High flow nasal therapy versus noninvasive ventilation as initial ventilatory strategy in COPD exacerbation: a multicenter non-inferiority randomized trial

Effects of high-flow nasal cannula oxygen therapy in bronchiectasis and hypercapnia: a retrospective observational study

BACKGROUND

The effectiveness of high-flow nasal cannula (HFNC) therapy in patients with bronchiectasis experiencing hypercapnia remains unclear. Our aim was to retrospectively analyze the short-term outcomes of HFNC therapy in such patients, and to further explore the predictors of HFNC treatment failure in this particular patient population.

METHODS

A retrospective review was conducted on patients with bronchiectasis who received HFNC (n = 70) for hypercapnia (arterial partial pressure of carbon dioxide, PaCO2 ≥ 45 mmHg) between September 2019 and September 2023.

RESULTS

In the study population, 30% of patients presented with acidemia (arterial pH < 7.35) at baseline. Within 24 h of HFNC treatment, there was a significant reduction in PaCO2 levels by a mean of 4.0 ± 12.7 mmHg (95% CI -7.0 to -1.0 mmHg). Concurrently, arterial pH showed a statistically significant increase with a mean change of 0.03 ± 0.06 (95% CI 0.01 to 0.04). The overall hospital mortality rate in our study was 17.5%. The median length of hospital stay was 11.0 days (interquartile range [IQR] 8.0 to 16.0 days). Sub-analysis revealed no statistically significant differences in hospital mortality (19.0% vs. 20.4%, p = 0.896), length of hospital stay (median 14.0 days [IQR 9.0 to 18.0 days] vs. 10.0 days [IQR 7.0 to 16.0 days], p = 0.117) and duration of HFNC application (median 5.0 days [IQR 2.0 to 8.5 days] vs. 6.0 days [IQR 4.9 to 9.5 days], p = 0.076) between the acidemia group and the non-acidemia group (arterial pH ≥ 7.35). However, more patients in the non-acidemia group had do-not-intubate orders. The overall treatment failure rate for HFNC was 28.6%. Logistic regression analysis identified the APACHE II score (OR 1.24 per point) as the independent predictor of HFNC failure.

CONCLUSIONS

In patients with bronchiectasis and hypercapnia, HFNC as an initial respiratory support can effectively reduce PaCO2 level within 24 h of treatment. A high APACHE II score has emerged as a prognostic indicator for HFNC treatment failure. These observations highlight randomized controlled trials to meticulously evaluate the efficacy of HFNC in this specific population.

Noninvasive Ventilation in the Cardiac Intensive Care Unit

Over the last several decades, the cardiac intensive care unit (CICU) has seen an increase in the complexity of the patient population and etiologies requiring CICU admission. Currently, respiratory failure is the most common reason for admission to the contemporary CICU. As a result, noninvasive ventilation (NIV), including noninvasive positive-pressure ventilation and high-flow nasal cannula, has been increasingly utilized in the management of patients admitted to the CICU. In this review, we detail the different NIV modalities and summarize the evidence supporting their use in conditions frequently encountered in the CICU. We describe the unique pathophysiologic interactions between positive pressure ventilation and left and/or right ventricular dysfunction. Additionally, we discuss the evidence and strategies for utilization of NIV as a method to reduce extubation failure in patients who required invasive mechanical ventilation. Lastly, we examine unique considerations for managing respiratory failure in certain, high-risk patient populations such as those with right ventricular failure, severe valvular disease, and adult congenital heart disease. Overall, it is critical for clinicians who practice in the CICU to be experts with the application, risks, benefits, and modalities of NIV in cardiac patients with respiratory failure.

Noninvasive respiratory support in the emergency department: Controversies and state-of-the-art recommendations

Acute respiratory failure is a common reason for emergency department visits and hospital admissions. Diverse underlying physiologic abnormalities lead to unique aspects about the most common causes of acute respiratory failure: acute decompensated heart failure, acute exacerbation of chronic obstructive pulmonary disease, and acute de novo hypoxemic respiratory failure. Noninvasive respiratory support strategies are increasingly used methods to support work of breathing and improve gas exchange abnormalities to improve outcomes relative to conventional oxygen therapy or invasive mechanical ventilation. Noninvasive respiratory support includes noninvasive positive pressure ventilation and nasal high flow, each with unique physiologic mechanisms. This paper will review the physiology of respiratory failure and noninvasive respiratory support modalities and offer data and guideline-driven recommendations in the context of key clinical controversies.

Effect of budesonide/glycopyrrolate/formoterol fumarate metered dose inhaler combined with nasal high-flow nasal cannula on elderly patients with COPD and respiratory failure

Objective

To explore the clinical effect of budesonide/glycopyrrolate/formoterol fumarate metered dose inhaler (BGF MDI) combined with high-flow nasal cannula (HFNC) in the treatment of elderly patients with chronic obstructive pulmonary disease (COPD) and respiratory failure.

Methods

The clinical records of 94 elderly patients with COPD and respiratory failure who were treated in Yongkang First People's Hospital from February 2022 to January 2023 were retrospectively selected. Among them, 46 patients received HFNC alone (Control-group) and 48 patients received HFNC combined with BGF MDI (Study-group). The treatment effect, arterial blood gas status, pulmonary function, and acute physiology and chronic health evaluation (APACHE) II score before and after treatment were analyzed in both groups.

Results

The total efficacy of treatment in the Study-group (95.8%) was higher than that in the Control-group (78.3%) (P<0.05). After treatment, the partial pressure of arterial carbon dioxide (PaCO2), residual volume, and APACHE II scores in the two groups decreased compared to those before treatment, with the Study-group lower overall. However, arterial oxygen saturation (SaO2), oxygen partial pressure (PaO2), the percentage of peak expiratory flow (PEF), and forced expiratory volume in one second (FEV1) as percent of predicted (%FEV1) were higher than before treatment, and higher in the Study-group (P<0.05).

Conclusions

Compared with HFNC alone, BGF MDI combined with HFNC can effectively regulate the arterial blood gas status of elderly patients with COPD and respiratory failure, restore pulmonary function, and improve the overall treatment effect.

High-flow nasal cannula may prolong the length of hospital stay in patients with hypercapnic acute COPD exacerbation

BACKGROUND

High-flow nasal cannula (HFNC) is increasingly used in patients with acute exacerbation of COPD (AECOPD). We aimed to confirm whether the baseline bicarbonate is an independent predictor of outcomes in patients with hypercapnic AECOPD receiving HFNC.

METHODS

This was a secondary analysis of a multicentre randomised trial that enrolled 330 patients with non-acidotic hypercapnic AECOPD supported by HFNC or conventional oxygen treatment (COT). We compared the length of stay (LOS) in hospital and the rate of non-invasive positive pressure ventilation (NPPV) use according to baseline bicarbonate levels using the log-rank test or Cox proportional hazard model.

RESULTS

In the high bicarbonate subgroup (n = 165, bicarbonate 35.0[33.3-37.9] mmol/L, partial pressure of arterial carbon dioxide [PaCO2] 56.8[52.0-62.8] mmHg), patients supported by HFNC had a remarkably prolonged LOS in hospital when compared to COT (HR 1.59[1.16-2.17], p = 0.004), whereas patients in the low bicarbonate subgroup (n = 165, bicarbonate 28.8[27.0-30.4] mmol/L, PaCO2 48.0[46.0-50.0] mmHg) had a comparable LOS in hospital regardless of respiratory support modalities. The rate of NPPV use in patients with high baseline bicarbonate level was significantly higher than that in patients with low baseline bicarbonate level (19.4 % vs. 3.0 %, p < 0.0001). Patients with high bicarbonate level in HFNC group had a lower rate of NPPV use compared to COT group (15.4 % vs. 23.0 %, p = 0.217).

