Evaluation of esophageal injuries after defibrillation with transesophageal ultrasound probe in the mid-esophagus in pigs.

OBJECTIVE: Transesophageal echocardiography (TEE) is becoming increasingly utilized by emergency medicine providers during cardiac arrest. Intra-arrest, TEE confers several benefits including shorter pauses in chest compressions and direct visualization of cardiac compressions. Many ultrasound probe manufacturers recommend against performing defibrillation with the TEE probe in the mid-esophagus for fear of causing esophageal injury or damage to the probe, however no literature exists that has investigated this concern. To assess this, we performed cardiopulmonary resuscitation (CPR) and multiple defibrillations in 8 swine with a TEE probe in place. METHODS: We performed TEE on 8 adult swine during CPR and performed multiple 200 J defibrillations with the TEE probe in the mid-esophagus. Post-mortem, esophagi were dissected and inspected for evidence of injury. RESULTS: On macroscopic inspection of 8 esophagi, no evidence of hematoma, thermal injury, or perforation was noted. CONCLUSION: Our study suggests that performing defibrillation during CPR with a TEE probe in place in the mid-esophagus is likely safe and low risk for significant esophageal injury. This further bolsters the use of TEE in CPR and would enable continuous visualization of cardiac activity without the need to remove the TEE probe for defibrillation.

A Stress Test of Artificial Intelligence: Can Deep Learning Models Trained From Formal Echocardiography Accurately Interpret Point-of-Care Ultrasound?

OBJECTIVES: To test if a deep learning (DL) model trained on echocardiography images could accurately segment the left ventricle (LV) and predict ejection fraction on apical 4-chamber images acquired by point-of-care ultrasound (POCUS). METHODS: We created a dataset of 333 videos from cardiac POCUS exams acquired in the emergency department. For each video we derived two ground-truth labels. First, we segmented the LV from one image frame and second, we classified the EF as normal, reduced, or severely reduced. We then classified the media's quality as optimal, adequate, or inadequate. With this dataset we tested the accuracy of automated LV segmentation and EF classification by the best-in-class echocardiography trained DL model EchoNet-Dynamic. RESULTS: The mean Dice similarity coefficient for LV segmentation was 0.72 (N = 333; 95% CI 0.70-0.74). Cohen's kappa coefficient for agreement between predicted and ground-truth EF classification was 0.16 (N = 333). The area under the receiver-operating curve for the diagnosis of heart failure was 0.74 (N = 333). Model performance improved with video quality for the tasks of LV segmentation and diagnosis of heart failure, but was unchanged with EF classification. For all tasks the model was less accurate than the published benchmarks for EchoNet-Dynamic. CONCLUSIONS: Performance of a DL model trained on formal echocardiography worsened when challenged with images captured during resuscitations. DL models intended for assessing bedside ultrasound should be trained on datasets composed of POCUS images. Such datasets have yet to be made publicly available.

Effect of the COVID-19 pandemic on CT scans ordered from the emergency department for abdominal complaints.

PURPOSE: The COVID-19 pandemic has affected healthcare systems and patients alike across the USA. We seek to elucidate changes in abdominal imaging ordered from the emergency department (ED) in a healthcare system undergoing non-surge conditions in April 2020 compared to April 2019. METHODS: We performed a retrospective, observational study comparing patients undergoing CT scans of the abdomen and pelvis ordered from the ED in April 2020 vs. April 2019 at a single healthcare center. Via review of the radiology report and electronic medical record, we determined the positive or negative status of these scans. We evaluated percentages of positive CT scans and differences in outcomes, including admission rates, interventions, and mortality. RESULTS: Comparing 2020 to 2019, there was a 31.6% decrease in the number of CT scans performed from the ED. We found a higher percentage of positive CT findings, 58.2% vs. 50.8% (p = 0.025), and increased admission rates, 40.8% vs. 34.1% (p = 0.036). Differences were found in rates of appendicitis, colitis, and cholangitis. No difference was found in ICU admissions, interventions, or in-hospital mortality. CONCLUSION: During the COVID-19 pandemic in a region undergoing non-surge conditions, we found increased rates of positive CT scans performed from the ED for abdominal complaints with an increased percentage of hospital admissions compared to a control year. No differences in ICU admissions or rates of procedural intervention were found to suggest higher acuity of pathology on presentation. Our findings suggest appropriately decreased healthcare utilization in our study period, driven by pre-hospital patient self-selection.

