Utility of High Flow Nasal Oxygen versus Non-Invasive Ventilation in Severe Covid-19 Pneumonia: Retrospective Comparative Analysis and Assessment in Present Scenario Patients

Background: The pandemic of COVID-19 since its beginning has created havoc all-round the globe. The role of oxygen therapy remains constant. Various modalities have been studied for oxygen delivery to hypoxic patients but high flow nasal oxygen (HFNO) has lately gained importance in terms of non-invasive oxygen delivery, easy administration and great improvement in patient's recovery. We conducted this retrospective analysis with the primary objective of looking for the proportion of patients who were successfully weaned off of HFNO or non-invasive ventilation (NIV) and the secondary aim was to look for duration of hospital stay and its effect on clinical recovery based on laboratory parameters. Methods: All patients, positive for COVID-19 infection by real-time reverse transcriptase polymerase chain reaction (RTPCR) were admitted to covid ICU or ward with oxygen requirement and were treated with either NIV or HFNO were enrolled for the study. Patients were grouped under H group (HFNO) or N group (NIV). Daily ABG readings, chest x-ray, respiratory rate, hemodynamic parameters and urine output were noted on 12 hourly intervals. Any changes in above parameters along with need for intubation were assessed. Results: Patients from both the groups showed significant improvement in their oxygen saturation by the fifth day of their treatment. Fourteen patients from the NIV group and 10 from the HFNO group had saturation >90% by Day 5. Of those who presented with saturation of <85%, 2 out of 5 in the NIV group (40%) and 1 of the 2 patients in the HFNO group (50%) showed improvement in their oxygen saturation. The P/F was statistically comparable (p 0.928) in both groups. The levels of bio markers, and the improvement was comparable and correlated with clinical improvement as well. Conclusion: We conclude that though HFNO is accepted better than NIV, the improvement in the respiratory status of the patient was comparable with both the treatment modalities and hence we do not recommend use of HFNO, especially in a situation of gross deficit of oxygen availability as compared to the exponential rise in the demand. © 2023 Tehran University of Medical Sciences.

A clinical case of prolonged CPAP ventilation in a patient with COVID-19-associated pneumonia

Non-invasive ventilation (NIV) via a mask to maintain a constant positive airway pressure (CPAP mask) is the method of choice for the treatment of pulmonary disorders in severe COVID-19-associated pneumonia. Nowadays, there are no studies which had shown the effectiveness of the ROX-index in predicting the efficacy of NIV in patients with acute hypoxic respiratory failure (AHRF). This clinical case describes our experience of effective use of ROX-index in patients with AHRF because of coronavirus dis-ease, SARS-CoV-2-associated, who underwent non-invasive lung ventilation through CPAP mask. © 2022. The Authors.

The COVID-19 Driving Force: How It Shaped the Evidence of Non-Invasive Respiratory Support.

During the COVID-19 pandemic, the use of non-invasive respiratory support (NIRS) became crucial in treating patients with acute hypoxemic respiratory failure. Despite the fear of viral aerosolization, non-invasive respiratory support has gained attention as a way to alleviate ICU overcrowding and reduce the risks associated with intubation. The COVID-19 pandemic has led to an unprecedented increased demand for research, resulting in numerous publications on observational studies, clinical trials, reviews, and meta-analyses in the past three years. This comprehensive narrative overview describes the physiological rationale, pre-COVID-19 evidence, and results of observational studies and randomized control trials regarding the use of high-flow nasal oxygen, non-invasive mechanical ventilation, and continuous positive airway pressure in adult patients with COVID-19 and associated acute hypoxemic respiratory failure. The review also highlights the significance of guidelines and recommendations provided by international societies and the need for further well-designed research to determine the optimal use of NIRS in treating this population.