CONCLUSIONS

Among patients with non-acidotic hypercapnic AECOPD with high baseline bicarbonate level, HFNC is significantly associated with a prolonged LOS in hospital, which may be due to the reduced escalation of NPPV treatment.

TRIAL REGISTRATION

clinicaltrials.gov (NCT03003559).

High flow nasal cannula versus noninvasive ventilation in the treatment of acute hypercapnic respiratory failure: A systematic review and meta-analysis

Chronic obstructive pulmonary disease can lead to acute hypercapnic respiratory failure (AHRF), often treated using noninvasive ventilation (NIV). Emerging research suggests the potential utility of high flow nasal cannula (HFNC) for AHRF. This systematic review and meta-analysis aimed to determine the effect of HFNC versus NIV on AHRF management. A search of electronic databases (CINAHL, MEDLINE, and Academic Search Complete), web sources, and trial registries was last conducted on 9 February 2023. Quality and risk of bias assessments were conducted. Meta-analyses were used to synthesise data. Seven randomised controlled trials were included. No statistically significant differences between HFNC and NIV were found within the following outcomes of interest: (i) correction of pCO2: standardised mean difference (SMD) = -0.16, 95% confidence interval (CI) (-0.34 to 0.02), p = 0.08; (ii) correction of pH: SMD = -0.05, 95% CI (-0.25 to 0.14), p = 0.59; (iii) correction of pO2: SMD = -0.15, 95% CI (-0.40 to 0.09), p = 0.22; (iv) intubation rates: risk ratio (RR) = 0.87, 95% CI (0.41 to 1.82), p = 0.71; (v) mortality rates: RR = 0.85, 95% CI (0.47 to 1.56), p = 0.61; and (vi) treatment switch: RR = 1.30, 95% CI (0.43 to 3.94), p = 0.64. More controlled trials with large sample sizes are required to investigate the management of AHRF of various aetiologies. HFNC may be used as a final exhaustive measure for COPD-related AHRF where NIV is not tolerated, and when it is not clinically indicated to extend to endotracheal intubation.

[Non-invasive Mechanical Ventilation in Acute Respiratory Failure. Clinical Practice Guidelines - on behalf of the German Society of Pneumology and Ventilatory Medicine]

The guideline update outlines the advantages as well as the limitations of NIV in the treatment of acute respiratory failure in daily clinical practice and in different indications.Non-invasive ventilation (NIV) has a high value in therapy of hypercapnic acute respiratory failure, as it significantly reduces the length of ICU stay and hospitalization as well as mortality.Patients with cardiopulmonary edema and acute respiratory failure should be treated with continuous positive airway pressure (CPAP) and oxygen in addition to necessary cardiological interventions. This should be done already prehospital and in the emergency department.In case of other forms of acute hypoxaemic respiratory failure with only mild or moderately disturbed gas exchange (PaO2/FiO2 > 150 mmHg) there is no significant advantage or disadvantage compared to high flow nasal oxygen (HFNO). In severe forms of ARDS NIV is associated with high rates of treatment failure and mortality, especially in cases with NIV-failure and delayed intubation.NIV should be used for preoxygenation before intubation. In patients at risk, NIV is recommended to reduce extubation failure. In the weaning process from invasive ventilation NIV essentially reduces the risk of reintubation in hypercapnic patients. NIV is regarded useful within palliative care for reduction of dyspnea and improving quality of life, but here in concurrence to HFNO, which is regarded as more comfortable. Meanwhile NIV is also recommended in prehospital setting, especially in hypercapnic respiratory failure and pulmonary edema.With appropriate monitoring in an intensive care unit NIV can also be successfully applied in pediatric patients with acute respiratory insufficiency.

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.

Effects of High-Flow Nasal Cannula on Right Heart Dysfunction in Patients with Acute-on-Chronic Respiratory Failure and Pulmonary Hypertension

High-flow nasal cannula (HFNC) has several benefits in patients affected by different forms of acute respiratory failure, based on its own mechanisms. We postulated that HFNC may have some advantages over conventional oxygen therapy (COT) on the heart function in patients with acute-on-chronic respiratory failure with concomitant pulmonary hypertension (PH). We therefore designed this retrospective observational study to assess if HFNC improves the right and left ventricle functions and morphologies, arterial blood gases (ABGs), and patients' dyspnea, compared to COT. We enrolled 17 hospitalized patients receiving HFNC, matched with 17 patients receiving COT. Echocardiographic evaluation was performed at the time of admission (baseline) and 10 days after (T10). HFNC showed significant improvements in right ventricular morphology and function, and a reduction in sPAP. However, there were no significant changes in the left heart measurements with HFNC application. Conversely, COT did not lead to any modifications in echocardiographic measurements. In both groups, oxygenation significantly improved from baseline to T10 (in the HFNC group, from 155 ± 47 to 204 ± 61 mmHg while in the COT group, from 157 ± 27 to 207 ± 27 mmHg; p < 0.0001 for both comparisons). In conclusion, these data suggest an improvement of oxygenation with both treatments; however, only HFNC was able to improve the right ventricular morphology and function after 10 days from the beginning of treatment in a small cohort of patients with acute-on-chronic respiratory failure with PH.

Management of Chronic Obstructive Pulmonary Disease (COPD) Exacerbations in Hospitalized Patients From Admission to Discharge: A Comprehensive Review of Therapeutic Interventions

Chronic obstructive pulmonary disease (COPD) is a common and debilitating condition that often necessitates hospitalization for exacerbations. Since COPD exacerbations can cause significant morbidity and mortality, managing them is crucial for patient care. Effective management of COPD exacerbations is essential to prevent complications, as COPD exacerbations are associated with increased healthcare costs and decreased quality of life. This review aims to comprehensively discuss the management of COPD exacerbations, covering various pharmacologic and non-pharmacologic strategies. These include inhaled bronchodilators, systemic steroids, antibiotics, invasive and non-invasive ventilation, oxygen therapy, smoking cessation, immunization with pneumococcal vaccine, inhalers at discharge, pulmonary rehabilitation, long-term oxygen therapy (LTOT), ambulatory oxygen therapy, short-burst oxygen therapy, extracorporeal membrane oxygenation (ECMO), lung volume reduction surgery (LVRS), endobronchial procedures, and lung transplant. It is drawn upon various sources, including clinical studies, systemic reviews, and observational studies, to provide a comprehensive overview of current practices and identify areas for future research and innovation in managing COPD exacerbations. Addressing these areas of interest can improve patient outcomes and quality of life.

Exacerbations of COPD

COPD exacerbations are associated with significant morbidity, mortality, and increased health care expenditures. The recently published Global Initiative for Chronic Obstructive Lung Disease (GOLD) recommendations have further refined the definition of an exacerbation. A better understanding of the risk factors associated with the development of an exacerbation exists, and improvements are being made in earlier detection approaches. Pharmacologic treatment strategies have been the cornerstone of effective therapy. In addition, both pharmacologic and non-pharmacologic strategies have been proven successful in the prevention of future exacerbations. Newer technologies, including the use of artificial intelligence and wearable monitoring devices, are now being used to help in the earlier detection of exacerbations. Such preventive and earlier detection strategies can help to develop a more personalized care model and improve outcomes for patients with COPD.

