Hyperoxaemia

BACKGROUND: The optimal target oxygen saturation (SpO2 ) range for hospital inpatients not at risk of hypercapnia is unknown. The objective of this study was to assess the impact on oxygen usage and National Early Warning Score 2 (NEWS2) of changing the standard SpO2 target range from 94-98% to 92-96%. METHODS: In a metropolitan UK hospital, a database of electronic bedside SpO2 measurements, oxygen prescriptions and NEWS2 records was reviewed. Logistic regression was used to compare the proportion of hypoxaemic SpO2 values (<90%) and NEWS2 records ≥5 in 2019, when the target SpO2 range was 94-98%; with 2022, when the target range was 92-96%...

BACKGROUND: The oxygen reserve index (ORi) is a real-time, continuous index measured with multi-wavelength pulse CO-oximetry technology. It estimates mild hyperoxemia in humans, which is defined as a partial pressure of oxygen (PaO2 ) level between 100 and 200 mmHg. The objectives of this study were to assess the correlation between ORi and PaO2 , as well as to determine its ability in detecting mild hyperoxemia in dogs. METHODS: This prospective observational study enrolled 37 anaesthetised and mechanically ventilated dogs undergoing elective procedures...

BACKGROUND: The effect of conservative vs. liberal oxygen therapy on 90-day in-hospital mortality in adults who have nonhypoxic ischaemic encephalopathy acute brain injuries and conditions and are receiving invasive mechanical ventilation in the intensive care unit (ICU) is uncertain. OBJECTIVE: The objective of this study was to summarise the protocol and statistical analysis plan for the Mega-ROX Brains trial. DESIGN SETTING AND PARTICIPANTS: Mega-ROX Brains is an international randomised clinical trial, which will be conducted within an overarching 40,000-participant, registry-embedded clinical trial comparing conservative and liberal ICU oxygen therapy regimens...

BACKGROUND: The effect of conservative vs. liberal oxygen therapy on 90-day in-hospital mortality in adults with sepsis receiving unplanned invasive mechanical ventilation in the intensive care unit (ICU) is uncertain. OBJECTIVE: The objective of this study was to summarise the protocol and statistical analysis plan for the Mega-ROX Sepsis trial. DESIGN SETTING AND PARTICIPANTS: The Mega-ROX Sepsis trial is an international randomised clinical trial that will be conducted within an overarching 40,000-patient registry-embedded clinical trial comparing conservative and liberal ICU oxygen therapy regimens...

OBJECTIVE: This randomised study in preterm infants on non-invasive respiratory support investigated the effectiveness of automated oxygen control (A-FiO2 ) in keeping the oxygen saturation (SpO2 ) within a target range (TR) during a 28-day period compared with manual titration (M-FiO2 ). DESIGN: A single-centre randomised control trial. SETTING: A level III neonatal intensive care unit. PATIENTS: Preterm infants (<28 weeks' gestation) on non-invasive respiratory support...

INTRODUCTION: There is clinical equipoise as to whether hyperoxia is injurious to the myocardium, both in the setting of acute ischaemic insults and on the stable myocardium. This study examined the effect of extreme hyperoxia - in the form of hyperbaric oxygen treatment - on the myocardium through measurement of high-sensitivity cardiac troponin. METHODS: Forty-eight individuals were enrolled to undergo a series of 30 exposures to hyperbaric oxygen for treatment of non-cardiac pathologies...

A significant focus of post-resuscitation research over the last decade has included optimising oxygenation. This has primarily occurred due to an improved understanding of the possible harmful biological effects of high oxygenation, particularly the neurotoxicity of oxygen free radicals. Animal studies and some observational research in humans suggest harm with the occurrence of severe hyperoxaemia (PaO2 > 300 mmHg) in the post-resuscitation phase. This early data informed in a change in treatment recommendations, with the International Liaison Committee on Resuscitation (ILCOR) recommending the avoidance of hyperoxaemia...

BACKGROUND: Ventilated infants frequently require supplemental oxygen, but its use should be monitored carefully due to associated complications. The achievement of oxygen saturation (SpO2 ) targets can be challenging as neonates experience frequent fluctuations of their oxygen levels that further increase the risk of complications. Closed-loop automated oxygen control systems (CLAC) improve achievement of oxygen saturation targets, reduce hyperoxaemic episodes and facilitate weaning of the inspired oxygen concentration in ventilated infants born at or near term...

UNLABELLED: Faster resolution of hypoxaemic or hyperoxaemic events in preterm infants may reduce long-term neurodevelopmental impairment. Automatic titration of inspiratory oxygen increases time within the oxygen saturation target range and may provide a more prompt response to hypoxic and hyperoxic events. We assessed routinely performed follow-up at 2 years of age after the implementation of automated oxygen control (AOC) as standard care and compared this with a historical cohort...

BACKGROUND: An association between post-arrest hyperoxaemia and worse outcomes has been reported for out-of-hospital cardiac arrest (OHCA) patients, but little is known about the relationship between intra-arrest hyperoxaemia and clinically relevant outcomes. This study aimed to investigate the association between intra-arrest hyperoxaemia and outcomes for OHCA patients. METHODS: This was an observational study using a registry database of OHCA cases that occurred between 2014 and 2017 in Japan...

