Automated electronic medical record sepsis detection in the emergency department

Background. While often first treated in the emergency department (ED), identification of sepsis is difficult. Electronic medical record (EMR) clinical decision tools offer a novel strategy for identifying patients with sepsis. The objective of this study was to test the accuracy of an EMR-based, automated sepsis identification system.Methods. We tested an EMR-based sepsis identification tool at a major academic, urban ED with 64,000 annual visits. The EMR system collected vital sign and laboratory test information on all ED patients, triggering a “sepsis alert” for those with ≥2 SIRS (systemic inflammatory response syndrome) criteria (fever, tachycardia, tachypnea, leukocytosis) plus ≥1 major organ dysfunction (SBP ≤ 90 mm Hg, lactic acid ≥2.0 mg/dL). We confirmed the presence of sepsis through manual review of physician, nursing, and laboratory records. We also reviewed a random selection of ED cases that did not trigger a sepsis alert. We evaluated the diagnostic accuracy of the sepsis identification tool.Results. From January 1 through March 31, 2012, there were 795 automated sepsis alerts. We randomly selected 300 cases without a sepsis alert from the same period. The true prevalence of sepsis was 355/795 (44.7%) among alerts and 0/300 (0%) among non-alerts. The positive predictive value of the sepsis alert was 44.7% (95% CI [41.2–48.2%]). Pneumonia and respiratory infections (38%) and urinary tract infection (32.7%) were the most common infections among the 355 patients with true sepsis (true positives). Among false-positive sepsis alerts, the most common medical conditions were gastrointestinal (26.1%), traumatic (25.7%), and cardiovascular (20.0%) conditions. Rates of hospital admission were: true-positive sepsis alert 91.0%, false-positive alert 83.0%, no sepsis alert 5.7%.Conclusions. This ED EMR-based automated sepsis identification system was able to detect cases with sepsis. Automated EMR-based detection may provide a viable strategy for identifying sepsis in the ED

Molecules with ALMA at Planet-forming Scales (MAPS). VIII. CO gap in AS 209-gas depletion or chemical processing?

Funding: I.C. was supported by NASA through the NASA Hubble Fellowship grant HST-HF2-51405.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. J.D.I. acknowledges support from the Science and Technology Facilities Council of the United Kingdom (STFC) under ST/T000287/1. C.W. acknowledges financial support from the University of Leeds, SFTC, and UKRI (grant Nos. ST/R000549/1, ST/T000287/1, and MR/T040726/1).Emission substructures in gas and dust are common in protoplanetary disks. Such substructures can be linked to planet formation or planets themselves. We explore the observed gas substructures in AS 209 using thermochemical modeling with RAC2D and high-spatial-resolution data from the Molecules with ALMA at Planet-forming Scales (MAPS) program. The observations of C18O J = 2-1 emission exhibit a strong depression at 88 au overlapping with the positions of multiple gaps in millimeter dust continuum emission. We find that the observed CO column density is consistent with either gas surface-density perturbations or chemical processing, while C2H column density traces changes in the C/O ratio rather than the H2 gas surface density. However, the presence of a massive planet (>0.2 MJup) would be required to account for this level of gas depression, which conflicts with constraints set by the dust emission and the pressure profile measured by gas kinematics. Based on our models, we infer that a local decrease of CO abundance is required to explain the observed structure in CO, dominating over a possible gap-carving planet present and its effect on the H2 surface density. This paper is part of the MAPS special issue of the Astrophysical Journal Supplement.Publisher PDFPeer reviewe

Molecules with ALMA at Planet-forming Scales (MAPS). XI. CN and HCN as tracers of photochemistry in disks

