• Conventional nasal cannula oxygen therapy
• High-flow nasal cannula oxygen therapy
• Hypoxemia
• Intensive care unit
• Randomized clinical trial
• Sedation
• Upper gastrointestinal endoscopy

• Adult intensive & critical care
• Respiratory Distress Syndrome
• Respiratory Therapy

• Humans
• Emergency Service, Hospital
• Equivalence Trials as Topic
• France
• Hypoxia/therapy
• Multicenter Studies as Topic
• Oxygen Inhalation Therapy/methods
• Prospective Studies
• Respiratory Distress Syndrome/therapy
• Respiratory Insufficiency/therapy
• Treatment Outcome

• Programme Hospitalier de Recherche Clinique Interégional 2020

• acute dyspnea
• acute hypercapnic failure
• acute hypoxemic respiratory failure
• high-flow nasal cannula
• high-flow nasal oxygenation
• noninvasive ventilation

• Cardiac surgery
• High-flow nasal cannula
• Meta-analysis
• Oxygen therapy

• Adult
• Humans
• Cannula
• Cardiac Surgical Procedures/methods
• Oxygen Inhalation Therapy/methods
• Oxygen Inhalation Therapy/instrumentation
• Postoperative Care/methods

• Critical care
• Intubation, Intratracheal
• Organ dysfunction scores
• Oxygen inhalation therapy
• Prospective studies
• Respiration, Artificial
• Respiratory distress syndrome
• Respiratory insufficiency

• Humans
• Adult
• Middle Aged
• Cannula/adverse effects
• Prospective Studies
• Intubation, Intratracheal/adverse effects
• Noninvasive Ventilation/adverse effects
• Australia
• Oxygen Inhalation Therapy/adverse effects
• Oxygen
• Respiratory Insufficiency/therapy
• Pneumonia/therapy
• Retrospective Studies

• Apgar scores
• fetal heart rate
• fetal heart rate tracing
• hyperoxygenation
• maternal outcomes
• neonatal
• umbilical artery pH

• Pregnancy
• Infant, Newborn
• Humans
• Female
• Adolescent
• Adult
• Cardiotocography
• Labor, Obstetric
• Oxygen
• Umbilical Arteries
• Malondialdehyde

• FiO2
• Hypoxemia
• Hypoxia
• Low flow oxygen therapy
• Prediction formula

• Adult
• Humans
• Oxygen Inhalation Therapy
• Oxygen
• Ventilators, Mechanical
• Lung
• Respiratory Rate
• Respiration, Artificial

• ILD
• NHF
• breathing pattern
• hypercapnia
• lung fibrosis
• nasal high-flow

• none TNI medical AG (Wuerzburg, Germany)

• Oxygen Inhalation Therapy/adverse effects
• Oxygen

• COVID-19
• adult intensive & critical care
• respiratory infections

• Pregnancy
• Adult
• Child
• Humans
• Female
• Cannula
• COVID-19/therapy
• Oxygen
• Oxygen Inhalation Therapy
• Noninvasive Ventilation
• Respiratory Distress Syndrome/therapy
• Intubation, Intratracheal
• Respiratory Insufficiency/therapy

• Clinical Science and Technology Specific Projects of Jiangsu Province
• National Natural Science Foundation of China

• Individualized care
• Prognosis
• SOFA score
• Severe burns

• Hypoxia
• Intensive care unit
• Oxygen saturation
• Pulse oximetry

• Hypoxemic respiratory failure
• Non-invasive ventilation
• Self-inflicted lung injury

We investigated the impact of surgical masks (SM) during oxygen therapy using oxygen masks in volunteer- and simulation-based studies.

Fifteen volunteers wore the Hudson RCI^® or Open-Face Mask^® with/without an SM. The fraction of inspired oxygen concentration (FIO₂), end-tidal CO₂ (EtCO₂), partial pressure of inspired CO₂ (PICO₂), and respiratory rate (RR) were measured. The oxygen flow rate increased from 0 to 10 L/min. In the simulation-based study, FIO₂ was measured using a simulator that reproduced spontaneous breathing. RR was 12 or 24 bpm, and the tidal volume (Tv) was 300, 500, or 700 mL. The effect of oxygen mask fitting conditions was also examined. The primary outcome measure was FIO₂ at 6 L/min.

