High-flow nasal oxygen therapy and noninvasive ventilation in the management of acute hypoxemic respiratory failure

Ward-delivered nasal high-flow oxygen and non-invasive ventilation are safe for people with acute respiratory failure: a cohort study

BACKGROUND AND AIMS

Ward-delivered non-invasive respiratory supports (NIRS) (conventional oxygen therapy (COT), high-flow nasal oxygen (HFNO), continuous positive airway pressure (CPAP) and non-invasive ventilation (NIV)), are often used to treat hospitalised patients with acute respiratory failure (ARF) both in high acuity and general wards. This study aimed to describe the processes of care adopted and examine patient outcomes from a specialist, ward-delivered NIRS service caring for people with COVID-19 in general wards or in a respiratory care unit (RCU).

METHODS

A cohort study was undertaken including all consecutive patients admitted to a quaternary hospital with ARF secondary to COVID-19 and requiring ward-delivered NIRS between 28 February 2020 and 18 March 2022. NIRS use, processes of care and patient outcomes were examined.

RESULTS

Six hundred sixty-eight patients were included, with 61% male and a mean age of 64 years (interquartile range 48-79 years). All received COT. Fifty eight percent of patients required additional NIRS: HFNO (36.2%), CPAP (19.8%) and NIV (1.9%). Eighty-two percent of patients had oxygen saturation targets documented. After the implementation of the RCU, significantly more nurse consultant-led CPAP prescriptions were initiated (P = 0.004) and fewer patients required review by the ICU team (P = 0.001) or transfer to ICU (P = 0.050). Forty-nine patients died (7.3%), with most (62.8%) being discharged directly home.

CONCLUSION

This study highlights that ward-delivered NIRS is feasible and safe for people with COVID-19 and ARF. The combination of ward and RCU-delivered NIRS was particularly effective. Further research is required to determine the optimal models of respiratory care required for a broader range of patients and to understand how these should be implemented.

Impact of the Early Use of High-flow Nasal Cannula in Patients with Post-traumatic Lung Contusion: A Randomized Clinical Trial

Background

Patients with pulmonary contusion (PC) following blunt chest trauma are at risk of developing acute lung injury. High-flow nasal cannula (HFNC) is an established method for managing hypoxic respiratory failure (HRF).

Aim

This study aims to evaluate the efficacy of oxygen therapy delivered through HFNC vs venturi mask (VM) in patients with hypoxia following traumatic lung contusion, to reduce the need for intubation and ventilation.

Materials and methods

This is an open-label randomized controlled trial conducted on 120 patients with HRF following traumatic PC and a PaO2/FiO2 of 100-200 mm Hg. Patients were divided into two groups: Group A (60 patients) received oxygen therapy through HFNC, while group B (60 patients) received oxygen therapy through VM.

Results

High-flow nasal cannula significantly improved pulmonary oxygenation as early as 1 hour after randomization and the after with statistically significant improvement of PaO2/FiO2 over time (p < 0.001). However, it was associated with a nonsignificant reduction in the rate of intubation and mechanical ventilation (p = 0.255) and a nonsignificant reduction in the mortality rate (p = 0.491). The extent of PC was found to be an independent predictor of mortality (p = 0.589) and length of hospital stay (p = 0.581) by multivariate analysis.

Conclusion

The early use of HFNC is associated with a significant improvement in pulmonary oxygenation. We suggest that HFNC can be used as a first-line oxygen therapy in hypoxic patients with lung contusion following blunt chest trauma.

How to cite this article

Elsayed RG, Hafez AF, Maarouf MM, AbdElAziz FKE. Impact of the Early Use of High-flow Nasal Cannula in Patients with Post-traumatic Lung Contusion: A Randomized Clinical Trial. Indian J Crit Care Med 2025;29(2):117-124.

Exploring Heterogeneity in the Cost-Effectiveness of High-Flow Nasal Cannula Therapy in Acutely Ill Children-Insights From the Step-Up First-line Support for Assistance in Breathing in Children Trial Using a Machine Learning Method

OBJECTIVES

To investigate heterogeneity in the cost-effectiveness of high-flow nasal cannula (HFNC) therapy compared with continuous positive airway pressure (CPAP) for acutely ill children requiring noninvasive respiratory support.

METHODS

Using data from the First-line Support for Assistance in Breathing in Children trial, we explore heterogeneity at the patient and subgroup levels using 2 causal forest approaches and a seemingly unrelated regression approach for comparison. First-line Support for Assistance in Breathing in Children is a noninferiority randomized controlled trial (ISRCTN60048867) involving 24 UK pediatric intensive care units. The Step-up trial focuses on acutely ill children aged 0 to 15 years, requiring noninvasive respiratory support. A total of 600 children were randomly assigned to HFNC and CPAP groups in a 1:1 allocation ratio, with 94 patients excluded because of data unavailability.

RESULTS

The primary outcome is the incremental net monetary benefit (INB) of HFNC compared with CPAP, using a willingness-to-pay threshold of £20 000 per quality-adjusted life year gain. INB is derived from total costs and quality-adjusted life years at 6 months. Subgroup analysis showed that some subgroups, such as male children, those aged less than 12 months, and those without severe respiratory distress at randomization, had more favorable INB results. Patient-level analysis revealed heterogeneity in INB estimates, particularly driven by the cost component, with greater uncertainty for those with higher INBs.

CONCLUSIONS

The estimated overall INB of HFNC is significantly larger for specific patient subgroups, suggesting that the cost-effectiveness of HFNC can be heterogeneous, which highlights the importance of considering patient characteristics in evaluating the cost-effectiveness of HFNC.

The starting temperature of high-flow nasal cannula and perceived comfort in critically ill patients: A pragmatic randomized controlled trial

BACKGROUND

High-flow nasal cannula (HFNC) therapy is a non-invasive respiratory treatment characterized by high tolerability, which largely derives from the patient's comfort.

AIM

The primary aim of this study was to explore whether the patient's perceived comfort was the same regardless of different approaches used to reach the target humidification temperature. The secondary aim was to assess the patient's perceived nasal dryness and humidity.

STUDY DESIGN

This single-centre, pragmatic, randomized trial was registered at clinicaltrials.gov (NCT05688189). Patients in the intensive care unit (ICU) in need of HFNC therapy were randomly assigned to one of three study arms: a two-step increase (31 to 34 to 37°C), a one-step increase in temperature (34-37°C) or no temperature increase (started and remained at 37°C). The patients were asked to rate their perceived comfort, as well as their perceived nasal dryness and humidity on a scale from 1 (lowest value) to 5 (highest value).

RESULTS

We enrolled 21 patients, aged 34-85 years. The mean (±1 standard deviation) comfort level was 3.3 (1.3) for patients who received a one-step increase, 3.1 (1.3) for those who received no increase and 2.7 (1.7) for those who received a two-step increase (p = .714). There was also no difference in nasal dryness (p = .05) or humidity (p = .612) across the study arms. Greater comfort was fairly correlated with less nasal humidity (ρ = -0.34, 95% confidence interval -0.68 to 0.07) but not with nasal dryness (ρ = 0.01, p = .94).

CONCLUSIONS

After 30 min of HFNC therapy at a target temperature of 37°C, overall comfort was rated similarly in the three study arms. Additional studies are needed to accumulate evidence corroborating the findings of this study.

RELEVANCE TO CLINICAL PRACTICE

The temperature of the mixture of air and oxygen is a fundamental component of HFNC therapy. A pragmatic approach irrespective of the initial temperature setting seems to yield a similar comfort score in hospitalized patients with mild respiratory failure because of extrapulmonary causes.

Managing Multiorgan Failure in Acute on Chronic Liver Failure

Acute-on-chronic liver failure (ACLF) is defined as a clinical syndrome that develops in patients with chronic liver disease characterized by the presence of organ failure and high short-term mortality, although there is still no worldwide consensus on diagnostic criteria. Management of ACLF is mainly based on treatment of "precipitating factors" (the most common are infections, alcohol-associated hepatitis, hepatitis B flare, and bleeding) and support of organ failure, which often requires admission to the intensive care unit. Liver transplantation should be considered in patients with ACLF grades 2 to 3 as a potentially life-saving treatment. When a transplant is not indicated, palliative care should be considered after 3 to 7 days of full organ support in patients with at least four organ failures or a CLIF-C ACLF score of >70. This review summarizes the current knowledge on the management of organ failure in patients with ACLF, focusing on recent advances.

