High-flow nasal cannula oxygen therapy as an emerging option for respiratory failure: the present and the future

Palliative Care and Noninvasive Ventilation

Palliative care is important for many patients who require noninvasive ventilation. The particular needs of patients with neuromuscular disease and chronic obstructive pulmonary disease are explored. Advance care planning is explored with tips for undertaking this important communication task. Brief comments regarding symptom burden, weaning, voluntary assisted dying, and self-care are included.

Efficacy and safety of high-flow nasal cannula therapy in elderly patients with acute respiratory failure

INTRODUCTION

To assess the efficacy and safety of high-flow nasal cannula (HFNC) in elderly patients with acute respiratory failure (ARF) not due to COVID-19, refractory to treatment with conventional oxygen therapy and/or intolerant to noninvasive ventilation (NIV) or continuous positive airway pressure (CPAP) and without criteria for admission to intensive care units (ICU).

METHODS

Prospective observational study of patients with ARF treated with HFNC who presented clinical and arterial blood gas deterioration after 24 h of medical treatment and oxygenation by conventional systems. The degree of dyspnoea, gas exchange parameters (arterial O2 pressure/inspired O2 fraction ratio (PaO2/FiO2); oxygen saturation measured by oximetry/ inspired fraction of oxygen (Sp02/Fi02), ROX index), degree of patient tolerance and mortality were evaluated. These were measured at discharge from the emergency department (ED), 24 h after treatment with conventional oxygenation and 60, 120 min and 24 h after initiation of HFNC. The results were analyzed for all patients as a whole and for patients with hypercapnia (arterial carbon dioxide tension (PaCO2) < 45 mmHg) separately.

RESULTS

200 patients were included in the study between November 2019 and November 2020, with a mean age of 83 years, predominantly women (61.9%), obese (Body Mass Index (BMI) 31.1), with high comorbidity (Charlson index 4) and mild-moderate degree of dependence (Barthel 60). A number of 128 patients (64%) were hypercapnic. None had respiratory acidosis (pH 7.39). Evaluation at 60 min, 120 min and 24 h showed significant improvement in all patients and in the subgroup of hypercapnic patients with respect to baseline parameters in respiratory rate (RR), dyspnoea, ROX index, PaO2/FiO2, SpO2/FiO2 and patient comfort. No changes in PaCO2 or level of consciousness were observed. HFNC was well tolerated. Ten patients (5%) died due to progression of the disease causing ARF.

CONCLUSIONS

HFNC is an effective and safe alternative in elderly patients with ARF not due to COVID-19, refractory to treatment with conventional oxygen therapy and/or intolerant to NIV or CPAP and without criteria for admission to ICU.

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 Cannula System in Respiratory Failure Associated with Interstitial Lung Diseases: A Systematic Review and Narrative Synthesis

Background: High-flow nasal cannula (HFNC) therapy has emerged as a promising treatment modality for interstitial lung disease (ILD)-related respiratory failure. This systematic review aims to evaluate the efficacy and safety of HFNC therapy in patients with ILDs. Methods: A comprehensive literature search was conducted using major electronic databases to identify relevant studies investigating the use of HFNC therapy in ILD patients with respiratory failure. Outcome measures of interest included improvements in oxygenation, dyspnea relief, respiratory rate control, hospital length of stay, and mortality. Results: Twelve studies were analyzed with an overall population of 715 patients included. Idiopathic Pulmonary Fibrosis (IPF) was the most prevalent type of ILD. Evaluated clinical settings were acute (7 studies), chronic (2 studies), and end-stage (3 studies) ILDs. The HFNC as a support for acute respiratory failure seems not inferior to non-invasive ventilation while offering better comfort and patient's perception. Poor data are available about use in chronic/long-term or rehabilitative settings. In end of life/palliative care, an HFNC might improve quality of life. Despite the promising results, further research is warranted to establish optimal HFNC protocols, identify patient subgroups most likely to benefit, and explore long-term outcomes. Conclusions: Overall, the HFNC appears to be a valuable therapeutic option for managing respiratory failure in ILD patients, offering potential improvements in oxygenation and symptom relief.

Peripheral nervous system and neuromuscular disorders in the emergency department: A review

INTRODUCTION

Acute presentations and emergencies in neuromuscular disorders (NMDs) often challenge clinical acumen. The objective of this review is to refine the reader's approach to history taking, clinical localization and early diagnosis, as well as emergency management of neuromuscular emergencies.

