visual instruction regarding the head turn parameters. However, most participants achieved more than one success, in fact, all with at least five successes, immediately after training (13 of 14, 93%) and again 2 weeks after training (nine of 11, 82%). The median (interquartile range) number of successful HITs was 0 (0, mean 0.79) during baseline testing, 7.5 (5.8) immediately after training, and 10 (8.0) 2 weeks after training (p < 0.01, Kruskal-Wallis). The median confidence rating increased from 1.5 (1) before baseline testing to 3 (1.5) after follow-up testing (p = 0.02, Mann-Whitney U). Conclusions: Prior to motor training, most participants failed to properly perform the HIT. Feedback training with VOG devices may facilitate development of the skills required to properly perform the HIT. Further study is needed to assess the ability to train the interpretive aspect of the HIT and other components of the HINTS examination.

Database derived from an electronic medical record-based surveillance network of US emergency department patients with acute respiratory illness.

BACKGROUND: For surveillance of episodic illness, the emergency department (ED) represents one of the largest interfaces for generalizable data about segments of the US public experiencing a need for unscheduled care. This protocol manuscript describes the development and operation of a national network linking symptom, clinical, laboratory and disposition data that provides a public database dedicated to the surveillance of acute respiratory infections (ARIs) in EDs. METHODS: The Respiratory Virus Laboratory Emergency Department Network Surveillance (RESP-LENS) network includes 26 academic investigators, from 24 sites, with 91 hospitals, and the Centers for Disease Control and Prevention (CDC) to survey viral infections. All data originate from electronic medical records (EMRs) accessed by structured query language (SQL) coding. Each Tuesday, data are imported into the standard data form for ARI visits that occurred the prior week (termed the index file); outcomes at 30 days and ED volume are also recorded. Up to 325 data fields can be populated for each case. Data are transferred from sites into an encrypted Google Cloud Platform, then programmatically checked for compliance, parsed, and aggregated into a central database housed on a second cloud platform prior to transfer to CDC. RESULTS: As of August, 2023, the network has reported data on over 870,000 ARI cases selected from approximately 5.2 million ED encounters. Post-contracting challenges to network execution have included local shifts in testing policies and platforms, delays in ICD-10 coding to detect ARI cases, and site-level personnel turnover. The network is addressing these challenges and is poised to begin streaming weekly data for dissemination. CONCLUSIONS: The RESP-LENS network provides a weekly updated database that is a public health resource to survey the epidemiology, viral causes, and outcomes of ED patients with acute respiratory infections.

Diagnostic management of acute pulmonary embolism: a prediction model based on a patient data meta-analysis.

AIMS: Risk stratification is used for decisions regarding need for imaging in patients with clinically suspected acute pulmonary embolism (PE). The aim was to develop a clinical prediction model that provides an individualized, accurate probability estimate for the presence of acute PE in patients with suspected disease based on readily available clinical items and D-dimer concentrations. METHODS AND RESULTS: An individual patient data meta-analysis was performed based on sixteen cross-sectional or prospective studies with data from 28 305 adult patients with clinically suspected PE from various clinical settings, including primary care, emergency care, hospitalized and nursing home patients. A multilevel logistic regression model was built and validated including ten a priori defined objective candidate predictors to predict objectively confirmed PE at baseline or venous thromboembolism (VTE) during follow-up of 30 to 90 days. Multiple imputation was used for missing data. Backward elimination was performed with a P-value <0.10. Discrimination (c-statistic with 95% confidence intervals [CI] and prediction intervals [PI]) and calibration (outcome:expected [O:E] ratio and calibration plot) were evaluated based on internal-external cross-validation. The accuracy of the model was subsequently compared with algorithms based on the Wells score and D-dimer testing. The final model included age (in years), sex, previous VTE, recent surgery or immobilization, haemoptysis, cancer, clinical signs of deep vein thrombosis, inpatient status, D-dimer (in µg/L), and an interaction term between age and D-dimer. The pooled c-statistic was 0.87 (95% CI, 0.85-0.89; 95% PI, 0.77-0.93) and overall calibration was very good (pooled O:E ratio, 0.99; 95% CI, 0.87-1.14; 95% PI, 0.55-1.79). The model slightly overestimated VTE probability in the lower range of estimated probabilities. Discrimination of the current model in the validation data sets was better than that of the Wells score combined with a D-dimer threshold based on age (c-statistic 0.73; 95% CI, 0.70-0.75) or structured clinical pretest probability (c-statistic 0.79; 95% CI, 0.76-0.81). CONCLUSION: The present model provides an absolute, individualized probability of PE presence in a broad population of patients with suspected PE, with very good discrimination and calibration. Its clinical utility needs to be evaluated in a prospective management or impact study. REGISTRATION: PROSPERO ID 89366.