Efficacy of high-flow nasal oxygen therapy started in the emergency room versus conventional oxygen therapy in patients with acute hypoxaemic respiratory distress: protocol for a French multicentric, prospective, open and randomised superiority study protocol (HIFLOWED)

INTRODUCTION

Acute respiratory failure is a life-threatening condition frequently found in the emergency department. High-flow nasal oxygen (HFNO) is increasingly used in emergency departments for patients with hypoxaemic acute respiratory failure. However, despite the increasing number of studies, its potential advantages regarding the need for therapeutic escalation and mortality have not been precisely evaluated. Our objective is to compare conventional oxygen therapy to HFNO when they are initiated during the first hour following the patient's arrival at the emergency department, with the hypothesis that HFNO would reduce the need for ventilatory therapy escalation.

METHODS AND ANALYSIS

This is a multicentric, prospective, open and randomised superiority study. 500 inpatients will be randomised (1:1) to receive conventional oxygen therapy or HNFO. The primary outcome is a failure in the oxygen therapy defined as the need for a therapeutic escalation within 4 hours after therapy initiation.

ETHICS AND DISSEMINATION

The study has been submitted and approved by the Comité de Protection des Personnes Nord Ouest IV (20 October 2020). As required, a notification was sent to the Agence nationale de sécurité du médicament et des produits de santé (22 October 2020). The research results will be published in peer-reviewed publications and presented at international conferences.

TRIAL REGISTRATION NUMBER

NCT04607967.

A Comprehensive Review on High-Flow Nasal Cannula Oxygen Therapy in Critical Care: Evidence-Based Insights and Future Directions

High-flow nasal cannula (HFNC) therapy has emerged as a significant advancement in respiratory support, offering a non-invasive alternative to traditional oxygen delivery methods in critical care settings. This review comprehensively evaluates HFNC therapy, focusing on its definition, historical evolution, and current clinical applications. HFNC therapy delivers humidified and heated oxygen at high flow rates through a nasal cannula, enhancing oxygenation and patient comfort. The review highlights the physiological mechanisms underlying HFNC and its efficacy in managing acute respiratory failure, chronic obstructive pulmonary disease exacerbations, and postoperative respiratory support. Key findings from clinical trials and meta-analyses are discussed, emphasizing HFNC's advantages over conventional methods, such as reduced intubation rates and shorter ICU stays. The review also addresses safety considerations, including potential risks and complications associated with HFNC therapy. Furthermore, it explores future directions for research and technological advancements aimed at optimizing HFNC use in diverse patient populations. This review aims to provide evidence-based insights to inform clinical practice and guide future investigations in respiratory therapy.

High-flow nasal oxygen therapy compared with conventional oxygen therapy in hospitalised patients with respiratory illness: a systematic review and meta-analysis

BACKGROUND

High-flow nasal oxygen therapy (HFNO) is used in diverse hospital settings to treat patients with acute respiratory failure (ARF). This systematic review aims to summarise the evidence regarding any benefits HFNO therapy has compared with conventional oxygen therapy (COT) for patients with ARF.

METHODS

Three databases (Embase, Medline and CENTRAL) were searched on 22 March 2023 for studies evaluating HFNO compared with COT for the treatment of ARF, with the primary outcome being hospital mortality and secondary outcomes including (but not limited to) escalation to invasive mechanical ventilation (IMV) or non-invasive ventilation (NIV). Risk of bias was assessed using the Cochrane risk-of-bias tool (randomised controlled trials (RCTs)), ROBINS-I (non-randomised trials) or Newcastle-Ottawa Scale (observational studies). RCTs and observational studies were pooled together for primary analyses, and secondary analyses used RCT data only. Treatment effects were pooled using the random effects model.

RESULTS

63 studies (26 RCTs, 13 cross-over and 24 observational studies) were included, with 10 230 participants. There was no significant difference in the primary outcome of hospital mortality (risk ratio, RR 1.08, 95% CI 0.93 to 1.26; p=0.29; 17 studies, n=5887) between HFNO and COT for all causes ARF. However, compared with COT, HFNO significantly reduced the overall need for escalation to IMV (RR 0.85, 95% CI 0.76 to 0.95 p=0.003; 39 studies, n=8932); and overall need for escalation to NIV (RR 0.70, 95% CI 0.50 to 0.98; p=0.04; 16 studies, n=3076). In subgroup analyses, when considering patients by illness types, those with acute-on-chronic respiratory failure who received HFNO compared with COT had a significant reduction in-hospital mortality (RR 0.58, 95% CI 0.37 to 0.91; p=0.02).

DISCUSSION

HFNO was superior to COT in reducing the need for escalation to both IMV and NIV but had no impact on the primary outcome of hospital mortality. These findings support recommendations that HFNO may be considered as first-line therapy for ARF.

PROSPERO REGISTRATION NUMBER

CRD42021264837.

Coronavirus Disease 2019: Past, Present, and Future

Severe acute respiratory syndrome coronavirus 2 is one of the most impactful diseases experienced in the past century. While the official national health emergency concluded in May of 2023, coronavirus disease 2019 (COVID-19) continues to mutate. As the summer of 2023, all countries were experiencing a new surge of cases from the EG.5 Omicron variant. Additionally, a new genetically distinct Omicron descendant BA2.86 had been detected in multiple countries including the United States. This article seeks to offer lessons learned from the pandemic, summarize best evidence for current management of patients with COVID-19, and give insights into future directions with this disease.

New Insight into Laryngo-Tracheal Surgery: High-Flow Oxygen Therapy to Prevent Early Complications after Surgery

BACKGROUND

Early post-operative airway management after laryngo-tracheal surgery is crucial. Acute respiratory failure due to glottis' edema may occur, requiring reintubation. This can prolong ventilatory assistance, jeopardizing anastomosis. To date, only judicious steroid administration and fluid management are available to avoid more invasive procedures. High-flow oxygen therapy (HFOT) is a noninvasive O2 support method providing humidification, warmed air, and Positive End-Expiratory Pressure (AIRVO2). No data about HFOT use to prevent early complications after laryngo-tracheal surgery are reported in the literature.

METHODS

Between September 2020 and September 2022, 107 consecutive patients who underwent laryngo-tracheal surgery received HFOT (Group A). Data and long-term results were compared with those of 80 patients operated between September 2018 and August 2020 (Group B), when HFOT was not available. All patients were operated in a single center. No pre- or post-operative settings changed, except for HFOT introduction. We analyzed and compared the risk for "delayed" reintubation (unexpected reintubation within the first 24-48 h after extubating/laryngeal mask removal) in the two groups.

RESULTS

No patients reported HFOT-related adverse events. The control group (B) presented "delayed" reintubation in 37% (p = 0.027), intensive care unit admission in 67% (p = 0.005) and longer hospital stay (p = 0.001) compared to the HFOT group (A). The minor complications' rate was 3% in both group and overall mortality was 0%. Re-stenosis was described in 4.6% of the HFOT group, without a statistically significant difference (p = 0.7006).

CONCLUSIONS

Our study is the first to investigate HFOT use in patients undergoing laryngo-tracheal surgery, potentially representing a consistent innovation in the peri-operative management of these patients. With the limitation of a retrospective series, we would suggest HFOT use for preventing post-operative reintubation rate, possibly reducing ICU admissions and hospital stays.

High-flow nasal oxygen in resource-constrained, non-intensive, high-care wards for COVID-19 acute hypoxaemic respiratory failure: Comparing outcomes of the first v. third waves at a tertiary centre in South Africa

Background

High-flow nasal oxygen (HFNO) is an accepted treatment for severe COVID-19-related acute hypoxaemic respiratory failure (AHRF).

Objectives

To determine whether treatment outcomes at Groote Schuur Hospital, Cape Town, South Africa, during the third COVID-19 wave would be affected by increased institutional experience and capacity for HNFO and more restrictive admission criteria for respiratory high-care wards and intensive care units.

Methods

We included consecutive patients with COVID-19-related AHRF treated with HFNO during the first and third COVID-19 waves. The primary endpoint was comparison of HFNO failure (composite of the need for intubation or death while on HFNO) between waves.

Results

A total of 744 patients were included: 343 in the first COVID-19 wave and 401 in the third. Patients treated with HFNO in the first wave were older (median (interquartile range) age 53 (46 - 61) years v. 47 (40 - 56) years; p<0.001), and had higher prevalences of diabetes (46.9% v. 36.9%; p=0.006), hypertension (51.0% v. 35.2%; p<0.001), obesity (33.5% v. 26.2%; p=0.029) and HIV infection (12.5% v. 5.5%; p<0.001). The partial pressure of arterial oxygen to fraction of inspired oxygen (PaO2 /FiO2 ) ratio at HFNO initiation and the ratio of oxygen saturation/FiO2 to respiratory rate within 6 hours (ROX-6 score) after HFNO commencement were lower in the first wave compared with the third (median 57.9 (47.3 - 74.3) mmHg v. 64.3 (51.2 - 79.0) mmHg; p=0.005 and 3.19 (2.37 - 3.77) v. 3.43 (2.93 - 4.00); p<0.001, respectively). The likelihood of HFNO failure (57.1% v. 59.6%; p=0.498) and mortality (46.9% v. 52.1%; p=0.159) did not differ significantly between the first and third waves.