METHODS

An extensive literature search was performed to identify relevant studies. We prioritized meta-analysis, systematic reviews, and position statements where possible to inform any recommendations.

SUMMARY

The spectrum of clinical presentations and etiologies ranges from neurotoxic envenomation or infection to autoimmune disease such as Guillain-Barré Syndrome (GBS) and myasthenia gravis (MG). Delayed diagnosis is not uncommon when presentations occur "de novo," respiratory failure is dominant or isolated, or in the case of atypical scenarios such as GBS variants, severe autonomic dysfunction, or rhabdomyolysis. Diseases of the central nervous system, systemic and musculoskeletal disorders can mimic presentations in neuromuscular disorders.

CONCLUSIONS

Fortunately, early diagnosis and management can improve prognosis. This article provides a comprehensive review of acute presentations in neuromuscular disorders relevant for the emergency physician.

High-Flow Nasal Cannula Oxygen Therapy in the Management of Respiratory Failure: A Review

High-flow nasal cannula (HFNC) oxygen therapy is gaining traction globally as a treatment for respiratory failure. There are several physiological benefits, and there is a growing body of evidence showing improved quality of life and patient comfort with HFNC, both in acute and home settings. Due to the increased burden of long-term respiratory conditions such as chronic obstructive pulmonary disease (COPD) on healthcare systems worldwide, the role of ward-based and post-discharge interventions in the prevention of hospital readmissions is an area of increasing interest. In this narrative review, we outline the physiological effects of HFNC and assess its applications in both the hospital and home settings for acute and chronic respiratory failure. We also consider the evidence of non-invasive ventilation (NIV) versus HFNC in the hospital setting and the application of HFNC at home in stable hypercapnic respiratory failure to improve the quality of life and prevent readmissions. We also look at applications of HFNC in specific circumstances, such as the perioperative period, emergency department, and acute (mainly critical care) setting including in immunocompromised patients and palliative care.

High-Flow Oxygen Therapy in the Perioperative Setting and Procedural Sedation: A Review of Current Evidence

High-flow oxygen therapy (HFOT) is a respiratory support system, through which high flows of humidified and heated gas are delivered to hypoxemic patients. Several mechanisms explain how HFOT improves arterial blood gases and enhances patients' comfort. Some mechanisms are well understood, but others are still unclear and under investigation. HFOT is an interesting oxygen-delivery modality in perioperative medicine that has many clinical applications in the intensive care unit (ICU) and the operating room (OR). The purpose of this article was to review the literature for a comprehensive understanding of HFOT in the perioperative period, as well as its uses in procedural sedation. This review will focus on the HFOT definition, its physiological benefits, and their mechanisms, its clinical uses in anesthesia, and when it is contraindicated.

Effect of modified high-flow oxygen therapy on positive end-expiratory pressure and end-expiratory lung volume based on simulated lung platform

Objective

The aim of this study was to assess the effect of modified high-flow oxygen therapy on end-expiratory lung volume (EELV) and positive end-expiratory pressure (PEEP) in tracheotomized patients with normal pulmonary, acute hypoxic respiratory failure (AHRF) or chronic obstructive pulmonary disease (COPD).

Methods

A ventilator and an artificial lung model were used to simulate the normal or strong inspiratory effort state of normal lung, AHRF and COPD patients. The traditional high-flow respiratory humidification therapy device connected with a standard interface (group A), and the modified therapy device added two types of resistance valves (group B, inner diameter 7.7 mm, length 24.0 mm; group C, inner diameter 7.7 mm, length 34.0 mm) to the exhalation end of the standard interface. The changes of end-expiratory lung volume (ΔEELV) and PEEP with the increase of flow rate (10 L/min, 20 L/min, 30 L/min, 40 L/min, 50 L/min, 60 L/min) in the three groups was recorded.

