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Introduction: Although largely used, the place of oxygen therapy and its devices in patients with acute hypoxemic respiratory failure (ARF) deserves to be clarified. The French Intensive Care Society (Société de Réanimation de Langue Française, SRLF) and the French Emergency Medicine Society (Société Française de Médecine d'Urgence, SFMU) organized a consensus conference on oxygen therapy in ARF (excluding acute cardiogenic pulmonary oedema and hypercapnic exacerbation of chronic obstructive diseases) in December 2023. Methods: A committee without any conflict of interest (CoI) with the subject defined 7 generic questions and drew up a list of sub questions according to the population, intervention, comparison and outcomes (PICO) model. An independent work group reviewed the literature using predefined keywords. The quality of the data was assessed using the GRADE methodology. Fifteen experts in the field from both societies proposed their own answers in a public session and answered questions from the jury (a panel of 16 critical-care and emergency medicine physicians, nurses and physiotherapists without any CoI) and the public. The jury then met alone for 48 h to write its recommendations. Results: The jury provided 22 statements answering 11 questions: in patients with ARF (1) What are the criteria for initiating oxygen therapy? (2) What are the targets of oxygen saturation? (3) What is the role of blood gas analysis? (4) When should an arterial catheter be inserted? (5) Should standard oxygen therapy, high-flow nasal cannula oxygen therapy (HFNC) or continuous positive airway pressure (CPAP) be preferred? (6) What are the indications for non-invasive ventilation (NIV)? (7) What are the indications for invasive mechanical ventilation? (8) Should awake prone position be used? (9) What is the role of physiotherapy? (10) Which criteria necessarily lead to ICU admission? (11) Which oxygenation device should be preferred for patients for whom a do-not-intubate decision has been made? Conclusion: These recommendations should optimize the use of oxygen during ARF. [ABSTRACT FROM AUTHOR]

Background. Preoxygenation prior to induction of general anesthesia is intended to increase the oxygen reserve in the lungs. This technique delays the onset of hypoxemia during the placement of the tracheal tube. Objective. To observe the benefits of oxygen through nasal cannula when used as an adjunct during preoxygenation. Methods. We enrolled 30 healthy volunteers and conducted a sequence of six preoxygenation tests. These included 3‐minute tidal volume breathing and 8 vital capacity breaths, with and without oxygen flowing through the nasal cannula as an adjunct. Subjects were kept at a supine position with a face mask on their faces. Their baseline vitals were measured and end‐tidal O2 (ETO2) was recorded at the end of each test. The comfort of each technique was also assessed. Results. When comparing the efficacy of the two preoxygenation methods, we found that the addition of oxygen through the nasal cannula improved the efficacy of preoxygenation with both the 3‐minute tidal volume breathing method and the 8 vital capacity method (p < 0.001). The three‐minute tidal volume breathing technique had higher end‐tidal oxygen when compared to the eight vital capacity breaths. Conclusions. The administration of oxygen through a nasal cannula during preoxygenation improves the efficacy of preoxygenation in healthy volunteers. Tidal volume breathing for three minutes achieves a higher end‐tidal oxygen concentration compared to eight vital capacity breaths over one minute. [ABSTRACT FROM AUTHOR]

While concerns about high-flow nasal cannula oxygen (HFNC) overuse and associated increased use of hospital resources are rapidly spreading, a two-tiered approach in its use is recommended by recent bronchiolitis guidelines. However, data on its effects in practice have not been reported. We aimed to analyze the trends in use of HFNC, hospitalizations, length of stay (LOS), and intensive care unit (ICU) admissions for bronchiolitis in a tertiary care center using a two-tiered HFNC approach since its introduction in practice. We retrospectively included data of children < 12 months of age who presented to the Paediatric Emergency Department (PED) and were hospitalized for bronchiolitis at our institution in the epidemic season between October 1st and April 30th during the years 2012–2023 and compared the clinical data across the years. Of the 687 hospitalized children included, 79.9% required oxygen supplementation. Use of HFNC significantly increased since its implementation (from 25% in 2012–2013 to over 60% since 2019–2020, p < 0.0001) and was most frequently administered as rescue treatment (in 57.5% of patients). There was no increased trend in ICU admissions (between 1.5% and 10.0% of hospitalizations across seasons, p = 0.40), while LOS, after increasing between 2013 and 2016 (medians between 4.0 and 5.4 days), remained stable thereafter (medians between 3.8 and 4.3 days). Conclusions: The use of HFNC according to a two-tiered approach does not appear to be associated with an increase in ICU utilization or LOS. What is Known: • Bronchiolitis is one of the most common reasons for hospitalization in infants. • Use high-flow nasal canulae oxygen (HFNC) has rapidly spread outside the intensive care unit (ICU) to treat infants with bronchiolitis, although increasing evidence has dampened the initial enthusiasm about their effectiveness. • Concerns nowadays are rising about HFNC overuse and associated increased use of hospital resources, including escalation of care to ICU. What is New: • A more selective use of HFNC according to a "two-tiered approach", intended as a second-line rescue treatment in non-severely ill children who fail standard oxygen therapy, is not associated with increased ICU and length of hospital stay. [ABSTRACT FROM AUTHOR]

OBJECTIVES: To clarify the mechanistic basis for the success or failure of noninvasive ventilation (NIV) in acute hypoxemic respiratory failure (AHRF). DESIGN: We created digital twins based on mechanistic computational models of individual patients with AHRF. SETTING: Interdisciplinary Collaboration in Systems Medicine Research Network. SUBJECTS: We used individual patient data from 30 moderate-to-severe AHRF patients who had failed high-flow nasal cannula (HFNC) therapy and subsequently underwent a trial of NIV. INTERVENTIONS: Using the digital twins, we evaluated lung mechanics, quantified the separate contributions of external support and patient respiratory effort to lung injury indices, and investigated their relative impact on NIV success or failure. MEASUREMENTS AND MAIN RESULTS: In digital twins of patients who successfully completed/failed NIV, after 2 hours of the trial the mean (sd) of the change in total lung stress was -10.9 (6.2)/-0.35 (3.38) cm H2O, mechanical power -13.4 (12.2)/-1.0 (5.4) J/min, and total lung strain 0.02 (0.24)/0.16 (0.30). In the digital twins, positive end-expiratory pressure (PEEP) produced by HFNC was similar to that set during NIV. In digital twins of patients who failed NIV vs. those who succeeded, intrinsic PEEP was 3.5 (0.6) vs. 2.3 (0.8) cm H2O, inspiratory pressure support was 8.3 (5.9) vs. 22.3 (7.2) cm H2O, and tidal volume was 10.9 (1.2) vs. 9.4 (1.8) mL/kg. In digital twins, successful NIV increased respiratory system compliance +25.0 (16.4) mL/cm H2O, lowered inspiratory muscle pressure -9.7 (9.6) cm H2O, and reduced the contribution of patient spontaneous breathing to total driving pressure by 57.0%. CONCLUSIONS: In digital twins of AHRF patients, successful NIV improved lung mechanics, lowering respiratory effort and indices associated with lung injury. NIV failed in patients for whom only low levels of positive inspiratory pressure support could be applied without risking patient self-inflicted lung injury due to excessive tidal volumes. [ABSTRACT FROM AUTHOR]

Long-term oxygen therapy (LTOT) is a treatment that involves the provision of supplemental oxygen to individuals with respiratory disease to correct hypoxemia in the post-acute care environment. Over 1.5 million adults in the United States use supplemental oxygen for various respiratory disorders. This paper explores literature published on LTOT from September 2022-September 2023. Upon the conclusion of this literature review, 4 distinct categories emerged. This paper highlights the significant findings associated with the 4 categories: supplemental oxygen and COVID-19, telemonitoring, LTOT equipment, and in-home high-flow nasal cannula. [ABSTRACT FROM AUTHOR]

Endotracheal intubation is a common lifesaving procedure that often is performed outside the operating room in a variety of clinical scenarios. Providers who perform intubation outside the operating room have variable degrees of training, skill development, and experience. A large number of studies were published in 2023 on the topic of intubations outside the operating room across a wide variety of settings and patient populations. Here, we review relevant papers on this topic published in 2023. [ABSTRACT FROM AUTHOR]

BACKGROUND: High-flow nasal cannula (HFNC) systems employ different methods to provide aerosol to patients. This study compared delivery efficiency, particle size, and regional deposition of aerosolized bronchodilators during HFNC in neonatal, pediatric, and adult upper-airway and lung models between a proximal aerosol adapter and distal aerosol circuit chamber. METHODS: A filter was connected to the upper airway to a spontaneously breathing lung model. Albuterol was nebulized using the aerosol adapter and circuit at different clinical flow settings. The aerosol mass deposited in the upper airway and lung was quantified. Particle size was measured with a laser diffractometer. Regional deposition was assessed with a gamma camera at each nebulizer location and patient model with minimum flow settings. RESULTS: Inhaled lung doses ranged from 0.2-0.8% for neonates, 0.2-2.2% for the small child, and 0.5-5.2% for the adult models. Neonatal inhaled lung doses were not different between the aerosol circuit and adapter, but the aerosol circuit showed marginally greater lung doses in the pediatric and adult patient models. Impacted aerosols and condensation in the non-heated HFNC and aerosol delivery components contributed to the dispersion of coarse liquid droplets, high deposition (11-44%), and occlusion of the supine neonatal upper airway. In contrast, the upright pediatric and adult upper-airway models had minimal deposition (0.3-7.0%) and high fugitive losses (~24%) from liquid droplets leaking out of the nose. The high impactive losses in the aerosol adapter (56%) were better contained than in the aerosol circuit, resulting in less cannula sputter (5% vs 22%), fewer fugitive losses (18% vs 24%), and smaller inhaled aerosols (5 µm vs 13 µm). CONCLUSIONS: The inhaled lung dose was low (1-5%) during HFNC. Approaches that streamline aerosol delivery are needed to provide safe and effective therapy to patients receiving aerosolized medications with this HFNC system. [ABSTRACT FROM AUTHOR]