Acute Hypercapnic Respiratory Failure in COPD

COPD is a progressive inflammatory process affecting both the airways and alveolar structures of the lungs. Exacerbations of COPD are episodes of acute worsening of this inflammatory process, often triggered by infections. The most severe exacerbations are characterized by substantial air trapping and inspiratory muscle overload, which leads to hypercapnic respiratory failure. Pharmacologic therapies focus on intense bronchodilator administration (usually by aerosol), corticosteroids, and antibiotics. Respiratory life support technologies are often needed for severe exacerbations and range from carefully titrated supplemental O2 administration to positive-pressure ventilation (both invasive and noninvasive). Future life support strategies will likely involve extracorporeal life support technologies.

High-Flow Nasal Oxygen versus Noninvasive Ventilation in Acute Exacerbation of Chronic Obstructive Pulmonary Disease Patients: A Meta-Analysis of Randomized Controlled Trials

Background

High-flow nasal cannula (HFNC) can be used in stable chronic obstructive pulmonary disease (COPD) patients, but the effect of HFNC on clinical outcomes in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is still uncertain.

Methods

We searched electronic literature databases for randomized controlled trials (RCTs) comparing HFNC with noninvasive ventilation (NIV) in hypercapnic patients with AECOPD. The primary endpoint of this meta-analysis was PaCO₂, PaO_2, and SpO₂. The secondary outcomes were the respiratory rate, mortality, complications, and intubation rate.

Results

We included 7 RCTs with a total of 481 patients. There were no significant differences on measures of PaCO₂ (MD = -0.42, 95%CI -3.60 to 2.75, Z = 0.26, and P = 0.79), PaO₂ (MD = -1.36, 95%CI -4.69 to 1.97, Z = 0.80, and P = 0.42), and SpO₂ (MD = -0.78, 95%CI -1.67 to 0.11, Z = 1.72, P = 0.08) between the HFNC group and the NIV group. There was no significant difference in measures of the mortality and intubation rate between the HFNC group (OR = 0.72, 95%CI 0.30 to 1.69, Z = 0.76, and P = 0.44) and the NIV group (OR = 2.38, 95%CI 0.49 to 11.50, Z = 1.08, and P = 0.28), respectively. But the respiratory rate in the HFNC group was lower than that in the NIV group (MD = -1.13, 95%CI -2.13 to -0.14, Z = 2.23, and P = 0.03), and fewer complications were found in the HFNC group (OR = 0.26, 95%CI 0.14 to 0.47, Z = 4.46, and P < 0.00001).

Conclusion

NIV was noninferior to HFNC in decreasing PaCO₂ and increasing PaO₂ and SpO₂. Similarly, the mortality and intubation rate was similar among the two groups. The respiratory rate and complications were inferior in the AECOPD group treated with HFNC.

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.

Respiratory Care Management of COPD Exacerbations

A COPD exacerbation is characterized by an increase in symptoms such as dyspnea, cough, and sputum production that worsens over a period of 2 weeks. Exacerbations are common. Respiratory therapists and physicians in an acute care setting often treat these patients. Targeted O2 therapy improves outcomes and should be titrated to an SpO2 of 88-92%. Arterial blood gases remain the standard approach to assessing gas exchange in patients with COPD exacerbation. The limitations of arterial blood gas surrogates (pulse oximetry, capnography, transcutaneous monitoring, peripheral venous blood gases) should be appreciated so that they can be used wisely. Inhaled short-acting bronchodilators can be provided by nebulizer (jet or mesh), pressurized metered-dose inhaler (pMDI), pMDI with spacer or valved holding chamber, soft mist inhaler, or dry powder inhaler. The available evidence for the use of heliox for COPD exacerbation is weak. Noninvasive ventilation (NIV) is standard therapy for patients who present with COPD exacerbation and is supported by clinical practice guidelines. Robust high-level evidence with patient important outcomes is lacking for the use of high-flow nasal cannula in patients with COPD exacerbation. Management of auto-PEEP is the priority in mechanically ventilated patients with COPD. This is achieved by reducing airway resistance and decreasing minute ventilation. Trigger asynchrony and cycle asynchrony are addressed to improve patient-ventilator interaction. Patients with COPD should be extubated to NIV. Additional high-level evidence is needed before widespread use of extracorporeal CO2 removal. Care coordination can improve the effectiveness of care for patients with COPD exacerbation. Evidence-based practices improve outcomes in patients with COPD exacerbation.

Comparison of High Flow Nasal Therapy with Non-Invasive Ventilation and Conventional Oxygen Therapy for Acute Hypercapnic Respiratory Failure: A Meta-Analysis of Randomized Controlled Trials

Purpose

We aimed to evaluate whether high flow nasal cannula (HFNC) is an effective and safe method for adult patients with acute hypercapnic respiratory failure (AHRF).

Methods

We searched the Cochrane Library, Embase, and PubMed databases from inception to August 2022 to obtain randomized controlled trials (RCTs) that compared HFNC with conventional oxygen treatment (COT) or non-invasive ventilation (NIV) in patients with AHRF, and then performed a meta-analysis.

Results

A total of ten parallel RCTs with 1265 individuals were identified. Of them, two studies compared HFNC with COT and eight studies compared HFNC with NIV. In terms of intubation rate, mortality, and arterial blood gas (ABG) improvement, HFNC showed comparable effects to NIV and COT. However, HFNC was more comfortable (mean difference [MD] -1.87, 95% confidence interval [CI] =-2.59, -1.15, P <0.00001, I² =0%) and resulted in fewer adverse events (odds ratio [OR] 0.12, 95% CI=0.06, 0.28, P<0.00001, I² = 0%), compared with NIV. In comparison to NIV, HFNC could significantly lower heart rate (HR) (MD -4.66, 95% CI=-6.82, -2.50, P <0.0001, I² =0%), respiratory rate (RR) (MD -1.17, 95% CI=-2.03, -0.31, P =0.008, I² =0%), and hospital stay length (MD -0.80, 95% CI=-1.44, -0.16, P =0.01, I² =0%). NIV showed a decreased frequency in the treatment crossover rate, compared with HFNC in patients with pH<7.30 (OR 5.78, 95% CI=1.50, 22.31, P = 0.01, I²: not applicable). Contrary to COT, HFNC could considerably reduce the need for NIV (OR 0.57, 95% CI=0.35, 0.91, P=0.02, I²=0%).

Conclusion

HFNC was effective and safe in patients with AHRF. However, in patients with pH <7.30, HFNC may result in a higher incidence of treatment crossover, compared with NIV. Compared to COT, HFNC may decrease the need for NIV in patients with compensated hypercapnia.

High-Flow Nasal Cannula versus Noninvasive Ventilation in AECOPD Patients with Respiratory Acidosis: A Retrospective Propensity Score-Matched Study

Background

Limited data are available about the clinical outcomes of AECOPD patients with respiratory acidosis treated with HFNC versus NIV.

Methods

We conducted a retrospective study to compare the efficacy of HFNC with NIV as initial ventilation support strategy in AECOPD patients with respiratory acidosis. Propensity score matching (PSM) was implemented to increase between-group comparability. Kaplan-Meier analysis was utilized to evaluate differences between the HFNC success, HFNC failure, and NIV groups. Univariate analysis was performed to identify the features that differed significantly between the HFNC success and HFNC failure groups.