An Aerosol Containment and Filtration Tent for Intubation During the COVID-19 Pandemic.

Background. Exposure to infectious droplets confers a high risk for infection transmission by the SARS-CoV-2 coronavirus. Aerosolizing procedures pose particular concern for increasing healthcare workers' (HCWs) risks of infection. Multiple creative personal protective equipment solutions have been utilized to minimize exposure to infectious particles; however, the overall benefit of many of these devices is limited by a number of factors. Methods. We designed an intubation tent consisting of a metal frame and a clear plastic sheet. The flexible walls of our tent offer increased maneuverability & access, although the efficacy in reducing risk of transmission to HCWs remained unclear. Using an atomizer, particle generator, and matchstick smoke, we simulated the generation of infectious respiratory droplets and aerosols and tested whether our device effectively decreased the concentration of these particles to which a provider might be exposed. Finally, we tested whether the addition of a vacuum fan fit with a high efficiency particulate air filter designed to evacuate contaminated air would influence particle concentrations inside and outside the tent. Results. Droplet dispersion tests with the tent in place showed that the simulated droplet distribution was limited to surfaces within the tent. Aerosol testing under a variety of circumstances consistently showed only a minor rise in particle concentration in the air outside the tent despite an initial peak of particle concentration during generation within. All testing demonstrated declining inside concentrations over time. Conclusions. Our simulations suggest our device has the potential to effectively decrease HCWs' exposure to infectious droplets and aerosolized viral particles.

Transesophageal Echocardiography During Cardiopulmonary Resuscitation Is Associated With Shorter Compression Pauses Compared With Transthoracic Echocardiography.

STUDY OBJECTIVE: Point-of-care ultrasonography provides diagnostic information in addition to visual pulse checks during cardiopulmonary resuscitation (CPR). The most commonly used modality, transthoracic echocardiography, has unfortunately been repeatedly associated with prolonged pauses in chest compressions, which correlate with worsened neurologic outcomes. Unlike transthoracic echocardiography, transesophageal echocardiography does not require cessation of compressions for adequate imaging and provides the diagnostic benefit of point-of-care ultrasonography. To assess a benefit of transesophageal echocardiography, we compare the duration of chest compression pauses between transesophageal echocardiography, transthoracic echocardiography, and manual pulse checks on video recordings of cardiac arrest resuscitations. METHODS: We analyzed 139 pulse check CPR pauses among 25 patients during cardiac arrest. RESULTS: Transesophageal echocardiography provided the shortest mean pulse check duration (9 seconds [95% confidence interval {CI} 5 to 12 seconds]). Mean pulse check duration with transthoracic echocardiography was 19 seconds (95% CI 16 to 22 seconds), and it was 11 seconds (95% CI 8 to 14 seconds) with manual checks. Intraclass correlation coefficient between abstractors for a portion of individual and average times was 0.99 and 0.99, respectively (P<.001 for both). CONCLUSION: Our study suggests that pulse check times with transesophageal echocardiography are shorter versus with transthoracic echocardiography for ED point-of-care ultrasonography during cardiac arrest resuscitations, and further emphasizes the need for careful attention to compression pause duration when using transthoracic echocardiography for point-of-care ultrasonography during ED cardiac arrest resuscitations.

Transesophageal echocardiography identification of aortic dissection during cardiac arrest and cessation of ECMO initiation.

