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P085: Remember that patient you saw last week – Characteristics of patients experiencing unanticipated death following emergency department discharge
- R. Hoang, K. Sampsel, A. Willmore, K. Yelle-Labre, V. Thiruganasambandamoorthy, L. Calder
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- Journal:
- Canadian Journal of Emergency Medicine / Volume 22 / Issue S1 / May 2020
- Published online by Cambridge University Press:
- 13 May 2020, p. S95
- Print publication:
- May 2020
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Background: The emergency department (ED) is an at-risk area for medical error. We measured the frequency and characteristics of patients with unanticipated death within 7 days of ED discharge and whether medical error contributed. Aim Statement: This study aimed to calculate the frequency of patients experiencing death within 7 days after ED discharge and determine whether these deaths were related to their index ED visit, were unanticipated, and whether possible medical error occurred. Measures & Design: We performed a single-centre health records review of 200 consecutive cases from an eligible 458,634 ED visits from 2014-2017 in two urban, academic, tertiary care EDs. We included patients evaluated by an emergency physician who were discharged and died within 7 days. Three trained and blinded reviewers determined if deaths were related to the index visit, anticipated or unanticipated, or due to potential medical error. Reviewers performed content analysis to identify themes. Evaluation/Results: Of the 200 cases, 129 had sufficient information for analysis, translating to 44 deaths per 100,000 ED discharges. We found 13 cases per 100,000 ED discharges were related and unanticipated deaths and 18 of these were due to potential medical errors. Over half (52.7%) of 129 patients displayed abnormal vital signs at discharge. Patients experienced pneumonia (27.1%) as their most common cause of death. Patient characteristic themes were: difficult historian, multiple complaints, multiple comorbidities, acute progression of chronic disease, recurrent falls. Provider themes were: failure to consider infectious etiology, failure to admit high-risk elderly patient, missed diagnosis. System themes included multiple ED visits or recent admission, no repeat vital signs recorded. Discussion/Impact: Though the frequency of related and unanticipated deaths and those due to medical error was low, these results highlight opportunities to potentially enhance ED discharge decisions. These data add to the growing body of ED diagnostic error literature and emphasize the importance of identifying potentially high risk patients as well as being cognizant of the common medical errors leading to patient harm.
5 - The composition of Titan's atmosphere
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- By B. Bézard, LESIA, Observatoire de Paris, Section de Meudon, R. V. Yelle, University of Arizona, C. A. Nixon, University of Martland
- Edited by Ingo Müller-Wodarg, Imperial College London, Caitlin A. Griffith, University of Arizona, Emmanuel Lellouch, Observatoire de Paris, Meudon, Thomas E. Cravens, University of Kansas
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- Book:
- Titan
- Published online:
- 05 January 2014
- Print publication:
- 24 February 2014, pp 158-189
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Summary
5.1 Introduction
Titan's atmosphere harbors a suite of hydrocarbons and nitrogen-bearing compounds formed from the dissociation of the two main species, nitrogen (N2)and methane (CH4). It also contains oxygen compounds, likely produced from an influx of water and/or oxygen. The mixing ratios of these photochemical species vary with altitude, latitude, and time as a consequence of various chemical sources and sinks and of the atmospheric transport that redistributes them both vertically and horizontally. It is important to characterize and monitor the distribution of these chemical species because they play an important role in the radiative budget and provide insight into the seasonally varying atmospheric circulation. They can also help us understand the complex chemistry at work in Titan's atmosphere, leading to the formation of thick haze layers, which in turn affect the heat balance and general circulation. This chapter reviews the neutral composition of Titan's atmosphere, from the troposphere up to the thermosphere (~ 1400 km), and its vertical, horizontal, and temporal variations. These topics are interwoven with the origin and evolution, the general circulation, the clouds and weather, and the atmospheric chemistry of Titan that are the subjects of Chapters 1, 4, 6, and 7.
5.1.1 Historical perspective
The first unquestionable evidence for an atmosphere on Titan was the discovery of several absorption bands of methane in near-infrared spectra of the satellite (Kuiper, 1944). But it was not until the 1970s that Titan became an object of intense study.