Respiratory support for adult patients with COVID-19

The COVID-19 pandemic is creating unique strains on the healthcare system. While only a small percentage of patients require mechanical ventilation and ICU care, the enormous size of the populations affected means that these critical resources may become limited. A number of non-invasive options exist to avert mechanical ventilation and ICU admission. This is a clinical review of these options and their applicability in adult COVID-19 patients. Summary recommendations include: (1) Avoid nebulized therapies. Consider metered dose inhaler alternatives. (2) Provide supplemental oxygen following usual treatment principles for hypoxic respiratory failure. Maintain awareness of the aerosol-generating potential of all devices, including nasal cannulas, simple face masks, and venturi masks. Use non-rebreather masks when possible. Be attentive to aerosol generation and the use of personal protective equipment. (3) High flow nasal oxygen is preferred for patients with higher oxygen support requirements. Non-invasive positive pressure ventilation may be associated with higher risk of nosocomial transmission. If used, measures special precautions should be used reduce aerosol formation. (4) Early intubation/mechanical ventilation may be prudent for patients deemed likely to progress to critical illness, multi-organ failure, or acute respiratory distress syndrome (ARDS).Copyright © 2020 The Authors. JACEP Open published by Wiley Periodicals LLC on behalf of the American College of Emergency Physicians.

Factors associated with non-invasive positive pressure ventilation failure in a COVID-19 intermediate care unit.

BACKGROUND: The use of non-invasive positive pressure ventilation (NIPPV) in COVID-19 patients with hypoxaemia is still under debate. The aim was to evaluate the efficacy of NIPPV (CPAP, HELMET-CPAP or NIV) in COVID-19 patients treated in the dedicated COVID-19 Intermediate Care Unit of Coimbra Hospital and University Centre, Portugal, and to assess factors associated with NIPPV failure. METHODS: Patients admitted from December 1st 2020 to February 28th 2021, treated with NIPPV due to COVID-19 were included. Failure was defined as orotracheal intubation (OTI) or death during hospital stay. Factors associated with NIPPV failure were included in a univariate binary logistic regression analysis; those with a significance level of p < 0.001 entered a multivariate logistic regression model. RESULTS: A total of 163 patients were included, 64.4% were males (n = 105). The median age was 66 years (IQR 56-75). NIPPV failure was observed in 66 (40.5%) patients, 26 (39.4%) were intubated and 40 (60.6%) died during their hospital stay. The highest CRP (OR 1.164; 95%CI 1.036-1.308) and morphine use (OR 24.771; 95%CI 1.809-339.241) were identified as predictors of failure after applying multivariate logistic regression. Adherence to prone positioning (OR 0.109; 95%CI 0.017-0.700) and a higher value of the lowest platelet count during hospital stay (OR 0.977; 95%CI 0.960-0.994) were associated with a favorable outcome. CONCLUSIONS: NIPPV was successful in over half of patients. Highest CRP during hospital stay and morphine use were predictors of failure. Adherence to prone positioning and a higher value of the lowest platelet count during hospital stay were associated with a favourable outcome.

Corrigendum: Comfort during non-invasive ventilation.

[This corrects the article DOI: 10.3389/fmed.2022.874250.].

An Australian COVID-19 respiratory care unit experience.

BACKGROUND: Coronavirus disease (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with a heterogeneous presentation ranging from severe pneumonitis to asymptomatic infection. International studies have demonstrated the utility of respiratory care units (RCUs) to facilitate the delivery of non-invasive ventilation techniques to patients with COVID-19 pneumonitis. AIMS: This study aims to describe the patient characteristics, flow and outcomes of admissions to the Royal Melbourne Hospital (RMH) COVID-19 RCU (CRCU) during its initial period of operation. METHODS: Single-centre retrospective cohort study, all patients admitted to CRCU between 17 September and 10 December 2021 were included in this study. Patient demographics, including comorbidities and limitations of medical treatment, were analysed. Admission source and discharge destination were reviewed. Length of stay was recorded. Finally, in-hospital and CRCU mortality were analysed. RESULTS: Ninety-seven patients, comprising 111 admissions, occurred during the study period with median age of 65 years (48% female). Most patients were admitted from and discharged to the ward. Twenty patients died in hospital (21%), with age, 4C score, comorbidity and presence of obstructive lung disease predicting mortality (area under the curve (AUC) 0.85, P < 0.001). Mortality was significantly higher in those over 65 years of age compared to those under 65 (P < 0.001), or those deemed not for intubation compared to those for intubation (P = 0.0019). CONCLUSIONS: This study demonstrates the feasibility of operating a CRCU within an Australian tertiary healthcare setting.