BACKGROUND: The ratio of oxygen saturation index (ROX index; or .../.../breathing frequency) has been shown to predict risk of intubation after high-flow nasal cannula (HFNC) support among adults with acute hypoxemic respiratory failure primarily due to pneumonia. However, its predictive value for other subtypes of respiratory failure is unknown. This study investigated whether the ROX index predicts liberation from HFNC or noninvasive ventilation (NIV), intubation with mechanical ventilation, or death in adults admitted for respiratory failure due to an exacerbation of COPD. METHODS: We performed a retrospective study of 260 adults hospitalized with a COPD exacerbation and treated with HFNC and/or NIV (continuous or bi-level). ROX index scores were collected at treatment initiation and predefined time intervals throughout HFNC and/or NIV treatment or until the subject was intubated or died. A ROX index score of ≥ 4.88 was applied to the cohort to determine if the same score would perform similarly in this different cohort. Accuracy of the ROX index was determined by calculating the area under the receiver operator curve. RESULTS: A total of 47 subjects (18%) required invasive mechanical ventilation or died while on HFNC/NIV. The ROX index at treatment initiation, 1 h, and 6 h demonstrated the best prediction accuracy for avoidance of invasive mechanical ventilation or death (area under the receiver operator curve 0.73 [95% CI 0.66-0.80], 0.72 [95% CI 0.65-0.79], and 0.72 [95% CI 0.63-0.82], respectively). The optimal cutoff value for sensitivity (Sn) and specificity (Sp) was a ROX index score > 6.88 (sensitivity 62%, specificity 57%). CONCLUSIONS: The ROX index applied to adults with COPD exacerbations treated with HFNC and/or NIV required higher scores to achieve similar prediction of low risk of treatment failure when compared to subjects with hypoxemic respiratory failure/pneumonia. ROX scores < 4.88 did not accurately predict intubation or death. [ABSTRACT FROM AUTHOR]

BACKGROUND: When treating acute respiratory failure, both hypoxemia and hyperoxemia should be avoided. ... should be monitored closely and O2 flows adjusted accordingly. Achieving this goal might be easier with automated O2 titration compared with manual titration of fixed-flow O2. We evaluated the feasibility of using an automated O2 titration device in subjects treated for acute hypoxemic respiratory failure in a tertiary care hospital. METHODS: Health-care workers received education and training about oxygen therapy, and were familiarized with an automated O2 titration device (FreeO2,). A coordinator was available from 8:00 AM to 5:00 PM during weekdays to provide technical assistance. The ability of the device to maintain ... within the prescribed therapeutic window was recorded. Basic clinical information was recorded. RESULTS: Subjects were enrolled from November 2020 to August 2022. We trained 508 health-care workers on the use of automated O2 titration, which was finally used on 872 occasions in 763 subjects, distributed on the respiratory, COVID-19, and thoracic surgery wards, and in the emergency department. Clinical information could be retrieved for 609 subjects (80%) who were on the system for a median (interquartile range) of 3 (2-6) d, which represented 2,567 subject-days of clinical experience with the device. In the 82 subjects (14%) for whom this information was available, the system maintained ... within the prescribed targets 89% of the time. Ninety-six subjects experienced clinical deterioration as defined by the need to be transferred to the ICU and/or requirement of high flow nasal oxygen but none of these events were judged to be related to the O2 device. CONCLUSIONS: Automated O2 titration could be successfully implemented in hospitalized subjects with hypoxemic respiratory failure from various causes. This experience should foster further improvement of the device and recommendations for an optimized utilization. [ABSTRACT FROM AUTHOR]

Objectives: To determine predictors of high-flow nasal cannula (HFNC) failure in COVID-19 patients in a hospital in northern Peru. Methodology: A retrospective cohort study was conducted during the months of March and May 2021. Data collection was based on a follow-up of 156 hospitalized patients with a diagnosis of COVID-19 who were users of HFNC. Epidemiological factors and clinical outcomes of treatment were analyzed from medical records. Epidemiological, analytical, and HFNC use-related characteristics were described using measures of absolute and relative frequencies, measures of central tendency, and dispersion. A multivariate Poisson regression analysis with robust variance and a 95% confidence interval was performed. Results: We found that age, SpO2/FiO2, work of breathing (WOB scale) at admission, degree of involvement, type of infiltrate on CT scan, lymphocytes, c-reactive protein, and D-dimer were significantly associated with failure of HFNC (p < 0.05). In addition, the WOB scale, PaO2/FiO2, SaO2/FiO2, and ROX index were variables that presented statistical significance (p < 0.0001). In the multivariate analysis model, a risk of failure of HFNC was determined with age > = 60 years [RRa 1.39 (1.05–1.85)] and PaO2/FiO2 score less than 100 [Rra 1.65 (0.99–2.76)]. Conclusions: Predictors to failure of HFNC are age older than 60 years and minimally significantly lower PaO2/FiO2 than 100. [ABSTRACT FROM AUTHOR]

With the increasing prevalence of obesity and morbid obesity, this subgroup's contribution to patients presenting for elective procedures requiring sedation is significant. Gastrointestinal (GI) procedures clearly form the largest group of such procedures. These procedures may be intended to treat obesity such as the insertion of an intragastric balloon or one or more unrelated procedures such as a screening colonoscopy and (or) diagnostic/therapeutic endoscopy. Regardless of the procedure, these patients pose significant challenges in terms of choice of sedatives, dosing, airway management, ventilation, and oxygenation. An understanding of dissimilarity in the handling of different groups of medications used by an anesthesia provider and alterations in airway anatomy is critical for providing safe sedation. Administration of sedative medications and conduct of anesthesia requires dose modifications and airway adjuncts. In this review, we discuss the above issues in detail, with a particular focus on GI endoscopy. [ABSTRACT FROM AUTHOR]

Background: Respiratory functions may be impaired in cesarean section (C/S) delivery performed under spinal anesthesia (SA) and oxygen supplementation may be required. Therefore, we conducted a randomized controlled study aimed to evaluate the effects of different oxygen administrations in pregnant women on the lungs during C/S under SA using ultrasound and oxygen reserve index (ORI). Methods: We conducted a randomized, controlled, single-center study from May 1, 2021, to March 31, 2022. A total of 90 patients scheduled for C/S under SA were randomly divided into 3 groups. Following the SA, patients in group 0 were treated with room air, in Group 3 were administered 3 L/min O₂ with a nasal cannula (NC), in Group 6 were administered 6 L/min O₂ with a simple face mask. In addition to routine monitoring, ORI values were measured. Lung aeration was evaluated through the modified lung ultrasound score (LUS) before the procedure (T0), at minute 0 (T1), 20 (T2), and hour 6 (T3) after the procedure, and ∆LUS values were recorded. Results: After SA, the ORI values of Group 3 were higher than Group 0 at all times (p < 0.05), while the intraoperative 1st minute and the 10th, 25th and 40th minutes after delivery (p = 0.001, p = 0.027, p = 0.001, p = 0.019) was higher than Group 6. When the LUS values of each group were compared with the T0 values a decrease was observed in Group 3 and Group 6 (p < 0.001, p = 0.016). While ∆LUS values were always higher in Group 3 than in Group 0, they were higher only in T1 and T2 in Group 6. Conclusion: We determined that it would be appropriate to prefer 3 L/min supplemental oxygen therapy with NC in C/S to be performed under SA. [ABSTRACT FROM AUTHOR]

Introduction: The use of high-flow nasal cannula (HFNC) in patients with acute hypoxemic respiratory failure has been increasing in the emergency department (ED). However, studies are lacking on the prediction of HFNC failure before therapy initiation in the ED. We investigated whether the existing indices, such as the ratio of pulse oximetry oxygen saturation/fraction of inspired oxygen to respiratory rate (ROX) and ratio of ROX index to heart rate (ROX-HR), can accurately predict HFNC failure at the conventional oxygen therapy phase in the ED. Methods: This retrospective single-center study included patients treated with HFNC in the ED. The ROX and ROX-HR indices were calculated before initiating HFNC. An estimated fraction of inspired oxygen was used for conventional oxygen therapy. We plotted each index's receiver operating characteristics curve and calculated the area under the curve (AUC) for diagnostic capacity. The optimal cutoff values were assessed using the Youden index. The primary outcome was HFNC failure, defined as intubation in the ED. Results: Among the 97 included patients, 25 (25.8%) failed HFNC therapy in the ED. The ROX and ROX-HR indices measured before initiating HFNC showed AUCs of 0.709 and 0.754, respectively. A ROX index of <5.614 and a ROX-HR index of <6.152 were associated with a high risk of intubation, even after correcting for confounding variables. Conclusion: The ROX and ROX-HR indices measured before initiating HFNC provide a relatively fair predictive value of HFNC failure in the ED. [ABSTRACT FROM AUTHOR]

