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

Hard Cases Make Bad History: Doctors and children between the wars

B1 - Research Book Chapter

Origins of ‘the gap’: perspectives on the historical demography of aboriginal victorians

Australia enjoys ninth place out of 190 countries on the United Nations Life Expectancy Index. Aboriginal Australians—as a fourth-world people within a first-world society—rank in the bottom half of the Index, just below Guatemala and Bangladesh. Progress on closing ‘the gap’ in health and wellbeing has been slow, despite initial rapid gains in infant mortality. The barriers are inter-generational trauma, inherited disadvantage, poverty and systemic racism. This paper reports on the Koori Health Research Database, a cradle-to-grave dataset of Aboriginal Victorians from the 1840s. It finds that population recovery after the nadir reached at the end of the nineteenth century, was hindered by high acquired secondary infertility among women vulnerable to sexual abuse, violence and sexually transmitted infections. Improvements in survival and the health transition were ‘blocked’ by barriers to land acquisition and full citizenship, as has happened in New Zealand. The dramatic recovery of the population of people now identifying as Aboriginal in Victoria has come from out-marriage.Funding for this project was provided by the Australian Research Council (McCalman; Land and Life: Aborigines, Convicts and Immigrants in Victoria, 1835–1985; DP110102368), the Swedish Research Council (Axelsson, Kukutai, Kippen; Indigenous Health in Transition: a Longitudinal Study of Colonisation, State and the Health of Indigenous Peoples in Sweden, Australia and New Zealand, 1850– 2000; 2012–5490) and the Australian National Data Service (Kippen, McCalman, Silcot; Founders and Survivors: Genealogical Connections; AP20

Colonial health transitions: Aboriginal and 'poor white' infant mortality compared, Victoria 1850-1910

This paper presents results from the first two longitudinal historical cradle-to-grave datasets constructed in Australia: the Aboriginal population of the state of Victoria, reconstituted using genealogical research and vital registrations, 1835-1930; and an impoverished European population sample born at the Melbourne Lying-In Hospital, 1857-1900 and traced until 1985. It investigates the comparative infant mortality between these two severely disadvantaged population samples and finds apparently contradictory results. Aboriginal people had shorter survival at all ages apart from infancy. Infant mortality among the poor white women delivering in an urban charity hospital was extreme but their survival at all later life stages was superior to that of the Aborigines. Critical for both groups of babies and their mothers was the presence or absence of household support during pregnancy and the first year of life, and the poor whites' birth weights embodied a social gradient of degrees of family and breadwinner support. Aboriginal babies spent their first year of life, despite the community trauma of cruel government 'management' and exclusion from entitlements, in an ecology that protected them from the disorders of feeding and gastrointestinal disease that cut down so many of the poor white babies. The differences in both mortality and causes of death indicate very different relationships between babies and their mothers and fathers and with the state. The sudden fall in the Lying-In Hospital infant mortality from 1887 was effected by direct state and medical interventions. The equally sudden and continuing rise in infant mortality among the Victorian Aboriginal community can be traced to their expulsion from the support of the reserves and the commencement of decades of 'invisibility' and denial of state entitlements and medical care

Building a life course dataset from Australian convict records Founders & Survivors: Australian life courses in historical context 1803-1920

Founders & Survivors is a multi-university and public collaborative project that is building a transnational and intergenerational dataset of life courses generated from the UNESCO recognised convict records of Tasmania. This chapter outlines the technical history of the project: Mass digitization and archiving online of over 100,000 images, manual scholarly transcription and the building of a prosopography database. This comprises a relational genealogy database integrated with an XML (BaseX) source database. Individual life histories are compiled dynamically from diverse sources, linked by a combination of machine matching and human judgment, and managed by an independent link management module. Using Google Docs over 50 online volunteers crowdsourced the convict genealogies and coded the data. Manual linkage and scholarly verification remained essential for the collation of prosopographical data and manual coding was necessary for statistical analysis