Conclusion

Despite differences in patient characteristics, circulating viral variant and institutional experience with HFNO, treatment outcomes were very similar in the first and third COVID-19 waves. We conclude that once AHRF is established in COVID-19 pneumonia, the comorbidity profile and HFNO provider experience do not appear to affect outcome.

Study synopsis

What the study adds. This study adds to the body of evidence demonstrating the utility of high-flow nasal oxygen (HFNO) in avoiding invasive mechanical ventilation (IMV) in patients with severe COVID-19 hypoxaemic respiratory failure, and shows that this utility remained consistent across different waves of the COVID-19 pandemic.Implications of the study. In resource-constrained settings, HFNO is a feasible non-invasive alternative to IMV and can be employed with favourable and consistent outcomes outside traditional critical care wards. It also confirms that the degree of gas exchange abnormality, and not pre-existing patient-related factors, circulating wave variant or provider experience, is the main predictor of HFNO failure.

Severe Community-Acquired Pneumonia: Noninvasive Mechanical Ventilation, Intubation, and HFNT

Severe acute respiratory failure (ARF) is a major issue in patients with severe community-acquired pneumonia (CAP). Standard oxygen therapy is the first-line therapy for ARF in the less severe cases. However, respiratory supports may be delivered in more severe clinical condition. In cases with life-threatening ARF, invasive mechanical ventilation (IMV) will be required. Noninvasive strategies such as high-flow nasal therapy (HFNT) or noninvasive ventilation (NIV) by either face mask or helmet might cover the gap between standard oxygen and IMV. The objective of all the supporting measures for ARF is to gain time for the antimicrobial treatment to cure the pneumonia. There is uncertainty regarding which patients with severe CAP are most likely to benefit from each noninvasive support strategy. HFNT may be the first-line approach in the majority of patients. While NIV may be relatively contraindicated in patients with excessive secretions, facial hair/structure resulting in air leaks or poor compliance, NIV may be preferable in those with increased work of breathing, respiratory muscle fatigue, and congestive heart failure, in which the positive pressure of NIV may positively impact hemodynamics. A trial of NIV might be considered for select patients with hypoxemic ARF if there are no contraindications, with close monitoring by an experienced clinical team who can intubate patients promptly if they deteriorate. In such cases, individual clinician judgement is key to choose NIV, interface, and settings. Due to the paucity of studies addressing IMV in this population, the protective mechanical ventilation strategies recommended by guidelines for acute respiratory distress syndrome can be reasonably applied in patients with severe CAP.

High-Flow and Low-Flow Oxygen Delivery by Nasal Cannula Evaluated in Infant and Adult Airway Replicas

BACKGROUND

The nasal cannula is widely regarded as a safe and effective means of administering low- and high-flow oxygen to patients irrespective of their age. However, variability in delivered oxygen concentration (FDO2 FDO2 ) via nasal cannula has the potential to pose health risks. The present study aimed to evaluate predictive equations for FDO2 over a large parameter space, including variation in breathing, oxygen flow, and upper-airway geometry representative of both young children and adults.

METHODS

Realistic nasal airway geometries were previously collected from medical scans of adults, infants, and neonates. Nasal airway replicas based on these geometries were used to measure the FDO2 for low-flow oxygen delivery during simulated spontaneous breathing. The present study extends previously published data sets to include higher oxygen flows. The extended data sets included nasal cannula oxygen flows that ranged from 6 to 65 L/min for the adult replicas, and from 0.5 to 6 L/min for the infant replicas. For both age groups, FDO2 was measured over a range of breathing frequencies, inspiratory to expiratory time ratios, and tidal volumes. Measured FDO2 values were compared with values predicted by using a previously derived flow-weighted equation.

RESULTS

For both age groups, FDO2 was observed to increase nonlinearly with the ratio between oxygen flow supplied to the nasal cannula and the average inhalation flow. The previously derived flow-weighted equation over-predicted FDO2 at higher oxygen flows. A new empirical equation, therefore, was proposed to predict FDO2 for either age group as a function of nasal cannula flow, tidal volume, and inspiratory time. Predicted FDO2 values matched measured values, with average relative errors of 2.4% for infants and 4.3% for adults.

CONCLUSIONS

A new predictive equation for FDO2 was obtained that accurately matched measured data in both adult and infant airway replicas for low- and high-flow regimens.

Comparison of the Efficacies of High-Flow Nasal Cannula Oxygen Therapy and Non-invasive Nasal Cannula Ventilation in Preventing Intubation

OBJECTIVE

This study aimed to compare high-flow nasal cannula oxygen therapy (nc-HFOT) and non-invasive nasal cannula ventilation (nc-NIV) in terms of intubation requirements.

MATERIALS AND METHODS

The study was conducted retrospectively on cases followed up in the pediatric intensive care unit (PICU) between October 2019 and December 2021.

RESULTS

Of all cases, 43 (55.8%) were male, and the median age was 16 months. The median PRISM-3 score for all cases was 2.5 (range: 0-3). Among the cases 45 cases (58.4%) received nc-HFOT treatment, and 32 cases (41.6%) received nc-NIV treatment. The median duration of respiratory support for all cases was 2 days, and 14 cases (18.2%) needed intubation. The median PICU stay day for all cases was 7 days, and the median hospital stay day was 11 days. The median age, PICU, and hospital stay days of the nc-NIV group were significantly higher (P < .05). In the logistic regression analysis, the probability of requiring intubation in cases initially nc-NIV was performed was found to be 4.95 times higher than those using nc-HFOT (OR: 4.95, 95% CI: 1.3-18.8, P = 0.01). Additionally, cases with underlying chronic diseases were found to have a 5.9 times increased likelihood of requiring intubation compared to those without (OR: 5.9, 95% CI: 1.41-24.5, P = .01). Five cases (6.5%) were lost during intensive care stay.

CONCLUSION

The application of nc-NIV increases intubation by 4.95 times compared to the application of nc-HFOT. The intubation rate in cases with underlying chronic diseases is also 5.9 times higher than those without.

A New Global Definition of Acute Respiratory Distress Syndrome

Background: Since publication of the 2012 Berlin definition of acute respiratory distress syndrome (ARDS), several developments have supported the need for an expansion of the definition, including the use of high-flow nasal oxygen, the expansion of the use of pulse oximetry in place of arterial blood gases, the use of ultrasound for chest imaging, and the need for applicability in resource-limited settings. Methods: A consensus conference of 32 critical care ARDS experts was convened, had six virtual meetings (June 2021 to March 2022), and subsequently obtained input from members of several critical care societies. The goal was to develop a definition that would 1) identify patients with the currently accepted conceptual framework for ARDS, 2) facilitate rapid ARDS diagnosis for clinical care and research, 3) be applicable in resource-limited settings, 4) be useful for testing specific therapies, and 5) be practical for communication to patients and caregivers. Results: The committee made four main recommendations: 1) include high-flow nasal oxygen with a minimum flow rate of ⩾30 L/min; 2) use PaO2:FiO2 ⩽ 300 mm Hg or oxygen saturation as measured by pulse oximetry SpO2:FiO2 ⩽ 315 (if oxygen saturation as measured by pulse oximetry is ⩽97%) to identify hypoxemia; 3) retain bilateral opacities for imaging criteria but add ultrasound as an imaging modality, especially in resource-limited areas; and 4) in resource-limited settings, do not require positive end-expiratory pressure, oxygen flow rate, or specific respiratory support devices. Conclusions: We propose a new global definition of ARDS that builds on the Berlin definition. The recommendations also identify areas for future research, including the need for prospective assessments of the feasibility, reliability, and prognostic validity of the proposed global definition.

Understanding the use of oxygen delivery devices

Many nurses will care for a patient who requires oxygen therapy, either to treat an acute respiratory condition, such as a lung infection, or a chronic condition, such as chronic obstructive pulmonary disease. This article discusses the physiology of gaseous exchange and provides an overview of some of the main respiratory conditions that may result in the need for oxygen therapy. The author also describes the oxygen delivery devices commonly used in clinical practice, such as simple face masks and nasal cannulas, to assist nurses in selecting the most appropriate device.