Results

Under simulated conditions of normal lung, AHRF and COPD, as the flow rate increased by using the modified therapy device, the PEEP values in all groups showed an exponential increasing trend, and the ΔEELV also increased accordingly. In addition, under the same flow rate level, the PEEP values of the two modified high-flow oxygen therapies (Group B and Group C) were significantly higher than those of the standard high-flow oxygen therapy (Group A) (p < 0.05). In the normal lung model with normal or strong inspiratory effort, and in the AHRF or COPD model with strong inspiratory effort, when the flow rate was higher than 30 L/min, the PEEP levels of Group B were significantly lower than those of Group C (p < 0.05). In the AHRF model with normal inspiratory effort, when the flow rate was between 10 L/min and 60 L/min, the PEEP levels of Group B were significantly lower than those of Group C (p < 0.05). Moreover, in the COPD model with normal inspiratory effort, the PEEP levels of Group B were significantly lower than that of Group C only when the flow rate was 60 L/min (p < 0.05).

Conclusion

The addition of different types of resistance valves to the high-flow exhalation end may be a feasible solution to improve the clinical efficacy of tracheotomized high-flow oxygen therapy.

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.

Nocturnal nasal high-flow oxygen therapy in elderly patients with concomitant chronic obstructive pulmonary disease and obstructive sleep apnea

PURPOSE

The coexistence of obstructive sleep apnea (OSA) and chronic obstructive pulmonary disease (COPD) is known as "overlap syndrome" (OS). Patients with OS are usually older than patients with OSA alone, suffer from more profound oxygen desaturation during the obstructive events often accompanied by sustained nocturnal hypoventilation. Although oxygen-enriched positive airway pressure (PAP) is the treatment of choice in these patients, this therapy is often poorly tolerated particularly by the elderly. The aim of this study was to assess the usefulness of nocturnal oxygen therapy via nasal high flow (NHF-OT) as a possible alternative to PAP in patients with OS.

METHODS

Patients > 65 years old with OS and nocturnal respiratory failure (time spent below SaO2 90% (T90) > 30%) had cardio-respiratory monitoring performed at baseline, during NHF-OT, or during conventional oxygen therapy (COT).

RESULTS

A total of 40 patients were enrolled in the study. NHF-OT significantly reduced the apnea-hypopnea index (AHI) in all patients compared to baseline and COT. The mean basal AHI was 25.4 ± 8.6. During COT and NHF-OT, the AHI was 19.4 ± 7 and 5.4 ± 4.6, respectively (P < 0.001) and 19 patients reached an AHI < 5 during NHF-OT. The mean nocturnal SaO2% was 86.2 ± 2.6 at baseline and at equivalent FiO2 it significantly increased to 91.8 ± 2.4 during COT and to 93.9 ± 2.5 during NHF-OT (P < 0.001). The T90% was 48.7 ± 20.1 at baseline, 16.8 ± 11.7 during COT, and 8.8 ± 8.0 during NHF-OT (P < 0.001).

CONCLUSIONS

In elderly patients with OS, nocturnal treatment with NHF-OT significantly reduces obstructive episodes and improves oxygenation. As the treatment is generally well tolerated compared to PAP, NHF-OT may be a possible alternative therapy in this subgroup of patients.

Tube or tubeless: an anesthetic strategy for upper airway surgery

Since the patient's airway is shared between an anesthesiologist and a surgeon, airway management during upper airway surgery can be challenging. Beyond the conventional method of general anesthesia, high-flow nasal oxygenation (HFNO) has recently been used as a key technique for tubeless anesthesia. HFNO provides humidified, heated oxygen up to 70 L/min, which promises improved oxygenation and ventilation, allowing for prolonged apneic oxygenation. In previous physiological and clinical studies, HFNO has been demonstrated that tubeless anesthesia safely provide an uninterrupted surgical field during laryngeal surgeries. Although tubeless anesthesia remains uncommon, it can be a good alternative to conventional anesthesia if an anesthesiologist and a surgeon select appropriate patients together with sufficient experience. A safe strategy for tubeless anesthesia, along with appropriate backup plans, including endotracheal intubation and high-frequency jet ventilation, should be considered for upper airway surgery.

The efficacy of high-flow nasal cannula (HFNC) versus non-invasive ventilation (NIV) in patients at high risk of extubation failure: a systematic review and meta-analysis

BACKGROUND

Studies suggest that high-flow nasal cannula (HFNC) and non-invasive ventilation (NIV) can prevent reintubation in critically ill patients with a low risk of extubation failure. However, the safety and effectiveness in patients at high risk of extubation failure are still debated. Therefore, we conducted a systematic review and meta-analysis to compare the efficacies of HFNC and NIV in high-risk patients.