Cardiac arrest is a challenging clinical presentation that emergency medicine providers often encounter. Aortic dissection is an uncommon etiology in all-comers presenting in cardiac arrest. The use of bedside point of care echocardiography to aid in resuscitative efforts is expanding, particularly with the increasing use of transesophageal echocardiography (TEE) by emergency medicine providers. Additionally, emergency department initiation of extracorporeal membrane oxygenation (ECMO) is a relatively newer development in emergency department practice. We report the case of a 64-year old male presenting to the emergency department in cardiac arrest with TEE identification of aortic dissection as the etiology resulting in discontinuation of ECMO initiation attempts.

Emergency physician-performed transesophageal echocardiography for extracorporeal life support vascular cannula placement.

INTRODUCTION: There is growing interest and application of extracorporeal membrane oxygenation (ECMO) as a life-saving procedure for out-of-hospital cardiac arrest (OHCA), also called extracorporeal life support (ECLS). Extracorporeal membrane oxygenation cannulation with ongoing chest compressions is challenging, and transesophageal echocardiography (TEE) is an invaluable tool with which to guide ECMO wire guidance and cannula positioning. METHODS: We describe our protocol for TEE guidance by emergency physicians in our hospital. RESULTS: Of our first 12 cases of ECLS, 10 have had TEE guidance by an emergency physician with successful placement and without complication or need for repositioning. Emergency physician-performed TEE for ECLS vascular cannula placement has been both feasible and useful in our experience and warrants further study.

Diagnosis of appendicitis by bedside ultrasound in the ED.

BACKGROUND: Computed tomography (CT) has largely become standard of care for diagnosing appendicitis at the expense of increased patient radiation exposure, cost, and time to surgical intervention. To date, there are very limited data on the accuracy of bedside ultrasound (BUS) for the diagnosis of appendicitis in adults. OBJECTIVE: The objective of this study is to evaluate test characteristics of BUS for diagnosis of acute appendicitis in the emergency department. METHODS: Data were prospectively collected on 97 cases of suspected appendicitis, which had BUS performed by trained residents with attending supervision between August 2011 and November 2013. All BUS interpretation and additional diagnostic imaging were left to the discretion of the physician or surgical consultants. A blinded ultrasound fellowship-trained physician reviewed all images after clinical treatment. Bedside ultrasound findings and patient outcomes were reported. RESULTS: A total of 97 adult cases underwent diagnostic ultrasound scans for suspected appendicitis. Of 97 cases, 34 had acute appendicitis by surgery/pathology report. Twenty-four BUS were positive for acute appendicitis and 11 were nondiagnostic. Of 24 positive ultrasounds, 23 had appendicitis on pathology report. There was 1 false-positive result, yielding a sensitivity of 67.65% (95% confidence limits, 49.5%-82.6%) and a specificity of 98.41% (95% confidence limits, 91.4%-99.7%). Of 23 positive BUS, 12 cases went to the Operating Room without an abdominal CT yielding a 12% reduction in CT utilization. If all positive BUS went to the OR without a CT scan, this would yield a 24% reduction in CT utilization. CONCLUSIONS: Bedside ultrasound may be an appropriate initial test to evaluate patients with suspected acute appendicitis in the emergency department.

Accuracy of ultrasound-guided marking of the cricothyroid membrane before simulated failed intubation.

BACKGROUND: Interest in the use of dynamic ultrasound (US) for cricothyrotomy has sparked a debate regarding its applicability in a crash airway situation. Ultrasound-guided marking of the cricothyroid membrane (CTM) as a preintubation procedure may be better than the dynamic method. No prior study has evaluated the accuracy of using US to premark the CTM before attempted intubation. OBJECTIVES: To determine the feasibility of US-guided marking of the CTM before attempted simulated intubation so that this marking may be used as the location for the initial incision after failed intubation. METHODS: Resident and attending physicians participated. Ultrasound was used to identify and mark the CTM with an invisible pen. Failed intubation was simulated, and the same operator then identified the CTM with US and marked the location with a black pen. The difference in the preintervention and postintervention markings was measured in millimeters. The length of the CTM was also measured as a reference. RESULTS: Twenty-three models and operators were used for data collection. The average CTM sagittal length was 13.9 mm (95% confidence interval [CI], 13.4-14.4). The average sagittal and axial differences before and after simulated intubation were found to be 0.91 mm (95% CI, 0.35-1.47) and 1.04 mm (95% CI, 0.38-1.7), respectively. The sagittal variability is 1/15 the total length of the CTM. CONCLUSIONS: Ultrasound marking of the CTM of healthy volunteers before simulated intubation accurately identifies the CTM after neck manipulation expected during a failed intubation. Further research is indicated to determine the clinical applicability of this model.