Clinical study of NFNC in the treatment of acute exacerbation chronic obstructive pulmonary disease patients with respiratory failure

BACKGROUND

Most patients with acute exacerbation chronic obstructive pulmonary disease (AECOPD) have respiratory failure that necessitates active correction and the improvement of oxygenation is particularly important during treatment. High flow nasal cannula (HFNC) oxygen therapy is a non-invasive respiratory aid that is widely used in the clinic that improves oxygenation state, reduces dead space ventilation and breathing effort, protects the loss of cilia in the airways, and improves patient comfort.

AIM

To compare HFNC and non-invasive positive pressure ventilation in the treatment of patients with AECOPD.

METHODS

Eighty AECOPD patients were included in the study. The patients were in the intensive care department of our hospital from October 2019 to October 2021. The patients were divided into the control and treatment groups according to the different treatment methods with 40 patients in each group. Differences in patient comfort, blood gas analysis and infection indices were analyzed between the two groups.

RESULTS

After treatment, symptoms including nasal, throat and chest discomfort were significantly lower in the treatment group compared to the control group on the 3^rd and 5^th days (P < 0.05). Before treatment, the PaO₂, PaO₂/FiO₂, PaCO₂, and SaO₂ in the two groups of patients were not significantly different (P > 0.05). After treatment, the same indicators were significantly improved in both patient groups but had improved more in the treatment group compared to the control group (P < 0.05). After treatment, the white blood cell count, and the levels of C-reactive protein and calcitonin in patients in the treatment group were significantly higher compared to patients in the control group (P < 0.05).

CONCLUSION

HFNC treatment can improve the ventilation of AECOPD patients whilst also improving patient comfort, and reducing complications. HFNC is a clinically valuable technique for the treatment of AECOPD.

Managing the deteriorating child with suspected group A Streptococcus infection

Group A Streptococcus bacteria can cause various pyogenic infections such as tonsillitis, pharyngitis, scarlet fever, impetigo, erysipelas, cellulitis and pneumonia. Most group A Streptococcus infections in children are mild and respond positively to treatment with antibiotics. However, some children develop severe infection accompanied by complications such as sepsis and will require urgent treatment, which may include non-invasive or invasive ventilation and the administration of fluids and vasoactive agents. In some instances, for example if there are no beds available in the paediatric intensive care unit, these interventions may be undertaken in a ward setting. This article gives an overview of group A Streptococcus infection, including two rare but severe complications, streptococcal toxic shock syndrome and necrotising fasciitis. It uses a fictionalised case study to examine the management of the deteriorating child with suspected group A Streptococcus infection, including respiratory support, haemodynamic support and symptom management.

The Safety of a High-Flow Nasal Cannula in Neuromuscular Disease Patients with Acute Respiratory Failure: A Retrospective Case-Series Study

(1) Background: Although Non-Invasive Ventilation (NIV) is effective in preventing mortality and endotracheal intubation in patients with Acute Respiratory Failure (ARF) linked to a neuromuscular disorder, its efficacy can be affected by patient intolerance. A High-Flow Nasal Cannula (HFNC) appears to have a significant advantage over NIV as far as patient tolerance is concerned. The aim of the study was to investigate HFNC's safety profile in a group of consecutive Neuromuscular Disease (NMD) patients intolerant to NIV who were admitted to an Intermediate Respiratory Care Unit (IRCU) for ARF. (2) Methods: The clinical course of nine NMD patients intolerant to NIV and switched to HFNC was reported. HFNC was provided during daytime hours and NIV during the night-time to the NIV-intolerant patients. HFNC was utilized 24 h a day in those patients who were intolerant of even nocturnal NIV. (3) Results: HFNC was simple to use and it was well tolerated by all of the patients. Three out of nine patients experienced treatment failure, consisting of the need for ETI and/or death during their IRCU stay. The remaining 6 had a favorable outcome. Treatment failure was linked to the utilization of HFNC 24 h a day. (4) Conclusion: HFNC during the daytime hours, together with nocturnal NIV, seems to be a safe therapeutic approach for NMD patients with ARF. A round-the-clock use of HFNC tends to be linked to a high likelihood of failure.

Comparison of High Flow Nasal Cannula and Continuous Positive Airway Pressure in COVID-19 Patients With Acute Respiratory Distress Syndrome in Critical Care Unit: A Randomized Control Study

Background and objective Acute hypoxic respiratory failure in coronavirus disease 2019 (COVID-19) pneumonia has been treated with oxygen delivered by oxygen masks and non-invasive ventilation (NIV) with continuous positive airway pressure (CPAP), and more recently with high-flow nasal cannula (HFNC) devices. There is a paucity of randomized controlled trials to compare the efficacy of CPAP with HFNC in COVID-19 pneumonia. We conceptualized a randomized control study to compare the efficacy of HFNC and CPAP in reducing the need for invasive mechanical ventilation, estimation of mechanical ventilation-free days, and risk of intubation in COVID-19 patients with hypoxic respiratory failure. Methodology One hundred consecutive patients who satisfied the inclusion criteria were included in the trial. The patients were then randomly allocated to receive either CPAP or HFNC with settings as per the study protocol. The patients were deemed to have achieved the study endpoint when they were intubated due to any reason or successfully weaned from NIV to conventional oxygen therapies. The number of patients who required invasive ventilation and the number of invasive ventilation-free days were recorded and analyzed. Results Nineteen (38%) patients in the CPAP group and 30 (60%) patients in the HFNC group required invasive mechanical ventilation and the difference was statistically significant (p = 0.03, 95%CI: 0.1829-0.9129). The median number of days free of invasive mechanical ventilation in the CPAP group (median=5 (interquartile range (IQR(=5,6)) was more than in the HFNC group (median=4 (IQR=3,4)) and this difference was statistically significant (p<0.000). The secondary analysis of risk evaluation for intubation done using the Cox regression model showed no significant factors that could have contributed to intubation in the study population. The Kaplan-Meyer curve was used to express the probability of a patient getting intubated and the calculated hazard ratio was 2.29. Conclusion The administration of CPAP significantly reduced the intubation rate and prolonged invasive mechanical ventilation-free period in COVID-19 patients with hypoxic respiratory failure. We also inferred a two-fold increase in the risk of intubation in patients receiving HFNC compared to CPAP.

International Survey of High-Flow Nasal Therapy Use for Respiratory Failure in Adult Patients

(1) Background: High-flow nasal therapy (HFNT) has shown several benefits in addressing respiratory failure. However, the quality of evidence and the guidance for safe practice are lacking. This survey aimed to understand HFNT practice and the needs of the clinical community to support safe practice. (2) Method: A survey questionnaire was developed and distributed to relevant healthcare professionals through national networks in the UK, USA and Canada; responses were collected between October 2020 and April 2021. (3) Results: In the UK and Canada, HFNT was used in 95% of hospitals, with the highest use being in the emergency department. HNFT was widely used outside of a critical care setting. HFNT was mostly used to treat acute type 1 respiratory failure (98%), followed by acute type 2 respiratory failure and chronic respiratory failure. Guideline development was felt to be important (96%) and urgent (81%). Auditing of practice was lacking in 71% of hospitals. In the USA, HFNT was broadly similar to UK and Canadian practice. (4) Conclusions: The survey results reveal several key points: (a) HFNT is used in clinical conditions with limited evidence; (b) there is a lack of auditing; (c) it is used in wards that may not have the appropriate skill mix; and (d) there is a lack of guidance for HFNT use.

Comparison of the efficacy and comfort of high-flow nasal cannula with different initial flow settings in patients with acute hypoxemic respiratory failure: a systematic review and network meta-analysis

BACKGROUND

High-flow nasal cannula (HFNC) has been proven effective in improving patients with acute hypoxemic respiratory failure (AHRF), but a discussion of its use for initial flow settings still need to be provided. We aimed to compare the effectiveness and comfort evaluation of HFNC with different initial flow settings in patients with AHRF.

METHODS

Studies published by October 10, 2022, were searched exhaustively in PubMed, Embase, Web of Science, Cochrane Library (CENTRAL), and the China National Knowledge Infrastructure (CNKI) database. Network meta-analysis (NMA) was performed with STATA 17.0 and R software (version 4.2.1). A Bayesian framework was applied for this NMA. Comparisons of competing models based on the deviance information criterion (DIC) were used to select the best model for NMA. The primary outcome is the intubation at day 28. Secondary outcomes included short-term and long-term mortality, comfort score, length of ICU or hospital stay, and 24-h PaO₂/FiO₂.