An apex predator engineers wetland food-web heterogeneity through nutrient enrichment and habitat modification.

The potential for animals to modify spatial patterns of nutrient limitation for autotrophs and habitat availability for other members of their communities is increasingly recognized. However, net trophic effects of consumers acting as ecosystem engineers remain poorly known. The American Alligator Alligator mississippiensis is an abundant predator capable of dramatic modifications of physical habitat through the creation and maintenance of pond-like basins, but its role in influencing community structure and nutrient dynamics is less appreciated. We investigated if alligators engineer differences in nutrient availability and changes to community structure by their creation of 'alligator ponds' compared to the surrounding phosphorus (P)-limited oligotrophic marsh. We used a halo sampling design of three distinct habitats extending outward from 10 active alligator ponds across a hydrological gradient in the Everglades, USA. We performed nutrient analysis on basal food-web resources and quantitative community analyses, and stoichiometric analyses on plants and animals. Our findings demonstrate that alligators act as ecosystem engineers and enhance food-web heterogeneity by increasing nutrient availability, manipulating physical structure and altering algal, plant and animal communities. Flocculent detritus, an unconsolidated layer of particulate organic matter and soil, showed strong patterns of P enrichment in ponds. Higher P availability in alligator ponds also resulted in bottom-up trophic transfer of nutrients as evidenced by higher growth rates (lower N:P) for plants and aquatic consumers. Edge habitats surrounding alligator ponds contained the most diverse communities of invertebrates and plants, but low total abundance of fishes, likely driven by high densities of emergent macrophytes. Pond communities exhibited higher abundance of fish compared to edge habitat and were dominated by compositions of small invertebrates that track high nutrient availability in the water column. Marshes contained high numbers of animals that are closely tied to periphyton mats, which were absent from other habitats. Alligator-engineered habitats are ecologically important by providing nutrient-enriched 'hotspots' in an oligotrophic system, habitat heterogeneity to marshes, and refuges for other fauna during seasonal disturbances. This work adds to growing evidence that efforts to model community dynamics should routinely consider animal-mediated bottom-up processes like ecosystem engineering.

ChatGPT and conversational artificial intelligence: Friend, foe, or future of research?

Artificial intelligence (AI) and machine learning are increasingly utilized across healthcare. More recently, there has been a rise in the use AI within research, particularly through novel conversational AI platforms, such as ChatGPT. In this Controversies paper, we discuss the advantages, limitations, and future directions for ChatGPT and other forms of conversational AI in research and scholarly dissemination.

Bedside exclusion of pulmonary embolism in children without radiation (BEEPER): a national study of the Pediatric Emergency Care Applied Research Network-Study protocol.

Background: The Pulmonary Embolism Rule Out Criteria (PERC) Peds rule, derived from the PERC rule, was derived to estimate a low pretest probability for pulmonary embolism (PE) in children but has not been prospectively validated. Objective: The objective of this study was to present a protocol for an ongoing multicenter prospective observational study that evaluates the diagnostic accuracy of the PERC-Peds rule. Methods: This protocol is identified by the acronym, BEdside Exclusion of Pulmonary Embolism without Radiation in children. The study aims were designed to prospectively validate, or if necessary, refine, the accuracy of PERC-Peds and D-dimer in excluding PE among children with clinical suspicion or testing for PE. Multiple ancillary studies will examine clinical characteristics and epidemiology of the participants. Children aged 4 through 17 years were being enrolled at 21 sites through the Pediatric Emergency Care Applied Research Network (PECARN). Patients taking anticoagulant therapy are excluded. PERC-Peds criteria data, clinical gestalt, and demographic information are collected in real time. The criterion standard outcome is image-confirmed venous thromboembolism within 45 days, determined from independent expert adjudication. We assessed interrater reliability of the PERC-Peds, frequency of PERC-Peds use in routine clinical care, and descriptive characteristics of missed eligible and missed patients with PE. Results: Enrollment is currently 60% complete with an anticipated data lock in 2025. Conclusions: This prospective multicenter observational study will not only test whether a set of simple criteria can safely exclude PE without need for imaging but also provide a resource to fill a critical knowledge gap about clinical characteristics of children with suspected and diagnosed PE.

Hydrology-mediated ecological function of a large wetland threatened by an invasive predator.

