OBJECTIVE: Acute hypoxaemic respiratory failure (AHRF) is a common reason for intensive care unit (ICU) admission. However, patient characteristics, outcomes, and trends over time are unclear. We describe the epidemiology and outcomes of patients with AHRF over time.
METHODS: In this binational, registry-based study from 2005 to 2022, we included all adults admitted to an Australian or New Zealand ICU with an arterial blood gas within the first 24 h of ICU stay. AHRF was defined as a partial pressure of oxygen/inspired oxygen ratio (PaO2/FiO2) ≤ 300. The primary outcome was adjusted in-hospital mortality, categorised based on PaO2/FiO2 (mild: 200-300, moderate: 100-200, and severe < 100, and non-linearly). We investigated how adjusted mortality evolved based on temporal trends (by year of admission), sex, age, admission diagnosis and the receipt of mechanical ventilation.
RESULTS: Of 1,560,221 patients, 826,106 (52.9%) were admitted with or developed AHRF within the first 24 h of ICU stay. Of these 826,106 patients, 51.4% had mild, 39.3% had moderate, and 9.3% had severe AHRF. Compared to patients without AHRF (5.3%), patients with mild (8%), moderate (14.2%) and severe (29.9%) AHRF had higher in-hospital mortality rates. As PaO2/FiO2 ratio decreased, adjusted in-hospital mortality progressively increased, particularly below an inflection point at a PaO2/FiO2 ratio of 200. The adjusted in-hospital mortality for all patients decreased over time (13.3% in 2005 to 8.2% in 2022), and this trend was similar in patients with and without AHRF.
CONCLUSIONS: The healthcare burden due to AHRF may be larger than expected, and mortality rates remain high in severe AHRF. Although mortality has decreased over time, this may reflect improvements in ICU care in general, rather than specifically in AHRF. More research is required to earlier identify AHRF and stratify these patients at risk of deterioration early, and to validate our findings.

UNASSIGNED: Approximately 25% of the general population has a patent foramen ovale (PFO) that remains asymptomatic in the vast majority. Right-to-left shunt (RLS)-mediated hypoxaemia is a rare associated condition of PFO.
UNASSIGNED: This report describes a case of percutaneous PFO closure for hypoxaemia in a 73-year-old patient showing immediate clinical benefit. She experienced progressive dyspnoea on exertion requiring oxygen therapy. SaO2 was 87% at rest without oxygen therapy, which increased to 98% after percutaneous PFO closure.
UNASSIGNED: Most PFOs remain clinically insignificant but RLS-mediated hypoxaemia is a rare phenomenon that can occur even at advanced age. Percutaneous PFO closure is a safe and effective therapy option that provides immediate improvement of hypoxaemia.

BACKGROUND: Trauma poses a significant global health challenge. Despite advancements in the management of severely injured patients, (poly)trauma continues to be a primary contributor to morbidity and mortality worldwide. In the context of trauma resuscitation, supplemental oxygen is commonly administered generously as suggested by guidelines. Yet, it remains uncertain whether the trauma population might derive advantages from a more conservative approach to supplemental oxygen.
METHODS: In this retrospective cohort study from two Swiss trauma centers, severely injured adult (> 16 years) trauma patients with an Injury Severity Score (ISS) ≥ 16 were divided into four groups according to the first blood gas analysis taken: hypoxaemia (PaO2 < 10.7 kPa/80 mmHg), normoxaemia (PaO2 10.7-16.0 kPa/80-120 mmHg), which served as reference, moderate hyperoxaemia (PaO2 > 16.0-40 kPa/120-300 mmHg) and severe hyperoxaemia (PaO2 > 40 kPa/300 mmHg). The primary outcome was 28-day mortality. Length of hospital stay (LOS) and length of intensive care unit stay (LOS-ICU) were analyzed as secondary outcomes.
RESULTS: Of 1,189 trauma patients, 41.3% had hyperoxaemia (18.8% with severe hyperoxaemia) and 19.3% had hypoxaemia. No difference was found for 28-day mortality (hypoxaemia: 15.7%, normoxaemia: 14.1%, hyperoxaemia: 13.8%, severe hyperoxaemia: 16.0%, p = 0.846). Patients with severe hyperoxaemia had a significant prolonged LOS (median 12.5 [IQR 7-18.5] days vs. 10 [7-17], p = 0.040) and extended LOS-ICU (3.8 [1.8-9] vs. 2 [1-5] days, p = 0.149) compared to normoxaemic patients. In multivariable analysis, oxygen group was not associated with the primary outcome 28-day mortality or LOS-ICU. Severe hyperoxaemia patients had a tendency towards longer hospital stay (adjusted coefficient 2.23 days [95% CI: - 0.32; 4.79], p = 0.087).
CONCLUSIONS: Hyperoxaemia was not associated with an increased 28-day mortality when compared to normoxaemia. However, both moderate and severe hyperoxaemia is frequently observed in trauma patients, and the presence of severe hyperoxaemia showed a tendency with extended hospital stay compared to normoxaemia patients. Robust randomized controlled trials are imperative to thoroughly evaluate the potential correlation between hyperoxaemia and outcomes in trauma patients . Trial Registration Retrospectively registered.