Background: Patients with obesity are at increased risk of postoperative pulmonary complications. CPAP has been used successfully to prevent and treat acute respiratory failure, but in many clinical scenarios, high-flow nasal cannula (HFNC) therapy is emerging as a possible alternative. We aimed to compare HFNC and CPAP in a sequential study measuring their effects on gas exchange, lung volumes, and gas distribution within the lungs measured through electrical impedance tomography (EIT). Methods: We enrolled 15 subjects undergoing laparoscopic bariatric surgery. Postoperatively they underwent the following oxygen therapy protocol (10 min/step): baseline air-entrainment mask, HFNC at increasing (40, 60, 80, and 100 L/min) and decreasing flows (80, 60, and 40 L/min), washout air-entrainment mask and CPAP (10 cm H2O). Primary outcome was the change in end-expiratory lung impedance (ΔEELI) measured by EIT data processing. Secondary outcomes were changes of global inhomogeneity (GI) index and tidal impedance variation (TIV) measured by EIT, arterial oxygenation, carbon dioxide content, pH, respiratory frequency, and subject's comfort. Results: Thirteen subjects completed the study. Compared to baseline, ΔEELI was higher during 10 cm H2O CPAP (P = .001) and HFNC 100 L/min (P = .02), as well as during decreasing flows HFNC 80, 60, and 40 L/min (P = .008, .004, and .02, respectively). GI index was lower during HFNC 100 compared to HFNC 60increasing (P = .044), HFNC 60decreasing (P = .02) HFNC 40decreasing (P = .01), and during 10 cm H2O CPAP compared to washout period (P = .01) and HFNC 40decreasing (P = .03). TIV was higher during 10 cm H2O CPAP compared to baseline (P = .008). Compared to baseline, breathing frequency was lower at HFNC 60increasing, HFNC 100, and HFNC 80decreasing (P = .01, .02, and .03, respectively). No differences were detected regarding arterial oxygenation, carbon dioxide content, pH, and subject's comfort. Conclusions: HFNC at a flow of 100 L/min induced postoperative pulmonary recruitment in bariatric subjects, with no significant differences compared to 10 cm H2O CPAP in terms of lung recruitment and ventilation distribution. [ABSTRACT FROM AUTHOR]

Systematic reviews have reported conflicting evidence on whether macrolide antibiotics reduce rates of chronic lung disease of prematurity (CLD) in at-risk preterm infants born at less than 30 weeks' gestation, including in those colonised with pulmonary Ureaplasma spp. Since an adequately powered trial has been lacking, we aimed to assess if the macrolide azithromycin improved survival without the development of physiologically defined moderate or severe CLD in preterm infants. AZTEC was a multicentre, double-blind, randomised, placebo-controlled trial conducted in 28 tertiary neonatal intensive care units in the UK. Infants were eligible if they were born at less than 30 weeks' gestation and had received at least 2 h of either non-invasive (continuous positive airway pressure or humidified high flow nasal cannula therapy) or invasive respiratory support (via endotracheal tube) within 72 h of birth. Eligible infants were randomly allocated in a 1:1 ratio using random permuted blocks of four to receive either intravenous azithromycin at 20 mg/kg per day for 3 days followed by 10 mg/kg for 7 days, or to placebo. Allocation was stratified by centre and gestational age at birth (<28 weeks vs ≥28 weeks). Azithromycin and placebo vials were encased in tamper-evident custom cardboard cartons to ensure masking for clinicians, parents, and the research team. The primary outcome was survival without development of physiologically defined moderate or severe CLD at 36 weeks' postmenstrual age. Outcomes and safety were analysed on an intention-to-treat basis (all randomly allocated infants, regardless of any post-randomisation events). The study was registered with ISRCRN (11650227) and is closed. Infants were recruited between Oct 9, 2019, and March 22, 2022. 799 (53·1%) of 1505 eligible infants underwent random allocation; three infants were withdrawn, including consent to use their data, leaving 796 infants for analysis. Survival without moderate or severe CLD occurred in 166 (42%) of 394 infants in the intervention group and 179 (45%) of 402 in the placebo group (three-level adjusted OR [aOR] 0·84, 95% CI 0·55–1·29, p=0·43). Pulmonary Ureaplasma spp colonisation did not influence treatment effect. Overall, seven serious adverse events were reported for the azithromycin group (five graded as severe, two as moderate), and six serious adverse events were reported in the placebo group (two severe, two moderate, and two mild), as assessed by the local principal investigators. Since prophylactic use of azithromycin did not improve survival without development of physiologically-defined CLD, regardless of Ureaplasma spp colonisation, it cannot be recommended in clinical practice. UK National Institute for Health and Care Research. [ABSTRACT FROM AUTHOR]

Background: Heated humidified high-flow nasal cannulas (HHHFNCs) are increasingly used as an alternative strategy for weaning from nasal continuous positive airway pressure (NCPAP) in premature infants. However, the optimal pressure provided by HHHFNCs is unknown. This retrospective study investigated the pressure changes and associated factors during HHHFNC therapy in preterm infants. Methods: Clinically stable preterm neonates born with a birth weight of 2500 g or less and receiving HHHFNC therapy for weaning from NCPAP were enrolled. The flow of the HHHNFCs was adjusted to achieve an initial pressure equivalent to the positive expiratory pressure (PEEP) of NCPAP. Subsequent pressure changes in the HHHFNCs were measured by a GiO digital pressure gauge. Results: Nine premature infants were enrolled. Their gestational age (mean ± SD) was 28.33 ± 2.61 weeks, and the birth weight was 1102.00 ± 327.53 g. Overall, 437 pressure measurements were conducted. The median pressure of the HHHFNCs was 5 cmH2O. The generated pressure had a significant association with the body weight, postmenstrual age (PMA) and flow rate. A multiple regression model revealed that the measured pressure (cmH2O) = −5.769 + 1.021 × flow rate (L/min) − 0.797 × body weight (kg) + 0.035 × PMA (days) (r2 = 0.37, p < 0.001). Conclusions: The pressure provided by HHHFNCs is influenced by body weight, PMA, and flow rate. It is feasible to set the delivered pressure of HHHFNCs to match the applied PEEP of NCPAP initially, facilitating the weaning of preterm infants from NCPAP to HHHFNCs. [ABSTRACT FROM AUTHOR]

Objective Methods Results Conclusion The aim of the present study was to assess the predictors of need for paediatric intensive care unit (PICU) admission for inter‐hospital transfer patients to a tertiary paediatric hospital ED on high flow (HF) or continuous positive airway pressure (CPAP) ventilation.Single‐centre retrospective study of patients transferred to the state's tertiary paediatric hospital. Demographic information and disease management information was obtained.Between October 2021 and September 2022, 53 patients were transferred to the tertiary hospital on HF or CPAP. Of these, 23 required admission to PICU. Those admitted to PICU had a higher median fraction of inspired oxygen than those not admitted (0.4 vs 0.3, respectively, P = 0.013). Patients transported by road (vs flight) were more likely (20/23 patients, RR = 3.15, P = 0.016) to be admitted to PICU (56% vs 18%). Those who had received CPAP prior to or during transfer were more likely to require PICU admission (P = 0.012).We have demonstrated that children who require CPAP to manage their respiratory disease are more likely to require PICU care on transfer to the tertiary paediatric hospital. In addition, those patients being transferred from secondary metropolitan hospitals after a trial of HF are also likely to require PICU care. This suggests that these patients should be directly admitted to PICU, allowing for improved patient experience and flow as well as reducing unnecessary ED resource utilisation. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the impact of High Flow Nasal Cannula (HFNC) introduction outside of Paediatric Critical Care Units (PCCU), on PCCU admissions and intubation rates. Secondarily, to identify escalation predictors. Methods: Retrospective observational study with matched PCCU admissions and intubation rates, 2‐years before (Group 1) and 2‐years after (Group 2) HFNC introduction outside of PCCU. Within Group 2, we compared those admitted to PCCU (escalation) and those who did not (non‐escalation). Observations, change in observations and time to starting HFNC were analysed. Results: Pre‐ and post‐introduction comparison: Of 980 admissions in Group 1, 55 were admitted to PCCU, whereas of 1209 admission in Group 2, there were 85 admissions, P = 0.188. Group 1 had 25 intubations compared to 23 in Group 2, P = 0.309. Over twice as many children had some form of respiratory support in Group 2. Post‐introduction: 104 children commenced HFNC, 72% for bronchiolitis. Median age was 4 months in the non‐escalation group and 6.5 months in the escalation group, P = 0.663. Thirty‐eight children escalated to PCCU: 33 required CPAP/BiPAP, 4 were intubated with 1 remaining on HFNC. Comparisons of age, gender, comorbidities, observations, change in observations and time to starting HFNC showed no significant escalation predictors. Conclusions: This study identified no statistically significant predictors of escalation. There was an observed increase in PCCU admissions with decreased intubations. The resource implications of this therapy are significant and further studies should examine cost effectiveness of HFNC use outside of PCCU. [ABSTRACT FROM AUTHOR]

Objective: To determine the effect of different types of probes for lung ultrasound in neonates. Design: Prospective, blinded, randomized, comparative study between 2020 and 2022. Setting: Single-center study at a third level neonatal unit. Patients: Hemodynamically stable infants with either nasal continuous positive airway pressure, high flow nasal cannula or without respiratory support. Intervention: Lung ultrasound using either an echo or microconvex probe. As control, the linear probe was used. Main outcome measures: Primary outcome measure was neonatologist performed lung ultrasound (NPLUS) score. Secondary outcome measures were number of B-Lines, thickness of the pleural line and subjective image quality. Furthermore, correlation between NPLUS results and clinical data was assessed. Results: A total of 1584 video loops from 66 patients, with a mean corrected gestational age of 33.8 weeks (SD 4.23) and weight of 1950g (SD 910), respectively, were analyzed. NPLUS score was estimated lower with the echo- and microconvex probe compared to the linear probe, with a coefficient of -2.95 (p < 0.001) and -1.09 (p = 0.19), respectively. Correlation between the pulse oximetric saturation/fraction of inspired oxygen ratio and NPLUS score was moderately strong and best using the microconvex probe (Spearman's rho = -0.63, p<0.001). Conclusion: Our results not only confirm the current recommendations, but also demonstrate the extent of the varying results when different probes are used. The differences we discovered call for caution in interpreting scores, especially in the context of guiding therapies and communicating prognoses. Finally, the correlation between NPLUS score and clinical parameters contributes to validating the use of this diagnostic tool. [ABSTRACT FROM AUTHOR]