Results

After screening 2219 hospitalization records, 44 patients from the HFNC group and 44 from the NIV group were successfully matched after PSM. The 30-day mortality (4.5% versus 6.8%, p = 0.645) and 90-day mortality (4.5% versus 11.4%, p = 0.237) did not differ between the HFNC and NIV groups. Length of ICU stay (median: 11 versus 18 days, p = 0.001), length of hospital stay (median: 14 versus 20 days, p = 0.001), and hospital cost (median: 4392 versus 8403 $USD, p = 0.001) were significantly lower in the HFNC group compared with NIV group. The treatment failure rate was much higher in the HFNC group than in the NIV group (38.6% versus 11.4%, p = 0.003). However, patients who experienced HFNC failure and switched to NIV showed similar clinical outcomes to those who first received NIV. Univariate analysis showed that log NT-proBNP was an important factor for HFNC failure (p = 0.007).

Conclusions

Compared with NIV, HFNC followed by NIV as rescue therapy may be a viable initial ventilation support strategy for AECOPD patients with respiratory acidosis. NT-proBNP may be an important factor for HFNC failure in these patients. Further well-designed randomized controlled trials are needed for more accurate and reliable results.

High-Flow Nasal Therapy in Acute and Chronic Respiratory Failure: Past, Present, and Future

High-flow nasal therapy (HFNT) was introduced into clinical practice in the early 2000s as a form of noninvasive respiratory support (NIRS) [...]

The use of high-flow nasal cannula in patients with chronic obstructive pulmonary disease under exacerbation and stable phases: A systematic review and meta-analysis

BACKGROUND

High-flow nasal cannula (HFNC) has been increasingly utilized in patients with chronic obstructive pulmonary disease (COPD); however, the effects on reducing the need for intubation or reintubation remain unclear.

OBJECTIVES

We aimed to investigate whether HFNC therapy was superior to conventional oxygen therapy (COT) or noninvasive ventilation (NIV) in patients with COPD.

METHODS

A literature search was performed in electronic databases until October 1st, 2022. The primary outcome was the need for intubation/reintubation. All analyses were performed using R (version 4.0.3) and STATA SE (version 15.1).

RESULTS

When HFNC therapy was compared with NIV in patients with COPD under initial respiratory support and postextubation, no significant differences were found in the risk of intubation (RR 0.84, 95% CI 0.36 to 1.98) and reintubation (RR 1.35, 95% CI 0.73 to 2.50). Compared to NIV, HFNC therapy did not decrease the partial pressure of carbon dioxide or increase the partial pressure of oxygen to the fraction of inspired oxygen. However, HFNC therapy was associated with a lower incidence of skin breakdown (RR 0.52, 95% CI 0.39 to 0.69) and a higher comfort score (SMD 0.90, 95% CI 0.60 to 1.20) than NIV. When HFNC therapy was compared with COT during initial respiratory treatment for COPD exacerbation, a lower risk of treatment failure was found (RR 0.58, 95% CI 0.37 to 0.89). When HFNC therapy was compared with long-term oxygen therapy, quality of life (measured by SGRQ-C) was significantly improved (SMD -0.42, 95% CI -0.69 to -0.14).

CONCLUSION

HFNC therapy might be used as an alternative to NIV for COPD exacerbation with mild-moderate hypercapnia under close monitoring and is a potential domiciliary treatment for stable COPD.

Noninvasive positive pressure in acute exacerbations of chronic obstructive pulmonary disease

PURPOSE OF REVIEW

Noninvasive positive pressure ventilation (NIV) is standard of care for patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD). We review the most current evidence and highlight areas of uncertainty and ongoing research. We highlight key concepts for the clinician caring for patients with AECOPD which require NIV.

RECENT FINDINGS

Implementation of NIV in AECOPD is not uniform in spite of the evidence and guidelines. Initiation of NIV should be done early and following protocols. Low-intensity NIV remains the standard of care, although research and guidelines are evaluating higher intensity NIV. Scores to predict NIV failure continue to be refined to allow early identification and interventions. Several areas of uncertainty remain, among them are interventions to improve tolerance, length of support and titration and nutritional support during NIV.

SUMMARY

The use of NIV in AECOPD is the standard of care as it has demonstrated benefits in several patient-centered outcomes. Current developments and research is related to the implementation and adjustment of NIV.

High-Flow Nasal Cannula Oxygen Therapy versus Non-Invasive Ventilation in AIDS Patients with Acute Respiratory Failure: A Randomized Controlled Trial

BACKGROUND

Acute respiratory failure (ARF) remains the most common diagnosis for intensive care unit (ICU) admission in acquired immunodeficiency syndrome (AIDS) patients.

METHODS

We conducted a single-center, prospective, open-labeled, randomized controlled trial at the ICU, Beijing Ditan Hospital, China. AIDS patients with ARF were enrolled and randomly assigned in a 1:1 ratio to receive either high-flow nasal cannula (HFNC) oxygen therapy or non-invasive ventilation (NIV) immediately after randomization. The primary outcome was the need for endotracheal intubation on day 28.

RESULTS

120 AIDS patients were enrolled and 56 patients in the HFNC group and 57 patients in the NIV group after secondary exclusion. Pneumocystis pneumonia (PCP) was the main etiology for ARF (94.7%). The intubation rates on day 28 were similar to HFNC and NIV (28.6% vs. 35.1%, p = 0.457). Kaplan-Meier curves showed no statistical difference in cumulative intubation rates between the two groups (log-rank test 0.401, p = 0.527). The number of airway care interventions in the HFNC group was fewer than in the NIV group (6 (5-7) vs. 8 (6-9), p < 0.001). The rate of intolerance in the HFNC group was lower than in the NIV group (1.8% vs. 14.0%, p = 0.032). The VAS scores of device discomfort in the HFNC group were lower than that in the NIV group at 2 h (4 (4-5) vs. 5 (4-7), p = 0.042) and at 24 h (4 (3-4) vs. 4 (3-6), p = 0.036). The respiratory rate in the HFNC group was lower than that in the NIV group at 24 h (25 ± 4/min vs. 27 ± 5/min, p = 0.041).

CONCLUSIONS

Among AIDS patients with ARF, there was no statistical significance of the intubation rate between HFNC and NIV. HFNC had better tolerance and device comfort, fewer airway care interventions, and a lower respiratory rate than NIV.

CLINICAL TRIAL NUMBER

Chictr.org (ChiCTR1900022241).

Monitoring the patient-ventilator asynchrony during non-invasive ventilation

Patient-ventilator asynchrony is a major issue during non-invasive ventilation and may lead to discomfort and treatment failure. Therefore, the identification and prompt management of asynchronies are of paramount importance during non-invasive ventilation (NIV), in both pediatric and adult populations. In this review, we first define the different forms of asynchronies, their classification, and the method of quantification. We, therefore, describe the technique to properly detect patient-ventilator asynchronies during NIV in pediatric and adult patients with acute respiratory failure, separately. Then, we describe the actions that can be implemented in an attempt to reduce the occurrence of asynchronies, including the use of non-conventional modes of ventilation. In the end, we analyzed what the literature reports on the impact of asynchronies on the clinical outcomes of infants, children, and adults.