Does High Flow Nasal Cannula avoid intubation and improve the mortality of adult patients in acute respiratory failure in the intensive care setting, when compared to others methods as Conventional Oxygen Therapy or Non-Invasive Ventilation? A narrative review

High-flow oxygen therapy via nasal cannula (HFNC) has been used for many years to oxygenate patients in respiratory failure. However, scientific data in literature are divergent about its value to prevent invasive mechanical ventilation and mortality. The use of HFNC has increased following the COVID-19 pandemic. Our review considers the impact of HFNC on intubation rates and mortality compared with conventional oxygen therapy (COT) and noninvasive ventilation (NIV). HFNC would decrease the use of invasive mechanical ventilation compared to COT and would be equivalent to NIV. Combination of NIV and HFNC would have a benefit compared to NIV alone. Some etiologies of respiratory failure would benefit more from this technique as post-extubation critical ill patient or COVID-19 pneumonia. HFNC seems to reduce mortality in COVID-19 patients compared to NIV. Several clinical studies are needed to refine the indications of this technique.

High flow nasal oxygen (HFNO) in the treatment of COVID-19 infection of adult patients from - An emergency perspective: A systematic review and meta-analysis

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by SARS-CoV-2, which was first discovered in Wuhan, China. The disease has grown into a global pandemic causing mild to moderate symptoms in most people. The disease can also exhibit serious illnesses, especially for patients with other chronic diseases such as cardiovascular diseases, diabetes, chronic respiratory disease, or cancer. In such cases of severe illness, high flow nasal oxygen (HFNO) has been used to provide oxygenation to COVID-19 patients. However, the efficiency of HFNO remains uncertain, prompting the conduction of this systematic review to evaluate the effectiveness of the therapy. A thorough search for relevant and original articles was carried out on five electronic databases, including ScienceDirect, PubMed, Cochrane Library, Embase, and Google Scholar. No time limitation was placed during the search as it included all the articles related to COVID-19 from 2019 to 2022. The search strategy utilized in this systematic review yielded 504 articles, of which only 10 met the eligibility criteria and were included. Our meta-analysis reveals that HFNO success rate was higher than HFNO failure rates (0.52 (95% CI;0.47, 0.56) and 0.48 (95% CI;0.44, 0.53), respectively), however, the difference was statistically insignificant. HFNO was associated with a significant decrease in mortality and intubation rates (0.28 (95% CI;0.19, 0.39) and 0.28 (95% CI;0.18, 0.41), respectively). Our statistical analysis has shown that significantly lower ROX index (5.07 +/- 1.66, p = 0.028) and PaO2/FiO2 (100 +/- 27.51, p = 0.031) are associated with HFNO failure, while a significantly lower respiratory rate (RR) (23.17 +/- 4.167, p = 0.006) is associated with HFNO success. No statistically significant difference was observed in SpO2/FiO2 ratio between the HFNO success and failure groups (154.23 +/- 42.74 vs. 124.025 +/- 28.50, p = 0.62, respectively). Based on the results from our meta-analysis, the success or failure of HFNO in treating COVID-19 adult patients remains uncertain. However, HFNO has been shown to be an effective treatment in reducing mortality and intubation rates. Therefore, HFNO can be recommended for COVID-19 patients but with close monitoring and should be carried out by experienced healthcare workers.Copyright © 2023 The Authors

Comfort During Non-invasive Ventilation.

Non-invasive ventilation (NIV) has been shown to be effective in avoiding intubation and improving survival in patients with acute hypoxemic respiratory failure (ARF) when compared to conventional oxygen therapy. However, NIV is associated with high failure rates due, in most cases, to patient discomfort. Therefore, increasing attention has been paid to all those interventions aimed at enhancing patient's tolerance to NIV. Several practical aspects have been considered to improve patient adaptation. In particular, the choice of the interface and the ventilatory setting adopted for NIV play a key role in the success of respiratory assistance. Among the different NIV interfaces, tolerance is poorest for the nasal and oronasal masks, while helmet appears to be better tolerated, resulting in longer use and lower NIV failure rates. The choice of fixing system also significantly affects patient comfort due to pain and possible pressure ulcers related to the device. The ventilatory setting adopted for NIV is associated with varying degrees of patient comfort: patients are more comfortable with pressure-support ventilation (PSV) than controlled ventilation. Furthermore, the use of electrical activity of the diaphragm (EADi)-driven ventilation has been demonstrated to improve patient comfort when compared to PSV, while reducing neural drive and effort. If non-pharmacological remedies fail, sedation can be employed to improve patient's tolerance to NIV. Sedation facilitates ventilation, reduces anxiety, promotes sleep, and modulates physiological responses to stress. Judicious use of sedation may be an option to increase the chances of success in some patients at risk for intubation because of NIV intolerance consequent to pain, discomfort, claustrophobia, or agitation. During the Coronavirus Disease-19 (COVID-19) pandemic, NIV has been extensively employed to face off the massive request for ventilatory assistance. Prone positioning in non-intubated awake COVID-19 patients may improve oxygenation, reduce work of breathing, and, possibly, prevent intubation. Despite these advantages, maintaining prone position can be particularly challenging because poor comfort has been described as the main cause of prone position discontinuation. In conclusion, comfort is one of the major determinants of NIV success. All the strategies aimed to increase comfort during NIV should be pursued.