Purpose: Intravenous sedation (IVS) with propofol (PPF) is commonly performed in dental treatment, particular in patients with dentophobia, with gag reflex, or undergoing implant surgeries, as PPF has the advantages of rapid induction and recovery. However, PPF and other intravenous sedatives may cause respiratory depression. Thus, IVS with PPF requires oxygen administration. But airway burn may occur when high-concentration oxygen is stored in the oral cavity and catches fire. For these reasons, the present study aimed to elucidate the changes in oxygen concentration (OC) under IVS with PPF and oxygen administration. Patients and methods: Nineteen healthy male volunteers participated in the study. None of them had missing teeth, nasal congestion, or temporomandibular joint dysfunction. They were sedated with a continuous PPF infusion dose of 6 mg/kg/hr for 25 min, followed by administration of 3 L/min oxygen via a nasal cannula. The OC was measured at two sites, namely, the median maxillary anterior teeth (MMAT) and median maxillary soft palate (MMSP), before PPF infusion (baseline) and 14, 15– 18 (Term 1), 19, and 20– 23 (Term 2) min after the start of infusion. Results: Compared with the values at baseline, the OC in the MMSP significantly increased at each time point, whereas the OC in the MMAT significantly increased at Term 2. Furthermore, in the comparison of the OC before and after the use of a mouth prop, the OC exhibited an upward trend, but no statistically significant differences were observed between the two time points in the MMAT and MMSP. In IVS with PPF and oxygen administration, the OC in the pharynx increases as the sedative level deepens. Conclusion: Oxygen administration should be temporarily discontinued, and suction should be performed to decrease the OC in the oral cavity when sparking procedures during IVS with PPF and oxygen administration are performed. [ABSTRACT FROM AUTHOR]

BACKGROUND: Patients with COPD and other lung diseases are treated with long-term oxygen therapy (LTOT). Portable oxygen sources are required to administer LTOT while maintaining patient autonomy. Existing portable oxygen equipment has limitations that can hinder patient mobility. A novel nasal interface is presented in this study, aiming to enhance breath detection and triggering efficiency of portable pulsed-flow oxygen devices, thereby improving patient mobility and independence. METHOD: To examine the effectiveness of the new interface, 8 respiratory therapists participated in trials using different oxygen sources (tank with oxygen-conserving device, SimplyGo Mini portable oxygen concentrator [POC], and OxyGo NEXT POC) and breathing types (nasal and oral) while using either the new nasal interface or a standard cannula. Each trial was video recorded so participant breaths could be retroactively matched with a pulse/no-pulse response, and triggering success rates were calculated by dividing the number of oxygen pulses by the number of breaths in each trial. After each trial, volunteers were asked to rate their perceived breathing resistance. RESULTS: Nasal breathing consistently resulted in higher triggering success rates compared to oral breathing for pulsed-flow oxygen devices. POCs exhibited higher triggering success rates than did the oxygen tanks with conserving device. However, there were no significant differences in triggering success rates between the two POC models. The new nasal interface demonstrated improved triggering success rates compared to the standard cannula. Whereas the new nasal inter- face was associated with a slight increase in perceived breathing resistance during nasal breathing trials, participants reported manageable resistance levels when using the interface. CONCLUSIONS: This study demonstrates that the new nasal interface can improve triggering success rates of pulsed-flow oxygen devices during both nasal and oral breathing scenarios. Further research involving patient trials is recommended to understand the clinical implications of improved pulse triggering. [ABSTRACT FROM AUTHOR]

Tubeless upper airway surgery in children is a complex procedure in which surgeons and anaesthetists share the same operating field. These procedures are often interrupted for rescue oxygen therapy. The efficacy of nasal high-flow oxygen to decrease the frequency of rescue interruptions in children undergoing upper airway surgery is unknown. In this multicentre randomised trial conducted in five tertiary hospitals in Australia, children aged 0–16 years who required tubeless upper airway surgery were randomised (1:1) by a web-based randomisation tool to either nasal high-flow oxygen delivery or standard oxygen therapy (oxygen flows of up to 6 L/min). Randomisation was stratified by site and age (<1 year, 1–4 years, and 5–16 years). Subsequent tubeless upper airway surgery procedures in the same child could be included if there were more than 2 weeks between the procedures, and repeat surgical procedures meeting this condition were considered to be independent events. The oxygen therapy could not be masked, but the investigators remained blinded until outcome data were locked. The primary outcome was successful anaesthesia without interruption of the surgical procedure for rescue oxygenation. A rescue oxygenation event was defined as an interruption of the surgical procedure to deliver positive pressure ventilation using either bag mask technique, insertion of an endotracheal tube, or laryngeal mask to improve oxygenation. There were ten secondary outcomes, including the proportion of procedures with a hypoxaemic event (SpO 2 <90%). Analyses were done on an intention-to-treat (ITT) basis. Safety was assessed in all enrolled participants. This trial is registered in the Australian New Zealand Clinical Trials Registry, ACTRN12618000949280, and is completed. From Sept 4, 2018, to April 12, 2021, 581 procedures in 487 children were randomly assigned to high-flow oxygen (297 procedures) or standard care (284 procedures); after exclusions, 528 procedures (267 assigned to high-flow oxygen and 261 assigned to standard care) in 483 children (293 male and 190 female) were included in the ITT analysis. The primary outcome of successful anaesthesia without interruption for tubeless airway surgery was achieved in 236 (88%) of 267 procedures on high-flow oxygen and in 229 (88%) of 261 procedures on standard care (adjusted risk ratio [RR] 1·02, 95% CI 0·96–1·08, p=0·82). There were 51 (19%) procedures with a hypoxaemic event in the high-flow oxygen group and 57 (22%) in the standard care group (RR 0·86, 95% CI 0·58–1·24). Of the other prespecified secondary outcomes, none showed a significant difference between groups. Adverse events of epistaxis, laryngospasm, bronchospasm, hypoxaemia, bradycardia, cardiac arrest, hypotension, or death were similar in both study groups. Nasal high-flow oxygen during tubeless upper airway surgery did not reduce the proportion of interruptions of the procedures for rescue oxygenation compared with standard care. There were no differences in adverse events between the intervention groups. These results suggest that both approaches, nasal high-flow or standard oxygen, are suitable alternatives to maintain oxygenation in children undergoing upper airway surgery. Thrasher Research Fund, the Australian and New Zealand College of Anaesthetists, the Society for Paediatric Anaesthesia in New Zealand and Australia. [ABSTRACT FROM AUTHOR]

The controversial topic of oral feeding while on noninvasive ventilation remains at the forefront of preterm intensive care management. The intersection of pulmonary, neurologic, and gastrointestinal maturation coalesces at a postmenstrual age that requires changes in practices compared with those used in older infants. Various animal models in the past decades aimed to gain physiological knowledge of noninvasive ventilation effects on the suck–swallow–breathe coordination sequence. However, the preterm infant poses nuanced anatomic challenges. Although concerns for oral feeding while on noninvasive ventilation include aspiration risks and potential inpatient obstacles, there is evidence to support the feasibility, initiation, and progression of oral feedings while an infant is supported on high-flow nasal cannula and continuous positive airway pressure. There is evidence to support that this may accelerate attainment of oral feeding milestones and, thus, eventual hospital discharge. More recent multidisciplinary institutional protocols may provide cautious guidance on evaluation and algorithms to assess infants who may benefit from initiation and advancement of oral feeding versus awaiting further maturation. [ABSTRACT FROM AUTHOR]

Background: Noninvasive ventilation (NIV) is widely employed as the initial treatment for patients with chronic acute exacerbation of obstructive pulmonary disease (AECOPD). Nevertheless, high-flow nasal cannula (HFNC) has been increasingly utilized and investigated to mitigate the issues associated with NIV. Flow rate may play a significant role in diaphragmatic function among subjects recovering from AECOPD. Based on these observations, we conducted a physiological study to assess the impact of HFNC therapy on diaphragmatic function, as measured by US, respiratory rate (RR), gas exchange, and patient comfort at various flow rates. Methods: A prospective physiological pilot study enrolled subjects with a diagnosis of AECOPD who required NIV for more than 24 h. After stabilization, these subjects underwent a 30-min trial using NIV and HFNC at different sequential flow rates (30–60 L/min). At the end of each trial, diaphragmatic displacement (DD, cm) and diaphragmatic thickness fraction (DTF, %) were measured using ultrasound. Additionally, other physiological variables, such as RR, gas exchange, and patient comfort, were recorded. Results: A total of 20 patients were included in the study. DD was no different among trials (p = 0.753). DTF (%) was significantly lower with HFNC-30 L/min compared to HFNC-50 and 60 L/min (p < 0.001 for all comparisons). No significant differences were found in arterial pH and PaCO2 at discontinuation of NIV and at the end of HFNC trials (p > 0.050). During HFNC trials, RR remained unchanged without statistically significant differences (p = 0.611). However, we observed that HFNC improved comfort compared to NIV (p < 0.001 for all comparisons). Interestingly, HFNC at 30 and 40 L/min showed greater comfort during trials. Conclusions: In subjects recovering from AECOPD and receiving HFNC, flows above 40 L/min may not offer additional benefits in terms of comfort and decreased respiratory effort. HFNC could be a suitable alternative to COT during breaks off NIV. [ABSTRACT FROM AUTHOR]