Highlights del 55.° Congreso SEPAR

The 55th SEPAR Congress was held in Pamplona from 2 to 4 of June 2022. Once again, it was the referral scientific meeting for specialists in pulmonology, thoracic surgery, nursing, physiotherapy, paediatric respiratory diseases and other disciplines involved in respiratory care. The Spanish Society of Pulmonology and Thoracic Surgery showed its national and international leadership in the management of respiratory diseases, which was reflected in a program with an excellent content and a high scientific level. In this review, we offer a summary of some notable aspects covered in six selected areas of interest: pulmonary vascular diseases, non-invasive mechanical ventilation and sleep disorders, asthma, chronic obstructive pulmonary disease (COPD), interstitial lung diseases (ILD), and interventional pulmonolgy and lung transplant.

High-flow nasal cannula therapy with sequential noninvasive ventilation versus noninvasive ventilation alone as the initial ventilatory strategy in acute COPD exacerbations: study protocol for a randomized controlled trial

BACKGROUND

Noninvasive ventilation (NIV) is the recommended mode of ventilation used in acute respiratory failure secondary to an acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Recent data has shown that high-flow nasal cannula (HFNC) treatment can be an alternative for patients with hypercapnic respiratory failure. The purpose of this study is to evaluate HFNC with sequential NIV versus NIV alone as the initial ventilatory strategy in AECOPD.

METHODS

This investigator-initiated, unblinded, single center, randomized controlled trial will be conducted in the emergency department, emergency intensive care unit, or respiratory intensive care unit of a tertiary-care urban teaching hospital. A total of 66 patients will be enrolled and randomized into the intervention group (HFNC with sequential NIV) or the control group (NIV group). The primary endpoint will be the mean difference in PaCO₂ from baseline to 24 h after randomization. Secondary endpoints include the mean difference in PaCO₂ from baseline to 6, 12, and 18 h, as well as the dyspnea score, overall discomfort score, rate of treatment failure, respiratory rate, rate of endotracheal intubation, length of hospital stay, and mortality.

DISCUSSION

Taking the advantages of both HFNC and NIV on AECOPD patients into account, we designed this clinical trial to investigate the combination of these ventilatory strategies. This trial will help us understand how HFNC with sequential NIV compares to NIV alone in treating AECOPD patients.

TRIAL REGISTRATION

ChiCTR2100054809.

Long-Term Domiciliary High-Flow Nasal Therapy in Patients with Bronchiectasis: A Preliminary Retrospective Observational Case-Control Study

High-flow nasal therapy (HFNT) provides several pathophysiological benefits in chronic respiratory disorders. We aimed to evaluate the effectiveness of long-term HFNT in patients with bronchiectasis (BE).

METHODS

This is a retrospective bicentric case-control study of outpatients with BE on optimized medical treatment with a severe exacerbation requiring hospitalization in the previous year. Patients on long-term home HFNT (cases) and patients on optimized medical treatment alone (controls) were matched by age, sex, bronchiectasis severity index, and exacerbations in the previous year. Data on BE exacerbations, hospitalizations/year, mucus features, respiratory symptoms, and pulmonary function were collected. The primary outcome was the change from baseline in the exacerbation rates at 12 months between groups.

RESULTS

20 patients in the HFNT group and 20 controls were included. A significant reduction in exacerbations [-1.9 (-2.8 to -0.9), p = 0.0005] and hospitalizations [-0.7 (-1.1 to -0.3), p = 0.0006] was found in the HFNT group vs controls. A slight improvement in pulmonary function [FEV₁% +6,1% (+1% to +11.3%) (p = 0.0219), FVC% +4.6% (+0.8% to +8.3%) (p = 0.0188) and FEF_25-75% +13.4 (+11 to +15.9) (p = 0.0189) was also found in the HFNT group compared to controls.

CONCLUSIONS

In this preliminary study, long-term domiciliary HFNT improved the clinical course of patients with BE.

Greek Guidelines for the Management of COPD, a Proposal of a Holistic Approach Based on the needs of the Greek Community

Despite that COPD remains one of the most common respiratory diseases worldwide, it can be managed effectively with certain treatments and, more importantly, be prevented by the early implementation of various measures. The pathology and pathophysiology of this disease continue to be studied, with new pharmacological and invasive therapies emerging. In this consensus paper, the Working Group of the Hellenic Thoracic Society aimed to consolidate the up-to-date information and new advances in the treatment of COPD. Local and international data on its prevalence are presented, with revised strategies on the diagnostic approach and the evaluation of risk assessment and disease severity classification. Emphasis is placed on the management and therapy of patients with COPD, covering both common principles, specialized modalities, and algorithms to distinguish between home care and the need for hospitalization. Although pharmacological treatment is commonly recognized in COPD, an integrative approach of pulmonary rehabilitation, physical activity, patient education, and self-assessment should be encountered for a comprehensive treatment, prevention of exacerbations, and increased quality of life in patients.

High-flow nasal cannula versus non-invasive ventilation for acute hypercapnic respiratory failure in adults: a systematic review and meta-analysis of randomized trials

Background

Non-invasive ventilation (NIV) with bi-level positive pressure ventilation is a first-line intervention for selected patients with acute hypercapnic respiratory failure. Compared to conventional oxygen therapy, NIV may reduce endotracheal intubation, death, and intensive care unit length of stay (LOS), but its use is often limited by patient tolerance and treatment failure. High-flow nasal cannula (HFNC) is a potential alternative treatment in this patient population and may be better tolerated.

Research question

For patients presenting with acute hypercapnic respiratory failure, is HFNC an effective alternative to NIV in reducing the need for intubation?

Methods

We searched EMBASE, MEDLINE, and the Cochrane library from database inception through to October 2021 for randomized clinical trials (RCT) of adults with acute hypercapnic respiratory failure assigned to receive HFNC or NIV. The Cochrane risk-of-bias tool for randomized trials was used to assess risk of bias. We calculated pooled relative risks (RR) for dichotomous outcomes and mean differences (MD) for continuous outcomes, with corresponding 95% confidence intervals (CI) using a random-effects model.

Results

We included eight RCTs (n = 528) in the final analysis. The use of HFNC compared to NIV did not reduce the risk of our primary outcome of mortality (RR 0.86, 95% CI 0.48–1.56, low certainty), or our secondary outcomes including endotracheal intubation (RR 0.80, 95% CI 0.46–1.39, low certainty), or hospital LOS (MD − 0.82 days, 95% CI − 1.83–0.20, high certainty). There was no difference in change in partial pressure of carbon dioxide between groups (MD − 1.87 mmHg, 95% CI − 5.34–1.60, moderate certainty).

Interpretation

The current body of evidence is limited in determining whether HFNC may be either superior, inferior, or equivalent to NIV for patients with acute hypercapnic respiratory failure given imprecision and study heterogeneity. Further studies are needed to better understand the effect of HFNC on this population.

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.

High-flow nasal cannula oxygen therapy for admitted COPD-patients. A retrospective cohort study

BACKGROUND

The use of High-flow nasal cannula (HFNC) is increasing in admitted COPD-patients and could provide a step in between non-invasive ventilation (NIV) and standard oxygen supply. Recent studies demonstrated that HFNC is capable of facilitating secretion removal and reduce the work of breathing. Therefore, it might be of advantage in the treatment of acute exacerbations of COPD (AECOPD). No randomized trials have assessed this for admitted COPD-patients on a regular ward and only limited data from non-randomized studies is available.

