Variability in Interpretation of Echocardiographic Signs of Tamponade: A Survey of Emergency Physician Sonographers.

BACKGROUND: Cardiac tamponade is associated with high mortality, and making the diagnosis is a core skill of emergency physicians. Proper diagnosis relies on specific clinical and echocardiographic findings. It is not known whether expert sonographers consistently recognize echocardiographic signs of tamponade. OBJECTIVES: To assess whether expert sonographers agree on echocardiographic signs of tamponade. METHODS: A 20-question survey consisting of 18 cine loops and 2 still images was distributed to the Academy of Emergency Ultrasound Section of the Society for Academic Emergency Medicine. Respondents answered "yes" or "no" to whether there was echocardiographic evidence of tamponade. Subgroup analyses of demographics and echocardiographic views were reported. The data were analyzed using Krippendorff's alpha (α) to assess interrater reliability (IRR) between respondents. RESULTS: Eighty-four physicians responded and 56 completed the survey. All partial and completed surveys were analyzed. The overall IRR was poor (α = 0.60, 95% confidence interval [CI] 0.44-0.76). Residency graduation within 5 years (α = 0.66, 95% CI 0.5-0.8) was associated with higher IRR compared with those > 5 years (α = 0.53, 95% CI 0.37-0.69). The highest IRR was observed when images of mitral valve inflow pulse-wave Doppler (α = 0.81, CI 0.70-0.92) were used and the poorest IRR was on images from the parasternal short view (α = 0.28, 95% CI 0.05-0.49). CONCLUSION: There was poor agreement among expert emergency medicine sonographers in identifying echocardiographic signs of cardiac tamponade from a single cine loop or clip without clinical context. Further investigation is warranted to understand differences in recognition of clinical tamponade.

A consensus list of ultrasound competencies for graduating emergency medicine residents.

Objectives: Emergency ultrasound (EUS) is a critical component of emergency medicine (EM) resident education. Currently, there is no consensus list of competencies for EUS training, and graduating residents have varying levels of skill and comfort. The objective of this study was to define a widely accepted comprehensive list of EUS competencies for graduating EM residents through a modified Delphi method. Methods: We developed a list of EUS applications through a comprehensive literature search, the American College of Emergency Physicians list of core EUS benchmarks, and the Council of Emergency Medicine Residency-Academy of Emergency Ultrasound consensus document. We assembled a multi-institutional expert panel including 15 faculty members from diverse practice environments and geographical regions. The panel voted on the list of competencies through two rounds of a modified Delphi process using a modified Likert scale (1 = not at all important, 5 = very important) to determine levels of agreement for each application-with revisions occurring between the two rounds. High agreement for consensus was set at >80%. Results: Fifteen of 15 panelists completed the first-round survey (100%) that included 359 topics related to EUS. After the first round, 195 applications achieved high agreement, four applications achieved medium agreement, and 164 applications achieved low agreement. After the discussion, we removed three questions and added 13 questions. Fifteen of 15 panelists completed the second round of the survey (100%) with 209 of the 369 applications achieving consensus. Conclusion: Our final list represents expert opinion on EUS competencies for graduating EM residents. We hope to use this consensus list to implement a more consistent EUS curriculum for graduating EM residents and to standardize EUS training across EM residency programs.

Operative Hysteroscopy Intravascular Absorption Syndrome Causing Hyponatremia with Associated Cerebral and Pulmonary Edema.

Operative hysteroscopy intravascular absorption syndrome is an iatrogenic syndrome caused by absorption of hypo-osmolar distension medium during hysteroscopy, which can lead to rapid hyponatremia with resulting cerebral and pulmonary edema. We present a case of a 47-year-old female who underwent hysteroscopic myomectomy at an outpatient ambulatory surgical center who was brought to the emergency department with dyspnea, hypoxia, and altered mental status. Workup showed hyponatremia with cerebral edema on computed tomography of the head and pulmonary edema on chest radiograph. The patient improved after resuscitation with intravenous saline and supplemental oxygen, and she was discharged home the next day.

Zebrafish models to study drug abuse-related phenotypes.

Mounting evidence implicates the zebrafish (Danio rerio) as a promising model species for reward and addiction research. Modeling drug abuse-related behavior in both adult and larval zebrafish produced a wealth of clinically translatable data, also demonstrating their sensitivity to various drugs of abuse and the ability to develop tolerance. Several studies have also applied withdrawal paradigms to model the adverse effects of drug abuse in zebrafish. In this review, we summarize recent findings of a wide spectrum of zebrafish drug abuse-related behavioral and physiological phenotypes, discuss the existing challenges, and outline potential future directions of research in this field.

Measuring behavioral and endocrine responses to novelty stress in adult zebrafish.

Several behavioral assays are currently used for high-throughput neurophenotyping and screening of genetic mutations and psychotropic drugs in zebrafish (Danio rerio). In this protocol, we describe a battery of two assays to characterize anxiety-related behavioral and endocrine phenotypes in adult zebrafish. Here, we detail how to use the 'novel tank' test to assess behavioral indices of anxiety (including reduced exploration, increased freezing behavior and erratic movement), which are quantifiable using manual registration and computer-aided video-tracking analyses. In addition, we describe how to analyze whole-body zebrafish cortisol concentrations that correspond to their behavior in the novel tank test. This protocol is an easy, inexpensive and effective alternative to other methods of measuring stress responses in zebrafish, thus enabling the rapid acquisition and analysis of large amounts of data. As will be shown here, fish anxiety-like behavior can be either attenuated or exaggerated depending on stress or drug exposure, with cortisol levels generally expected to parallel anxiety behaviors. This protocol can be completed over the course of 2 d, with a variable testing duration depending on the number of fish used.

Characterization of behavioral and endocrine effects of LSD on zebrafish.