In the volunteer-based study, FIO₂ was reduced when the SM was used with the Hudson RCI^® or Open-Face Mask^®. The FIO₂ drop was larger with the Open-Face Mask^® than with the Hudson RCI^®. The RR, EtCO₂, and PICO₂ significantly changed with the SM, but the differences were not clinically meaningful. In the simulation-based study, the SM with the Hudson RCI^® did not reduce FIO₂, but the SM with the Open-Face Mask^® significantly decreased FIO₂ under several conditions. However, the SM with the Hudson Mask^® reduced FIO₂ when the fit of the mask was inadequate. With the Open-Face Mask^®, lower RR and Tv resulted in larger differences in FIO₂.

The SM decreased FIO₂ during oxygen therapy with oxygen masks. The impact of SM depended on the type of the oxygen mask, mask fitting, and respiratory condition.

The online version contains supplementary material available at 10.1007/s00540-022-03083-2.

• FIO2
• Fraction of inspired oxygen
• Oxygen mask
• Oxygen therapy
• Surgical mask

• bronchiolitis
• children
• high-flow nasal cannula (HFNC)
• oxygen therapy
• pediatric
• respiratory distress
• respiratory failure

Purpose: The fraction of inspired oxygen while administering oxygen to patients must be measured as it represents the alveolar oxygen concentration, which is important from a respiratory physiology viewpoint. Therefore, the purpose of this study was to compare the fractions of inspired oxygen obtained through different oxygen delivery devices.

Methods: A simulation model of spontaneous respiration was used. The fractions of inspired oxygen obtained through low- and high-flow nasal cannulas and a simple oxygen mask were measured. The fraction of inspired air was measured every second for 30 s after 120 s of oxygen administration. This was measured three times under each condition.

Results: With a low-flow nasal cannula, airflow reduced both the intratracheal fraction of inspired oxygen and extraoral oxygen concentration, indicating that exhalatory respiration occurred during rebreathing and may be involved in increasing the intratracheal fraction of inspired oxygen.

Conclusion: Oxygen administration during expiratory flow may lead to an increased oxygen concentration in the anatomical dead space, which may be involved in the increase in the fraction of inspired oxygen. With a high-flow nasal cannula, a high fraction of inspired oxygen can be achieved even at a flow rate of 10 L/min. When determining the optimum amount of oxygen, it is necessary to set an appropriate flow rate for patients and specific conditions without being bound by the fraction of inspired oxygen values alone. It might be difficult to estimate the fraction of inspired oxygen while using a low-flow nasal cannula and simple oxygen mask in clinical situations.

• COVID-19
• Fraction of inspired oxygen
• Oxygen mask
• Preventing infection
• Respiratory infections
• Surgical mask

High-flow nasal cannula (HFNC), a relatively new technique in acute hypoxemic respiratory failure (AHRF), is gaining popularity in intensive care units (ICUs). Our study aims to identify the predictive factors for failure of HFNC.

This is a 5-year retrospective cohort study in patients with AHRF using HFNC in an ICU of a regional hospital in Hong Kong. The primary outcome is to identify the predictive factors for failure of HFNC which is defined as escalation of treatment to noninvasive ventilation, mechanical ventilation, extracorporeal membrane oxygenation, or death.

Of the 124 ICU patients with AHRF, 69 (55.65%) failed in the use of HFNC. The patients failing HFNC had higher Acute physiology and Chronic Health Evaluation IV scores, lower Glasgow Coma Scale scores, lower platelet counts and serum sodium levels upon ICU admission, and higher pH on day of HFNC commencement. They had higher respiratory rates before HFNC and higher heart rates before and 1 h after HFNC. The respiratory rate-oxygenation (ROX) index which is defined as a ratio of SpO₂/FiO₂ to respiratory rate was significantly lower in the failure group 1 h and 12 h after HFNC. By multivariate binary logistic regression, failure of HFNC is associated with lower ROX index at 12 h after HFNC.

ROX index at 12 h serves as a valuable tool to monitor the responsiveness to HFNC treatment. Close monitoring is required to identify patient failing using HFNC.