METHODS

We searched eight databases (MEDLINE, Cochrane Library, EMBASE, CINAHL Complete, Web of Science, China National Knowledge Infrastructure, Wan-Fang Database, and Chinese Biological Medical Database) with reintubation as a primary outcome measure. The secondary outcomes included mortality, intensive care unit (ICU) length of stay (LOS), incidence of adverse events, and respiratory function indices. Statistical data analysis was performed using RevMan software.

RESULTS

Thirteen randomized clinical trials (RCTs) with 1457 patients were included. The HFNC and NIV groups showed no differences in reintubation (RR 1.10, 95% CI 0.87-1.40, I² = 0%, P = 0.42), mortality (RR 1.09, 95% CI 0.82-1.46, I² = 0%, P = 0.54), and respiratory function indices (partial pressure of carbon dioxide [PaCO₂]: MD - 1.31, 95% CI - 2.76-0.13, I² = 81%, P = 0.07; oxygenation index [P/F]: MD - 2.18, 95% CI - 8.49-4.13, I² = 57%, P = 0.50; respiratory rate [Rr]: MD - 0.50, 95% CI - 1.88-0.88, I² = 80%, P = 0.47). However, HFNC reduced adverse events (abdominal distension: RR 0.09, 95% CI 0.04-0.24, I² = 0%, P < 0.01; aspiration: RR 0.30, 95% CI 0.09-1.07, I² = 0%, P = 0.06; facial injury: RR 0.27, 95% CI 0.09-0.88, I² = 0%, P = 0.03; delirium: RR 0.30, 95%CI 0.07-1.39, I² = 0%, P = 0.12; pulmonary complications: RR 0.67, 95% CI 0.46-0.99, I² = 0%, P = 0.05; intolerance: RR 0.22, 95% CI 0.08-0.57, I² = 0%, P < 0.01) and may have shortened LOS (MD - 1.03, 95% CI - 1.86-- 0.20, I² = 93%, P = 0.02). Subgroup analysis by language, extubation method, NIV parameter settings, and HFNC flow rate revealed higher heterogeneity in LOS, PaCO₂, and Rr.

CONCLUSIONS

In adult patients at a high risk of extubation failure, HFNC reduced the incidence of adverse events but did not affect reintubation and mortality. Consequently, whether or not HFNC can reduce LOS and improve respiratory function remains inconclusive.

The Danish respiratory society guideline for long-term high flow nasal cannula treatment, with or without supplementary oxygen

Introduction

Long-term High Flow Nasal Cannula (LT-HFNC), defined as High Flow Nasal Cannula treatment provided to patients with chronic pulmonary conditions during stable phases, has emerged as a home treatment in different categories of patients with chronic lung diseases in recent years.

Methods

This paper summarizes the physiological effects of LT-HFNC and evaluates the clinical knowledge to date about treatment in patients with chronic obstructive lung disease, interstitial lung disease and bronchiectasis. The guideline is translated and summarized in this paper and presented unabridged as an appendix to the paper.

Results

The paper describes the working process behind the Danish Respiratory Society's National guideline for treatment of stable disease, which has been written to support clinicians in both evidence-based decision making and practical issues concerning the treatment.

High flow nasal cannula therapy in the pediatric home setting

BACKGROUND

High-flow nasal cannula (HFNC) therapy may be better tolerated than traditional noninvasive ventilation (NIV) and is rapidly gaining acceptance in pediatric acute care. In Israel, HFNC is approved for domestic use. We aim to describe its indications, efficacy, parental satisfaction, and safety.

METHODS

Retrospective study of children treated with home HFNC therapy in three pediatric centers. Data included demographic parameters, indication of use, weight and days of hospitalization before and after initiation. Safety, tolerability, and parental satisfaction were assessed via standardized telephone questionnaire.