Invasive species are one of the greatest threats to ecosystems, disrupting ecosystem function and leading to the collapse and extinction of native species. While populations of native fishes in the Everglades are tied to the system's natural hydrological dynamics, Asian Swamp Eels (Monopterus albus/javanensis) are drought-resistant fish first reported from Florida in 1997 and the Everglades in 2007. Using a 26-year dataset that included a 13-year baseline period prior to swamp eel arrival in Taylor Slough, we assessed population changes of common small fishes and decapods that are important prey for larger vertebrate predators. After invasion, populations of two crayfishes collapsed by >95 %, two fishes declined by >80 %, two fishes had intermediate declines of 44-66 %, and three species remained unchanged. Species most strongly reduced were those dependent on predator-free habitats at the onset of the wet season, indicating drought-resistant swamp eels have introduced novel predator effects and disrupted the hydrology-mediated production of aquatic animals that are prey for many larger predators. Ongoing Everglades restoration is designed to restore hydrological conditions that support production of crayfishes and fishes, and nesting wading birds reliant on them. Water management may have facilitated the invasion of swamp eels. Our results suggest that the continued spread of swamp eels may result in adverse consequences for Everglades trophic dynamics and potentially diminish benefits expected from the $20B+ restoration.

Worsened outcomes of newly diagnosed cancer in patients with recent emergency care visits: A retrospective cohort study of 3699 adults in a safety net health system.

INTRODUCTION: Many patients receive a suspected diagnosis of cancer through an emergency department (ED) visit. Time to treatment for a new diagnosis of cancer is directly associated with improved outcomes with little no describing the ED utilization prior to the diagnosis of cancer. We hypothesize that patients that have an ED visit in proximity to a diagnosis of cancer will have worse outcomes, including mortality. METHODS: This study is a retrospective cohort study of all patients with cancer diagnosed at Eskenazi Health (Indiana) between 2016 and 2019. Individual health characteristics, ED utilization, cancer types, and mortality were studied. We compared those patients seen in the ED within 6 months prior to their diagnosis (cases) to patients not seen in the ED (controls). RESULTS: A total of 3699 patients with cancer were included, with 1239 cases (33.50%). Patients of black race had higher frequencies in the cases vs. controls (46.57% vs. 40.68%). Lung cancer was the most frequently observed cancer among cases vs. controls (11.70% vs. 5.57%). For the cases, 232 patients were deceased (18.72%) compared with 247 patients among the controls (10.04%, p < 0.0001, OR 2.06 95% confidence interval [CI] 1.70-2.51). An ED visit in past 6 months (OR = 1.73, 95% CI 1.38-2.18) and Medicaid insurance type (versus commercial, OR = 4.16, 95% CI 2.45-7.07) were associated with of mortality. Female gender (OR = 0.76, 95% CI 0.67-0.88), tobacco use (OR = 1.62, 95% CI 138-1.90), and Medicaid insurance type (versus commercial, OR = 2.56, 95% CI 2.07-3.47) were associated with prior ED use. CONCLUSIONS: Over one third of patients with cancer were seen in the ED within 6 months prior to their cancer diagnosis. Higher mortality rates were observed for those seen in the ED. Future studies are needed to investigate the association and impact that the ED has on eventual cancer diagnoses and outcomes.

Primer on Logistic Regression for Emergency Care Researchers.

BACKGROUND: Logistic regression plays a fundamental role in the production of decision rules, risk assessment, and in establishing cause and effect relationships. This primer is aimed at novice researchers with minimal statistical expertise. OBJECTIVE: Introduce the logit equation and provide a hands-on example to facilitate understanding of its benefits and limitations. DISCUSSION: This primer reviews the mathematical basis of a logit equation by comparing and contrasting it with the simple straight-line (linear) equation. After gaining an understanding of the meaning of beta coefficients, readers are encouraged to download a free statistical program and database to produce a logistic regression analysis. Using this example, the narrative then discusses commonly used methods to describe model fitness, including the C-statistic, chi square, Akaike and Bayesian Information Criteria, McFadden's pseudo R2, and the Hosmer-Lemeshow test. The authors provide a how-to discussion for variable selection and estimate of sample size. However, logistic regression alone can seldom establish causal inference without further steps to explore the often complex relationship amongst variables and outcomes, such as with the use of a directed acyclic graphs. We present key elements that generally should be considered when appraising an article that uses logistic regression. This primer provides a basic understanding of the theory, hands-on construction, model analysis, and limitations of logistic regression in emergency care research. CONCLUSIONS: Logistic regression can provide information about the association of independent variables with important clinical outcomes, which can be the first step to show predictiveness or causation of variables on the outcomes of interest. © 2022 Elsevier Inc.

A Novel Orderset Driven Emergency Department Atrial Fibrillation Algorithm to Increase Discharge and Risk-appropriate Anticoagulation.

