• A retrospective study
• Acute hypoxic respiratory failure
• Failure of high-flow oxygen therapy

• conventional oxygen therapy
• esophageal cancer
• high-flow nasal cannula
• hypoxemia
• postoperative complications
• respiratory support

• Humans
• Esophagectomy/adverse effects
• Male
• Female
• Oxygen Inhalation Therapy/methods
• Middle Aged
• Hypoxia/therapy
• Hypoxia/etiology
• Retrospective Studies
• Aged
• Postoperative Complications/prevention & control
• Postoperative Complications/therapy
• Esophageal Neoplasms/surgery
• Cannula
• Blood Gas Analysis

• COPD Exacerbations
• COVID-19
• Critical Care
• Non invasive ventilation
• Pneumonia

• Humans
• Oxygen Inhalation Therapy/methods
• Respiratory Insufficiency/therapy
• Respiratory Insufficiency/mortality
• Hospital Mortality
• Hospitalization/statistics & numerical data
• Noninvasive Ventilation/methods
• Randomized Controlled Trials as Topic
• Respiration, Artificial/methods
• Treatment Outcome

• COVID-19
• Clinical trial
• MSC-Exo
• Mesenchymal stem cells
• Treatment

• Humans
• COVID-19/therapy
• Mesenchymal Stem Cells/cytology
• Mesenchymal Stem Cell Transplantation/methods
• SARS-CoV-2
• Exosomes

• FRF-TP-22-007A1 Fundamental Research Funds for the Central Universities

• aerosolized particles and droplets
• capnography
• infectious disease droplet transmission
• microspheres
• patient-to-professional disease transmission
• respiratory aerosols and droplets
• respiratory protective devices

• Humans
• Carbon Dioxide
• Vacuum
• Respiratory Aerosols and Droplets
• Respiration
• Nebulizers and Vaporizers
• Aerosols

• Clinical outcome
• Colorectal cancer
• Disease severity
• Intensive care unit
• Lactate
• Lactate dehydrogenase

• COVID-19
• conventional oxygen therapy
• high-flow nasal cannula

• Humans
• Cannula
• COVID-19/therapy
• Noninvasive Ventilation/adverse effects
• Noninvasive Ventilation/methods
• Oxygen
• Oxygen Inhalation Therapy/adverse effects
• Respiratory Insufficiency/therapy
• Respiratory Insufficiency/etiology

• Department of Science and Technology of Liaoning Province
• Science and Technology Planning Project

• Acute hypoxemic respiratory failure
• COVID19
• Conventional oxygen therapy
• High-flow nasal cannula therapy
• Intubation
• Mortality

• Dog
• High-flow nasal cannula
• Hypoxemia
• Non-invasive ventilation
• Optiflow
• Oxygen supplementation
• Respiratory distress

• Dogs
• Humans
• Animals
• Oxygen/therapeutic use
• Oxygen Inhalation Therapy/veterinary
• Pneumonia/therapy
• Pneumonia/veterinary
• Body Fluids
• Hospitalization
• Dog Diseases/therapy

• 341581 Academy of Finland
• 341581 Academy of Finland
• 341581 Academy of Finland
• 341581 Academy of Finland
• University of Helsinki including Helsinki University Central Hospital

• Coronavirus
• Oxygen inhalation therapy
• Respiratory distress syndrome
• Risk

• Humans
• Adult
• COVID-19/epidemiology
• COVID-19/therapy
• SARS-CoV-2
• Oxygen/therapeutic use
• Inpatients
• Communicable Diseases

• 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

• Acute respiratory distress syndrome
• Coronavirus infections
• Mortality
• Noninvasive ventilation
• Pandemics

• Adult
• Humans
• SARS-CoV-2
• Cannula/adverse effects
• COVID-19/complications
• COVID-19/therapy
• Respiration, Artificial
• Respiratory Distress Syndrome/etiology
• Respiratory Distress Syndrome/therapy
• Noninvasive Ventilation/adverse effects
• Risk Factors
• Oxygen Inhalation Therapy
• Respiratory Insufficiency/therapy

• Pontifical Xavierian University

• COVID-19
• intensive care units
• intratracheal
• intubation
• nasal cannula
• oxygen inhalation therapy
• respiratory insufficiency

• High-flow nasal cannula oxygen therapy
• intensive care unit
• reintubation
• respiratory failure

• covid-19 retro
• noninvasive mechanical ventilation
• pandemics
• prediction tools
• resource management
• respiratory insufficiency
• treatment failure