RESULTS

Median (interquartile range [IQR]) age of initiating home HFNC in 75 children was 8.3 (2.2, 29.6) months. Indications were obstructive sleep apnea (33; 44%), airway malacia (19; 25%), chronic lung disease (15; 20%), neuromuscular disease (4; 5%), and postextubation support (4; 5%). Weight standard deviation score rose from -2.3 pre-HFNC to -1.7 at 6.7 months post-HFNC initiation, p < 0.001. Hospital admission days during the 2 months pre- versus post-HFNC initiation were 22 (5.5, 60) and 5 (0, 14.7) respectively, p < 0.008. Median (IQR) parental satisfaction score was 5/5 (4, 5). Fifty of 60 (83%) respondents would recommend home HFNC to other families in a similar situation. There were no serious adverse events.

CONCLUSION

In our population, domestic HFNC appeared safe and well tolerated for a variety of indications. Its introduction was associated with improved weight gain, fewer hospitalization days and high parental satisfaction. Further work is required to characterize groups of children most likely to benefit from HFNC, as opposed to traditional modes of NIV.

[The role of the physiotherapist in the assessment and management of dyspnea]

The role of the physiotherapist in the assessment and management of dyspnea. Dyspnea is the most common symptom in cardio-respiratory diseases. Recently improved comprehension of dyspnea mechanisms have underlined the need for three-faceted assessment. The three key aspects correspond to the "breathing, thinking, functioning" clinical model, which proposes a multidimensional - respiratory, emotional and functional - approach. Before initiating treatment, it is essential for several reasons to assess each specific case, determining the type of dyspnea affecting the patient, appraising the impact of shortness of breath, and estimating the effectiveness of the treatment applied. The physiotherapist has a major role to assume in the care of dyspneic patients, not only in assessment followed by treatment but also as a major collaborator in a multidisciplinary team, especially with regard to pulmonary rehabilitation. The aim of this review is to inventory the existing assessment tools and the possible physiotherapies for dyspnea, using a holistic approach designed to facilitate the choice of techniques and to improve quality of care by fully addressing the patient's needs.

Clinical review of high-flow nasal oxygen therapy in human and veterinary patients

Oxygen therapy is the first-line treatment for hypoxemic acute respiratory failure. In veterinary medicine this has traditionally been provided via mask, low-flow nasal oxygen cannulas, oxygen cages and invasive positive pressure ventilation. Traditional non-invasive modalities are limited by the maximum flow rate and fraction of inspired oxygen (FiO₂) that can be delivered, variability in oxygen delivery and patient compliance. The invasive techniques are able to provide higher FiO₂ in a more predictable manner but are limited by sedation/anesthesia requirements, potential complications and cost. High-flow nasal oxygen therapy (HFNOT) represents an alternative to conventional oxygen therapy. This modality delivers heated and humidified medical gas at adjustable flow rates, up to 60 L/min, and FiO₂, up to 100%, via nasal cannulas. It has been proposed that HFNOT improves pulmonary mechanics and reduces respiratory fatigue via reduction of anatomical dead space, provision of low-level positive end-expiratory pressure (PEEP), provision of constant FiO₂ at rates corresponding to patient requirements and through improved patient tolerance. Investigations into the use of HFNOT in veterinary patients have increased in frequency since its clinical use was first reported in dogs with acute respiratory failure in 2016. Current indications in dogs include acute respiratory failure associated with pulmonary parenchymal disease, upper airway obstruction and carbon monoxide intoxication. The use of HFNOT has also been advocated in certain conditions in cats and foals. HFNOT is also being used with increasing frequency in the treatment of a widening range of conditions in humans. Although there remains conflict regarding its use and efficacy in some patient groups, overall these reports indicate that HFNOT decreases breathing frequency and work of breathing and reduces the need for escalation of respiratory support. In addition, they provide insight into potential future veterinary applications. Complications of HFNOT have been rarely reported in humans and animals. These are usually self-limiting and typically result in lower morbidity and mortality than those associated with invasive ventilation techniques.

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.

An Analysis of the Effect of Noninvasive Positive Pressure Ventilation on Patients with Respiratory Failure Complicated by Diabetes Mellitus

Objective

To observe the clinical effectiveness of noninvasive positive pressure ventilation in patients with respiratory failure complicated by diabetes.

Methods

From May 2021 to May 2022, 90 patients with respiratory failure complicated by diabetes treated in our hospital were recruited and randomly assigned to receive either medication (control group) or noninvasive positive pressure ventilation (study group), with 45 patients in each group. The clinical endpoint was therapeutic outcomes.