Quality of life 1 month after acute pulmonary embolism in emergency department patients.

OBJECTIVE: The Pulmonary Embolism Quality-of-Life (PEmb-QoL) questionnaire assesses quality of life (QoL) after pulmonary embolism (PE). We aimed to determine whether any clinical or pathophysiologic features of PE were associated with worse PEmb-QoL scores 1 month after PE. METHODS: In this prospective multicenter registry, we conducted PEmb-QoL questionnaires. We determined differences in QoL domain scores for four primary variables: clinical deterioration (death, cardiac arrest, respiratory failure, hypotension requiring fluid bolus, catecholamine support, or new dysrhythmia), right ventricular dysfunction (RVD), PE risk stratification, and subsequent rehospitalization. For overall QoL score, we fit a multivariable regression model that included these four primary variables as independent variables. RESULTS: Of 788 PE patients participating in QoL assessments, 156 (19.8%) had a clinical deterioration event, 236 (30.7%) had RVD of which 38 (16.1%) had escalated interventions. For those without and with clinical deterioration, social limitations had mean (±SD) scores of 2.07 (±1.27) and 2.36 (±1.47), respectively (p = 0.027). For intensity of complaints, mean (±SD) scores for patients without RVD (4.32 ± 2.69) were significantly higher than for those with RVD with or without reperfusion interventions (3.82 ± 1.81 and 3.83 ± 2.11, respectively; p = 0.043). There were no domain score differences between PE risk stratification groups. All domain scores were worse for patients with rehospitalization versus without. By multivariable analysis, worse total PEmb-QoL scores with effect sizes were subsequent rehospitalization 11.29 (6.68-15.89), chronic obstructive pulmonary disease (COPD) 8.17 (3.91-12.43), and longer index hospital length of stay 0.06 (0.03-0.08). CONCLUSIONS: Acute clinical deterioration, RVD, and PE severity were not predictors of QoL at 1 month post-PE. Independent predictors of worsened QoL were rehospitalization, COPD, and index hospital length of stay.

Comparing predictive performance of pulmonary embolism risk stratification tools for acute clinical deterioration.

Objectives: Existing pulmonary embolism (PE) risk scores were developed to predict death within weeks, but not more proximate adverse events. We determined the ability of 3 PE risk stratification tools (simplified pulmonary embolism severity index [sPESI], 2019 European Society of Cardiology guidelines [ESC], and PE short-term clinical outcomes risk estimation [PE-SCORE]) to predict 5-day clinical deterioration after emergency department (ED) diagnosis of PE. Methods: We analyzed data from six EDs on ED patients with confirmed PE. Clinical deterioration was defined as death, respiratory failure, cardiac arrest, new dysrhythmia, sustained hypotension requiring vasopressors or volume resuscitation, or escalated intervention within 5 days of PE diagnosis. We determined sensitivity and specificity of sPESI, ESC, and PE-SCORE for predicting clinical deterioration. Results: Of 1569 patients, 24.5% had clinical deterioration within 5 days. sPESI, ESC, and PE-SCORE classifications were low-risk in 558 (35.6%), 167 (10.6%), and 309 (19.6%), respectively. Sensitivities of sPESI, ESC, and PE-SCORE for clinical deterioration were 81.8 (78, 85.7), 98.7 (97.6, 99.8), and 96.1 (94.2, 98), respectively. Specificities of sPESI, ESC, and PE-SCORE for clinical deterioration were 41.2 (38.4, 44), 13.7 (11.7, 15.6), and 24.8 (22.4, 27.3). Areas under the curve were 61.5 (59.1, 63.9), 56.2 (55.1, 57.3), and 60.5 (58.9, 62.0). Negative predictive values were 87.5 (84.7, 90.2), 97 (94.4, 99.6), and 95.1 (92.7, 97.5). Conclusions: ESC and PE-SCORE were better than sPESI for detecting clinical deterioration within 5 days after PE diagnosis.