• Clinical respiratory medicine
• critical care medicine
• ventilation

• Diffuser mask
• OxyMask
• Oxygen therapy
• Oxygen-delivery device
• Pediatric respiratory physiology

• Conventional Oxygen Therapy
• High Flow Nasal Cannula Oxygen Therapy
• Positive End Expiratory Pressure
• Respiratory Distress
• Veterinary

• delivered oxygen concentration
• nasal cannula
• normal lung model
• obstructive lung model
• oxygen therapy
• restrictive lung model
• simulation study

Guideline recommendations state oxygen should be administered to acutely unwell patients to achieve a target oxygen saturation (SpO₂) range. The current practice of manual oxygen titration frequently results in SpO₂ outside of a prescribed range. The aim of this study was to assess the efficacy of automatic oxygen titration using a closed-loop feedback system to achieve SpO₂ within a prescribed target range

An open-label randomised parallel group trial was undertaken comparing automatic oxygen titration using a novel nasal high-flow device to manual oxygen titration using nasal high flow. Medical inpatients requiring oxygen therapy in Wellington Regional Hospital, New Zealand with a prescribed target SpO₂ range of 88%–92% or 92%–96% were recruited and randomised equally between the interventions for a period of 24 hours. The primary outcome was the proportion of time spent with SpO₂ within the prescribed range.

20 patients were included in the analysis. Automatic oxygen titration resulted in a median (IQR) 96.2% (95.2–97.8) of time within the target range compared with 71% (59.4–88.3) with manual titration; difference (95% CI) 24.2% (7.9% to 35%), p<0.001. There was a reduction in the time spent with SpO₂ ≥2% above and ≥2% below range in the automatic titration group, although the point estimate for the differences were small; −1% (−8.2% to −0.04%), p=0.017 and −2.4% (−11.5% to 0.3%), p=0.05 respectively.

Nasal high-flow with automatic oxygen titration resulted in a greater proportion of time spent with SpO₂ in target range compared with manual titration.

The trial was registered with the Australian and New Zealand Clinical Trials Registry (ACTRN12619000901101).

• copd exacerbations
• pneumonia

• Delivered oxygen
• Nasal cannula
• Rebreather mask

COVID‐19 is a major, urgent, and ongoing threat to global health. Globally more than 24 million have been infected and the disease has claimed more than a million lives as of November 2020. Predicting which patients will need respiratory support is important to guiding individual patient treatment and also to ensuring sufficient resources are available. The ability of six common Early Warning Scores (EWS) to identify respiratory deterioration defined as the need for advanced respiratory support (high‐flow nasal oxygen, continuous positive airways pressure, non‐invasive ventilation, intubation) within a prediction window of 24 h is evaluated. It is shown that these scores perform sub‐optimally at this specific task. Therefore, an alternative EWS based on the Gradient Boosting Trees (GBT) algorithm is developed that is able to predict deterioration within the next 24 h with high AUROC 94% and an accuracy, sensitivity, and specificity of 70%, 96%, 70%, respectively. The GBT model outperformed the best EWS (LDTEWS:NEWS), increasing the AUROC by 14%. Our GBT model makes the prediction based on the current and baseline measures of routinely available vital signs and blood tests.

Supplemental Digital Content is available in the text.

Hyperoxia is common among critically ill patients and may increase morbidity and mortality. However, limited evidence exists for critically injured patients. The objective of this study was to determine the association between hyperoxia and in-hospital mortality in adult trauma patients requiring ICU admission.

This multicenter, retrospective cohort study was conducted at two level I trauma centers and one level II trauma center in CO between October 2015 and June 2018. All adult trauma patients requiring ICU admission within 24 hours of emergency department arrival were eligible. The primary exposure was oxygenation during the first 7 days of hospitalization.

None.

Primary outcome was in-hospital mortality. Secondary outcomes were hospital-free days and ventilator-free days. We included 3,464 critically injured patients with a mean age of 52.6 years. Sixty-five percent were male, and 66% had blunt trauma mechanism of injury. The primary outcome of in-hospital mortality occurred in 264 patients (7.6%). Of 226,057 patient-hours, 46% were spent in hyperoxia (oxygen saturation > 96%) and 52% in normoxia (oxygen saturation 90–96%). During periods of hyperoxia, the adjusted risk for mortality was higher with greater oxygen administration. At oxygen saturation of 100%, the adjusted risk scores for mortality (95% CI) at Fio₂ of 100%, 80%, 60%, and 50% were 6.4 (3.5–11.8), 5.4 (3.4–8.6), 2.7 (1.7–4.1), and 1.5 (1.1–2.2), respectively. At oxygen saturation of 98%, the adjusted risk scores for mortality (95% CI) at Fio₂ of 100%, 80%, 60%, and 50% were 7.7 (4.3–13.5), 6.3 (4.1–9.7), 3.2 (2.2–4.8), and 1.9 (1.4–2.7), respectively.