Results

Noninvasive positive pressure ventilation resulted in significantly lower Self-Rating Anxiety Scale (SAS) and Self-Rating Depression Scale (SDS) scores versus medications (P < 0.05). Patients with noninvasive positive pressure ventilation showed better pulmonary function indices versus those with medications (P > 0.05). There was no significant difference in arterial oxygen (PaO₂), carbon dioxide partial pressure (PaCO₂), and arterial oxygen pressure/inspired fraction of O₂ (PaO₂/FiO₂) between the two groups prior to the intervention (P > 0.05). However, patients in the study group had significantly elevated PaO₂ and PaO₂/FiO₂ and lower PaCO₂ levels than those in the control group (P < 0.05). Following the intervention, noninvasive positive pressure ventilation resulted in significantly lower inflammatory factor levels versus medications (P > 0.05). After the intervention, markedly better glucose control was observed in the study group versus the control group (P < 0.05). The incidence of complications in the control group was 2.38%, which was significantly lower than that of the control group (16.67) (P < 0.05).

Conclusion

Noninvasive positive pressure ventilation effectively suppresses the inflammatory response, improves the blood gas analysis index, and eliminates the negative emotions of patients, thereby maintaining hemodynamic stability and improving clinical efficacy with a better safety profile. Further studies are recommended prior to clinical promotion.

The impact of an autonomous nurse-led high-flow nasal cannula oxygen protocol on clinical outcomes of infants with bronchiolitis

OBJECTIVE

To investigate the relationship of the implementation of a nurse-led high-flow nasal cannula oxygen protocol on the clinical outcomes of infants with bronchiolitis in a regional paediatric unit.

BACKGROUND

Bronchiolitis is a common lower respiratory illness and is the leading cause for hospitalisation of infants globally. Standard care involves the provision of supportive measures. Historically, supplemental oxygen was provided by low-flow nasal cannula. High-flow nasal cannula oxygen has been increasingly adopted despite limited evidence of its efficacy.

METHODS

This study employed non-equivalent, post-implementation only design to explore clinical outcomes of infants with bronchiolitis admitted for high-flow nasal cannula oxygen therapy. The study compared infants in the 24 months before and after the initiation of a high-flow nasal cannula protocol. The primary clinical outcome was length of stay, secondary outcomes included time on high flow, weaning time, escalation of care and time outside of physiological parameters. Implementation strategy evaluation was measured by compliance with applying the protocol, reported as episodes of variance, and duration of variance. The StaRI checklist was selected as the most appropriate reporting guideline.

RESULTS

A total of 80 patients were admitted with bronchiolitis and received high-flow nasal cannula oxygen therapy during a 48-month period; 37 patients were prior, and 43 after, the introduction of a nurse-led high-flow nasal cannula protocol. Length of stay was significantly reduced in the post-implementation group compared to the historical control group (83.8 vs. 61.3 h). Time on high flow and weaning time was decreased in the post-implementation group compared to the control group (33.5 vs. 26.7 h and 26 vs.12.25 h, respectively); however, these did not reach statistical significance. There was varied application of the HFNC protocol.

CONCLUSIONS

The implementation of a nurse-led high-flow nasal cannula protocol was associated with a reduced length of stay.

RELEVANCE TO CLINICAL PRACTICE

This study demonstrated that infants with bronchiolitis that were treated with a nurse-led high-flow nasal cannula (HFNC) therapy protocol had positive effects on clinical outcomes including a shorter length of stay than compared with those with physician-directed care in a regional paediatric unit. A weight-based (2 L/kg) HFNC therapy was safely administered to infants with bronchiolitis in a regional hospital paediatric ward with no paediatric intensive care unit (PICU).

Effect of humidified high-flow nasal cannula oxygen therapy on respiratory function recovery in stable COPD patients

OBJECTIVE

To investigate the effect of humidified high-flow nasal cannula oxygen therapy (HFNC) on the application effect and respiratory functional recovery of stable COPD patients.

METHODS

The data of 116 patients with stable COPD treated in our hospital from March 2019 to January 2021 were analyzed retrospectively. Among them, 54 patients treated with conventional oxygen therapy (COT) were enrolled into the control group (CG), and the remaining 62 treated with HFNC were divided to the experimental group (EG). The clinical efficacy and adverse reactions of both groups were assessed, and the blood gas analysis indexes pH, PaO₂, PaCO₂, respiratory function indexes FEV1, FEV1%, FEV1/FVC, quality of life and motor recovery were compared.