9 - Titan's upper atmosphere: thermal structure, dynamics, and energetics
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- By R. V. Yelle, University of Arizona, D. S. Snowden, University of Arizona, I. C. F. Müller-Wodarg, Imperial College London
- Edited by Ingo Müller-Wodarg, Imperial College London, Caitlin A. Griffith, University of Arizona, Emmanuel Lellouch, Observatoire de Paris, Meudon, Thomas E. Cravens, University of Kansas
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- Book:
- Titan
- Published online:
- 05 January 2014
- Print publication:
- 24 February 2014, pp 322-354
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Summary
9.1 Introduction and some history
Titan, with its dense atmosphere, low gravity, weak solar insolation, and complex composition, provides a unique example of a planetary upper atmosphere. The large mass of the atmosphere, coupled with low gravity, results in a greatly extended atmosphere where the plane parallel assumption, nearly universal in terrestrial and giant planet atmosphere studies, no longer applies. Moreover, the weak gravity results in large escape rates that may play a significant role in upper atmospheric thermal balance. The weak solar insolation means that in many cases dynamical processes can dominate over solar processes, while at the same time the complex composition causes radiative cooling processes to be more important than in most other planetary upper atmospheres. Most of the time Titan orbits within Saturn's magnetosphere and the interaction with energetic particle populations may significantly alter the upper atmosphere. Measurements by the Cassini spacecraft have allowed us to greatly extend our knowledge of the thermal balance in Titan's upper atmosphere, although the main result so far may be the realization that the simple descriptions employed before Cassini fail to capture the complexity and variability of this enigmatic atmosphere. To understand the progress enabled by Cassini-Huygens measurements, we first review our knowledge of thermal balance in Titan's upper atmosphere based on observations by the Voyager spacecraft and ground-based telescopes.
The Deep Space 1 Encounter With Comet 19P/Borrelly
- Diane H. Wooden, L. A. Soderblom, D. T. Britt, R. H. Brown, B. R. Sandel, R. V. Yelle, B. J. Buratti, M. D. Hicks, R. M. Nelson, M. D. Rayman, J. Oberst, N. Thomas
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- Journal:
- International Astronomical Union Colloquium/ Volume 186 /
- pp. 301-324
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NASA's Deep Space 1 (DSl) spacecraft successfully encountered comet 19P/Borrelly near perihelion and the Miniature Integrated Camera and Spectrometer (MICAS) imaging system onboard DS1 returned the first high-resolution images of a Jupiter-family comet nucleus and surrounding environment. The images span solar phase angles from 88° to 52°, providing stereoscopic coverage of the dust coma and nucleus. Numerous surface features are revealed on the 8-km long nucleus in the highest resolution images (47-58 m/pixel). A smooth, broad basin containing brighter regions and mesa-like structures is present in the central part of the nucleus that seems to be the source of jet-like dust features seen in the coma. High ridges seen along the jagged terminator lead to rugged terrain on both ends of the nucleus containing dark patches and smaller series of parallel grooves. No evidence of impact craters with diameters larger than about 200-m are present, indicating a young and active surface. The nucleus is very dark with albedo variations from 0.007 to 0.035. Short-wavelength, infrared spectra from 1.3 to 2.6 μm revealed a hot, dry surface consistent with less than about 10% actively sublimating. Two types of dust features are seen: broad fans and highly collimated “jets” in the sunward hemisphere that can be traced to the surface. The source region of the main jet feature, which resolved into at least three smaller “jets” near the surface, is consistent with an area around the rotation pole that is constantly illuminated by the sun during the encounter. Within a few nuclear radii, entrained dust is rapidly accelerated and fragmented and geometrical effects caused from extended source regions are present, as evidenced in radial intensity profiles centered on the jet features that show an increase in source strength with increasing cometocentric distance. Asymmetries in the dust from dayside to nightside are pronounced and may show evidence of lateral flow transporting dust to structures observed in the nightside coma. A summary of the initial results of the Deep Space 1 Mission is provided, highlighting the new knowledge that has been gained thus far.