During hyperoxia, higher oxygen administration was independently associated with a greater risk of mortality among critically injured patients. Level of evidence: Cohort study, level III.

• critical care
• hyperoxia
• injuries
• intensive care units
• oxygenation
• trauma

• High-flow nasal cannula
• Hypoxemia
• MIMIC
• Ventilator weaning

• Aged
• Cannula
• Critical Care
• Databases, Factual
• Female
• Humans
• Hypoxia/mortality
• Hypoxia/therapy
• Male
• Middle Aged
• Noninvasive Ventilation/adverse effects
• Oxygen
• Oxygen Inhalation Therapy
• Respiratory Insufficiency/mortality
• Respiratory Insufficiency/therapy
• Retrospective Studies
• Time Factors

• colonoscopy
• deep sedation
• gastrointestinal endoscopy
• gastroscopy
• high-flow nasal oxygenation
• hypoxaemia

• COVID-19
• acute hypoxaemic respiratory failure
• inspired oxygen concentration
• oxygen therapy
• surgical mask

• Acute respiratory distress syndrome
• Chest trauma
• Intensive care
• Neutrophil-to-lymphocyte ratio

• Adult
• Aged
• Biomarkers/blood
• Clinical Decision Rules
• Emergency Service, Hospital
• Female
• Humans
• Lymphocytes/metabolism
• Male
• Middle Aged
• Neutrophils/metabolism
• Patient Admission
• Respiratory Distress Syndrome/blood
• Respiratory Distress Syndrome/diagnosis
• Respiratory Distress Syndrome/etiology
• Retrospective Studies
• Rib Fractures/complications
• Rib Fractures/immunology
• Risk Assessment
• Risk Factors
• Severity of Illness Index
• Thoracic Injuries/complications
• Thoracic Injuries/immunology
• Wounds, Nonpenetrating/complications
• Wounds, Nonpenetrating/immunology

• COVID-19
• case series
• hypoxemic respiratory failure
• intubation
• prone positioning

Conventional oxygen therapy (COT) and noninvasive ventilation (NIV) have been considered for decades as frontline treatment for acute or chronic respiratory failure. However, COT can be insufficient in severe hypoxaemia whereas NIV, although highly effective, is poorly tolerated by patients and its use requires a specific expertise. High-flow nasal cannula (HFNC) is an emerging technique, designed to provide oxygen at high flows with an optimal degree of heat and humidification, which is well tolerated and easy to use in all clinical settings. Physiologically, HFNC reduces the anatomical dead space and improves carbon dioxide wash-out, reduces the work of breathing, and generates a positive end-expiratory pressure and a constant fraction of inspired oxygen. Clinically, HFNC effectively reduces dyspnoea and improves oxygenation in respiratory failure from a variety of aetiologies, thus avoiding escalation to more invasive supports. In recent years it has been adopted to treat de novo hypoxaemic respiratory failure, exacerbation of chronic obstructive pulmonary disease (COPD), postintubation hypoxaemia and used for palliative respiratory care. While the use of HFNC in acute respiratory failure is now routine as an alternative to COT and sometimes NIV, new potential applications in patients with chronic respiratory diseases (e.g. domiciliary treatment of patients with stable COPD), are currently under evaluation and will become a topic of great interest in the coming years.

• high-flow nasal cannula
• oxygen therapy
• respiratory failure

• Acute respiratory distress syndrome
• Critical care
• Hospital medicine
• Hypoxaemia
• Hypoxia
• Intensive care

There are few studies on the safety and respiratory consequences of the use of a skeletal traction (ST) device in the management of femoral shaft fractures with damage control orthopaedics (DCO) strategy, particularly in cases of prolonged use. The aim of this study was to assess the influence of ST compared with an external fixator (EF) on respiratory complications and mechanical ventilation requirements in patients with severe trauma with a femoral shaft fracture managed by DCO strategy.