RESULTS

This NMA included 23 randomized controlled trials (RCTs) with 5774 patients. With NIV as the control, the HFNC_high group was significantly associated with lower intubation rates (odds ratio [OR] 0.72 95% credible interval [CrI] 0.56 to 0.93; moderate quality evidence) and short-term mortality (OR 0.81 95% CrI 0.69 to 0.96; moderate quality evidence). Using HFNC_Moderate (Mod) group (mean difference [MD] - 1.98 95% CrI -3.98 to 0.01; very low quality evidence) as a comparator, the HFNC_Low group had a slight advantage in comfort scores but no statistically significant difference. Of all possible interventions, the HFNC_High group had the highest probability of being the best in reducing intubation rates (73.04%), short-term (82.74%) and long-term mortality (67.08%). While surface under the cumulative ranking curve value (SUCRA) indicated that the HFNC_Low group had the highest probability of being the best in terms of comfort scores.

CONCLUSIONS

The high initial flow settings (50-60 L/min) performed better in decreasing the occurrence of intubation and mortality, albeit with poor comfort scores. Treatment of HFNC for AHRF patients ought to be initiated from moderate flow rates (30-40 L/min), and individualized flow settings can make HFNC more sensible in clinical practice.

Using Vital Signs to Place Acutely Ill Patients Quickly and Easily into Clinically Helpful Pathophysiologic Categories: Derivation and Validation of Eight Pathophysiologic Categories in Two Distinct Patient Populations of Acutely Ill Patients

BACKGROUND

Early warning scores reliably identify patients at risk of imminent death, but do not provide insight into what may be wrong with the patient or what to do about it.

OBJECTIVE

Our aim was to explore whether the Shock Index (SI), pulse pressure (PP), and ROX Index can place acutely ill medical patients in pathophysiologic categories that could indicate the interventions required.

METHODS

A retrospective post-hoc analysis of previously obtained and reported clinical data for 45,784 acutely ill medical patients admitted to a major regional referral Canadian hospital between 2005 and 2010 and validated on 107,546 emergency admissions to four Dutch hospitals between 2017 and 2022.

RESULTS

SI, PP, and ROX values divided patients into eight mutually exclusive physiologic categories. Mortality was highest in patient categories that included ROX Index value < 22, and a ROX Index value < 22 multiplied the risk of any other abnormality. Patients with a ROX Index value < 22, PP < 42 mm Hg, and SI > 0.7 had the highest mortality and accounted for 40% of deaths within 24 h of admission, whereas patients with a PP ≥ 42 mm Hg, SI ≤ 0.7, and ROX Index value ≥ 22 had the lowest risk of death. These results were the same in both the Canadian and Dutch patient cohorts.

CONCLUSIONS

SI, PP, and ROX Index values can place acutely ill medical patients into eight mutually exclusive pathophysiologic categories with different mortality rates. Future studies will assess the interventions needed by these categories and their value in guiding treatment and disposition decisions.

Computational design and experimental analysis of a novel visor for COVID-19 patients receiving high-flow nasal oxygen therapy

The Covid-19 global pandemic has reshaped the requirements of healthcare sectors worldwide. Following the exposure risks associated with Covid-19, this paper aims to design, optimise, and validate a wearable medical device that reduces the risk of transmission of contagious droplets from infected patients in a hospital setting. This study specifically focuses on those receiving high-flow nasal oxygen therapy. The design process consisted of optimising the geometry of the visor to ensure that the maximum possible percentage of harmful droplets exhaled by the patient can be successfully captured by a vacuum tube attached to the visor. This has been completed by deriving a number of concept designs and assessing their effectiveness, based on numerical analysis, computational fluid dynamics (CFD) simulations and experimental testing. The CFD results are validated using various experimental methods such as Schlieren imaging, particle measurement testing and laser sheet visualisation. Droplet capturing efficiency of the visor was measured through CFD and validated through experimental particle measurement testing. The results presented a 5% deviation between CFD and experimental results. Also, the modifications based on the validated CFD results improved the visor effectiveness by 47% and 38% for breathing and coughing events, respectively.

Transport of an adult with severe respiratory failure on high-flow nasal prongs during a prolonged aeromedical evacuation: A case study

This case describes the use of high-flow oxygen delivered via nasal prongs in the management of an adult patient with severe undifferentiated respiratory failure for the purposes of prolonged air medical transfer.

High flow nasal cannula for acute respiratory failure due to COVID-19 in patients with a 'do-not-intubate' order: A survival analysis

INTRODUCTION

High flow nasal cannula (HFNC) reduces the need for intubation in patients with hypoxaemic acute respiratory failure (ARF), but its added value in patients with severe coronavirus disease 2019 (COVID-19) and a do-not-intubate (DNI) order is unknown. We aimed to assess (variables associated with) survival in these patients.

MATERIALS AND METHODS

We described a multicentre retrospective observational cohort study in five hospitals in the Netherlands and assessed the survival in COVID-19 patients with severe acute respiratory failure and a DNI order who were treated with high flow nasal cannula. We also studied variables associated with survival.

RESULTS AND DISCUSSION

One-third of patients survived after 30 days. Survival was 43.9% in the subgroup of patients with a good WHO performance status and only 16.1% in patients with a poor WHO performance status. Patients who were admitted to the hospital for a longer period prior to HFNC initiation were less likely to survive. HFNC resulted in an increase in ROX values, reflective of improved oxygenation and/or decreased respiratory rate.

CONCLUSION

Our data suggest that a trial of HFNC could be considered to increase chances of survival in patients with ARF due to COVID-19 pneumonitis and a DNI order, especially in those with a good WHO performance status.

Current Considerations in Emergency Airway Management

Purpose of Review

Emergency airway management is populated by many new concepts, evolving equipment, and contemporary strategies for optimal procedural success. This review aims to discuss various topics within these realms and to continue the ongoing conversation regarding improvement of emergency airway management.

Recent Findings

Various literature, opinion pieces, podcasts, and trials have prompted renewed interest in the field of emergency airway management. Though common threads can be found, there is significant debate on optimal practice. Accompanying these conversations is continuous production of new equipment which can be beneficial to providers. However, this ongoing accumulation of material, data, and pathways can create challenges in remaining up to date. Rather than a comprehensive review of current literature and discussion of research findings, this article aims to discuss selected and impactful concepts in real time context and provide potentially immediate additions to emergency airway manager practice.

Summary

As emergency airway management evolves, it remains a significant task to maintain up to date on current trends, data, and new equipment. This article aims to discuss several of these items in a digestible fashion and provide immediate impact for emergency airway providers.

In vitro model for investigating aerosol dispersion in a simulated COVID-19 patient during high-flow nasal cannula treatment

The use of high-flow nasal cannula in the treatment of COVID-19 infected patients has proven to be a valuable treatment option to improve oxygenation. Early in the pandemic, there were concerns for the degree of risk of disease transmission to health care workers utilizing these treatments that are considered aerosol generating procedures. This study developed an in vitro model to examine the release of simulated patient-derived bioaerosol with and without high-flow nasal cannula at gas flow rates of 30 and 50 L/min. Aerosol dispersion was evaluated at 30 and 90 cm distances. Reduction of transmission risk was assessed using a surgical facemask on the manikin. Results indicated that the use of a facemask facilitated a 94-95% reduction in exhaled aerosol concentration at 30 cm and 22-60% reduction for 90 cm distance across both gas flow rates. This bench study confirms that this in vitro model can be used as a tool to assess the risk of disease transmission during aerosol generating procedures in a simulated patient and to test factors to mitigate the risk.

High-flow nasal oxygen in acute hypoxemic respiratory failure: A narrative review of the evidence before and after the COVID-19 pandemic

High-flow nasal oxygen (HFNO) is a type of non-invasive advanced respiratory support that allows the delivery of high-flow and humidified air through a nasal cannula. It can deliver a higher inspired oxygen fraction than conventional oxygen therapy (COT), improves secretion clearance, has a small positive end-expiratory pressure, and exhibits a washout effect on the upper air space that diminishes dead space ventilation. HFNO has been shown to reduce the work of breathing in acute hypoxemic respiratory failure (AHRF) and has become an interesting option for non-invasive respiratory support. Evidence published before the COVID-19 pandemic suggested a possible reduction of the need for invasive mechanical ventilation compared to COT. The COVID-19 pandemic has resulted in a substantial increase in AHRF worldwide, overwhelming both acute and intensive care unit capacity in most countries. This triggered new trials, adding to the body of evidence on HFNO in AHRF and its possible benefits compared to COT or non-invasive ventilation. We have summarized and discussed this recent evidence to inform the best supportive strategy in AHRF both related and unrelated to COVID-19.