Background Persistent mortality in adults hospitalized due to acute COVID-19 justifies pursuit of disease mechanisms and potential therapies. The aim was to evaluate which virus and host response factors were associated with mortality risk among participants in Therapeutics for Inpatients with COVID-19 (TICO/ACTIV-3) trials. Methods A secondary analysis of 2625 adults hospitalized for acute SARS-CoV-2 infection randomized to 1 of 5 antiviral products or matched placebo in 114 centers on 4 continents. Uniform, site-level collection of participant baseline clinical variables was performed. Research laboratories assayed baseline upper respiratory swabs for SARS-CoV-2 viral RNA and plasma for anti–SARS-CoV-2 antibodies, SARS-CoV-2 nucleocapsid antigen (viral Ag), and interleukin-6 (IL-6). Associations between factors and time to mortality by 90 days were assessed using univariate and multivariable Cox proportional hazards models. Results Viral Ag ≥4500 ng/L (vs <200 ng/L; adjusted hazard ratio [aHR], 2.07; 1.29–3.34), viral RNA (<35 000 copies/mL [aHR, 2.42; 1.09–5.34], ≥35 000 copies/mL [aHR, 2.84; 1.29–6.28], vs below detection), respiratory support (<4 L O2 [aHR, 1.84; 1.06–3.22]; ≥4 L O2 [aHR, 4.41; 2.63–7.39], or noninvasive ventilation/high-flow nasal cannula [aHR, 11.30; 6.46–19.75] vs no oxygen), renal impairment (aHR, 1.77; 1.29–2.42), and IL-6 >5.8 ng/L (aHR, 2.54 [1.74–3.70] vs ≤5.8 ng/L) were significantly associated with mortality risk in final adjusted analyses. Viral Ag, viral RNA, and IL-6 were not measured in real-time. Conclusions Baseline virus-specific, clinical, and biological variables are strongly associated with mortality risk within 90 days, revealing potential pathogen and host-response therapeutic targets for acute COVID-19 disease. [ABSTRACT FROM AUTHOR]

This study investigated the flow characteristics of the high-flow path of a two-dimensional supersonic intake in a turbine-based combined-cycle engine utilizing Reynolds-averaged Navier–Stokes (RANS) and detached eddy simulation (DES) turbulence schemes with a moving mesh in ANSYS to analyze the flow effects of varying rotational cowl angles. In addition, proper orthogonal decomposition (POD) was employed to analyze the flow modes. This study revealed that the mass flow rate and pressure recovery increased linearly with an increasing cowl opening angle, and fluctuations were observed when the cowl was positioned parallel to the ramp surface in DES transient solutions. Conversely, a significant decrease in mass flow rate and pressure recovery ratio occurred when the cowl angle was located at fixed − 4.78° in steady solutions. POD utilizing snapshots derived from RANS k-wSST and DES indicated that the first to fourth modes were dominant, accurately representing the original velocity field with a cumulative mode energy ratio of over 80 %. [ABSTRACT FROM AUTHOR]

Using High‐Throughput Experimentation (HTE), a visible light‐mediated etherification method was developed, employing the organic photocatalyst thioxanthen‐9‐one (TXO) and a commercially available, air‐stable nickel source. Design of Experiments (DoE) techniques were utilized in conjunction with HTE to identify optimal reaction conditions which are mild, cost‐effective, robust and therefore suitable for use in an industrial setting. A diverse substrate scope was prepared via parallel synthesis and selected examples were demonstrated on a 4.2 mmol scale in batch. Furthermore, the reaction was successfully performed on an 83 mmol scale, utilizing a standard jacketed reactor and Kessil PR160 L lamps. [ABSTRACT FROM AUTHOR]

Background and Objective: Interstitial lung disease (ILD) is characterized by dyspnoea on exertion and exercise‐induced hypoxaemia. High‐flow nasal cannula (HFNC) therapy reduces the respiratory workload through higher gas flow and oxygen supplementation, which may affect exercise tolerance. This study aimed to examine the effects of oxygen and gas flow rates through HFNC therapy on exercise tolerance in ILD patients. Methods: We conducted three‐treatment crossover study. All ILD patients performed the exercises on room air (ROOM AIR setting: flow, 0 L/min; fraction of inspired oxygen [FiO2], 0.21), HFNC (FLOW setting: flow 40 L/min, FiO2 0.21), and HFNC with oxygen supplementation (FLOW + OXYGEN setting: flow 40 L/min, FiO2 0.6). The primary endpoint was the endurance time, measured using constant‐load cycle ergometry exercise testing at a peak work rate of 80%. Results: Twenty‐five participants (10 men, 71.2 ± 6.7 years) were enrolled. The increase in exercise duration between the ROOM AIR and FLOW was 46.3 s (95% CI, −6.1 to 98.7; p = 0.083), and the FLOW and FLOW + OXYGEN was 91.5 s (39.1–143.9; p < 0.001). The percutaneous oxygen saturation (SpO2) at rest was significantly higher with the FLOW + OXYGEN setting than with the ROOM AIR and FLOW settings, and the difference persisted during exercise. At equivalent time points during exercise, the SpO2 with the FLOW setting was significantly higher than that with the ROOM AIR setting. Conclusion: Oxygen supplementation in HFNC therapy improved exercise tolerance and SpO2. We found that gas flow alone did not improve exercise tolerance, but improved SpO2 during exercise. [ABSTRACT FROM AUTHOR]

The orbital angular momentum (OAM) of light, which is associated with the rotation of the phase structure, gives rise to numerous novel physical phenomena inlight–matter interactions. However, the direct generation of scalar OAM lasers with power‐handling capability and controllable states at the source remains challenging owing to mode degeneracy, handedness selection, and nonlinear thermal effects, which can even lead to topological charge splitting. This paper proposes a novel approach that allows spatial mode‐conversion‐controlled laser oscillation in a high‐gain OAM laser cavity with an integrated spiral‐face output coupler (SFOC). By adapting position‐dependent resonant modes, scalar optical vortices with a record power level (>60 W), high purity (>90%), and controllable OAM states (ħ or −8ħ) are demonstrated. Further, the dynamic process of OAM generation and evolution in the cavity is revealed. The concept presented herein opens a new route for the generation of OAM laser sources toward high power levels and holds promise for advancing classical and quantum optics, particularly in the area of light–matter interactions. [ABSTRACT FROM AUTHOR]

OBJECTIVE: This study aimed to describe daytime and nighttime use and outcome of non-invasive respiratory intervention (NIRI) for infants born prematurely and for children with medical complexity (CMC) during a post-acute care hospital (PACH) admission. METHODS: Thirty-eight initial PACH admissions (October 2018 through September 2020) for premature infants (< 1 year; n = 19) and CMC (> 1 year; n = 19) requiring NIRI during the day and/or at night were retrospectively examined. Measures included: 1) daytime and nighttime NIRI use by type (supplemental oxygen therapy via low-flow nasal cannula or positive airway pressure [PAP] via high-flow nasal cannula, continuous positive airway pressure, or biphasic positive airway pressure at admission and discharge) and 2) daytime and nighttime NIRI outcome—reduction, increase, or no change from admission to discharge. RESULTS: For the total sample (n = 38), daytime vs nighttime NIRI use was significantly different (p < 0.001). At both admission and discharge, supplemental oxygen was the most common NIRI during the day, while PAP was most common at night. From admission to discharge, seven (18%) infants and children had a positive change (reduced NIRI) during the day, while nine (24%) had a positive change at night. At discharge, 11/38 (29%) infants and children required no daytime NIRI, while 4/38 (11%) required no day or night NIRI. CONCLUSION: NIRI use differs between day and night at PACH admission and discharge for CMC. Reductions in NIRI were achieved during the day and at night from PACH admission to discharge for both infants born prematurely and for children with varied congenital, neurological, or cardiac diagnoses. [ABSTRACT FROM AUTHOR]

Introduction: Noninvasive respiratory support may be provided to decrease the risk of postextubation failure following surgery. Despite these efforts, approximately 3%–27% of infants and children still experience respiratory failure after tracheal extubation following cardiac surgery. This systematic review evaluates studies comparing the efficacy of high‐flow nasal cannula to conventional oxygen therapy such as nasal cannula and other noninvasive ventilation techniques in preventing postextubation failure in this patient population. Methods: A systematic and comprehensive search was conducted in major databases including MEDLINE, EMBASE, Web of Science, and Central. The search encompassed articles focusing on the prophylactic use of high‐flow nasal cannula following tracheal extubation in pediatric patients undergoing cardiac surgery for congenital heart disease. The inclusion criteria for this review consisted of randomized clinical trials as well as observational, cohort, and case–control studies. Results: A total of 1295 studies were screened and 12 studies met the inclusion criteria. These 12 studies included a total of 1565 children, classified into three groups: seven studies compared high‐flow nasal cannula to noninvasive ventilation techniques, four studies compared high‐flow nasal cannula to conventional oxygen therapy, and one observational single‐arm study explored the use of high‐flow nasal cannula with no control group. There was no significant difference in the incidence of tracheal reintubation between high‐flow nasal cannula and conventional oxygen therapy (risk ratio [RR] = 0.67, 95% confidence interval [CI]: 0.24–1.90, p =.46). However, there was a lower incidence of tracheal reintubation in patients who were extubated to high‐flow nasal cannula versus those extubated to noninvasive ventilation techniques (RR = 0.45, 95% CI: 0.32–0.63, p <.01). The high‐flow nasal cannula group also demonstrated a lower mortality rate compared to the noninvasive ventilation techniques group (RR = 0.31, 95% CI: 0.16–0.61, p <.01) as well as a shorter postoperative length of stay (mean difference = −8.76 days, 95% CI: −13.08 to −4.45, p <.01) and shorter intensive care length of stay (mean difference = −4.63 days, 95% CI: −9.16 to −0.11, p =.04). Conclusion: High‐flow nasal cannula is more effective in reducing the rate of postextubation failure compared to other forms of noninvasive ventilation techniques following surgery for congenital heart disease in pediatric‐aged patients. high‐flow nasal cannula is also associated with lower mortality rates and shorter length of stay. However, when comparing high‐flow nasal cannula to conventional oxygen therapy, the findings were inconclusive primarily due to a limited number of scientific studies available on this specific comparison. Future study is needed to further define the benefit of high‐flow nasal cannula compared to conventional oxygen therapy and various types of noninvasive ventilation techniques. [ABSTRACT FROM AUTHOR]