Retour d'expérience sur les transports Smur des patients Covid-19

Dès la fin du mois de février 2020, les urgentistes français ont été confrontés à une situation inédite et complexe dans la gestion des cas les plus sévères d'infections pulmonaires associées au nouveau coronavirus (SARSCoV- 2). Les informations en provenance de Chine et les recommandations initiales de l'Organisation mondiale de la santé ont rapidement amené à considérer l'intubation et la ventilation mécanique précoce des malades atteints par la pneumonie de la Covid-19. Or, dès la fin du mois de mars 2020, grâce aux retours d'expérience et de prise en charge, d'abord de la part des réanimateurs et urgentistes italiens, puis espagnols, les pratiques et les recommandations concernant les modalités d'oxygénation et de ventilation des patients Covid-19 ont évolué. Le caractère exceptionnel de cette pandémie et la grande adaptabilité des services de Samu/Smur de France, en l'espace de quelques semaines, pour prendre en charge ces patients oxygénodépendants, justifient que nous en fassions le retour d'expérience, et ce, d'autant plus que nous sommes exposés à un risque de recrudescence d'infections respiratoires graves associées au SARS-CoV-2 à court terme, risquant de saturer une nouvelle fois notre système de santé. Nous détaillons donc ici le retour d'expérience des prises en charge médicales préhospitalières concernant principalement les supports d'oxygénation et de ventilation mécanique.Alternate abstract: At the end of February 2020, French emergency physicians were faced with a new and complex situation in the management of critical cases of SARS-CoV-2 infection. First information from China and the initial recommendations of the World Health Organization (WHO) quickly led us to consider early intubation and mechanical ventilation of patients with hypoxemic COVID-19 pneumonia. However, since the end of March 2020, feedback from Italian intensive care and emergency physicians, then Spanish, led to change in clinical practices and guidelines about oxygenation and mechanical or noninvasive ventilation of COVID-19 patients have evolved. The exceptional character of this pandemic and the great adaptability of French pre-hospital emergency medical services (Samu/Smur) in a few weeks, to manage those oxygen dependent patients, justified our feedback, especially because we are exposed to a risk of resurgence of serious short-term SARS-CoV-2-associated acute respiratory distress syndrome (ARDS), which could once again saturate our health system. We therefore detail here the feedback of pre-hospital medical care, mainly concerning the management of oxygenation and ventilation supports.

The role of non-invasive ventilation

Patients with severe COVID-19 usually develop acute respiratory distress syndrome (ARDS) characterised by acute hypoxemic respiratory failure (HRF) and bilateral pulmonary infiltrates [1, 2]. The common reason for HRF occurring in the course of ARDS is the ventilation-perfusion mismatch or the intrapulmonary shunt [3]. Generally, HRF is defined as an acute condition where the arterial oxygen tension is below 60 mmHg on room air or oxygen is required to maintain measurements of pulse oximetry above 90% with low or normal partial carbon dioxide pressure [4]. Therapeutic options are limited to target the ongoing pathological processes of ARDS, and hence mechanical ventilation continues to be the mainstay for patient management [5]. Non-invasive ventilation (NIV) and high flow nasal cannula oxygen therapy (HFNC) can play a role in providing respiratory support to COVID-19 patients before developing severe HRF or in circumstances where there is limited access to more invasive techniques [1]. © Springer Nature Switzerland AG 2020.