INTRODUCTION: Patients with atrial fibrillation (AF) are frequently admitted from the emergency department (ED), and when discharged, are not reliably prescribed indicated anticoagulation. We report the impact of a novel computerized ED AF pathway orderset on discharge rate and risk-appropriate anticoagulation in patients with primary AF. METHODS: The orderset included options for rate and rhythm control of primary AF, structured risk assessment for thrombotic complications, recommendations for anticoagulation as appropriate, and follow up with an electrophysiologist. All patients discharged from the ED in whom the AF orderset was utilized over an 18-month period comprised the primary study population. The primary outcome was the rate of appropriate anticoagulation or not according to confirmed CHADS-VASC and HASBLED scores. Additionally, the percentage of primary AF patients discharged directly from the ED was compared in the 18-month periods before and after introduction of the orderset. RESULTS: A total of 56 patients, average age 57.8 years and average initial heart rate 126 beats/minute, were included in the primary analysis. All 56 (100%; 95% confidence interval, 94-100) received guideline-concordant anticoagulation. The discharge rates in the pre- and postorderset implementation periods were 29% and 41%, respectively (95% confidence interval for 12% difference, 5-18). CONCLUSIONS: Our novel AF pathway orderset was associated with 100% guideline-concordant anticoagulation in patients discharged from the ED. Availability of the orderset was associated with a significant increase in the proportion of ED AF patients discharged.

D-dimer Thresholds to Exclude Pulmonary Embolism among COVID-19 Patients in the Emergency Department: Derivation with Independent Validation.

OBJECTIVE: To derive and validate a D-dimer cutoff for ruling out pulmonary embolism (PE) in COVID-19 patients presenting to the emergency department (ED). METHODS: A retrospective cohort study was performed in an integrated healthcare system including 22 adult ED's between March 1, 2020, and January 31, 2021. Results were validated among patients enrolled in the RECOVER Registry, representing data from 154 ED's from 26 US states. Consecutive ED patients with laboratory confirmed COVID-19, a D-dimer performed within 48 h of ED arrival, and with objectively confirmed PE were compared to those without PE. After identifying a D-dimer threshold at which the 95% confidence lower bound of the negative predictive value for PE was higher than 98% in the derivation cohort, it was validated using RECOVER registry data. RESULTS: Among 3978 patients with a D-dimer result, 3583 with confirmed COVID-19 infection were included in the derivation cohort. Overall, PE incidence was 4.1% and a D-dimer cutoff of <2 µ/mL (2000 ng/mL) was associated with a NPV of 98.5% (95% CI = 98.0%-98.9%). In the validation cohort of 13,091 patients with a D-dimer, 7748 had confirmed COVID-19 infection, and the PE incidence was 1.14%. A D-dimer cutoff of <2 µ/mL was associated with a NPV of 99.5% (95% CI = 99.3%-99.7%). CONCLUSION: A D-dimer cutoff of <2 µ/ml was associated with a high negative predictive value for PE among patients with COVID-19. However, the resultant sensitivity for PE result at that threshold without pre-test probability assessment would be considered clinically unsafe.

Increased Body Mass Index and Metabolic Syndrome Are Associated with Poor Outcomes in SARS-CoV-2-Positive Emergency Department Patients.

Background: Increased body mass index (BMI) and metabolic syndrome (MetS) have been associated with adverse outcomes in viral syndromes. We sought to examine associations of increased BMI and MetS on several clinical outcomes in patients tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Methods: The registry of suspected COVID-19 in emergency care (RECOVER) is an observational study of SARS-CoV-2-tested patients (n=27,051) across 155 United States emergency departments (EDs). We used multivariable logistic regression to test for associations of several predictor variables with various clinical outcomes. Results: We found that a BMI ≥30 kg/m2 increased odds of SARS-CoV-2 test positivity (odds ratio [OR], 1.30; 95% confidence interval [CI], 1.23-1.38), while MetS reduced odds of testing positive for SARS-CoV-2 (OR, 0.76; 95% CI, 0.71-0.82). Adjusted multivariable analysis found that MetS was significantly associated with the need for admission (OR, 2.11; 95% CI, 1.89-2.37), intensive care unit (ICU) care (OR, 1.58; 95% CI, 1.40-1.78), intubation (OR, 1.46; 95% CI, 1.28-1.66), mortality (OR, 1.29; 95% CI, 1.13-1.48), and venous thromboembolism (OR, 1.51; 95% CI, 1.07-2.13) in SARS-CoV-2-positive patients. Similarly, BMI ≥40 kg/m2 was significantly associated with ICU care (OR, 1.97; 95% CI, 1.65-2.35), intubation (OR, 2.69; 95% CI, 2.22-3.26), and mortality (OR, 1.50; 95% CI, 1.22-1.84). Conclusion: In this large nationwide sample of ED patients, we report a significant association of both high BMI and composite MetS with poor outcomes in SARS-CoV-2-positive patients. Findings suggest that composite MetS profile may be a more universal predictor of adverse disease outcomes, while the impact of BMI is more heavily modulated by SARS-CoV-2 status.