This document is a quality improvement short report that discusses the implementation of preductal and postductal oxygen saturation screening for newborns at West Suffolk Hospital. The aim of the project was to increase the detection of critical congenital heart defects (CHD) in newborns. The report highlights the challenges faced by midwives and neonatal nurses, such as increased workload and the cost of purchasing saturation monitors. The authors emphasize the importance of sharing data to overcome preconceptions about the need for screening and to reinforce its significance. The report concludes that the screening levels have been maintained at over 95% and encourages other hospitals to implement similar screening measures to reduce neonatal morbidity and mortality. [Extracted from the article]

Introduction: Before tracheal intubation, it is essential to provide sufficient oxygen reserve for emergency patients with full stomachs. Recent studies have demonstrated that high-flow nasal oxygen (HFNO) effectively pre-oxygenates and prolongs apneic oxygenation during tracheal intubation. Despite its effectiveness, the use of HFNO remains controversial due to concerns regarding carbon dioxide clearance. The air leakage and unknown upper airway obstruction during HFNO therapy cause reduced oxygen flow above the vocal cords, possibly weaken the carbon dioxide clearance. Methods: Patients requiring emergency surgery who had fasted < 8 h and not drunk < 2 h were randomly assigned to the high-flow group, who received 100% oxygen at 30–60 L/min through nasopharyngeal airway (NPA), or the mask group, who received 100% oxygen at 8 L/min. PaO2 and PaCO2 were measured immediately before pre-oxygenation (T0), anesthesia induction (T1), tracheal intubation (T2), and mechanical ventilation (T3). The gastric antrum's cross-sectional area (CSA) was measured using ultrasound technology at T0, T1, and T3. Details of complications, including hypoxemia, reflux, nasopharyngeal bleeding, postoperative pulmonary infection, postoperative nausea and vomiting (PONV), and postoperative nasopharyngeal pain, were recorded. The primary outcomes were PaCO2 measured at T1, T2, and T3. The secondary outcomes included PaO2 at T1, T2, and T3, CSA at T1 and T3, and complications happened during this trial. Results: Pre-oxygenation was administered by high-flow oxygen through NPA (n = 58) or facemask (n = 57) to 115 patients. The mean (SD) PaCO2 was 32.3 (6.7) mmHg in the high-flow group and 34.6 (5.2) mmHg in the mask group (P = 0.045) at T1, 45.0 (5.5) mmHg and 49.4 (4.6) mmHg (P < 0.001) at T2, and 47.9 (5.1) mmHg and 52.9 (4.6) mmHg (P < 0.001) at T3, respectively. The median ([IQR] [range]) PaO2 in the high-flow and mask groups was 404.5 (329.1–458.1 [159.8–552.9]) mmHg and 358.9 (274.0–413.3 [129.0–539.1]) mmHg (P = 0.007) at T1, 343.0 (251.6–428.7 [73.9–522.1]) mmHg and 258.3 (162.5–347.5 [56.0–481.0]) mmHg (P < 0.001) at T2, and 333.5 (229.9–411.4 [60.5–492.4]) mmHg and 149.8 (87.0–246.6 [51.2–447.5]) mmHg (P < 0.001) at T3, respectively. The CSA in the high-flow and mask groups was 371.9 (287.4–557.9 [129.0–991.2]) mm2 and 386.8 (292.0–537.3 [88.3–1651.7]) mm2 at T1 (P = 0.920) and 452.6 (343.7–618.4 [161.6–988.1]) mm2 and 385.6 (306.3–562.0 [105.5–922.9]) mm2 at T3 (P = 0.173), respectively. The number (proportion) of complications in the high-flow and mask groups is shown below: hypoxemia: 1 (1.7%) vs. 9 (15.8%, P = 0.019); reflux: 0 (0%) vs. 0 (0%); nasopharyngeal bleeding: 1 (1.7%) vs. 0 (0%, P = 1.000); pulmonary infection: 4 (6.9%) vs. 3 (5.3%, P = 1.000); PONV: 4 (6.9%) vs. 4 (7.0%, P = 1.000), and nasopharyngeal pain: 0 (0%) vs. 0 (0%). Conclusions: Compared to facemasks, pre-oxygenation with high-flow oxygen through NPA offers improved carbon dioxide clearance and enhanced oxygenation prior to tracheal intubation in patients undergoing emergency surgery, while the risk of gastric inflation had not been ruled out. Trial registration: This trial was registered prospectively at the Chinese Clinical Research Registry on 26/4/2022 (Registration number: ChiCTR2200059192). [ABSTRACT FROM AUTHOR]

Background: Acute pulmonary edema (APE) is one of the main diagnoses for dyspnea patients in emergency departments (ER). High-velocity nasal cannula (HVNC) might be considered as an alternative support for early management of APE in the ER. Objectives: to compare the effectiveness of HVNC therapy for those with APE to that of conventional oxygen therapy (COT). Methodology: This study was a randomized controlled trial with 60 APE patients admitted to the critical care and chest units at Beni-Suef University Hospital. We randomly assigned patients to Group A, who received COT. Group B received HVNC. All patients received a full history and evaluation, a chest X-ray, and a chest CT scan. A complete blood count (CBC), coagulation profile, renal function tests, and assessments of serum sodium, potassium, and arterial blood gas (ABG) were included in laboratory examinations. We conducted these tests at admission and again six hours later. Results: We linked the use of HVNC to a significant drop in respiratory rate. Both groups' PO2 levels increased while PCO2 decreased. The HVNC intervention was more effective in increasing PO2 and decreasing PCO2 levels than the COT. There was a trend in the HVNC group toward less reliance on mechanical ventilation (MV) as compared to COT. The length of time patients spent in the ICU dropped significantly for those receiving HVNC. Conclusion: In patients with APE, HVNC significantly improves ABG, ICU stay duration, and MV frequency compared to COT. [ABSTRACT FROM AUTHOR]

• The cost-effectiveness of implementing high-dose influenza vaccination (HD-QIV) was assessed. • A health-economic model was developed, including morbidity, mortality, and productivity. • HD-QIV is likely cost-effective for adults aged 60 and over in the Netherlands. We assess the cost-effectiveness of switching from standard-dose quadrivalent influenza vaccination (SD-QIV) to high-dose vaccination (HD-QIV) for Dutch adults aged 60 years and older. A health-economic model was used to compare the scenario where HD-QIV was implemented compared to the current standard, SD-QIV. This model used a lifetime horizon and assessed the cost-effectiveness from a societal perspective. A recently published meta-analysis was used to incorporate the benefits of HD-QIV, including cardiorespiratory hospitalizations, in analyses considering RCT only or combining RCT and RWE estimates in a scenario analysis. Implementing HD-QIV is cost effective at its list price, with an ICER of €5,400 per QALY gained. The main driver of these results is the prevention of cardiorespiratory hospitalizations. Other public health benefits are the prevention of GP consults and deaths. HD-QIV is highly likely to be cost-effective, reaching a 100% probability of being cost effective at the Dutch willingness-to-pay threshold of €20,000 per QALY. Implementing HD-QIV for adults aged 60 and over within the existing influenza vaccination campaign is highly cost effective. HD-QIV may support alleviating potential capacity issues in Dutch hospitals in the winter respiratory season. [ABSTRACT FROM AUTHOR]

Purpose: Few studies have compared patient characteristics, clinical management, and outcome of patients with COVID-19 between the different epidemic waves. In this study, we describe patient characteristics, treatment, and outcome of patients admitted for COVID-19 in the Antwerp University Hospital over the first three epidemic waves of 2020–2021. Methods: Retrospective observational study of COVID-19 patients in a Belgian tertiary referral hospital. All adult patients with COVID-19, hospitalized between February 29, 2020, and June 30, 2021, were included. Standardized routine medical data was collected from patient records. Risk factors were assessed with multivariable logistic regression. Results: We included 722 patients, during the first (n = 179), second (n = 347) and third (n = 194) wave. We observed the lowest disease severity at admission during the first wave, and more elderly and comorbid patients during the second wave. Throughout the subsequent waves we observed an increasing use of corticosteroids and high-flow oxygen therapy. In spite of increasing number of complications throughout the subsequent waves, mortality decreased each wave (16.6%,15.6% 11.9% in 1st, 2nd and 3rd wave respectively). C-reactive protein above 150 mg/L was predictive for the need for intensive care unit admission (odds ratio (OR) 3.77, 95% confidence interval (CI) 2.32–6.15). A Charlson comorbidity index ≥ 5 (OR 5.68, 95% CI 2.54–12.70) and interhospital transfers (OR 3.78, 95% CI 2.05–6.98) were associated with a higher mortality. Conclusions: We observed a reduction in mortality each wave, despite increasing comorbidity. Evolutions in patient management such as high-flow oxygen therapy on regular wards and corticosteroid use may explain this favorable evolution. [ABSTRACT FROM AUTHOR]