Comorbidities and Clinical Outcomes of Patients with COVID 19 in a Tertiary Care Center at Goa: A Prospective Observational Study

Background: It is believed that COVID-19, in those with comorbidities, has an increasingly rapid and severe progression, often resulting in mortality. This study explores various comorbid conditions, disease severity, and clinical outcomes in patients infected with COVID-19. Method(s): This is a prospective observational study. Clinical data of COVID-19 patients admitted at Goa Medical College between November 23, 2020, to December 23, 2020, are summarized and analyzed using Google forms, spreadsheets, and R programming language. Result(s): A total of 100 patient data was collected, including 5% mild, 61% moderate, and 34% severe cases. Fever (83%) was the most common symptom, followed by dry cough (83%), dyspnoea (79%), and fatigue (32%). The most common comorbidities identified were diabetes (66%), hypertension (57%), and cardiovascular and cerebrovascular conditions (27%). Clinical outcome in patients was pneumonia (84%), ARDS (40%), bronchiolitis (10%), and shock (3%). Conclusion(s): Our study estimated that older men with underlying hypertension, diabetes, cardiovascular, and cerebrovascular conditions are at higher risk for severe clinical form. Fever, cough, and dyspnea were the most common signs on admission. The laboratory parameters showed a significant increase in CRP, ferritin, LDH, procalcitonin, ESR, and d-dimer in the case of SARS-CoV-2 infection.Copyright © 2023, Institute of Medico-legal Publication. All rights reserved.

Usefulness and limitations of the acute respiratory distress syndrome definitions in non-intubated patients. A narrative review.

According to the Berlin Definition of acute respiratory distress syndrome (ARDS), a positive end-expiratory pressure (PEEP) of at least 5 cmH2O is required to diagnose and grade ARDS. While the Berlin consensus statement specifically acknowledges the role of non-invasive ventilation (NIV) in mild ARDS, this stratification has traditionally presumed a mechanically ventilated patient in the context of moderate to severe ARDS. This may not accurately reflect today's reality of clinical respiratory care. NIV and high-flow nasal cannula oxygen therapy (HFNO) have been used for managing of severe forms of acute hypoxemic respiratory failure with growing frequency, including in patients showing pathophysiological signs of ARDS. This became especially relevant during the COVID-19 pandemic. The levels of PEEP achieved with HFNO have been particularly controversial, and the exact FiO2 it achieves is subject to variability. Pinpointing the presence of ARDS in patients receiving HNFO and the severity in those receiving NIV therefore remains methodically problematic. This narrative review highlights the evolution of the ARDS definition in the context of non-invasive ventilatory support and provides an overview of the parallel development of definitions and ventilatory management of ARDS. It summarizes the methodology applied in clinical trials to classify ARDS in non-intubated patients and the respective consequences on treatment. As ARDS severity has significant therapeutic and prognostic consequences, and earlier treatment in non-intubated patients may be beneficial, closing this knowledge gap may ultimately be a relevant step to improve comparability in clinical trial design and outcomes.

TRPC6 inhibitor (BI 764198) to reduce risk and severity of ARDS due to COVID-19: a phase II randomised controlled trial.

BACKGROUND: Despite the availability of COVID-19 vaccinations, there remains a need to investigate treatments to reduce the risk or severity of potentially fatal complications of COVID-19, such as acute respiratory distress syndrome (ARDS). This study evaluated the efficacy and safety of the transient receptor potential channel C6 (TRPC6) inhibitor, BI 764198, in reducing the risk and/or severity of ARDS in patients hospitalised for COVID-19 and requiring non-invasive, supplemental oxygen support (oxygen by mask or nasal prongs, oxygen by non-invasive ventilation or high-flow nasal oxygen). METHODS: Multicentre, double-blind, randomised phase II trial comparing once-daily oral BI 764198 (n=65) with placebo (n=64) for 28 days (+2-month follow-up). PRIMARY ENDPOINT: proportion of patients alive and free of mechanical ventilation at day 29. Secondary endpoints: proportion of patients alive and discharged without oxygen (day 29); occurrence of either in-hospital mortality, intensive care unit admission or mechanical ventilation (day 29); time to first response (clinical improvement/recovery); ventilator-free days (day 29); and mortality (days 15, 29, 60 and 90). RESULTS: No difference was observed for the primary endpoint: BI 764198 (83.1%) versus placebo (87.5%) (estimated risk difference -5.39%; 95% CI -16.08 to 5.30; p=0.323). For secondary endpoints, a longer time to first response (rate ratio 0.67; 95% CI 0.46 to 0.99; p=0.045) and longer hospitalisation (+3.41 days; 95% CI 0.49 to 6.34; p=0.023) for BI 764198 versus placebo was observed; no other significant differences were observed. On-treatment adverse events were similar between trial arms and more fatal events were reported for BI 764198 (n=7) versus placebo (n=2). Treatment was stopped early based on an interim observation of a lack of efficacy and an imbalance of fatal events (Data Monitoring Committee recommendation). CONCLUSIONS: TRPC6 inhibition was not effective in reducing the risk and/or severity of ARDS in patients with COVID-19 requiring non-invasive, supplemental oxygen support. TRIAL REGISTRATION NUMBER: NCT04604184.