Effectiveness of high flow nasal cannula oxygen therapy in patients of acute pulmonary thromboembolism with acute hypoxemic respiratory failure

Background

Acute Pulmonary thromboembolism (PTE) is associated with acute hypoxemic respiratory failure (AHRF), which is a leading cause of death in these patients. High-Flow Nasal Cannula (HFNC) oxygen therapy is a cornerstone of the treatment of respiratory failure. The aim of the present study is to explore the efficacy of HFNC in the treatment of patients of acute PTE with acute hypoxemic respiratory failure in India.

Methods

This is a retrospective study of patients admitted to a tertiary care center with acute PTE with AHRF during the period from January 2018 to January 2020. After reviewing medical files, patients of acute PTE with AHRF treated with HFNC were included in the study. We analyzed the improvement in oxygenation parameters and respiratory rate, as well as outcome in these patients.

Results

During the above specified period, 12 patients suffering from PTE with AHRF were treated with HFNC. After 1 h of the initiation of HFNC along with anticoagulation, the respiratory parameters of patients significantly improved. HFNC was applied for a period of 6-10 days. None of the patients required intubation for AHRF, and all patients were discharged from the hospital on oral anticoagulants.

Conclusion

HFNC oxygen therapy in patients with acute PTE with AHRF showed rapid improvement of oxygenation and respiratory rate. HFNC oxygen therapy is an efficacious treatment for patients with AHRF secondary to acute PTE without any significant hemodynamic effect. It acts as a superior modality of oxygen therapy avoiding noninvasive and invasive ventilatory support.

Epidemiologic Characteristics of Adolescents with COVID-19 Disease with Acute Hypoxemic Respiratory Failure

We report our experience of COVID-19 disease with hypoxemic respiratory failure among patients aged 12–21 years admitted to the intensive care unit at two tertiary care institutions in Northeastern and Midwestern United States. Our results showed that during the main study period that spanned the initial surge at both geographic locations, adolescents with SARS-COV-2 infection admitted to the ICU with respiratory failure were more likely to be male, black, and morbidly obese and with two or more comorbidities. The majority (79%) were admitted with COVID-19-related pneumonia and 15 developed respiratory failure; two-thirds of patients with respiratory failure (9/15, 60%) required mechanical ventilation (MV). More than two-thirds of patients (11/15, 75%) with respiratory failure were obese with BMI > 30 compared to those without respiratory failure (p < 0.0001), and those with BMI > 40 were 4.3 times more likely to develop respiratory failure than those with normal BMI; 40% of patients with respiratory failure had two or more pre-existing medical comorbidities. Inflammatory markers were 2–20 times higher in patients with respiratory failure (p < 0.05). The majority of patients on MV (7/9) developed complications, including ARDS (acute respiratory distress syndrome), acute renal injury, and cerebral anoxic encephalopathy. Patients with respiratory failure had a significantly longer length of hospital stay than patients without respiratory failure (p < 0.05). The majority of the admitted adolescents in the ICU received steroid treatment. None of the patients died. An additional review of a 6-month postvaccination approval period indicated that the majority of ICU admissions were unvaccinated, obese, black patients and all patients who developed respiratory failure were unvaccinated. Our study highlights and supports the need for maximizing opportunities to address vaccination and healthcare gaps in adolescents as well as promoting public health measures including correct use of masks, effective vaccination campaigns for this age group, and additional passive preventive interventions for COVID-19 disease in adolescents especially with comorbid conditions, and in minority populations.

Noninvasive Mechanical Ventilation with Average Volume-Assured Pressure Support versus BiPAP S/T in De Novo Hypoxemic Respiratory Failure

Background

Bilevel positive airway pressure in spontaneous/time and average volume-assured pressure support (BiPAP·S/T-AVAPS) could maintain an adequate tidal volume by reducing the patient's inspiratory effort; however, this ventilatory strategy has not been compared with other ventilatory modes, especially the conventional BiPAP S/T mode, when noninvasive mechanical ventilation (NIMV) is used. The primary objective of this study was to determine the rate of success and failure of the use of BiPAP·S/T-AVAPS versus BiPAP·S/T alone in patients with mild-to-moderate "de novo" hypoxemic respiratory failure.

Methods

This was a matched-cohort study. Subjects with mild-to-moderate de novo hypoxemic respiratory failure were divided into two groups according to the ventilatory strategy used. The subjects in the BiPAP·S/T group were paired with those in the BiPAP·S/T-AVAPS group.

Results

A total of 58 subjects were studied. Twenty-nine subjects in the BiPAP·S/T group were paired with 29 subjects in the BiPAP·S/T-AVAPS group. Twenty patients (34.5%) presented with "failure of NIMV," while 38 (65.5%) patients did not. In addition, 13 (22.4%) patients died, while 45 (77.6%) recovered. No differences were found in the percentage of intubation (P=0.44) and mortality (P=0.1).

Conclusion

The BiPAP S/T-AVAPS ventilator mode was not superior to the BiPAP·S/T mode. A high mortality rate was observed in patients with NIMV failure in both modes. This trial is registered with https://doi.org/10.1186/ISRCTN17904857.

Nasal pillow noninvasive ventilation versus high-flow nasal therapy after extubation in surgical intensive care patients: A propensity-matched cohort study

Objective

To evaluate the tolerability and efficacy of nasal pillow-noninvasive ventilation (NP-NIV) compared with high-flow nasal therapy (HFNT) in postsurgical patients.

Methods

This propensity score-matched retrospective study enrolled postoperative patients that received NP-NIV (NP-NIV group) or HFNT (HFNT group) in the intensive care unit. Data were collected from their medical records and the tolerability and respiratory status before and after extubation were compared between the two groups.

Results

The study enrolled 83 patients in the NP-NIV group and 27 patients in the HFNT group. After propensity score matching, there were 19 patients in each group. After matching, there were no significant differences in the baseline demographic and clinical characteristics before extubation. The tolerability was similar in both groups. When the NP-NIV group was compared with the HFNT group, the respiratory rate was significantly lower (median 16 [interquartile range, 14–17] versus median 19 [interquartile range, 18–26], respectively) and the partial pressure of arterial oxygen/fraction of inspired oxygen ratio was significantly higher (median 205 [174–256] versus median 155 [130–192], respectively) at 1 h after extubation.

Conclusion

NP-NIV was equally well tolerated and provided better respiratory support than HFNT in postsurgical patients.

High-flow nasal cannula versus standard low-flow nasal cannula during deep sedation in patients undergoing radiofrequency atrial fibrillation catheter ablation: a single-centre randomised controlled trial

Background

To our knowledge, there are few trials studying the effect of high-flow nasal cannula (HFNC) during deep sedation. Our hypothesis is that high-flow nasal cannula (HFNC) will prevent hypoxemia and desaturation as compared to low-flow nasal cannula (LFNC) during prolonged deep sedation in patients with atrial fibrillation undergoing radiofrequency catheter ablation (RFCA).

Methods

A single-centre, randomised controlled trial with HFNC as the intervention and LFNC as the control group. A total of 94 adult patients per group undergoing elective radiofrequency atrial fibrillation catheter ablation under deep sedation. will be included. The primary outcome is the lowest oxygen saturation (SpO2). Secondary outcomes are as follows: the duration of lowest SpO2, cross over from oxygen therapy in both directions, incidence of SpO2 below 90% > 60 seconds, adverse sedation events, adverse effects of HFNC, mean CO2, peak CO2 and patients experience with oxygen therapy. The study will take place during the 2-day admission period for RFCA. Patients can fill out their questionnaires in the first week after treatment.

Discussion

HFNC is increasingly used as a technique for oxygen delivery in procedural sedation and analgesia. We hypothesise that HFNC is superior to the standard treatment LFNC in patients under deep sedation with respect to the incidence of desaturation. To our knowledge, there are no adequately powered clinical trial studies on the effects of HFNC in prolonged deep sedation.

Trial registration

ClinicalTrials.gov NCT04842253. Registered on 04 April 2021

ERS International Congress, Virtual 2021: Highlights from the Respiratory Intensive Care Assembly Early Career Members

Early Career Members of Assembly 2 (Respiratory Intensive Care) attended the European Respiratory Society International Congress through a virtual platform in 2021. Sessions of interest to our assembly members included symposia on the implications of acute respiratory distress syndrome phenotyping on diagnosis and treatment, safe applications of noninvasive ventilation in hypoxaemic respiratory failure, and new developments in mechanical ventilation and weaning, and a guidelines session on applying high-flow therapy in acute respiratory failure. These sessions are summarised in this article.