Background: Renal impairment is a predictor of coronavirus disease (COVID-19) severity. No studies have compared COVID-19 outcomes in patients with chronic kidney disease (CKD) and patients with impaired renal function without a prior diagnosis of CKD. This study aimed to identify the impact of pre-existing impaired renal function without CKD on COVID-19 outcomes. Methods: This retrospective study included 3,637 patients with COVID-19 classified into three groups by CKD history and estimated glomerular filtration rate (eGFR) on referral: Group 1 (n = 2,460), normal renal function without a CKD history; Group 2 (n = 905), impaired renal function without a CKD history; and Group 3 (n = 272), history of CKD. We compared the clinical characteristics of these groups and assessed the effect of CKD and impaired renal function on critical outcomes (requirement for respiratory support with high-flow oxygen devices, invasive mechanical ventilation, or extracorporeal membrane oxygen, and death during hospitalization) using multivariable logistic regression. Results: The prevalence of comorbidities (hypertension, diabetes, and cardiovascular disease) and incidence of inflammatory responses (white blood counts, and C-reactive protein, procalcitonin, and D-dimer levels) and complications (bacterial infection and heart failure) were higher in Groups 2 and 3 than that in Group 1. The incidence of critical outcomes was 10.8%, 17.7%, and 26.8% in Groups 1, 2, and 3, respectively. The mortality rate and the rate of requiring IMV support was lowest in Group 1 and highest in Group 3. Compared with Group 1, the risk of critical outcomes was higher in Group 2 (adjusted odds ratio [aOR]: 1.32, 95% confidence interval [CI]: 1.03–1.70, P = 0.030) and Group 3 (aOR: 1.94, 95% CI: 1.36–2.78, P < 0.001). Additionally, the eGFR was significantly associated with critical outcomes in Groups 2 (odds ratio [OR]: 2.89, 95% CI: 1.64–4.98, P < 0.001) and 3 (OR: 1.87, 95% CI: 1.08–3.23, P = 0.025) only. Conclusions: Clinicians should consider pre-existing CKD and impaired renal function at the time of COVID-19 diagnosis for the management of COVID-19. [ABSTRACT FROM AUTHOR]

Background: Hypoxemia can occur in people at ultra-high altitude (above 3500 m) even at rest, and patients undergoing gastroscopy under general anesthesia have higher risk of hypoxemia. Supplementary oxygen via standard nasal cannula (SNC) is the standard of care for most patients who undergo gastroscopy under general anesthesia, which provides oxygen flow up to 15 L/min. High-flow nasal cannula (HFNC) could deliver oxygen at a rate up to 60 L/min, which is recommended by the American Society of Anesthesiologists Practice Guidelines. We speculated that the benefit with HFNC is more prominent in high-altitude areas, and aimed to compare the incidence of hypoxemia during gastroscopy under general anesthesia at ultra-high altitude with oxygen supply via either HFNC or SNC. Methods: The trial was registered at at Chinese Clinical Trial Registry (ChiCTR2100045513; date of registration on 18/04/2021). Adult patients undergoing gastroscopy with anesthesia (estimated duration of anesthesia at ≥ 15 min) were randomized at a 1:1 ratio to receive HFNC oxygen or SNC oxygen. The primary outcome was hypoxemia (SpO2 < 90% for any duration). Secondary outcomes included severe hypoxemia (SpO2 < 75% for any duration or SpO2 < 90% but ≥ 75% for ≥ 60 s) and hypotension, as defined by reduction of mean arterial blood pressure by ≥ 25% from the baseline. Results: A total of 262 patients were enrolled: 129 in the HFNC group and 133 in the SNC group. All patients received the designated intervention. Student's t-test, Mann-Whitney U test and χ2 test were employed in the study. The rate of hypoxemia was 9.3% (12/129) in the HFNC group versus 36.8% (49/133) in the SNC group [risk ratio (95% confidence interval): 0.25(0.14–0.45); P < 0.001). The HFNC group also had lower rate of severe hypoxemia [0.0% (0/129) versus 11.3% (15/133); risk ratio (95% confidence interval): 0.03(0.00-0.55); P < 0.001, respectively]. The rate of hypotension did not differ between the 2 groups [22.5% (29/129) in HFNC group versus 21.1% (28/133) in SNC group; risk ratio (95% confidence interval): 1.07(0.67–1.69) ; P = 0.779]. Conclusion: HFNC oxygen reduced the incidence of hypoxemia during anesthesia in adult patients undergoing gastroscopy at ultra-high altitude. [ABSTRACT FROM AUTHOR]

Objective: This study aims to evaluate the respiratory rate-oxygenation index (ROX) and the ratio of pulse oximetry saturation (SpO2) to the fraction of inspired oxygen (FiO2) (SpO2/FiO2, [SF]) to determine whether these indices are predictive of outcome in dogs receiving high-flow nasal cannula oxygen therapy (HFNOT). Design: This is a prospective observational study. Setting: This study was carried out at two university teaching hospitals. Animals: In total, 88 dogs treated with HFNOT for hypoxemic respiratory failure due to various pulmonary diseases were selected. Measurements and main results: The ROX index was defined as the SF divided by the respiratory rate (RR). ROX and SF were calculated at baseline and for each hour of HFNOT. The overall success rate of HFNOT was 38% (N = 33/88). Variables predicting HFNOT success were determined using logistic regression, and the predictive power of each variable was assessed using the area under the receiver operating curve (AUC). ROX and SF were adequately predictive of HFNOT success when averaged over 0-16 h of treatment, with similar AUCs of 0.72 (95% confidence interval [CI] 0.60-0.83) and 0.77 (95% CI 0.66-0.87), respectively (p < 0.05). SF showed acceptable discriminatory power in predicting HFNOT outcome at 7 h, with an AUC of 0.77 (95% CI 0.61-0.93, p = 0.013), and the optimal cutoff for predicting HFNC failure at 7h was SF ≤191 (sensitivity 83% and specificity 76%). Conclusion: These indices were easily obtained in dogs undergoing HFNOT. The results suggest that ROX and SF may have clinical utility in predicting the outcomes of dogs on HFNOT. Future studies are warranted to confirm these findings in a larger number of dogs in specific disease populations. [ABSTRACT FROM AUTHOR]

Background: High-flow nasal cannula (HFNC) therapy has emerged as a promising treatment modality for interstitial lung disease (ILD)-related respiratory failure. This systematic review aims to evaluate the efficacy and safety of HFNC therapy in patients with ILDs. Methods: A comprehensive literature search was conducted using major electronic databases to identify relevant studies investigating the use of HFNC therapy in ILD patients with respiratory failure. Outcome measures of interest included improvements in oxygenation, dyspnea relief, respiratory rate control, hospital length of stay, and mortality. Results: Twelve studies were analyzed with an overall population of 715 patients included. Idiopathic Pulmonary Fibrosis (IPF) was the most prevalent type of ILD. Evaluated clinical settings were acute (7 studies), chronic (2 studies), and end-stage (3 studies) ILDs. The HFNC as a support for acute respiratory failure seems not inferior to non-invasive ventilation while offering better comfort and patient's perception. Poor data are available about use in chronic/long-term or rehabilitative settings. In end of life/palliative care, an HFNC might improve quality of life. Despite the promising results, further research is warranted to establish optimal HFNC protocols, identify patient subgroups most likely to benefit, and explore long-term outcomes. Conclusions: Overall, the HFNC appears to be a valuable therapeutic option for managing respiratory failure in ILD patients, offering potential improvements in oxygenation and symptom relief. [ABSTRACT FROM AUTHOR]

Background/Objectives: Coronavirus disease 2019 (COVID-19) course may differ among individuals—in particular, those with comorbidities may have severe pneumonia, requiring oxygen supplementation or mechanical ventilation. Post-COVID-19 long-term structural changes in imaging studies can contribute to persistent respiratory disturbance. This study aimed to investigate COVID-19 sequels affecting the possibility of persistent structural lung tissue abnormalities and their influence on the respiratory function of peripheral airways and gas transfer. Methods: Patients were divided into two groups according to severity grades described by the World Health Organization. Among the 176 hospitalized patients were 154 patients with mask oxygen supplementation and 22 patients with high-flow nasal cannula (HFNC) or mechanical ventilation. All tests were performed at 3, 6, and 9 months post-hospitalization. Results: Patients in the severe/critical group had lower lung volumes in FVC, FVC%, FEV1, FEV1%, LC, TLC%, and DLCO% at three months post-hospitalization. At 6 and 9 months, neither group had significant FVC and FEV1 value improvements. The MEF 25–75 values were not significantly higher in the mild/moderate group than in the severe/critical group at three months. There were weak significant correlations between FVC and FEV1, MEF50, MEF 75, plethysmography TLC, disturbances in DLCO, and total CT abnormalities in the severe/critical group at three months. In a mild/moderate group, there was a significant negative correlation between the spirometry, plethysmography parameters, and CT lesions in all periods. Conclusions: Persistent respiratory symptoms post-COVID-19 can result from fibrotic lung parenchyma and post-infectious stenotic small airway changes not visible in CT, probably due to persistent inflammation. [ABSTRACT FROM AUTHOR]