Lysergic acid diethylamide (LSD) is a potent hallucinogenic drug that strongly affects animal and human behavior. Although adult zebrafish (Danio rerio) are emerging as a promising neurobehavioral model, the effects of LSD on zebrafish have not been investigated previously. Several behavioral paradigms (the novel tank, observation cylinder, light-dark box, open field, T-maze, social preference and shoaling tests), as well as modern video-tracking tools and whole-body cortisol assay were used to characterize the effects of acute LSD in zebrafish. While lower doses (5-100 microg/L) did not affect zebrafish behavior, 250 microg/L LSD increased top dwelling and reduced freezing in the novel tank and observation cylinder tests, also affecting spatiotemporal patterns of activity (as assessed by 3D reconstruction of zebrafish traces and ethograms). LSD evoked mild thigmotaxis in the open field test, increased light behavior in the light-dark test, reduced the number of arm entries and freezing in the T-maze and social preference test, without affecting social preference. In contrast, LSD affected zebrafish shoaling (increasing the inter-fish distance in a group), and elevated whole-body cortisol levels. Overall, our findings show sensitivity of zebrafish to LSD action, and support the use of zebrafish models to study hallucinogenic drugs of abuse.

Neurosteroid vitamin D system as a nontraditional drug target in neuropsychopharmacology.

Vitamin D is becoming increasingly recognized as a nontraditional drug target for different brain pathologies. Although widely known for their role in calcium metabolism, vitamin D and its receptor have been linked to several brain disorders, including cognitive decline, epilepsy, affective disorders, and schizophrenia. Here we discuss mounting evidence, and parallel recent clinical and animal behavioral, genetic and pharmacological data to emphasize the emerging role of the neurosteroid vitamin D system in brain function.

The effects of chronic social defeat stress on mouse self-grooming behavior and its patterning.

Stress induced by social defeat is a strong modifier of animal anxiety and depression-like phenotypes. Self-grooming is a common rodent behavior, and has an ordered cephalo-caudal progression from licking of the paws to head, body, genitals and tail. Acute stress is known to alter grooming activity levels and disrupt its patterning. Following 15-17 days of chronic social defeat stress, grooming behavior was analyzed in adult male C57BL/6J mice exhibiting either dominant or subordinate behavior. Our study showed that subordinate mice experience higher levels of anxiety and display disorganized patterning of their grooming behaviors, which emerges as a behavioral marker of chronic social stress. These findings indicate that chronic social stress modulates grooming behavior in mice, thus illustrating the importance of grooming phenotypes for neurobehavioral stress research.

Modeling withdrawal syndrome in zebrafish.

The zebrafish (Danio rerio) is rapidly becoming a popular model species in behavioral neuroscience research. Zebrafish behavior is robustly affected by environmental and pharmacological manipulations, and can be examined using exploration-based paradigms, paralleled by analysis of endocrine (cortisol) stress responses. Discontinuation of various psychotropic drugs evokes withdrawal in both humans and rodents, characterized by increased anxiety. Sensitivity of zebrafish to drugs of abuse has been recently reported in the literature. Here we examine the effects of ethanol, diazepam, morphine and caffeine withdrawal on zebrafish behavior. Overall, discontinuation of ethanol, diazepam and morphine produced anxiogenic-like behavioral or endocrine responses, demonstrating the utility of zebrafish in translational research of withdrawal syndrome.

Analyzing habituation responses to novelty in zebrafish (Danio rerio).

Analysis of habituation is widely used to characterize animal cognitive phenotypes and their modulation. Although zebrafish (Danio rerio) are increasingly utilized in neurobehavioral research, their habituation responses have not been extensively investigated. Utilizing the novel tank test, we examine intra- and inter-session habituation and demonstrate robust habituation responses in adult zebrafish. Analyzing the intra-session habituation to novelty further, we also show that selected anxiogenic drugs (caffeine, pentylenetetrazole), as well as stress-inducing alarm pheromone, attenuated zebrafish habituation. Some acute anxiolytic agents, such as morphine and ethanol, while predictably reducing zebrafish anxiety, had no effects on habituation. Chronic ethanol and fluoxetine treatments improved intra-session habituation in zebrafish. In general, our study parallels literature on rodent habituation responses to novelty, and reconfirms zebrafish as a promising model for cognitive neurobehavioral research.

Understanding behavioral and physiological phenotypes of stress and anxiety in zebrafish.

The zebrafish (Danio rerio) is emerging as a promising model organism for experimental studies of stress and anxiety. Here we further validate zebrafish models of stress by analyzing how environmental and pharmacological manipulations affect their behavioral and physiological phenotypes. Experimental manipulations included exposure to alarm pheromone, chronic exposure to fluoxetine, acute exposure to caffeine, as well as acute and chronic exposure to ethanol. Acute (but not chronic) alarm pheromone and acute caffeine produced robust anxiogenic effects, including reduced exploration, increased erratic movements and freezing behavior in zebrafish tested in the novel tank diving test. In contrast, ethanol and fluoxetine had robust anxiolytic effects, including increased exploration and reduced erratic movements. The behavior of several zebrafish strains was also quantified to ascertain differences in their behavioral profiles, revealing high-anxiety (leopard, albino) and low-anxiety (wild type) strains. We also used LocoScan (CleverSys Inc.) video-tracking tool to quantify anxiety-related behaviors in zebrafish, and dissect anxiety-related phenotypes from locomotor activity. Finally, we developed a simple and effective method of measuring zebrafish physiological stress responses (based on a human salivary cortisol assay), and showed that alterations in whole-body cortisol levels in zebrafish parallel behavioral indices of anxiety. Collectively, our results confirm zebrafish as a valid, reliable, and high-throughput model of stress and affective disorders.