Hyperoxemia and excess oxygen use in early acute respiratory distress syndrome : Insights from the LUNG SAFE study

Publisher Copyright: © 2020 The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Background: Concerns exist regarding the prevalence and impact of unnecessary oxygen use in patients with acute respiratory distress syndrome (ARDS). We examined this issue in patients with ARDS enrolled in the Large observational study to UNderstand the Global impact of Severe Acute respiratory FailurE (LUNG SAFE) study. Methods: In this secondary analysis of the LUNG SAFE study, we wished to determine the prevalence and the outcomes associated with hyperoxemia on day 1, sustained hyperoxemia, and excessive oxygen use in patients with early ARDS. Patients who fulfilled criteria of ARDS on day 1 and day 2 of acute hypoxemic respiratory failure were categorized based on the presence of hyperoxemia (PaO2 > 100 mmHg) on day 1, sustained (i.e., present on day 1 and day 2) hyperoxemia, or excessive oxygen use (FIO2 ≥ 0.60 during hyperoxemia). Results: Of 2005 patients that met the inclusion criteria, 131 (6.5%) were hypoxemic (PaO2 < 55 mmHg), 607 (30%) had hyperoxemia on day 1, and 250 (12%) had sustained hyperoxemia. Excess FIO2 use occurred in 400 (66%) out of 607 patients with hyperoxemia. Excess FIO2 use decreased from day 1 to day 2 of ARDS, with most hyperoxemic patients on day 2 receiving relatively low FIO2. Multivariate analyses found no independent relationship between day 1 hyperoxemia, sustained hyperoxemia, or excess FIO2 use and adverse clinical outcomes. Mortality was 42% in patients with excess FIO2 use, compared to 39% in a propensity-matched sample of normoxemic (PaO2 55-100 mmHg) patients (P = 0.47). Conclusions: Hyperoxemia and excess oxygen use are both prevalent in early ARDS but are most often non-sustained. No relationship was found between hyperoxemia or excessive oxygen use and patient outcome in this cohort. Trial registration: LUNG-SAFE is registered with ClinicalTrials.gov, NCT02010073publishersversionPeer reviewe

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals &lt;1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Teaching psychiatric pharmacogenomics effectively: Evaluation of a novel interprofessional online course

IntroductionThe application of pharmacogenomic (PGx) testing to guide psychotropic use is increasing, but there is a lack of training opportunities for health care providers designed specifically around the unique issues impacting the use and interpretation of PGx in psychiatry. Furthermore, providing such education online greatly improves the accessibility of such training.ObjectiveThe objective was to design and evaluate a live online continuing education (CE) course on psychiatric PGx for health care providers.MethodsA multidisciplinary team of experts in psychiatry, PGx, and medical education research designed a three‐session online course to discuss key psychiatric PGx topics ranging from fundamental background material, selecting a test, and interpreting and applying results. A deliberate design of the program was to offer the course three times, in order to allow successive improvements to each iteration. To evaluate the course, pre‐ and post‐surveys were developed with the intent of capturing change in the four Dixon levels of CE evaluation on attendee perceptions and opinions, knowledge and attitudes, and impact on clinical practice and patient outcomes.ResultsIn the third course iteration, 32 health care providers registered. Among survey respondents, the course materials, speakers, organization, and online format were reviewed favorably by the majority of attendees. Perceived knowledge of PGx increased in every identified PGx topic domain and was largely reflected by improved knowledge assessment scores. A limited number of survey participants also indicated changes in clinical behavior and patient outcomes as a direct result of the material covered in this course.ConclusionsAmong survey respondents, this novel online PGx course proved effective at increasing provider understanding and confidence in key psychiatric PGx topic areas. It also demonstrated the viability of the online format, a vital characteristic to allow for future widespread dissemination.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/166349/1/jac51381_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/166349/2/jac51381.pd

Hydrogen Peroxide-Induced Oxidation of Mixtures of Alkanethiols and Their Quantitative Detection as Alkanesulfonates by Electrospray Ionization Mass Spectrometry

Finding optimal experimental conditions for generating stable negative ion electrospray ionization ion trap mass spectra (ESI-IT-MS) of alkanethiol-derived species is critical for quantitatively characterizing multicomponent alkanethiol-based self-assembled monolayers by this technique. Since alkanethiolates slowly oxidize in solution, purposeful oxidation of alkanethiols to their fully oxidized form (alkanesulfonates) is advantageous: sulfonates are chemically stable and have little affinity for covalent binding to metal surfaces. We have used ESI-IT-MS to characterize the products of H₂O₂ oxidation of simple <i>n</i>-alkanethiols in solution and have observed monomeric alkanesulfonate species as well as alkanesulfonic acid/alkanesulfonate adducts, yielding gas-phase dimers and trimers. MS intensities of both monomers and adducts exhibit a dependence on the ion transfer capillary temperature that is alkyl-chain-length-dependent and that appears to be correlated with C–S bond cleavage. The trend in optimal capillary temperatures indicates that entropic effects lead to lower thermal decomposition temperatures for short-chain species relative to the longer-chain homologues. MS calibration data from alkanesulfonate mixtures are characterized by large linear dynamic ranges (10^–6–10^–3 M) and detection limits influenced by their thermal decomposition. The high degree of precision in the calibration data should facilitate distinguishing among mixed SAMs having similar compositions

Risk Prediction Models for Hospital Mortality in General Medical Patients: A Systematic Review

Objective: To systematically review contemporary prediction models for hospital mortality developed or validated in general medical patients. Methods: We screened articles in five databases, from January 1, 2010, through April 7, 2022, and the bibliography of articles selected for final inclusion. We assessed the quality for risk of bias and applicability using the Prediction Model Risk of Bias Assessment Tool (PROBAST) and extracted data using the Critical Appraisal and Data Extraction for Systematic Reviews of Prediction Modelling Studies (CHARMS) checklist. Two investigators independently screened each article, assessed quality, and extracted data. Results: From 20,424 unique articles, we identified 15 models in 8 studies across 10 countries. The studies included 280,793 general medical patients and 19,923 hospital deaths. Models included 7 early warning scores, 2 comorbidities indices, and 6 combination models. Ten models were studied in all general medical patients (general models) and 7 in general medical patients with infection (infection models). Of the 15 models, 13 were developed using logistic or Poisson regression and 2 using machine learning methods. Also, 4 of 15 models reported on handling of missing values. None of the infection models had high discrimination, whereas 4 of 10 general models had high discrimination (area under curve >0.8). Only 1 model appropriately assessed calibration. All models had high risk of bias; 4 of 10 general models and 5 of 7 infection models had low concern for applicability for general medical patients. Conclusion: Mortality prediction models for general medical patients were sparse and differed in quality, applicability, and discrimination. These models require hospital-level validation and/or recalibration in general medical patients to guide mortality reduction interventions