Home high-flow nasal cannula (HFNC) use in the neonatal field has become prevalent as a noninvasive respiratory support, but its application in home care remains rare. We report two cases in which a home HFNC was effective in managing extremely low-birth-weight infants with severe bronchopulmonary dysplasia (BPD). Case 1 was a male infant born at 22 weeks' gestation weighing 435 g. Case 2 was a female infant born at 23 weeks' gestation weighing 450 g. Both patients had mothers with chronic placental abruption or chorioamnionitis. They transitioned from invasive mechanical ventilation to nasal CPAP (nCPAP) at 45 days (case 1) and 50 days (case 2) old. Subsequently, at 324 days (case 1) and 90 days (case 2) old, they transitioned to a HFNC, demonstrating stable oxygenation and ventilation, but faced difficulty in removal. Considering the drawbacks of prolonged hospitalization, the patients were discharged using a home HFNC at 404 days (case 1) and 391 days (case 2) old. For case 1, the HFNC was set at 4 L/min of room air and 2 L/min of oxygen, whereas for case 2, it was set at 5 L/min of room air and 1 L/min of oxygen. These settings maintained an SpO2 above 90% and a pCO2 below 60 mmHg. An HFNC offers advantages over nCPAP owing to its lower invasiveness and reduced discomfort for long-term use. However, reports on the use of a home HFNC for BPD are scarce. In recent years, while premature infant mortality has decreased worldwide, the incidence of BPD has risen, necessitating preparedness for prolonged ventilation in preterm infants. Home ventilators represent a strategy to prevent extended hospitalization, and based on our cases, home HFNC for BPD appears safe and effective, making it potentially useful for managing preterm infants requiring prolonged respiratory support in the future. [ABSTRACT FROM AUTHOR]

Introduction: The aim of this study was to systematically review the benefits and harms of using a high-flow nasal cannula (HFNC) for weaning continuous positive airway pressure (CPAP) support in preterm infants. Methods: Cochrane Central, EMBASE, Medline, and Web of Science were searched from inception to July 15, 2023. Randomised clinical trials (RCTs) comparing weaning CPAP using HFNC versus weaning CPAP alone and evaluating predefined outcomes were included. Two authors independently performed data extraction and methodological quality assessment. Meta-analysis was conducted using a random-effects model, and the certainty of evidence was assessed using Cochrane GRADE. Results: Among 843 identified records, seven RCTs involving 781 preterm infants were eligible for analysis. The meta-analysis found no statistically significant difference in duration of respiratory support when using HFNC for weaning compared to weaning CPAP alone (mean difference (95% confidence interval) 3.52 (−0.02, 7.05); 5 RCTs; participants = 488; I2 = 29%). The evidence certainty was downgraded to low due to study limitations and imprecision. There were no significant differences in secondary outcomes, except for a lower occurrence of nasal trauma with HFNC for weaning CPAP compared to weaning CPAP alone (relative risk (95% confidence interval) 0.61 (0.38, 0.99); 4 RCTs; participants = 335; I2 = 0%). The evidence certainty for the secondary outcomes was low to very low. Conclusion: Low certainty of evidence suggests using HFNC for weaning CPAP in preterm infants may not impact the duration of respiratory support. Caution is advised when considering HFNC for weaning CPAP, especially in extremely preterm infants, until additional supportive evidence on its safety becomes available. [ABSTRACT FROM AUTHOR]

BACKGROUND AND OBJECTIVES: High-flow nasal cannula (HFNC) for bronchiolitis increased over the past decade without clear benefit. This quality improvement collaborative aimed to reduce HFNC initiation and treatment duration by 30% from baseline. METHODS: Participating hospitals either reduced HFNC initiation (Pause) or treatment duration (Holiday) in patients aged <24 months admitted for bronchiolitis. Participants received either Pause or Holiday toolkits, including: intervention protocol, training/educational materials, electronic medical record queries for data acquisition, small-group coaching, webinars, and real-time access to run charts. Pause arm primary outcome was proportion of patients initiated on HFNC. Holiday arm primary outcome was geometric mean HFNC treatment duration. Length of stay (LOS) was balancing measure for both. Each arm served as contemporaneous controls for the other. Outcomes analyzed using interrupted time series (ITS) and linear mixed-effects regression. RESULTS: Seventy-one hospitals participated, 30 in the Pause (5746 patients) and 41 in the Holiday (7903 patients). Pause arm unadjusted HFNC initiation decreased 32% without LOS change. ITS showed immediate 16% decrease in initiation (95% confidence interval [CI] -27% to -5%). Compared with contemporaneous controls, Pause hospitals reduced HFNC initiation by 23% (95% CI -35% to -10%). Holiday arm unadjusted HFNC duration decreased 28% without LOS change. ITS showed immediate 11.8 hour decrease in duration (95% CI -18.3 hours to -5.2 hours). Compared with contemporaneous controls, Holiday hospitals reduced duration by 11 hours (95% CI -20.7 hours to -1.3 hours). CONCLUSIONS: This quality improvement collaborative reduced HFNC initiation and duration without LOS increase. Contemporaneous control analysis supports intervention effects rather than secular trends toward less use. [ABSTRACT FROM AUTHOR]

Objective: To determine the association between vaccination status and mortality among critically ill patients admitted in a dedicated Covid hospital of Tripura who required invasive mechanical ventilation. Material and Methods: This study was conducted at a dedicated Covid hospital of Tripura for a period of six months, i.e., from June 2021 to November 2021. A total of 304 patients were enrolled for this study. Baseline epidemiological, radiological data along with other information like heart rate, pulse rate, oxygen saturation (SpO2), etc., were collected through patient record sheet in all cases during hospitalization. Statistical analysis was done by using SPSS 25 version. Results: Admission and mortality rates in hospital and advanced oxygen support like bi‑level positive airway pressure (BiPAP), high‑flow nasal cannula (HFNOC), and ventilator use incidences were higher in non‑vaccinated patients (17.1%) in comparison to double‑dose‑vaccinated (0.98%) and single‑dose (2.3%)‑vaccinated patients. Conclusion: This retrospective data analysis of Covid‑19 positive patients admitted in the dedicated Covid Hospital of Tripura suggests that severe infection, need for invasive and non‑invasive ventilation, and death were significantly less in the vaccinated patients as compared to the vaccine‑naive one. [ABSTRACT FROM AUTHOR]

Background: In infants treated with a low-flow nasal cannula (LFNC), the oxygen concentration delivered to the lungs (i.e., the effective FiO2) is difficult to estimate. The existing mathematical formulas rely on important assumptions regarding the values of respiratory parameters and, thus, may be inaccurate. We aimed to assess oxygen delivery by LFNC to small infants using realistic simulations on a mechanical breathing model. Methods: A mechanical breathing simulator (infant upper-airway replica, single-space breathing compartment, electric motor, microcontroller) was developed. Breathing simulations (n = 1200) were performed at various tidal volume (VT), inspiratory time (Ti), and respiratory rate (RR) combinations and different cannula flows. Results: Minute ventilation (MV) was the most significant predictor of effective FiO2. FiO2 was higher at lower VT and higher Ti values. Benaron and Benitz's formula underestimated the effective FiO2 at lower MV values, while Finer's formula significantly overestimated it. A set of predictive FiO2 charts was developed based on cannula flow, infant body weight, and RR. Conclusions: The effective FiO2 delivered by LFNC to small infants critically depends on VT, Ti, and RR. However, since VT and Ti values are not available in clinical practice, the existing mathematical formulas may be inaccurate. Our novel predictive FiO2 charts could assist in optimizing oxygen delivery by LFNC using easy-to-obtain parameters, such as infant body weight and RR. [ABSTRACT FROM AUTHOR]

The article discusses the use of high-flow nasal cannula (HFNC) therapy in the treatment of respiratory diseases. HFNC systems deliver heated and humidified gases at a set flow rate, improving carbon dioxide clearance and stabilizing alveolar oxygen fractions. The article highlights the physiological effects of HFNC, such as reducing respiratory drive and inspiratory effort. It also discusses the use of HFNC in acute hypoxemic respiratory failure and hypercapnic respiratory failure, as well as the importance of detecting HFNC failure. The article emphasizes the need for individualized therapy and close monitoring to optimize the benefits of HFNC. [Extracted from the article]

Purpose: Patients with hematological malignancies are at high risk for life-threatening complications. To date, little attention has been paid to the impact of hyperoxemia and excess oxygen use on mortality. The aim of this study was to investigate the association between partial pressure of arterial oxygen (PaO2) and 28-day mortality in critically ill patients with hematologic malignancies. Methods: Data from three international cohorts (Europe, Canada, Oceania) of patients who received respiratory support (noninvasive ventilation, high-flow nasal cannula, invasive mechanical ventilation) were obtained. We used mixed-effect Cox models to investigate the association between day one PaO2 or excess oxygen use (inspired fraction of oxygen ≥ 0.6 with PaO2 > 100 mmHg) on day-28 mortality. Results: 11,249 patients were included. On day one, 5716 patients (50.8%) had normoxemia (60 ≤ PaO2 ≤ 100 mmHg), 1454 (12.9%) hypoxemia (PaO2 < 60 mmHg), and 4079 patients (36.3%) hyperoxemia (PaO2 > 100 mmHg). Excess oxygen was used in 2201 patients (20%). Crude day-28 mortality rate was 40.6%. There was a significant association between PaO2 and day-28 mortality with a U-shaped relationship (p < 0.001). Higher PaO2 levels (> 100 mmHg) were associated with day-28 mortality with a dose–effect relationship. Subgroup analyses showed an association between hyperoxemia and mortality in patients admitted with neurological disorders; however, the opposite relationship was seen across those admitted with sepsis and neutropenia. Excess oxygen use was also associated with subsequent day-28 mortality (adjusted hazard ratio (aHR) [95% confidence interval (CI)]: 1.11[1.04–1.19]). This result persisted after propensity score analysis (matched HR associated with excess oxygen:1.31 [1.20–1.1.44]). Conclusion: In critically-ill patients with hematological malignancies, exposure to hyperoxemia and excess oxygen use were associated with increased mortality, with variable magnitude across subgroups. This might be a modifiable factor to improve mortality. [ABSTRACT FROM AUTHOR]