Background: During the first wave of COVID-19, the large influx of severely ill patients led to insufficient availability of beds in intensive care units and a shortage of ventilators. The shortage of ventilators, high mortality of intubated patients, and high risk of infections among healthcare workers involved in intubation were the main factors that led to the prevalence of noninvasive respiratory support during the pandemic. The high-flow nasal cannula (HFNC) is a commonly used, popular form of noninvasive respiratory support. Due to its unique physiological effects, HFNC can provide a high fraction of humidified oxygen and is satisfactorily comfortable for patients with COVID-19. However, before the COVID-19 era, there was little evidence on the application of HFNC in patients with acute respiratory failure caused by viral infection. Aim: This narrative review provides an overview of recent studies on the use of HFNC in patients with COVID-19-related acute hypoxemic respiratory failure. The main topics discussed include the probability of successful use of HFNC in these patients, whether late intubation increases mortality, the availability of convenient and accurate monitoring tools, comparison of HFNC with other types of noninvasive respiratory support, whether HFNC combined with the prone position is more clinically useful, and strategies to further reduce the infection risk associated with HFNC. The implication of this study is to identify some of the limitations and research gaps of the current literature and to give some advice for future research.

Hypoxemia is a common complication in older patients during postoperative recovery and can cause pulmonary complications. Therefore, reducing the incidence of postoperative hypoxemia is a clinical concern.

To investigate the clinical efficacy of high-flow nasal cannula oxygen (HFNCO) in the resuscitation period of older orthopedic patients.

In this prospective randomized controlled trial, 60 older patients who underwent orthopedic surgery under general anesthesia were randomly divided into two groups: those who used conventional face mask and those who used HFNCO. All patients were treated with 60% oxygen for 1 h after extubation. Patients in the conventional face mask group were treated with a combination of air (2 L) and oxygen (2 L) using a traditional mask, whereas those in the HFNCO group were treated with HFNCO at a constant temperature of 34 °C and flow rate of 40 L/min. We assessed the effectiveness of oxygen therapy by monitoring the patients’ arterial blood gas, peripheral oxygen saturation, and postoperative complications.

The characteristics of the patients were comparable between the groups. One hour after extubation, patients in HFNCO group had a significantly higher arterial partial pressure of oxygen (paO₂) than that of patients in conventional face mask group (P < 0.001). At extubation and 1 h after extubation, patients in both groups showed a significantly higher arterial partial pressure of carbon dioxide (paCO₂) than the baseline levels (P < 0.001). There were no differences in the saturation of peripheral oxygen, paO₂, and paCO₂ between the groups before anesthesia and before extubation (P > 0.05). There were statistically significant differences in paO₂ between the two groups before anesthesia and 1 h after extubation and immediately after extubation and 1 h after extubation (P < 0.001). However, there were no significant differences in the oxygen tolerance score before leaving the room, airway humidification, and pulmonary complications 3 d after surgery between the two groups (P > 0.05).

HFNCO can improve oxygen partial pressure and respiratory function in elderly patients undergoing orthopedic surgery under general endotracheal anesthesia. Thus, HFNCO can be used to prevent postoperative hypoxemia.

• Anesthesia recovery
• High flow nasal cannula oxygen
• Hypoxemia
• Older patients
• Orthopedic surgery
• Pulmonary complications

Pain is the main reason for hysteroscopy failure. In day-surgical settings, hysteroscopy procedures are commonly performed with the patient under sedation. Hypoxia is the most common adverse event during sedation and can lead to severe adverse events. This study aimed to compare the incidence of hypoxia when using high-flow nasal oxygen (HFNO) with that when using regular nasal oxygen in patients undergoing hysteroscopy with sedation.

In this single-center, prospective, randomized, single-blinded study, 960 female patients undergoing elective diagnostic or operative hysteroscopy were randomly enrolled into the following two groups: the regular nasal group [O₂ (3–6 L/min) covered by an HFNO] and the HFNO group [O₂ (30–60 L/min)] from September 2021 to December 2021. All women were sedated with propofol (1.5 mg/kg) and remifentanil (1.5 μg/kg) in the operating room. The primary outcome was the incidence of hypoxia (75% ≤ SpO₂ < 90%, < 60 s).

HFNO decreased the incidence of hypoxia (75% ≤ SpO₂ < 90%, < 60 s), subclinical respiratory depression (90% ≤ SpO₂ < 95%) and severe hypoxia (SpO₂ < 75% for any duration or 75% ≤ SpO₂ < 90% for ≥ 60 s) from 24.38 to 0.83%, from 11.25 to 1.46% and from 3.75 to 0%, respectively (P < 0.001).

In procedures conducted to treat female infertility, HFNO can reduce hypoxia during hysteroscopy in patients sedated with propofol, and it can prevent the occurrence of subclinical respiratory depression and severe hypoxia.

• National Natural Science Foundation of China

To identify factors associated with high-flow nasal cannula (HFNC) therapy failure in patients with severe COVID-19.

We retrospectively examined clinical and laboratory data upon admission, treatments, and outcomes of patients with severe COVID-19. Sequential Organ Failure Assessment (SOFA) scores were also calculated.