Electrocardiographic findings associated with early clinical deterioration in acute pulmonary embolism.

OBJECTIVES: We sought to determine associations of early electrocardiogram (ECG) patterns with clinical deterioration (CD) within 5 days and with RV abnormality (abnlRV) by echocardiography in pulmonary embolism (PE). METHODS: In this prospective, multicenter study of newly confirmed PE patients, early echocardiography and initial ECG were examined. Initial ECG patterns included lead-specific ST-segment elevation (STE) or depression (STD), T-wave inversion (TWI), supraventricular tachycardia (SVT), sinus tachycardia, and right bundle branch block as complete (cRBBB) or incomplete (iRBBB). We defined CD as respiratory failure, hypotension, dysrhythmia, cardiac arrest, escalated PE intervention, or death within 5 days. We calculated odds ratios (ORs) for CD and abnlRV with univariate and full multivariate models in the presence of other variables. RESULTS: Of 1676 patients, 1629 (97.2%) had both ECG and GDE; 415/1676 (24.7%) had CD, and 529/1629 (32.4%) had abnlRV. AbnlRV had an OR for CD of 4.25 (3.35, 5.38). By univariable analysis, the absence of abnormal ECG patterns had OR for CD and abnlRV of 0.34 (0.26, 0.44; p < 0.001) and 0.24 (0.18, 0.31; p < 0.001), respectively. By multivariable analyses, one ECG pattern had a significant OR for CD: SVT 2.87 (1.66, 5.00). Significant ORS for abnlRV were: TWI V2-4 4.0 (2.64, 6.12), iRBBB 2.63 (1.59, 4.38), STE aVR 2.42 (1.58, 3.74), S1-Q3-T3 2.42 (1.70, 3.47), and sinus tachycardia 1.68 (1.14, 2.49). CONCLUSIONS: SVT was an independent predictor of CD. TWI V2-4 , iRBBB, STE aVR, sinus tachycardia, and S1-Q3-T3 were independent predictors of abnlRV. Finding one or more of these ECG patterns may increase considerations for performance of echocardiography to look for RV abnormalities and, if present, inform concerns for early clinical deterioration.

Can right ventricular assessments improve triaging of low risk pulmonary embolism?

OBJECTIVES: Identifying right ventricle (RV) abnormalities is important to stratifying pulmonary embolism (PE) severity. Disposition decisions are influenced by concerns about early deterioration. Triaging strategies, like the Simplified Pulmonary Embolism Severity Index (sPESI), do not include RV assessments as predictors or early deterioration as outcome(s). We aimed to (1) determine if RV assessment variables add prognostic accuracy for 5-day clinical deterioration in patients classified low risk by sPESI, and (2) determine the prognostic importance of RV assessments compared to other variables and to each other. METHODS: We identified low risk sPESI patients (sPESI = 0) from a prospective PE registry. From a large field of candidate variables, we developed, and compared prognostic accuracy of, full and reduced random forest models (with and without RV assessment variables, respectively) on a validation database. We reported variable importance plots from full random forest and provided odds ratios for statistical inference of importance from multivariable logistic regression. Outcomes were death, cardiac arrest, hypotension, dysrhythmia, or respiratory failure within 5 days of PE. RESULTS: Of 1736 patients, 610 (35.1%) were low risk by sPESI and 72 (11.8%) experienced early deterioration. Of the 610, RV abnormality was present in 157 (25.7%) by CT, 121 (19.8%) by echocardiography, 132 (21.6%) by natriuretic peptide, and 107 (17.5%) by troponin. For deterioration, the receiver operating characteristics for full and reduced random forest prognostic models were 0.80 (0.77-0.82) and 0.71 (0.68-0.73), respectively. RV assessments were the top four in the variable importance plot for the random forest model. Echocardiography and CT significantly increased predicted probability of 5-day clinical deterioration by the multivariable logistic regression. CONCLUSIONS: A PE triaging strategy with RV imaging assessments had superior prognostic performance at classifying low risk for 5-day clinical deterioration versus one without.