OBJECTIVES

The aim of our study was to identify the reasons to initiate treatment with HFNC in a group of COPD-patients during an exacerbation, further identify those most likely to benefit from HFNC treatment and to find factors associated with treatment success on the pulmonary ward.

MATERIAL AND METHODS

This retrospective study included COPD-patients admitted to the pulmonary ward and treated with HFNC from April 2016 until April 2019. Only patients admitted with severe acute exacerbations were included. Patients who had an indication for NIV-treatment where treated with NIV and were included only if they subsequently needed HFNC, e.g. when they did not tolerate NIV. Known asthma patients were excluded.

RESULTS

A total of 173 patients were included. Stasis of sputum was the indication most reported to initiate HFNC-treatment. Treatment was well tolerated in 83% of the patients. Cardiac and vascular co-morbidities were significantly associated with a smaller chance of successful treatment (Respectively OR = 0.435; p = 0.013 and OR = 0.493;p = 0.035). Clinical assessment judged HFNC-treatment to be successful in 61% of the patients. Furthermore, in-hospital treatment with NIV was associated with a higher chance of HFNC failure afterwards (OR = 0.439; p = 0.045).

CONCLUSION

This large retrospective study showed that HFNC-treatment in patients with an AECOPD was initiated most often for sputum stasis as primary reason. Factors associated with improved outcomes of HFNC-treatment was the absence of vascular and/or cardiac co-morbidities and no need for in-hospital NIV-treatment.

Acute and long-term management of severe bronchiectasis with high flow nasal therapy: A case report

Bronchiectasis (BE) is a long-term, chronic lung condition featured by widened and scarred airways. These can alter the physiological mucociliary clearance, making it difficult to clear mucus and microorganisms, leading to frequent exacerbations. High flow nasal therapy (HFNT) is a noninvasive respiratory support that delivers heated and humidified gas eventually enriched with oxygen, through a nasal cannula.  Humidification is crucial for adequate airways mucociliary clearance, improving ciliary function and consequently reducing airways inflammation and recurrent infections. HFNT has been mostly used in patients with acute hypoxemic respiratory failure and in selected patients with chronic respiratory failure due to COPD. Still, evidence about its use in acute and long-term home setting in patients with clinically relevant BE are lacking. We report a case of severe widespread BE, already on top medical therapy and pulmonary rehabilitation, still suffering from difficult mucus expectoration and recurrent exacerbations, who has been additionally treated with HFNT, both in hospital and domiciliary, reporting significant improvements on relevant clinical and patient-centered outcomes. Thus, HFNT may confer additional benefits as an add-on treatment of patients with severe BE and respiratory failure.

High-Flow Nasal Cannula Oxygen Therapy versus Non-Invasive Ventilation for AECOPD Patients After Extubation: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objective

To evaluate the clinical efficacy of high-flow nasal oxygen therapy (HFNC) and non-invasive ventilation (NIV) in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) after extubation.

Research Methods

This systematic review and meta-analysis was conducted following the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA) statements. The primary outcome measures analyzed included: reintubation rate, mortality, complication rate, and ICU length of stay.

Results

Eight studies were included, with a total of 612 subjects, including 297 in the HFNC group and 315 in the NIV group. The effect of HFNC and NIV on the reintubation rate of AECOPD patients after extubation, RR (1.49 [95% CI,0.95 to 2.33], P = 0.082). Subgroup analysis with or without hypercapnia according to the included AECOPD population, with hypercapnia, RR (0.69 [95% CI,0.33 to 1.44], P=0.317), without hypercapnia, RR (2.61 [95% CI,1.41 to 4.83], P=0.002). Mortality, RR (0.92 [95% CI,0.56 to 1.52], P = 0.752). ICU length of stay, MD (−0.44 [95% CI,-1.01 to 0.13], P = 0.132). Complication rate, RR (0.22 [95% CI,0.13 to 0.39], P = 0.000). After subgroup analysis, the reintubation rate of HFNC and NIV has no statistical difference in patients with hypercapnia, but NIV can significantly reduce the reintubation rate in patients without hypercapnia. In the outcome measures of complication rate, HFNC significantly reduced complication rate compared with NIV. In mortality and ICU length of stay, analysis results showed that HFNC and NIV were not statistically different.

Conclusion

According to the available evidence, the application of HFNC can be used as an alternative treatment for NIV after extubation in AECOPD patients with hypercapnia, but in the patients without hypercapnia, HFNC is less effective than NIV.

Effect of High-Flow Nasal Cannula Therapy vs Continuous Positive Airway Pressure Therapy on Liberation From Respiratory Support in Acutely Ill Children Admitted to Pediatric Critical Care Units: A Randomized Clinical Trial

IMPORTANCE

The optimal first-line mode of noninvasive respiratory support for acutely ill children is not known.

OBJECTIVE

To evaluate the noninferiority of high-flow nasal cannula therapy (HFNC) as the first-line mode of noninvasive respiratory support for acute illness, compared with continuous positive airway pressure (CPAP), for time to liberation from all forms of respiratory support.

DESIGN, SETTING, AND PARTICIPANTS

Pragmatic, multicenter, randomized noninferiority clinical trial conducted in 24 pediatric critical care units in the United Kingdom among 600 acutely ill children aged 0 to 15 years who were clinically assessed to require noninvasive respiratory support, recruited between August 2019 and November 2021, with last follow-up completed in March 2022.

INTERVENTIONS

Patients were randomized 1:1 to commence either HFNC at a flow rate based on patient weight (n = 301) or CPAP of 7 to 8 cm H2O (n = 299).

MAIN OUTCOMES AND MEASURES

The primary outcome was time from randomization to liberation from respiratory support, defined as the start of a 48-hour period during which a participant was free from all forms of respiratory support (invasive or noninvasive), assessed against a noninferiority margin of an adjusted hazard ratio of 0.75. Seven secondary outcomes were assessed, including mortality at critical care unit discharge, intubation within 48 hours, and use of sedation.

RESULTS

Of the 600 randomized children, consent was not obtained for 5 (HFNC: 1; CPAP: 4) and respiratory support was not started in 22 (HFNC: 5; CPAP: 17); 573 children (HFNC: 295; CPAP: 278) were included in the primary analysis (median age, 9 months; 226 girls [39%]). The median time to liberation in the HFNC group was 52.9 hours (95% CI, 46.0-60.9 hours) vs 47.9 hours (95% CI, 40.5-55.7 hours) in the CPAP group (absolute difference, 5.0 hours [95% CI -10.1 to 17.4 hours]; adjusted hazard ratio 1.03 [1-sided 97.5% CI, 0.86-∞]). This met the criterion for noninferiority. Of the 7 prespecified secondary outcomes, 3 were significantly lower in the HFNC group: use of sedation (27.7% vs 37%; adjusted odds ratio, 0.59 [95% CI, 0.39-0.88]); mean duration of critical care stay (5 days vs 7.4 days; adjusted mean difference, -3 days [95% CI, -5.1 to -1 days]); and mean duration of acute hospital stay (13.8 days vs 19.5 days; adjusted mean difference, -7.6 days [95% CI, -13.2 to -1.9 days]). The most common adverse event was nasal trauma (HFNC: 6/295 [2.0%]; CPAP: 18/278 [6.5%]).

