The Effects of Escalation of Respiratory Support and Prolonged Invasive Ventilation on Outcomes of Cardiac Surgical Patients: A Retrospective Cohort Study

Abstract Objectives: The aim of this study was to determine the effects of escalation of respiratory support and prolonged postoperative invasive ventilation on patient–centered outcomes, and identify perioperative factors associated with these two respiratory complications. Design: A retrospective cohort analysis of cardiac surgical patients admitted to cardiothoracic intensive care unit (ICU) between August 2015 and January 2018. Escalation of respiratory support was defined as ‘unplanned continuous positive airway pressure’, ‘non-invasive ventilation’ or ‘reintubation’ following surgery; prolonged invasive ventilation was defined as ‘invasive ventilation beyond the first 12 hours following surgery’. The primary endpoint was the composite of escalation of respiratory support and prolonged ventilation. Setting: Tertiary cardiothoracic ICU. Participants: A total of 2,098 patients were included and analyzed. Interventions: None. Measurements and Main Results: The composite of escalation of support or prolonged ventilation occurred in 509 patients (24.3%). Patients who met the composite had higher mortality (2.9% vs 0.1%; P<0.001) and longer median [interquartile range] length of ICU (2.1 [1.0–4.9] vs 0.9 [0.8–1.0] days; P<0.0001) and hospital (10.6 [8.0–16.0] vs 7.2 [6.2–10.0] days; P<0.0001) stay. Hypoxemia and anemia on admission to ICU were the only two factors independently associated with need for escalation of respiratory support or prolonged invasive ventilation. Conclusions: Escalation of respiratory support or prolonged invasive ventilation are frequently seen in cardiac surgery patients, and are highly associated with increased mortality and morbidity. Hypoxemia and anemia on admission to ICU are potentially modifiable factors associated with escalation of respiratory support or prolonged invasive ventilation.ACM is supported by a Clinical Research Career Development Fellowship from the Wellcome Trust (WT 2055214/Z/16/Z). VZ is supported by an Academic Clinical Fellowship from the National Institute for Health Research (ACF-2016-09-011)

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

The Right Ventricle in ARDS.

ARDS is associated with poor clinical outcomes, with a pooled mortality rate of approximately 40% despite best standards of care. Current therapeutic strategies are based on improving oxygenation and pulmonary compliance while minimizing ventilator-induced lung injury. It has been demonstrated that relative hypoxemia can be well tolerated, and improvements in oxygenation do not necessarily translate into survival benefit. Cardiac failure, in particular right ventricular dysfunction (RVD), is commonly encountered in moderate to severe ARDS and is reported to be one of the major determinants of mortality. The prevalence rate of echocardiographically evident RVD in ARDS varies across studies, ranging from 22% to 50%. Although there is no definitive causal relationship between RVD and mortality, severe RVD is associated with increased mortality. Factors that can adversely affect RV function include hypoxic pulmonary vasoconstriction, hypercapnia, and invasive ventilation with high driving pressure. It might be expected that early diagnosis of RVD would be of benefit; however, echocardiographic markers (qualitative and quantitative) used to prospectively evaluate the right ventricle in ARDS have not been tested in adequately powered studies. In this review, we examine the prognostic implications and pathophysiology of RVD in ARDS and discuss available diagnostic modalities and treatment options. We aim to identify gaps in knowledge and directions for future research that could potentially improve clinical outcomes in this patient population