Funding: I.C. was supported by NASA through the NASA Hubble Fellowship grant HST-HF2-51405.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. A.S.B. acknowledges the studentship funded by the Science and Technology Facilities Council of the United Kingdom (STFC). J.D.I. acknowledges support from the Science and Technology Facilities Council of the United Kingdom (STFC) under ST/T000287/1. C.W. acknowledges financial support from the University of Leeds, STFC, and UKRI (grant Nos. ST/R000549/1, ST/T000287/1, MR/T040726/1).UV photochemistry in the surface layers of protoplanetary disks dramatically alters their composition relative to previous stages of star formation. The abundance ratio CN/HCN has long been proposed to trace the UV field in various astrophysical objects; however, to date the relationship between CN, HCN, and the UV field in disks remains ambiguous. As part of the ALMA Large Program MAPS (Molecules with ALMA at Planet-forming Scales), we present observations of CN N = 1-0 transitions at 0.″3 resolution toward five disk systems. All disks show bright CN emission within ~50-150 au, along with a diffuse emission shelf extending up to 600 au. In all sources we find that the CN/HCN column density ratio increases with disk radius from about unity to 100, likely tracing increased UV penetration that enhances selective HCN photodissociation in the outer disk. Additionally, multiple millimeter dust gaps and rings coincide with peaks and troughs, respectively, in the CN/HCN ratio, implying that some millimeter substructures are accompanied by changes to the UV penetration in more elevated disk layers. That the CN/HCN ratio is generally high (>1) points to a robust photochemistry shaping disk chemical compositions and also means that CN is the dominant carrier of the prebiotically interesting nitrile group at most disk radii. We also find that the local column densities of CN and HCN are positively correlated despite emitting from vertically stratified disk regions, indicating that different disk layers are chemically linked. This paper is part of the MAPS special issue of the Astrophysical Journal Supplement.Publisher PDFPeer reviewe

Molecules with ALMA at planet-forming scales. XX. The massive disk around GM Aurigae

Funding: K.R.S., K.Z., J.B., J.H., and I.C. acknowledge the support of NASA through Hubble Fellowship Program grants HST-HF2-51419.001, HST-HF2-51401.001, HST-HF2-51427.001-A, HST-HF2-51460.001-A, and HST-HF2-51405.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. J.D.I. acknowledges support from the Science and Technology Facilities Council of the United Kingdom (STFC) under ST/T000287/1. C.W. acknowledges financial support from the University of Leeds, STFC and UKRI (grant numbers ST/R000549/1, ST/T000287/1, MR/T040726/1).Gas mass remains one of the most difficult protoplanetary disk properties to constrain. With much of the protoplanetary disk too cold for the main gas constituent, H2, to emit, alternative tracers such as dust, CO, or the H2 isotopologue HD are used. However, relying on disk mass measurements from any single tracer requires assumptions about the tracer's abundance relative to H2 and the disk temperature structure. Using new Atacama Large Millimeter/submillimeter Array (ALMA) observations from the Molecules with ALMA at Planet-forming Scales (MAPS) ALMA Large Program as well as archival ALMA observations, we construct a disk physical/chemical model of the protoplanetary disk GM Aur. Our model is in good agreement with the spatially resolved CO isotopologue emission from 11 rotational transitions with spatial resolution ranging from 0"15 to 0"46 (24-73 au at 159 pc) and the spatially unresolved HD J = 1-0 detection from Herschel. Our best-fit model favors a cold protoplanetary disk with a total gas mass of approximately 0.2 M⊙, a factor of 10 reduction in CO gas inside roughly 100 au and a factor of 100 reduction outside of 100 au. Despite its large mass, the disk appears to be on the whole gravitationally stable based on the derived Toomre Q parameter. However, the region between 70 and 100 au, corresponding to one of the millimeter dust rings, is close to being unstable based on the calculated Toomre Q of <1.7. This paper is part of the MAPS special issue of the Astrophysical Journal Supplement.Publisher PDFPeer reviewe

Molecules with ALMA at Planet-forming Scales (MAPS). XVIII. Kinematic substructures in the disks of HD 163296 and MWC 480