Development and validation of a prognostic tool: Pulmonary embolism short-term clinical outcomes risk estimation (PE-SCORE).

OBJECTIVE: Develop and validate a prognostic model for clinical deterioration or death within days of pulmonary embolism (PE) diagnosis using point-of-care criteria. METHODS: We used prospective registry data from six emergency departments. The primary composite outcome was death or deterioration (respiratory failure, cardiac arrest, new dysrhythmia, sustained hypotension, and rescue reperfusion intervention) within 5 days. Candidate predictors included laboratory and imaging right ventricle (RV) assessments. The prognostic model was developed from 935 PE patients. Univariable analysis of 138 candidate variables was followed by penalized and standard logistic regression on 26 retained variables, and then tested with a validation database (N = 801). RESULTS: Logistic regression yielded a nine-variable model, then simplified to a nine-point tool (PE-SCORE): one point each for abnormal RV by echocardiography, abnormal RV by computed tomography, systolic blood pressure < 100 mmHg, dysrhythmia, suspected/confirmed systemic infection, syncope, medico-social admission reason, abnormal heart rate, and two points for creatinine greater than 2.0 mg/dL. In the development database, 22.4% had the primary outcome. Prognostic accuracy of logistic regression model versus PE-SCORE model: 0.83 (0.80, 0.86) vs. 0.78 (0.75, 0.82) using area under the curve (AUC) and 0.61 (0.57, 0.64) vs. 0.50 (0.39, 0.60) using precision-recall curve (AUCpr). In the validation database, 26.6% had the primary outcome. PE-SCORE had AUC 0.77 (0.73, 0.81) and AUCpr 0.63 (0.43, 0.81). As points increased, outcome proportions increased: a score of zero had 2% outcome, whereas scores of six and above had ≥ 69.6% outcomes. In the validation dataset, PE-SCORE zero had 8% outcome [no deaths], whereas all patients with PE-SCORE of six and above had the primary outcome. CONCLUSIONS: PE-SCORE model identifies PE patients at low- and high-risk for deterioration and may help guide decisions about early outpatient management versus need for hospital-based monitoring.

Mechanical chest compression devices are associated with poor neurological survival in a statewide registry: A propensity score analysis.

OBJECTIVE: To compare functional survival (discharge cerebral performance category 1 or 2) among victims of out-of-hospital cardiac arrest (OHCA) who had resuscitations performed using mechanical chest compression (mech-CC) devices vs. those using manual chest compressions (man-CC). METHODS: Observational cohort of 2600 cases of OHCA from a statewide, prospectively-collected cardiac arrest registry (Utah Cardiac Arrest Registry to Enhance Survival). Comparison of functional survival among those receiving mech-CC vs man-CC was performed using a mixed-effects Poisson model with inverse probability weighted propensity scores to control for selection bias. RESULTS: Overall, mech-CC was utilized in 405/2600 (16%) of the total arrests in Utah during this period. 371/405 (92%) were of the load-distributing band type (AutoPulse(®)) and 22/405 (5%) were mechanical piston devices (LUCAS™), while 12/405 (3%) employed other devices. The relative risk (RR) for functional survival comparing mech-CC to man-CC after propensity score adjustment was 0.41 (95% CI 0.24-0.70, p=0.001). CONCLUSIONS: Mechanical chest compression device use was associated with lower rates of functional survival in this propensity score analysis, controlling for Utstein variables and early return of spontaneous circulation.