We retrospectively reviewed all patients with severe trauma patients with a unilateral femoral shaft fracture admitted to our institution from 2010 to 2015. Patients who did not undergo definitive osteosynthesis during the first 24 h were included and divided into two groups: DCO-ST group and DCO-EF group. In addition to trauma severity, global management of respiratory complications, the incidence of acute respiratory distress syndrome (ARDS) and mechanical ventilation requirements and outcome were compared.

Fifty-five patients were managed with DCO strategy (mean Injury Severity Score, 28.4); there were 31 in the DCO-ST group and 24 in the DCO-EF group. No significant difference in terms of the main characteristics, initial severity and associated injuries was observed between the two groups. In contrast, ARDS was found more frequently in the DCO-ST group (81% versus 54%; P = 0.035). Number of ventilation days also tended to be higher in the DCO-ST group (9 days [IQR 3–15 days] versus 7 [IQR 2–16 days]; P = 0.24). No difference was found for mortality and hospitalization duration between the DCO-ST and DCO-EF groups.

The prolonged use of an ST device in the present cohort was associated with a higher incidence of impaired respiratory function. Therefore, our findings suggest that EF is preferable to ST in the DCO setting for femoral shaft fracture, especially in trauma patients at high risk of developing delayed respiratory failure.

• Acute respiratory distress syndrome
• External fixator
• Mechanical ventilation
• Multiple organ failure
• Skeletal traction

• fraction of inspired O2
• high-flow nasal cannula oxygen therapy
• lung simulation model
• positive end-expiratory pressure

• COPD
• hypercapnia
• nasal high-flow
• noninvasive ventilation

To evaluate the effectiveness of high-flow nasal humidified oxygen (HFNHO) therapy in patients with mild hypoxemia after extubation. This study included 316 patients with mild hypoxemia after extubation from May 2016 to May 2018 from two intensive care units in China. Compare the effects of the Venturi Mask and High-Flow Nasal Humidified Oxygen (HFNHO) therapy on Heart Rate (HR), Respiratory Rate (RR), Oxygen Saturation (SpO₂), Oxygen Partial Pressure (PO₂), Partial Pressure Of Carbon Dioxide (PCO₂), Oxygenation Index (PO₂/FiO₂) after extubation, the use of noninvasive mechanical ventilation and tracheal intubation after treatment failure were observed and recorded. Patients have both lower HR and RR than those who received mask treatment (75.4±18.5 vs. 83.0±20.4, p = 0.0004; 18±6.5 vs. 23.6±10.3, p<0.001, respectively). There was significant difference between those who had HFNHO and mask administration’s SpO₂ and PO₂ (94.1±6.4 vs. 87.5±1.5, p<0.001; 88.16±2.9 vs. 77.3±2.3, p<0.001, respectively). For the HFNHO group, patients had lower PCO₂ with the mask group. (41.3±0.99 vs 42.2±1.2, p<0.001). On the other hand, the levels of PO₂/FiO₂ was significantly higher in the HFNHO Group, (181.0±8.3 vs. 157.2±4.9, p<0.05). We concluded HFNHO therapy could significantly relieve the symptoms of dyspnea, improve oxygenation, reduce the use of noninvasive mechanical ventilation and reduce the rate of secondary tracheal intubation in patients with mild hypoxemia after extubation.

• Female
• Heart Rate
• Humans
• Humidity
• Hypoxia/physiopathology
• Hypoxia/therapy
• Male
• Middle Aged
• Nose
• Oxygen Inhalation Therapy
• Pressure
• Respiratory Rate

• acute respiratory failure
• cardiac surgery
• coronary artery bypass
• high-flow oxygen therapy by nasal cannulae
• hypoxemia
• noninvasive ventilation

• High-flow nasal cannula
• Mechanical ventilation
• Oxygen therapy
• Postextubation

• Airway Extubation/methods
• Cannula/standards
• Humans
• Noninvasive Ventilation/instrumentation
• Noninvasive Ventilation/methods
• Noninvasive Ventilation/standards
• Oxygen/administration & dosage
• Oxygen/therapeutic use
• Oxygen Inhalation Therapy/instrumentation
• Oxygen Inhalation Therapy/methods
• Recurrence
• Ventilator Weaning/methods

• NSFC81871585 National Natural Science Foundation of China
• 2018A030313058 Natural Science Foundation of Guangdong Province