Funding: K.Z., K.R.S., J.H., J.B., J.B.B., and I.C. acknowledge the support of NASA through Hubble Fellowship grants HST-HF2-51401.001, HST-HF2-51419.001, HST-HF2-51460.001-A, HSTHF2-51427.001-A, HST-HF2-51429.001-A, and HST-HF2-51405.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. A.S.B. acknowledges the studentship funded by the Science and Technology Facilities Council of the United Kingdom (STFC). C.W. acknowledges financial support from the University of Leeds, STFC, and UKRI (grant Nos. ST/R000549/1, ST/T000287/1, MR/T040726/1).We explore the dynamical structure of the protoplanetary disks surrounding HD 163296 and MWC 480 as part of the Molecules with ALMA at Planet-forming Scales (MAPS) large program. Using the J = 2-1 transitions of 12CO, 13CO, and C18O imaged at spatial resolutions of ~0"15 and with a channel spacing of 200 m s-1, we find perturbations from Keplerian rotation in the projected velocity fields of both disks (≲5% of the local Keplerian velocity), suggestive of large-scale (tens of astronomical units in size), coherent flows. By accounting for the azimuthal dependence on the projection of the velocity field, the velocity fields were decomposed into azimuthally averaged orthogonal components, vφ, vr, and vz. Using the optically thick 12CO emission as a probe of the gas temperature, local variations of ≍3 K (≍5% relative changes) were observed and found to be associated with the kinematic substructures. The MWC 480 disk hosts a suite of tightly wound spiral arms. The spirals arms, in conjunction with the highly localized perturbations in the gas velocity structure (kinematic planetary signatures), indicate a giant planet, ~1 MJup, at a radius of ≍245 au. In the disk of HD 163296, the kinematic substructures were consistent with previous studies of Pinte et al. and Teague et al. advocating for multiple ~1 MJup planets embedded in the disk. These results demonstrate that molecular line observations that characterize the dynamical structure of disks can be used to search for the signatures of embedded planets. This paper is part of the MAPS special issue of the Astrophysical Journal Supplement.Publisher PDFPeer reviewe

Molecules with ALMA at Planet-Forming Scales (MAPS). IX. Distribution and properties of the large organic molecules HC3N, CH3CN, and c-C3H2

Funding: J.D.I. acknowledges support from the Science and Technology Facilities Council of the United Kingdom (STFC) under ST/T000287/1. C.W. acknowledges financial support from the University of Leeds, STFC and UKRI (grant Nos. ST/R000549/1, ST/T000287/1, MR/T040726/1). A.S.B acknowledges the studentship funded by the Science and Technology Facilities Council of the United Kingdom (STFC). I.C. was supported by NASA through the NASA Hubble Fellowship grant HST-HF2-51405.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555.The precursors to larger, biologically relevant molecules are detected throughout interstellar space, but determining the presence and properties of these molecules during planet formation requires observations of protoplanetary disks at high angular resolution and sensitivity. Here, we present 0"3 observations of HC3N, CH3CN, and c-C3H2 in five protoplanetary disks observed as part of the Molecules with ALMA at Planet-forming Scales (MAPS) Large Program. We robustly detect all molecules in four of the disks (GM Aur, AS 209, HD 163296, and MWC 480) with tentative detections of c-C3H2 and CH3CN in IM Lup. We observe a range of morphologies-central peaks, single or double rings-with no clear correlation in morphology between molecule or disk. Emission is generally compact and on scales comparable with the millimeter dust continuum. We perform both disk-integrated and radially resolved rotational diagram analysis to derive column densities and rotational temperatures. The latter reveals 5-10 times more column density in the inner 50-100 au of the disks when compared with the disk-integrated analysis. We demonstrate that CH3CN originates from lower relative heights in the disks when compared with HC3N, in some cases directly tracing the disk midplane. Finally, we find good agreement between the ratio of small to large nitriles in the outer disks and comets. Our results indicate that the protoplanetary disks studied here are host to significant reservoirs of large organic molecules, and that this planet- and comet-building material can be chemically similar to that in our own solar system. This paper is part of the MAPS special issue of the Astrophysical Journal Supplement.Publisher PDFPeer reviewe

Molecules with ALMA at Planet-forming Scales (MAPS). XIII. HCO+ and disk ionization structure