INTRODUCTION: Supplemental oxygen is commonly used in trauma patients, although it may lead to hyperoxaemia that has been associated with pulmonary complications and increased mortality. The primary objective of this trial, TRAUMOX2, is to compare a restrictive versus liberal oxygen strategy the first 8 hours following trauma. METHODS AND ANALYSIS: TRAUMOX2 is an investigator-initiated, international, parallel-grouped, superiority, outcome assessor-blinded and analyst-blinded, randomised, controlled, clinical trial...

BACKGROUND: Multiple studies have investigated the association between hyperoxaemia following cardiac arrest (CA) and unfavourable outcomes; however, they have yielded inconsistent results. Most previous studies quantified oxygen exposure without considering its timing or duration. We investigated the relationship between unfavourable outcomes and supranormal arterial oxygen tension (PaO2 ), commonly defined as PaO2  > 100 mmHg, at specific time intervals within 24 h following CA...

Acute myocardial infarction (AMI) is a major cause of morbidity and mortality worldwide. Timely reperfusion with primary percutaneous coronary intervention (PPCI) remains the gold standard in patients presenting with ST-segment elevation myocardial infarction (STEMI), limiting infarct size, preserving left ventricular ejection fraction (LVEF), and improving clinical outcomes. Despite this, a significant proportion of STEMI patients develop post-infarct heart failure. We review the current understanding and up-to-date evidence base for therapeutic intervention of ischaemia-reperfusion injury (IRI), a combination of myocardial ischaemia secondary to acute coronary occlusion and reperfusion injury leading to further myocardial injury and cell death...

Oxygen (O2 ) toxicity remains a concern, particularly to the lung. This is mainly related to excessive production of reactive oxygen species (ROS). Supplemental O2 , i.e. inspiratory O2 concentrations (FI O2 ) > 0.21 may cause hyperoxaemia (i.e. arterial (a) PO2  > 100 mmHg) and, subsequently, hyperoxia (increased tissue O2 concentration), thereby enhancing ROS formation. Here, we review the pathophysiology of O2 toxicity and the potential harms of supplemental O2 in various ICU conditions...

BACKGROUND: Although supplemental oxygen can be lifesaving, liberal oxygen administration causing hyperoxaemia, may be harmful. The targets for oxygenation in patients with acute hypoxaemic respiratory failure acutely admitted to the intensive care unit (ICU) are strongly debated, and consensus on which targets to recommend has not been reached. The Handling Oxygenation Targets in the ICU (HOT-ICU) trial is a multicentre, randomised, parallel-group trial of a lower oxygenation target (arterial partial pressure of oxygen (PaO2 ) = 8 kPa) versus a higher oxygenation target (PaO2 = 12 kPa) in adult ICU patients with acute hypoxaemic respiratory failure...

BACKGROUND: Oxygen therapy is routinely administered to mechanically ventilated patients. However, there remains uncertainty about the optimal oxygen titration target in patients with the acute respiratory distress syndrome (ARDS). METHODS: Prospectively identified adult patients meeting the Berlin definition of ARDS between 1st January 2014 and 13th December 2016 were analyzed. Oxygen exposure variables were collected at 6-hourly intervals. The primary exposure was the average time-weighted partial pressure of arterial oxygen (PaO2 ) calculated over a maximum of 7 days from meeting ARDS criteria...

Nearly all patients receiving treatment in a peri-operative or intensive care setting receive supplemental oxygen therapy. It is biologically plausible that the dose of oxygen used might affect important patient outcomes. Most peri-operative research has focussed on oxygen regimens that target higher than normal blood oxygen levels. Whereas, intensive care research has mostly focussed on conservative oxygen regimens which assiduously avoid exposure to higher than normal blood oxygen levels. While such conservative oxygen therapy is preferred for spontaneously breathing patients with chronic obstructive pulmonary disease, the optimal oxygen regimen in other patient groups is not clear...

OBJECTIVE: The objective of this study was to compare two different modes of ventilation in maintaining oxygen saturation (SpO2) in target range (90%-95%) in ventilated preterm infants cared for with automatic control of oxygen delivery (A-FiO2). DESIGN: A single-centre randomised crossover study. SETTINGS: A level III neonatal intensive care unit. PATIENTS: Preterm infants receiving mechanical ventilation and oxygen requirement >21%...

Multiple studies among adults have suggested a non-linear relationship between arterial partial pressure of oxygen (PaO2 ) and clinical outcomes. Meta-analyses in this population suggest that high levels of supplemental oxygen resulting in hyperoxia are associated with mortality. This mini-review focuses on the non-neonatal pediatric literature examining the relationship between PaO2 and mortality. While only one pilot pediatric randomized-controlled trials exists, over the past decade, there have been at least eleven observational studies examining the relationship between PaO2 values and mortality in critically ill children...

OBJECTIVE: To compare the effect of two different automated oxygen control devices on target range (TR) time and occurrence of hypoxaemic and hyperoxaemic episodes. DESIGN: Randomised cross-over study. SETTING: Tertiary level neonatal unit in the Netherlands. PATIENTS: Preterm infants (n=15) born between 24+0 and 29+6 days of gestation, receiving invasive or non-invasive respiratory support with oxygen saturation (SpO2 ) TR of 91%-95%...