Early Career Members of @ERSAssembly2 attended the #ERSCongress 2021, and reported on symposia on ARDS phenotyping, noninvasive ventilation in hypoxic respiratory failure, ventilator weaning and high-flow therapy in acute respiratory failurehttps://bit.ly/3D68r50

High-Flow Nasal Cannula and COVID-19: A Clinical Review

During the coronavirus disease 2019 (COVID-19) pandemic, noninvasive respiratory support has played a central role in managing patients affected by moderate-to-severe acute hypoxemic respiratory failure, despite inadequate scientific evidence to support its usage. High-flow nasal cannula (HFNC) treatment has gained popularity because of its effectiveness in delivering a high fraction of humidified oxygen, which improves ventilatory efficiency and the respiratory pattern, as well as its reported high tolerability, ease of use, and application outside of ICUs. Nevertheless, the risk of infection transmission to health-care workers has raised some concerns about its use in the first wave of the pandemic outbreak, with controversial recommendations provided by different scientific societies. This narrative review provides an overview of the recent evidence on the physiologic rationale, risks, and benefits of using HFNC instead of conventional oxygen therapy and other types of noninvasive respiratory support devices, such as continuous positive airway pressure and noninvasive ventilation in patients affected by COVID-19 pneumonia with associated acute hypoxemic respiratory failure. It also summarizes the available evidence with regard to the clinical use of HFNC during the current pandemic and its reported outcomes, and highlights the risks of bioaerosol dispersion associated with HFNC use.

High-flow nasal cannula oxygenation in comparison with apnoeic oxygenation during foreign body removal by rigid bronchoscopy: A randomised controlled trial

Background and Aims:

This trial aimed to assess the safety and efficacy of oxygenation using a high-flow nasal cannula (HFNC) compared with the standard apnoeic oxygenation technique during foreign body (FB) removal by a rigid bronchoscope.

Methods:

A prospective, blinded, randomised, controlled trial was conducted on subjects planned for FB removal by a rigid bronchoscope. Inclusion criteria were male and female patients aged between 10 and 40 years. The primary outcome was the lowest oxygen saturation level monitored by pulse oximeter during the procedure, and the secondary outcome was the incidence of postoperative atelectasis.

Results:

Nearly 64 patients were randomised into either HFNC oxygenation (N = 32) or apnoeic oxygenation (N = 32) group. There were no significant differences between the studied groups regarding age, gender, weight, or cardiovascular variables. Intraoperative oxygen saturation was 4% higher in the HFNC group at different times. The end-tidal carbon dioxide measured on induction and after termination by 15 min showed no significant differences between the two groups; however, it was significantly higher in the apnoeic oxygenation group immediately after the procedure, after 5 min, and after 10 min of termination. No adverse effects from the increased end-tidal carbon dioxide were reported.

Conclusion:

HFNC was superior to apnoeic oxygenation technique in maintaining oxygenation status in patients undergoing rigid bronchoscopy for FB removal.

ERS Clinical Practice Guidelines: High-flow nasal cannula in acute respiratory failure

BACKGROUND

High-flow nasal cannula (HFNC) has become a frequently used non-invasive form of respiratory support in acute settings, however evidence supporting its use has only recently emerged. These guidelines provide evidence-based recommendations for the use of HFNC alongside other noninvasive forms of respiratory support in adults with acute respiratory failure (ARF).

MATERIALS AND METHODOLOGY

The European Respiratory Society Task Force panel included expert clinicians and methodologists in pulmonology and intensive care medicine. The Task Force used the GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) methods to summarize evidence and develop clinical recommendations for the use of HFNC alongside conventional oxygen therapy (COT) and non-invasive ventilation (NIV) for the management of adults in acute settings with ARF.

RESULTS

The Task Force developed 8 conditional recommendations, suggesting using: 1) HFNC over COT in hypoxemic ARF, 2) HFNC over NIV in hypoxemic ARF, 3)HFNC over COT during breaks from NIV, 4) either HFNC or COT in post-operative patients at low risk of pulmonary complications, 5) either HFNC or NIV in post-operative patients at high risk of pulmonary complications, 6) HFNC over COT in non-surgical patients at low risk of extubation failure, 7) NIV over HFNC for patients at high risk of extubation failure unless there are relative or absolute contraindications to NIV, 8) trialling NIV prior to use of HFNC in patients with chronic obstructive pulmonary disease (COPD) and hypercapnic ARF.

CONCLUSIONS

HFNC is a valuable intervention in adults with ARF. These conditional recommendations can assist clinicians in choosing the most appropriate form of non-invasive respiratory support to provide to patients in different acute settings.

Update on guidelines for the treatment of COPD in Taiwan using evidence and GRADE system-based recommendations

Chronic obstructive pulmonary disease (COPD) has significant contributions to morbidity and mortality world-wide. Early symptoms of COPD are not readily distinguishable, resulting in a low rate of diagnosis and intervention. Different guidelines and recommendatations for the diagnosis and treatment of COPD exist globally. The first edition of clinical practice guidelines for COPD was published in 2016 by the Ministry of Health and Welfare in Taiwan in collaboration with the Taiwan evidence-based medicine association and Cochrane Taiwan, and was revised in 2019 in order to update recent diagnostic and therapeutic modalities for COPD and its acute exacerbation. This revised guideline covered a range of topics highlighted in the Global Initiative for Chronic Obstructive Lung Disease (GOLD) report, including strategies for the diagnosis, assessment, monitoring, and management of stable COPD and exacerbations, with particular focus on evidence from Taiwan. The recommendations included in the revised guideline were formed based on a comprehensive systematic review or meta-analysis of specific clinical issues identified by an expert panel that surveyed relevant scientific evidence in the literature and guidelines published by the clinical communities and organizations nationally and internationally. The guidelines and recommendations are applicable to the clinical settings in Taiwan. We expect this revised guideline to facilitate the diagnosis, treatment and management of patients with COPD by physicians and health care professionals in Taiwan. Adaptations of the materials included herein for educational and training purposes is encouraged.

ROX index as a good predictor of high flow nasal cannula failure in COVID-19 patients with acute hypoxemic respiratory failure: A systematic review and meta-analysis

Purpose

Prediction of high flow nasal cannula (HFNC) failure in COVID-19 patients with acute hypoxemic respiratory failure (AHRF) may improve clinical management and stratification of patients for optimal treatment. We performed a systematic review and meta-analysis to determine performance of ROX index as a predictor of HFNC failure.

Materials and methods

Systematic search was performed in electronic databases (PubMed, Google Scholar, Web of Science and Cochrane Library) for articles published till 15 June 2021 investigating ROX index as a predictor for HFNC failure. Quality In Prognosis Studies (QUIPS) tool was used to analyze risk of bias for prognostic factors, by two independent authors.

Results

Eight retrospective or prospective cohort studies involving 1301 patients showed a good discriminatory value, summary area under the curve (sAUC) 0.81 (95% CI, 0.77–0.84) with sensitivity of 0.70 (95% CI, 0.59–0.80) and specificity of 0.79 (95% CI, 0.67–0.88) for predicting HNFC failure. The positive and negative likelihood ratio were 3.0 (95% CI, 2.2–5.3) and 0.37 (95% CI, 0.28–0.50) respectively, and was strongly associated with a promising predictive accuracy (Diagnostic odds ratio (DOR) 9, 95% CI, 5–16).

Conclusion

This meta-analysis suggests ROX index has good discriminating power for prediction of HFNC failure in COVID-19 patients with AHRF.

＜Editors' Choice＞ Effects of high-flow nasal cannula oxygen therapy on oral intake of do-not-intubate patients with respiratory diseases

High-flow nasal cannula (HFNC) oxygen therapy is used widely for hypoxemic respiratory failure. However, it is unknown whether the use of HFNC is compatible with retaining the ability to eat and drink of patients with end-stage respiratory diseases as a part of palliative care. A retrospective study was conducted on subjects with hypoxic respiratory failure due to end-stage respiratory diseases, including interstitial pneumonia and malignant respiratory diseases, who were treated with HFNC or reservoir mask oxygen therapy and died with do-not-resuscitate (DNR) and do-not-intubate (DNI) status. We compared the duration of eating solids and drinking liquids and clinical variables in the HFNC group with those in the reservoir mask group. The data from a total 43 subjects including 20 with HFNC and 23 with a reservoir mask were analyzed. Fitting HFNC to subjects temporarily improved oxygenation. Durations of survival, eating solids, and drinking liquids in the HFNC group were significantly longer than those in the reservoir mask group. No significant adverse effects were observed in either group. In conclusion, the use of HFNC led to prolonged survival while preserving the ability of oral intake in patients with DNR and DNI status.