Funding: K.Z., K.R.S., J.H., J.B., J.B.B., and I.C. acknowledge the support of NASA through Hubble Fellowship grants HST-HF2-51401.001, HST-HF2-51419.001, HST-HF2-51460.001-A, HST-HF2-51427.001-A, HST-HF2-51429.001-A, and HST-HF2-51405.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. J.D.I. acknowledges support from the Science and Technology Facilities Council of the United Kingdom (STFC) under ST/T000287/1. C.W. acknowledges financial support from the University of Leeds, STFC and UKRI (grant Nos. ST/R000549/1, ST/T000287/1, and MR/T040726/1).We observed HCO+ J = 1 - 0 and H13CO+ J = 1 - 0 emission toward the five protoplanetary disks around IM Lup, GM Aur, AS 209, HD 163296, and MWC 480 as part of the MAPS project. HCO+ is detected and mapped at 0"3 resolution in all five disks, while H13CO+ is detected (S/N > 6σ) toward GM Aur and HD 163296 and tentatively detected (S/N > 3σ) toward the other disks by a matched filter analysis. Inside a radius of R ~ 100 au, the HCO+ column density is flat or shows a central dip. At outer radii (≳100 au), the HCO+ column density decreases outward, while the column density ratio of HCO+/CO is mostly in the range of ~10-5-10-4. We derived the HCO+ abundance in the warm CO-rich layer, where HCO+ is expected to be the dominant molecular ion. At R ≳ 100 au, the HCO+ abundance is ~3 × 10-11 - 3 × 10-10, which is consistent with a template disk model with X-ray ionization. At the smaller radii, the abundance decreases inward, which indicates that the ionization degree is lower in denser gas, especially inside the CO snow line, where the CO-rich layer is in the midplane. Comparison of template disk models with the column densities of HCO+, N2H+, and N2D+ indicates that the midplane ionization rate is ≳10-18 s-1 for the disks around IM Lup, AS 209, and HD 163296. We also find hints of an increased HCO+ abundance around the location of dust continuum gaps in AS 209, HD 163296, and MWC 480. This paper is part of the MAPS special issue of the Astrophysical Journal Supplement.Publisher PDFPeer reviewe

Molecules with ALMA at Planet-forming Scales (MAPS). XII. Inferring the C/O and S/H ratios in protoplanetary disks with sulfur molecules

Funding: I.C. was supported by NASA through the NASA Hubble Fellowship grant HST-HF2-51405.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. C.W. acknowledges financial support from the University of Leeds, STFC, and UKRI (grant Nos. ST/R000549/1, ST/T000287/1, MR/T040726/1). J.D.I. acknowledges support from the Science and Technology Facilities Council of the United Kingdom (STFC) under ST/T000287/1.Sulfur-bearing molecules play an important role in prebiotic chemistry and planet habitability. They are also proposed probes of chemical ages, elemental C/O ratio, and grain chemistry processing. Commonly detected in diverse astrophysical objects, including the solar system, their distribution and chemistry remain, however, largely unknown in planet-forming disks. We present CS (2 - 1) observations at ~0"3 resolution performed within the ALMA MAPS Large Program toward the five disks around IM Lup, GM Aur, AS 209, HD 163296, and MWC 480. CS is detected in all five disks, displaying a variety of radial intensity profiles and spatial distributions across the sample, including intriguing apparent azimuthal asymmetries. Transitions of C2S and SO were also serendipitously covered, but only upper limits are found. For MWC 480, we present complementary ALMA observations at ~ 0"5 of CS, 13CS, C34S, H2CS, OCS, and SO2. We find a column density ratio N(H2CS)/N(CS) ~ 2/3, suggesting that a substantial part of the sulfur reservoir in disks is in organic form (i.e., CxHySz). Using astrochemical disk modeling tuned to MWC 480, we demonstrate that N(CS)/N(SO) is a promising probe for the elemental C/O ratio. The comparison with the observations provides a supersolar C/O. We also find a depleted gas-phase S/H ratio, suggesting either that part of the sulfur reservoir is locked in solid phase or that it remains in an unidentified gas-phase reservoir. This paper is part of the MAPS special issue of the Astrophysical Journal Supplement.Publisher PDFPeer reviewe