OBJECTIVE: To study the changes in dynamic compliance (Cdyn), ventilation/perfusion (V˙/ Q˙) mismatch and haemodynamic variables in hypoxaemic anaesthetized horses whose PaO2 increased following salbutamol inhalation.
METHODS: Retrospective, clinical, cohort study.
METHODS: A group of 73 client-owned horses treated with salbutamol when PaO2 <100 mmHg (13.3 kPa) during anaesthesia.
METHODS: Horses were divided into two groups: responders (R), where PaO2 after salbutamol ≥1.2 PaO2 before treatment (i.e. ≥20% increase), and non-responders (NR), where PaO2 after salbutamol <1.2 PaO2 before treatment. Demographic data and intraoperative variables before treatment were compared between R and NR. Cdyn, arterial to end-tidal carbon dioxide difference [P(a-E´)CO2], estimated ratio of dead space to tidal volume (est.VD/VT), estimated shunt fraction (F-shunt), heart rate, systolic, mean and diastolic arterial pressure and dobutamine requirements were compared before and after treatment within R and NR. For each variable, the difference (Δ) between values pre- and posttreatment was calculated and compared between groups R and NR. Numerical data were compared using univariate or bivariate analysis and categorical data were compared using chi-square test; p < 0.05.
RESULTS: Of the 73 horses 50 were classified as R while 23 horses were classified as NR. There was no statistical difference between R and NR for demographic data or initial intraoperative variables except for body weight [R: 531 (170-715) kg, NR: 540 (420-914) kg]. While salbutamol did not alter Cdyn in either group, it significantly decreased P(a-E´)CO2, est.VD/VT and F-shunt in R only. ΔP(a-E´)CO2, Δest.VD/VT and ΔF-shunt were significantly greater in R (-17.8%, -19.0% and -24.1%, respectively) than in NR (11.5%, 6.6% and -0.3%, respectively).
CONCLUSIONS: In hypoxaemic anaesthetized horses responding to inhaled salbutamol by a ≥1.2 increase in PaO2 no change in Cdyn was detected, but indicators of V˙/ Q˙ mismatch improved.

暂无摘要。

This Thoracic Society of Australia and New Zealand Guideline on the provision of home oxygen therapy in adults updates a previous Guideline from 2015. The Guideline is based upon a systematic review and meta-analysis of literature to September 2022 and the strength of recommendations is based on GRADE methodology. Long-term oxygen therapy (LTOT) is recommended for its mortality benefit for patients with COPD and other chronic respiratory diseases who have consistent evidence of significant hypoxaemia at rest (PaO2 ≤ 55 mm Hg or PaO2 ≤59 mm Hg in the presence of hypoxaemic sequalae) while in a stable state. Evidence does not support the use of LTOT for patients with COPD who have moderate hypoxaemia or isolated nocturnal hypoxaemia. In the absence of hypoxaemia, there is no evidence that oxygen provides greater palliation of breathlessness than air. Evidence does not support the use of supplemental oxygen therapy during pulmonary rehabilitation in those with COPD and exertional desaturation but normal resting arterial blood gases. Both positive and negative effects of LTOT have been described, including on quality of life. Education about how and when to use oxygen therapy in order to maximize its benefits, including the use of different delivery devices, expectations and limitations of therapy and information about hazards and risks associated with its use are key when embarking upon this treatment.