Improving access to ward-based respiratory failure management: a case study in the development of a respiratory care unit at an Australian metropolitan health service

This case study describes the implementation of a ward-based respiratory care unit to improve access to specialised respiratory failure management at an Australian metropolitan health service. Using a case study approach, we describe the conception, development and implementation of a respiratory care unit within a previously inexperienced ward. Key barriers and facilitators are explored and the importance of a safety culture and an aspiration for continuous quality improvement are detailed. Three key aspects of implementation were identified: physical environment, expertise and governance. Continuous review of clinical and quality data was also considered critical to success. Stakeholder engagement was identified as both a barrier and facilitator to successful implementation. Early success was demonstrated through increased utilisation of respiratory interventions but with less utilisation of the intensive care unit and no apparent deterioration in clinical outcomes. Successful implementation of ward-based management of respiratory failure can be undertaken within non-tertiary settings but requires a comprehensive plan. Essential aspects include the support of clinical champions, early and continuous stakeholder engagement and an aspirational culture of safety and continuous quality improvement. What is known about the topic? Non-invasive ventilation and high-flow oxygen therapy are now established as key treatments in the management of acute respiratory failure. Access to these treatments is often limited to critical care locations (emergency department, intensive care unit (ICU) and operating theatre), but ward-based use can be safe and effective when applied with appropriate clinical policies, expertise and staffing. What does this paper add? This report describes the successful and rapid development of a specialised respiratory care unit within an inexperienced ward at an Australian metropolitan health service. Prior to development of the unit, the health service only provided non-invasive ventilation and high-flow oxygen therapy within critical care locations. Successful implementation was associated with increased utilisation of these therapies with significantly less ICU utilisation and no apparent deterioration in outcomes. What are the implications for practitioners? An explanation of a model for implementation is provided that may help health services improve access to complex respiratory failure management outside of critical care locations. Key factors in the success of the model are identified and examined.

Recent updates in COVID-19 with emphasis on inhalation therapeutics: Nanostructured and targeting systems

The current world health threat posed by the novel coronavirus disease of 2019 (COVID-19) calls for the urgent development of effective therapeutic options. COVID-19 needs daunting routes such as nano-antivirals. Hence, the role of nanotechnology is very critical in combating this nano-enemy "virus." Although substantial resources are under ongoing attention for prevention and care, we would like to start sharing with readers our vision of the role of inhaled nanomaterials and targeting systems that can play an important role in the fight against the COVID-19. In this review, we underline the genomic structure of COVID-19, recent modes of virus transmission with measures to control the infection, pathogenesis, clinical presentation of SARS-CoV-2, and how much the virus affects the lung. Additionally, the recent therapeutic approaches for managing COVID-19 with emphasis on the value of nanomaterial-based technical approaches are discussed in this review. This review also focuses on the safe and efficient delivery of useable targeted therapies using designed nanocarriers. Moreover, the effectiveness and availability of active targeting of certain specific receptors expressed on the coronavirus surfaces via tailored ligand nanoparticles are manipulated. It was also highlighted in this review the role of inhaled medicines including antivirals and repurposed drugs for fighting the associated lung disorders and efficiency of developed vaccines. Moreover, the inhalation delivery safety techniques were also highlighted.

Implications of early respiratory support strategies on disease progression in critical COVID-19: a matched subanalysis of the prospective RISC-19-ICU cohort

BACKGROUND

Uncertainty about the optimal respiratory support strategies in critically ill COVID-19 patients is widespread. While the risks and benefits of noninvasive techniques versus early invasive mechanical ventilation (IMV) are intensely debated, actual evidence is lacking. We sought to assess the risks and benefits of different respiratory support strategies, employed in intensive care units during the first months of the COVID-19 pandemic on intubation and intensive care unit (ICU) mortality rates.

METHODS

Subanalysis of a prospective, multinational registry of critically ill COVID-19 patients. Patients were subclassified into standard oxygen therapy ≥10 L/min (SOT), high-flow oxygen therapy (HFNC), noninvasive positive-pressure ventilation (NIV), and early IMV, according to the respiratory support strategy employed at the day of admission to ICU. Propensity score matching was performed to ensure comparability between groups.

RESULTS

Initially, 1421 patients were assessed for possible study inclusion. Of these, 351 patients (85 SOT, 87 HFNC, 87 NIV, and 92 IMV) remained eligible for full analysis after propensity score matching. 55% of patients initially receiving noninvasive respiratory support required IMV. The intubation rate was lower in patients initially ventilated with HFNC and NIV compared to those who received SOT (SOT: 64%, HFNC: 52%, NIV: 49%, p = 0.025). Compared to the other respiratory support strategies, NIV was associated with a higher overall ICU mortality (SOT: 18%, HFNC: 20%, NIV: 37%, IMV: 25%, p = 0.016).

CONCLUSION

In this cohort of critically ill patients with COVID-19, a trial of HFNC appeared to be the most balanced initial respiratory support strategy, given the reduced intubation rate and comparable ICU mortality rate. Nonetheless, considering the uncertainty and stress associated with the COVID-19 pandemic, SOT and early IMV represented safe initial respiratory support strategies. The presented findings, in agreement with classic ARDS literature, suggest that NIV should be avoided whenever possible due to the elevated ICU mortality risk.

Oxygenation Strategy During Acute Respiratory Failure in Critically-Ill Immunocompromised Patients

OBJECTIVES

To assess the response to initial oxygenation strategy according to clinical variables available at admission.

DESIGN

Multicenter cohort study.

SETTING

Thirty French and Belgium medical ICU.

SUBJECTS

Immunocompromised patients with hypoxemic acute respiratory failure.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Data were extracted from the Groupe de Recherche en Reanimation Respiratoire du patient d'Onco-Hématologie database. Need for invasive mechanical ventilation was the primary endpoint. Secondary endpoint was day-28 mortality. Six-hundred forty-nine patients were included. First oxygenation strategies included standard oxygen (n = 245, 38%), noninvasive ventilation (n = 285; 44%), high-flow nasal cannula oxygen (n = 55; 8%), and noninvasive ventilation + high-flow nasal cannula oxygen (n = 64; 10%). Bilateral alveolar pattern (odds ratio = 1.67 [1.03-2.69]; p = 0.04), bacterial (odds ratio = 1.98 [1.07-3.65]; p = 0.03) or opportunistic infection (odds ratio = 4.75 [2.23-10.1]; p < 0.001), noninvasive ventilation use (odds ratio = 2.85 [1.73-4.70]; p < 0.001), Sequential Organ Failure Assessment score (odds ratio = 1.19 [1.10-1.28]; p < 0.001), and ratio of PaO2 and FIO2 less than 100 at ICU admission (odds ratio = 1.96 [1.27-3.02]; p = 0.0002) were independently associated with intubation rate. Day-28 mortality was independently associated with bacterial (odds ratio = 2.34 [1.10-4.97]; p = 0.03) or opportunistic infection (odds ratio = 4.96 [2.11-11.6]; p < 0.001), noninvasive ventilation use (odds ratio = 2.35 [1.35-4.09]; p = 0.003), Sequential Organ Failure Assessment score (odds ratio = 1.19 [1.10-1.28]; p < 0.001), and ratio of PaO2 and FIO2 less than 100 at ICU admission (odds ratio = 1.97 [1.26-3.09]; p = 0.003). High-flow nasal cannula oxygen use was neither associated with intubation nor mortality rates.

CONCLUSIONS

Some clinical characteristics at ICU admission including etiology and severity of acute respiratory failure enable to identify patients at high risk for intubation.

Ventilatory Support in Patients with COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused the novel coronavirus disease 2019 (COVID-19) pandemic, which spread throughout the world. Acute hypoxemic respiratory failure is the most dangerous complication of COVID-19 pneumonia. To date, no specific therapeutic drugs or vaccines have been proven efficacious. Ventilatory support is still a significant challenge for physicians facing COVID-19. The mechanisms underlying hypoxemia in those patients are not fully understood, but a new physiopathology model has been proposed. Oxygen therapy should be delivered to patients with mild to moderate hypoxemia. More severe patients could benefit from other treatments (high-flow nasal cannula, noninvasive ventilation or intubation, and invasive ventilation). Given the rapid evolution of COVID-19, there has been a paucity of the high-quality data that typically inform clinical practice guidelines from professional societies, and a worldwide consensus is still lacking. This chapter aims to illustrate the potentials of ventilatory support as therapeutic options for adult and pediatric patients affected by COVID-19 pneumonia.