RESULTS

After treatment, compared with the CG, the FEV1, FEV1% and FEV1/FVC in the EG were obviously higher (P<0.05). Besides, the pH and PaO₂ in the EG were markedly higher (P<0.05), while PaCO₂ was lower (P<0.05). The total effective rate, SGRQ scores and 6MWT in the EG were markedly higher than those in the CG (P<0.05), while the incidence of adverse reactions in the EG was lower (P<0.05).

CONCLUSION

HFNC can improve respiratory function and quality of life of stable COPD patients, with higher safety.

High-Flow Nasal Cannula Oxygen Therapy: Physiological Mechanisms and Clinical Applications in Children

High-flow nasal cannula (HFNC) oxygen therapy has rapidly become a popular modality of respiratory support in pediatric care. This is undoubtedly due to its ease of use and safety, which allows it to be used in a wide variety of settings, ranging from pediatric intensive care to patients' homes. HFNC devices make it possible to regulate gas flow and temperature, as well as allowing some nebulized drugs to be administered, features very useful in children, in which the balance between therapeutic effectiveness and adherence to treatment is pivotal. Although the physiological effects of HFNC are still under investigation, their mechanisms of action include delivery of fixed concentration of oxygen, generation of positive end-expiratory pressure, reduction of the work of breathing and clearance of the nasopharyngeal dead space, while providing optimal gas conditioning. Nevertheless, current evidence supports the use of HFNC mainly in moderate-to-severe bronchiolitis, whereas for asthma exacerbations and breath sleeping disorders there is a lack of randomized controlled trials comparing HFNC to continuous positive airway pressure (CPAP) and non-invasive ventilation (NIV), which are essentials for the identification of response and non-response predictors. In this regard, the development of clinical guidelines for HFNC, including flow settings, indications, and contraindications is urgently needed.

Meta-analysis comparing the efficiency of high-flow nasal cannula versus low-flow nasal cannula in patients undergoing endoscopic retrograde cholangiopancreatography

Endoscopic retrograde cholangiopancreatography (ERCP) identifies and treats pancreatic and biliary diseases. We conducted a systematic review and meta-analysis examining relevant papers in five databases to examine the frequency of hypoxia throughout the surgery and the lowest oxygen saturation level in patients under sedation. Our meta-analysis included three randomized controlled trials with 390 participants, 196 in the high-flow oxygen (HFNC) group and 194 in the low-flow oxygen (LFNC) group. Their ages ranged from 65.3 to 79 years. The pooled effect estimate showed that HFNC decreased the incidence of hypoxia during the procedure when compared to LFNC (odds ratio -0.84; 95% confidence interval [CI] -1.65, -0.02; P = 0.04), and the mean of lowest oxygen saturation in patients during sedation was significantly lower in LFNC compared to HFNC (mean difference 2.34; 95% CI 1.35, 3.32; P = 0.001). The pooled effect estimate showed that the HFNC group had a lower incidence rate of jaw thrusting adverse events during anesthesia than the LFNC group (risk difference -0.12; 95% CI -0.21, -0.04; P = 0.001). In summary, HFNC systems reduced the incidence of hypoxia for patients undergoing ERCP and had a higher mean lowest oxygen saturation during sedation.

High-Flow vs. Low-Flow Nasal Cannula in Reducing Hypoxemic Events During Bronchoscopic Procedures: A Systematic Review and Meta-Analysis

Introduction

High-flow nasal cannula (HFNC) oxygenation method has been proven to be successful in oxygenation of patients with respiratory failure and has exhibited clinical superiority compared to low-flow nasal cannula (LFNC).

Methods

We performed a systematic review and meta-analysis to evaluate the potential favorable impact of HFNC oxygenation during bronchoscopy and related procedures like endobronchial ultrasound-transbronchial needle aspiration. Only randomized control trials (RCTs) were included in the meta-analysis.

Results

Six randomized control trials with 1,170 patients were included in this meta-analysis. Patients who underwent bronchoscopy with the use of high-flow nasal cannula experienced less hypoxemic events/desaturations, less procedural interruptions and pneumothoraxes compared to patients under low-flow nasal cannula treatment. This beneficial effect of HFNC in hypoxemic events was persistent 10 min after the end of procedure.