UNASSIGNED: The fetal haemodynamic response to acute episodes of hypoxaemia are well characterised. However, how these responses change when the hypoxaemia becomes more chronic in nature such as that associated with fetal growth restriction (FGR), is less well understood. Herein, we utilised a combination of clinically relevant MRI techniques to comprehensively characterize and differentiate the haemodynamic responses occurring during acute and chronic periods of fetal hypoxaemia.
UNASSIGNED: Prior to conception, carunclectomy surgery was performed on non-pregnant ewes to induce FGR. At 108-110 days (d) gestational age (GA), pregnant ewes bearing control (n = 12) and FGR (n = 9) fetuses underwent fetal catheterisation surgery. At 117-119 days GA, ewes underwent MRI sessions where phase-contrast (PC) and T2 oximetry were used to measure blood flow and oxygenation, respectively, throughout the fetal circulation during a normoxia and then an acute hypoxia state.
UNASSIGNED: Fetal oxygen delivery (DO2) was lower in FGR fetuses than controls during the normoxia state but cerebral DO2 remained similar between fetal groups. Acute hypoxia reduced both overall fetal and cerebral DO2. FGR increased ductus venosus (DV) and foramen ovale (FO) blood flow during both the normoxia and acute hypoxia states. Pulmonary blood flow (PBF) was lower in FGR fetuses during the normoxia state but similar to controls during the acute hypoxia state when PBF in controls was decreased.
UNASSIGNED: Despite a prevailing level of chronic hypoxaemia, the FGR fetus upregulates the preferential streaming of oxygen-rich blood via the DV-FO pathway to maintain cerebral DO2. However, this upregulation is unable to maintain cerebral DO2 during further exposure to an acute episode of hypoxaemia. The haemodynamic alterations required at the level of the liver and lung to allow the DV-FO pathway to maintain cerebral DO2, may have lasting consequences on hepatic function and pulmonary vascular regulation after birth.

UNASSIGNED: In the United Kingdom, around 184,000 adults are admitted to an intensive care unit (ICU) each year with over 30% receiving mechanical ventilation. Oxygen is the commonest therapeutic intervention provided to these patients but it is unclear how much oxygen should be administered for the best clinical outcomes.
UNASSIGNED: The UK-ROX trial will evaluate the clinical and cost-effectiveness of conservative oxygen therapy (the minimum oxygen concentration required to maintain an oxygen saturation of 90% ± 2%) versus usual oxygen therapy in critically ill adults receiving supplemental oxygen when invasively mechanically ventilated in ICUs in England, Wales and Northern Ireland. The trial will recruit 16,500 patients from approximately 100 UK adult ICUs. Using a deferred consent model, enrolled participants will be randomly allocated (1:1) to conservative or usual oxygen therapy until ICU discharge or 90 days after randomisation.
UNASSIGNED: The primary clinical outcome is all cause mortality at 90 days following randomisation.
UNASSIGNED: The UK-ROX trial has received ethical approval from the South Central - Oxford C Research Ethics Committee (Reference: 20/SC/0423) and the Confidentiality Advisory Group (Reference: 22/CAG/0154). The trial commenced in May 2021 and, at the time of publication, 95 sites had opened to recruitment.

暂无摘要。

UNASSIGNED: Pneumonia is the leading cause of death in young children globally and is prevalent in the Papua New Guinea highlands. We investigated clinical predictors of hypoxic pneumonia to inform local treatment guidelines in this resource-limited setting.
UNASSIGNED: Between 2013 and 2020, two consecutive prospective observational studies were undertaken enrolling children 0-4 years presenting with pneumonia to health-care facilities in Goroka Town, Eastern Highlands Province. Logistic regression models were developed to identify clinical predictors of hypoxic pneumonia (oxygen saturation <90% on presentation). Model performance was compared against established criteria to identify severe pneumonia.
UNASSIGNED: There were 2067 cases of pneumonia; hypoxaemia was detected in 36.1%. The strongest independent predictors of hypoxic pneumonia were central cyanosis on examination (adjusted odds ratio [aOR] 5.14; 95% CI 3.47-7.60), reduced breath sounds (aOR 2.92; 95% CI 2.30-3.71), and nasal flaring or grunting (aOR 2.34; 95% CI 1.62-3.38). While the model developed to predict hypoxic pneumonia outperformed established pneumonia severity criteria, it was not sensitive enough to be clinically useful at this time.
UNASSIGNED: Given signs and symptoms are unable to accurately detect hypoxia, all health care facilities should be equipped with pulse oximeters. However, for the health care worker without access to pulse oximetry, consideration of central cyanosis, reduced breath sounds, nasal flaring or grunting, age-specific tachycardia, wheezing, parent-reported drowsiness, or bronchial breathing as suggestive of hypoxaemic pneumonia, and thus severe disease, may prove useful in guiding management, hospital referral and use of oxygen therapy.
UNASSIGNED: Funded by Pfizer Global and the Bill & Melinda Gates Foundation.