CONCLUSIONS AND RELEVANCE

Among acutely ill children clinically assessed to require noninvasive respiratory support in a pediatric critical care unit, HFNC compared with CPAP met the criterion for noninferiority for time to liberation from respiratory support.

TRIAL REGISTRATION

ISRCTN.org Identifier: ISRCTN60048867.

Use of high flow nasal cannula in patients with acute respiratory failure in general wards under intensivists supervision: a single center observational study

BACKGROUND

Few data exist on high flow nasal cannula (HFNC) use in patients with acute respiratory failure (ARF) admitted to general wards.

RATIONALE AND OBJECTIVES

To retrospectively evaluate feasibility and safety of HFNC in general wards under the intensivist-supervision and after specific training.

METHODS

Patients with ARF (dyspnea, respiratory rate-RR > 25/min, 150 < PaO₂/FiO₂ < 300 mmHg during oxygen therapy) admitted to nine wards of an academic hospital were included. Gas-exchange, RR, and comfort were assessed before HFNC and after 2 and 24 h of application.

RESULTS

150 patients (81 male, age 74 [60-80] years, SOFA 4 [2-4]), 123 with de-novo ARF underwent HFNC with flow 60 L/min [50-60], FiO₂ 50% [36-50] and temperature 34 °C [31-37]. HFNC was applied a total of 1399 days, with a median duration of 7 [3-11] days. No major adverse events or deaths were reported. HFNC did not affect gas exchange but reduced RR (25-22/min at 2-24 h, p < 0.001), and improved Dyspnea Borg Scale (3-1, p < 0.001) and comfort (3-4, p < 0.001) after 24 h. HFNC failed in 20 patients (19.2%): 3 (2.9%) for intolerance, 14 (13.4%) escalated to NIV/CPAP in the ward, 3 (2.9%) transferred to ICU. Among these, one continued HFNC, while the other 2 were intubated and they both died. Predictors of HFNC failure were higher Charlson's Comorbidity Index (OR 1.29 [1.07-1.55]; p = 0.004), higher APACHE II Score (OR 1.59 [1.09-4.17]; p = 0.003), and cardiac failure as cause of ARF (OR 5.26 [1.36-20.46]; p = 0.02).

CONCLUSION

In patients with mild-moderate ARF admitted to general wards, the use of HFNC after an initial training and daily supervision by intensivists was feasible and seemed safe. HFNC was effective in improving comfort, dyspnea, and respiratory rate without effects on gas exchanges. Trial registration This is a single-centre, noninterventional, retrospective analysis of clinical data.

High-flow nasal cannula versus conventional oxygen therapy in acute COPD exacerbation with mild hypercapnia: a multicenter randomized controlled trial

Background

High-flow nasal cannula (HFNC) can improve ventilatory function in patients with acute COPD exacerbation. However, its effect on clinical outcomes remains uncertain.

Methods

This randomized controlled trial was conducted from July 2017 to December 2020 in 16 tertiary hospitals in China. Patients with acute COPD exacerbation with mild hypercapnia (pH ≥ 7.35 and arterial partial pressure of carbon dioxide > 45 mmHg) were randomly assigned to either HFNC or conventional oxygen therapy. The primary outcome was the proportion of patients who met the criteria for intubation during hospitalization. Secondary outcomes included treatment failure (intolerance and need for non-invasive or invasive ventilation), length of hospital stay, hospital cost, mortality, and readmission at day 90.

Results

Among 337 randomized patients (median age, 70.0 years; 280 men [83.1%]; median pH 7.399; arterial partial pressure of carbon dioxide 51 mmHg), 330 completed the trial. 4/158 patients on HFNC and 1/172 patient on conventional oxygen therapy met the criteria for intubation (P = 0.198). Patients progressed to NPPV in both groups were comparable (15 [9.5%] in the HFNC group vs. 22 [12.8%] in the conventional oxygen therapy group; P = 0.343). Compared with conventional oxygen therapy, HFNC yielded a significantly longer median length of hospital stay (9.0 [interquartile range, 7.0–13.0] vs. 8.0 [interquartile range, 7.0–11.0] days) and a higher median hospital cost (approximately $2298 [interquartile range, $1613–$3782] vs. $2005 [interquartile range, $1439–$2968]). There were no significant differences in other secondary outcomes between groups.

Conclusions

In this multi-center randomized controlled study, HFNC compared to conventional oxygen therapy did not reduce need for intubation among acute COPD exacerbation patients with mild hypercapnia. The future studies should focus on patients with acute COPD exacerbation with respiratory acidosis (pH < 7.35). However, because the primary outcome rate was well below expected, the study was underpowered to show a meaningful difference between the two treatment groups.

Trial registration: NCT03003559. Registered on December 28, 2016.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-03973-7.

Noninvasive Oxygenation in Patients with Acute Respiratory Failure: Current Perspectives

Purpose of Review

High-flow nasal oxygen and noninvasive ventilation are two alternative strategies to standard oxygen in the management of acute respiratory failure.

Discussion

Although high-flow nasal oxygen has gained major popularity in ICUs due to its simplicity of application, good comfort for patients, efficiency in improving oxygenation and promising results in patients with acute hypoxemic respiratory failure, further large clinical trials are needed to confirm its superiority over standard oxygen. Non-invasive ventilation may have deleterious effects, especially in patients exerting strong inspiratory efforts, and no current recommendations support its use in this setting. Protective non-invasive ventilation using higher levels of positive-end expiratory pressure, more prolonged sessions and other interfaces such as the helmet may have beneficial physiological effects leading to it being proposed as alternative to high-flow nasal oxygen in acute hypoxemic respiratory failure. By contrast, non-invasive ventilation is the first-line strategy of oxygenation in patients with acute exacerbation of chronic lung disease, while high-flow nasal oxygen could be an alternative to non-invasive ventilation after partial reversal of respiratory acidosis. Questions remain about the target populations and non-invasive oxygen strategy representing the best alternative to standard oxygen in acute hypoxemic respiratory failure. As concerns acute on-chronic-respiratory failure, the place of high-flow nasal oxygen remains to be evaluated.

Research Progress on Diaphragm Ultrasound in Chronic Obstructive Pulmonary Disease: A Narrative Review

Chronic obstructive pulmonary disease (COPD) is a common disease of the respiratory system, and its prevalence and mortality remain high. COPD results in continuous impairment of lung function, which severely affects the patient's work and life. In severe cases, there will be acute respiratory failure, which endangers the lives of patients, and respiratory muscle dysfunction is one of the main reasons for this result. As the diaphragm is the most important inspiratory muscle, its dysfunction has a great impact on the deterioration of respiratory function in COPD patients. With the development of ultrasound, more and more studies have found that diaphragm ultrasound can play an important role in the diagnosis and treatment of COPD patients. The main purpose of this article is to review the research progress on diaphragm ultrasound in COPD and briefly introduce diaphragmatic ultrasound examination methods.