Research note: The founders and survivors project

This paper describes the multidisciplinary project Founders and Survivors: Australian Life Courses in Historical Context. Individual life courses, families and generations through the nineteenth and twentieth centuries are being reconstituted from a wid

Immunocompromised patients with acute respiratory distress syndrome: Secondary analysis of the LUNG SAFE database

Background: The aim of this study was to describe data on epidemiology, ventilatory management, and outcome of acute respiratory distress syndrome (ARDS) in immunocompromised patients. Methods: We performed a post hoc analysis on the cohort of immunocompromised patients enrolled in the Large Observational Study to Understand the Global Impact of Severe Acute Respiratory Failure (LUNG SAFE) study. The LUNG SAFE study was an international, prospective study including hypoxemic patients in 459 ICUs from 50 countries across 5 continents. Results: Of 2813 patients with ARDS, 584 (20.8%) were immunocompromised, 38.9% of whom had an unspecified cause. Pneumonia, nonpulmonary sepsis, and noncardiogenic shock were their most common risk factors for ARDS. Hospital mortality was higher in immunocompromised than in immunocompetent patients (52.4% vs 36.2%; p &lt; 0.0001), despite similar severity of ARDS. Decisions regarding limiting life-sustaining measures were significantly more frequent in immunocompromised patients (27.1% vs 18.6%; p &lt; 0.0001). Use of noninvasive ventilation (NIV) as first-line treatment was higher in immunocompromised patients (20.9% vs 15.9%; p = 0.0048), and immunodeficiency remained independently associated with the use of NIV after adjustment for confounders. Forty-eight percent of the patients treated with NIV were intubated, and their mortality was not different from that of the patients invasively ventilated ab initio. Conclusions: Immunosuppression is frequent in patients with ARDS, and infections are the main risk factors for ARDS in these immunocompromised patients. Their management differs from that of immunocompetent patients, particularly the greater use of NIV as first-line ventilation strategy. Compared with immunocompetent subjects, they have higher mortality regardless of ARDS severity as well as a higher frequency of limitation of life-sustaining measures. Nonetheless, nearly half of these patients survive to hospital discharge. Trial registration: ClinicalTrials.gov, NCT02010073. Registered on 12 December 2013

Mechanical ventilation in patients with cardiogenic pulmonary edema: a sub-analysis of the LUNG SAFE study

International audienceBackground: Patients with acute respiratory failure caused by cardiogenic pulmonary edema (CPE) may require mechanical ventilation that can cause further lung damage. Our aim was to determine the impact of ventilatory settings on CPE mortality. Methods: Patients from the LUNG SAFE cohort, a multicenter prospective cohort study of patients undergoing mechanical ventilation, were studied. Relationships between ventilatory parameters and outcomes (ICU discharge/ hospital mortality) were assessed using latent mixture analysis and a marginal structural model. Results: From 4499 patients, 391 meeting CPE criteria (median age 70 [interquartile range 59-78], 40% female) were included. ICU and hospital mortality were 34% and 40%, respectively. ICU survivors were younger (67 [57-77] vs 74 [64-80] years, p < 0.001) and had lower driving (12 [8-16] vs 15 [11-17] cmH 2 O, p < 0.001), plateau (20 [15-23] vs 22 [19-26] cmH 2 O, p < 0.001) and peak (21 [17-27] vs 26 [20-32] cmH 2 O, p < 0.001) pressures. Latent mixture analysis of patients receiving invasive mechanical ventilation on ICU day 1 revealed a subgroup ventilated with high pressures with lower probability of being discharged alive from the ICU (hazard ratio [HR] 0.79 [95% confidence interval 0.60-1.05], p = 0.103) and increased hospital mortality (HR 1.65 [1.16-2.36], p = 0.005). In a marginal structural model, driving pressures in the first week (HR 1.12 [1.06-1.18], p < 0.001) and tidal volume after day 7 (HR 0.69 [0.52-0.93], p = 0.015) were related to survival. Conclusions: Higher airway pressures in invasively ventilated patients with CPE are related to mortality. These patients may be exposed to an increased risk of ventilator-induced lung injury