Of 54 patients with severe COVID-19, HFNC therapy was successful in 28 (51.9%) and unsuccessful in 26 (48.1%). HFNC therapy failure was more common in patients aged ≥60 years and in men. Compared with patients with successful HFNC therapy, patients with HFNC therapy failure had higher percentages of fatigue, anorexia, and cardiovascular disease; a longer time from symptom onset to diagnosis; higher SOFA scores; a higher body temperature, respiratory rate, and heart rate; more complications, including acute respiratory distress syndrome, septic shock, myocardial damage, and acute kidney injury; a higher C-reactive protein concentration, neutrophil count, and prothrombin time; and a lower arterial partial pressure of oxygen/fraction of inspired oxygen (PaO₂/FiO₂). However, male sex, a low PaO₂/FiO₂, and a high SOFA score were the only independent factors significantly associated with HFNC therapy failure.

Male sex, a low PaO₂/FiO₂, and a high SOFA score were independently associated with HFNC therapy failure in patients with severe COVID-19.

• COVID-19
• SOFA score
• acute respiratory failure
• case series
• high-flow nasal cannula therapy
• risk factor

• COVID-19
• Coronavirus disease 2019
• Interferon alpha
• SARS‑CoV‑2
• Severe acute respiratory syndrome coronavirus 2

• ARDS
• COVID-19
• High-flow nasal cannula
• SARS-CoV-2
• acute hypoxemic respiratory failure

• COVID-19
• Cannula
• Humans
• Noninvasive Ventilation
• Oxygen Inhalation Therapy
• Respiratory Insufficiency/etiology
• Respiratory Insufficiency/therapy
• SARS-CoV-2

During the novel coronavirus disease 2019 (COVID-19) pandemic raging around the world, the effectiveness of respiratory support treatment has dominated people’s field of vision. This study aimed to compare the effectiveness and value of high-flow nasal cannula (HFNC) with noninvasive ventilation (NIV) for COVID-19 patients.

A comprehensive systematic review via PubMed, Web of Science, Cochrane, Scopus, WHO database, China Biology Medicine Disc (SINOMED), and China National Knowledge Infrastructure (CNKI) databases was conducted, followed by meta-analysis. RevMan 5.4 was used to analyze the results and risk of bias. The primary outcome is the number of deaths at day 28. The secondary outcomes are the occurrence of invasive mechanical ventilation (IMV), the number of deaths (no time-limited), length of intensive care unit (ICU) and hospital stay, ventilator-free days, and oxygenation index [partial pressure of arterial oxygen (PaO₂)/fraction of inhaled oxygen (FiO₂)] at 24 h.

In total, nine studies [one randomized controlled trial (RCT), seven retrospective studies, and one prospective study] totaling 1582 patients were enrolled in the meta-analysis. The results showed that the incidence of IMV, number of deaths (no time-limited), and length of ICU stay were not statistically significant in the HFNC group compared with the NIV group (ps = 0.71, 0.31, and 0.33, respectively). Whereas the HFNC group performed significant advantages in terms of the number of deaths at day 28, length of hospital stay and oxygenation index (p < 0.05). Only in the ventilator-free days did NIV show advantages over the HFNC group (p < 0.0001).

For COVID-19 patients, the use of HFNC therapy is associated with the reduction of the number of deaths at day 28 and length of hospital stay, and can significantly improve oxygenation index (PaO₂/FiO₂) at 24 h. However, there was no favorable between the HFNC and NIV groups in the occurrence of IMV. NIV group was superior only in terms of ventilator-free days.

• coronavirus disease 2019
• high-flow nasal cannula
• noninvasive ventilation

The coronavirus disease 2019 (COVID-19) has spread globally and can cause a shortage of medical resources, in particular, mechanical ventilators. High-flow nasal cannula oxygen therapy (HFNC) and non-invasive positive pressure ventilation (NPPV) are frequently used for acute respiratory failure patients as alternatives to invasive mechanical ventilation. They are drawing attention because of a potential role to save mechanical ventilators. However, their effectiveness and risk of viral spread are unclear. The latest network meta-analysis of pre-COVID-19 trials reported that treatment with non-invasive oxygenation strategies was associated with improved survival when compared with conventional oxygen therapy. During the COVID-19 pandemic, a lot of clinical research on COVID-19 related acute respiratory failure has been reported. Several observational studies and small trials have suggested HFNC or NPPV as an alternative of standard oxygen therapy to manage COVID-19 related acute respiratory failure, provided that appropriate infection prevention is applied by health care workers to avoid risks of the virus transmission. Awake proning is an emerging strategy to optimise the management of patients with COVID-19 acute respiratory failure. However, the benefits of awake proning have yet to be assessed in properly designed clinical research. Although HFNC and NPPV are probably effective for acute respiratory failure, the safety data are mostly based on observational and experimental reports. As such, they should be implemented carefully if adequate personal protective equipment and negative pressure rooms are available.

• Acute respiratory failure
• Awake proning
• COVID-19
• High-flow oxygen
• Non-invasive ventilation
• SARS-CoV-2