Pneumothorax in hospitalized COVID-19 patients with severe respiratory failure: Risk factors and outcome.

PNX was described as an uncommon complication in COVID-19 patients but clinical risk predictors and the potential role in patient's outcome are still unclear. We assessed prevalence, risk predictors and mortality of PNX in hospitalized COVID- 19 with severe respiratory failure performing a retrospective observational analysis of 184 patients admitted to our COVID-19 Respiratory Unit in Vercelli from October 2020 to March 2021. We compared patients with and without PNX reporting prevalence, clinical and radiological features, comorbidities, and outcomes. Prevalence of PNX was 8.1% and mortality was >86% (13/15) significantly higher than in patients without PNX (56/169) (P < 0.001). PNX was more likely to occur in patients with a history of cognitive decline (HR: 31.18) who received non-invasive ventilation (NIV) (p < 0.0071) and with low P/F ratio (HR: 0.99, p = 0.004). Blood chemistry in the PNX subgroup compared to patients without PNX showed a significant increase in LDH (420 U/L vs 345 U/L, respectively p = 0.003), ferritin (1111 mg/dl vs 660 mg/dl, respectively p = 0.006) and decreased lymphocytes (HR: 4.440, p = 0.004). PNX may be associated with a worse prognosis in terms of mortality in COVID patients. Possible mechanisms may include the hyperinflammatory status associated with critical illness, the use of NIV, the severity of respiratory failure and cognitive impairment. We suggest, in selected patients showing low P/F ratio, cognitive impairment and metabolic cytokine storm, an early treatment of systemic inflammation in association with high-flow oxygen therapy as a safer alternative to NIV in order to avoid fatalities connected with PNX.

Introducing helmet non-invasive ventilation during COVID-19 pandemic: Early experience of two centres.

Purpose: The helmet is a novel interface for delivering non-invasive ventilation (NIV). We conducted a case series to characterize introduction of the helmet interface in both COVID and non-COVID patients at two-centres. Methods: We enrolled all patients with respiratory failure admitted to the Juravinski Hospital (Hamilton, Canada) and St. Joseph's Health Center (Syracuse, New York) between November 1, 2020 and June 30, 2021 who used the helmet interface (Intersurgical StarMed) as part of this introduction into clinical practice. We collected patient demographics, reason for respiratory failure, NIV settings, device-related complications and outcomes. We report respiratory therapist's initial experiences with the helmet using descriptive results. Results: We included 16 patients with a mean age of 64.3 ± 10.9 years. The most common etiology for respiratory failure was pneumonia (81.3%). The median duration of NIV during the ICU admission was 67.5 (15.3, 80.8) hours, with a mean maximum PS of 13.9 ± 6.6 cm H2O and a mean maximum PEEP of 10.4 ± 5.1 cm H20. Three patients (18.7%) did not tolerate the helmet. Ten (62.5%) patients ultimately required intubation, and 7 (43.4%) patients died while in the ICU. The most common reason for intubation was worsening hypoxia (70%). No adverse events related to the helmet were recorded. Conclusion: Over the 8-month period of this study, we found that the helmet was well tolerated in over 80% of patients, although, more than half ultimately required intubation. Randomized controlled trials with this device are required to fully assess the efficacy of this interface.

Recent advances in the use of high flow nasal oxygen therapies.

High flow nasal oxygen is a relatively new option for treating patients with respiratory failure, which decreases work of breathing, improves tidal volume, and modestly increases positive end expiratory pressure. Despite well-described physiologic benefits, the clinical impact of high flow nasal oxygen is still under investigation. In this article, we review the most recent findings on the clinical efficacy of high flow nasal oxygen in Type I, II, III, and IV respiratory failure within adult and pediatric patients. Additionally, we discuss studies across clinical settings, including emergency departments, intensive care units, outpatient, and procedural settings.