Current Practice of High Flow through Nasal Cannula in Exacerbated COPD Patients

Acute Exacerbation of Chronic Obstructive Pulmonary Disease is a form of severe Acute Respiratory Failure (ARF) requiring Conventional Oxygen Therapy (COT) in the case of absence of acidosis or the application of Non-Invasive Ventilation (NIV) in case of respiratory acidosis. In the last decade, High Flow through Nasal Cannula (HFNC) has been increasingly used, mainly in patients with hypoxemic ARF. However, some studies were also published in AECOPD patients, and some evidence emerged. In this review, after describing the mechanism underlying potential clinical benefits, we analyzed the possible clinical application of HFNC to AECOPD patients. In the case of respiratory acidosis, the gold-standard treatment remains NIV, supported by strong evidence in favor. However, HFNC may be considered as an alternative to NIV if the latter fails for intolerance. HFNC should also be considered and preferred to COT at NIV breaks and weaning. Finally, HFNC should also be preferred to COT as first-line oxygen treatment in AECOPD patients without respiratory acidosis.

[Translated article] Spanish COPD Guidelines (GesEPOC) 2021 Update. Diagnosis and Treatment of COPD Exacerbation Syndrome

This article details the GesEPOC 2021 recommendations on the diagnosis and treatment of COPD exacerbation syndrome (CES). The guidelines propose a definition-based syndromic approach, a new classification of severity, and the recognition of different treatable traits (TT), representing a new step toward personalized medicine. The evidence is evaluated using GRADE methodology, with the incorporation of 6 new PICO questions. The diagnostic process comprises four stages: 1) establish a diagnosis of CES, 2) assess the severity of the episode, 3) identify the trigger, and 4) address TTs. This diagnostic process differentiates an outpatient approach, that recommends the inclusion of a basic battery of tests, from a more comprehensive hospital approach, that includes the study of different biomarkers and imaging tests. Bronchodilator treatment for immediate relief of symptoms is considered essential for all patients, while the use of antibiotics, systemic corticosteroids, oxygen therapy, and assisted ventilation and the treatment of comorbidities will vary depending on severity and possible TTs. The use of antibiotics will be indicated particularly if sputum color changes, when ventilatory assistance is required, in cases involving pneumonia, and in patients with elevated C-reactive protein (≥ 20 mg/L). Systemic corticosteroids are recommended in CES that requires admission and are suggested in moderate CES. These drugs are more effective in patients with blood eosinophil counts ≥ 300 cells/mm3. Acute-phase non-invasive mechanical ventilation is specified primarily for patients with CES who develop respiratory acidosis despite initial treatment.

Nasal high-flow compared to non-invasive ventilation in treatment of acute acidotic hypercapnic exacerbation of chronic obstructive pulmonary disease-protocol for a randomized controlled noninferiority trial (ELVIS)

Background

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) have a major negative impact on health status, rates of hospitalization, readmission, disease progression and mortality. Non-invasive ventilation (NIV) is the standard therapy for hypercapnic acidotic respiratory failure in AECOPD. Despite its beneficial effects, NIV is often poorly tolerated (11–34 % failure rate). An increasing number of studies have documented a beneficial effect of nasal high-flow (NHF) in acute hypercapnia. We designed a prospective, randomized, multi-centre, open label, non-inferiority trial to compare treatment failure in nasal NHF vs NIV in patients with acidotic hypercapnic AECOPD.

Methods

The study will be conducted in about 35 sites in Germany. Patients with hypercapnic AECOPD with respiratory acidosis (pH < 7.35) will be randomized 1:1 to NIV or NHF. The primary outcome is the combined endpoint of intubation, treatment failure or death at 72 h. The switch from one to the other device marks a device failure but acts as a rescue treatment in absence of intubation criteria. A sample size of 720 was calculated to have 80% power for showing that NHF is non-inferior to NIV with a margin of 8 percentage points. Linear regression will be used for the confirmatory analysis.

Discussion

If NHF is shown to be non-inferior to NIV in acidotic hypercapnic AECOPD, it could become an important alternative treatment.

Trial registration

ClinicalTrials.gov, NCT04881409, Registered on May 11, 2021

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05978-z.

Application of pulmonary rehabilitation in patients with pulmonary embolism (Review)

As a common clinical emergency, pulmonary embolism (PE) is the third most fatal cardiovascular disease worldwide. Although current sophisticated medical technology has considerably improved the prognosis of patients with PE, they remain at risk of developing long-term complications such as post-PE syndrome. Pulmonary rehabilitation is of great value for patients with chronic lung diseases since it can improve their quality of life while also relieving clinical symptoms. Rehabilitation therapy has been demonstrated to improve recovery and prognosis of patients with PE. Due to short implementation time and the small number of studies, its effectiveness and safety in PE warrant further investigation. The present review focused on elucidating PE pathogenesis, post-PE syndrome and the clinical application of pulmonary rehabilitation in patients with PE.

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.

β Agonist Delivery by High-Flow Nasal Cannula During COPD Exacerbation: A Prospective Physiological Study

BACKGROUND

Whereas high-flow nasal cannula (HFNC) oxygen therapy is increasingly used in patients with exacerbation of COPD, the effectiveness of β ₂ agonist nebulization through HFNC has been poorly assessed. We hypothesized that salbutamol vibrating-mesh nebulization through HFNC improves pulmonary function tests in subjects with COPD.

METHODS

We conducted a physiological crossover study including subjects admitted to the ICU for severe exacerbation of COPD. After subject improvement allowing a 3-h washout period without bronchodilator, pulmonary function tests were performed while breathing through HFNC alone and after salbutamol vibrating-mesh nebulization through HFNC. The primary end point consisted in the changes in FEV₁ before and after salbutamol nebulization. Secondary end points included the changes in FVC, peak expiratory flow (PEF), airway resistance, and clinical parameters.

RESULTS

Among the 15 subjects included, mean (SD) FEV₁ significantly increased after salbutamol nebulization from 931 mL (383) to 1,019 (432), mean difference +87 mL (95% CI 30-145) (P = .006). Similarly, FVC and PEF significantly increased, +174 mL (95% CI 66-282) (P = .004) and +0.3 L/min (95% CI 0-0.6) (P = .037), respectively. Airway resistances and breathing frequency did not significantly differ, whereas heart rate significantly increased after nebulization.

CONCLUSIONS

In subjects with severe exacerbation of COPD, salbutamol vibrating-mesh nebulization through HFNC induced a significant bronchodilator effect with volume and flow improvement.

Effects of high-flow nasal oxygen cannula versus other noninvasive ventilation in extubated patients: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

A systematic review and meta-analysis were performed to compare the effects of high-flow nasal oxygen cannula (HFNC) and noninvasive ventilation (NIV) in extubated patients with respiratory insufficiency.

METHODS

The Cochrane Library, PubMed, and ClinicalTrials.gov were searched from inception to 28 February 2021, to identify randomized controlled trials. The primary outcome was reintubation within 24-72 hours after a planned extubation. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated.

RESULTS

Six articles with1746 patients were included. The effect of HFNC on the reintubation rate was noninferior to that of NIV (OR = 1.11, 95% CI: 0.85-1.44). The rate of treatment failure was 20.40% with HFNC versus 20.92% with NIV; this difference was nonsignificant (OR = 0.97, 95% CI: 0.72-1.32, P = 0.85). HFNC reduced the rates of skin lesion occurrence (10.28% versus 23.82%, OR = 0.37, 95% CI: 0.26-0.53, P < 0.00001) and post-extubation respiratory failure (23.76% versus 25.56%, OR = 0.64, 95% CI: 0.46-0.88, P = 0.006), compared with NIV.

CONCLUSIONS

In extubated patients, HFNC was noninferior to NIV in the rate of reintubation and treatment failure. Compared with NIV, HFNC decreased the occurrence of skin lesions and post-extubation respiratory failure.