Conclusion

The high-flow nasal cannula (HFNC) oxygenation method could reduce hypoxemic events and related peri- and post-bronchoscopic complications.

Non-invasive Respiratory Support in COVID-19: A Narrative Review

Acute respiratory failure secondary to COVID-19 pneumonia may require a variety of non-pharmacological strategies in addition to oxygen therapy to avoid endotracheal intubation. The response to all these strategies, which include high nasal flow, continuous positive pressure, non-invasive ventilation, or even prone positioning in awake patients, can be highly variable depending on the predominant phenotypic involvement. Deciding when to replace conventional oxygen therapy with non-invasive respiratory support, which to choose, the role of combined methods, definitions, and attitudes toward treatment failure, and improved case improvement procedures are directly relevant clinical questions for the daily care of critically ill COVID-19 patients. The experience accumulated after more than a year of the pandemic should lead to developing recommendations that give answers to all these questions.

Nasal high flow oxygen therapy during acute admissions or periods of worsening symptoms

PURPOSE OF REVIEW

Nasal high flow therapy (NHF) is increasingly used in acute care settings. In this review, we consider recent advances in the utilization of NHF in chronic obstructive pulmonary disease (COPD), terminal cancer and symptom management. Considerations around NHF use during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic are also discussed.

RECENT FINDINGS

NHF enables humidification and high flows to be provided together with titrated, supplemental oxygen therapy. Compared to conventional oxygen therapy, NHF improves respiratory physiology by reducing workload, enhancing muco-ciliary clearance and improving dead space washout. Some studies suggest that early use of NHF in people being cared for in the emergency department leads to lower rates of invasive ventilation and noninvasive ventilation. There is also emerging evidence for NHF use in people with COPD and chronic respiratory failure, and in palliative care. NHF is comfortable, well-tolerated and safe for use in the management of breathlessness in people with cancer. NHF can be delivered by face mask to patients with SARS-CoV-2 infection, to ease the burden on critical care resources.

SUMMARY

The evidence base for NHF is rapidly growing and offers promise in relieving troublesome symptoms and for people receiving palliative care.

The efficacy and safety of high-flow nasal cannula therapy in patients with COPD and type II respiratory failure: a meta-analysis and systematic review

Background

High-flow nasal cannula (HFNC) and noninvasive ventilation (NIV) have been used for the treatment of COPD and respiratory failure in clinical settings. We aimed to evaluate the efficacy and safety of HFNC therapy in patients with COPD and type II respiratory failure, to provide evidence to the clinical COPD management.

Methods

We searched Cochrane et al. databases up to Dec 31, 2020 for randomized controlled trials (RCTs) on the use of HFNC therapy in patients with COPD and type II respiratory failure. Two researchers independently screened the literature according to the inclusion and exclusion criteria, and evaluated the quality of the literature and extracted data. We used Revman5.3 software for statistical analysis of collected data.

Results

A total of 6 RCTs involving 525 COPD and type II respiratory failure patients. Meta-analyses indicated that compared with NIV, HFNC could significantly reduce PaCO₂ level (MD = − 2.64, 95% CI (− 3.12 to − 2.15)), length of hospital stay ((MD = – 1.19, 95 CI (− 2.23 to − 0.05)), the incidence of nasal facial skin breakdown ((OR = 0.11, 95% CI (0.03–0.41)). And there were no significant differences between the two groups in PaO₂ ((MD = 2.92, 95% CI (− 0.05 to 5.90)), incidence of tracheal intubation ((OR = 0.74, 95% CI (0.34–1.59)) and mortality (OR = 0.77, 95% CI (0.28–2.11)).

Conclusions

HFNC is more advantageous over NIV in the treatment of COPD and type II respiratory failure. Future studies with larger sample size and strict design are needed to further elucidate the role of HFNC in COPD and respiratory failure.

Bronchoscopy during COVID-19 pandemic, ventilatory strategies and procedure measures

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has changed bronchoscopy practices worldwide. Bronchoscopy is a high-risk aerosol-generating procedure with a potential for direct SARS-CoV-2 exposure and hospital-acquired infection. Current guidelines about personal protective equipment and environment considerations represent key competencies to minimize droplets dispersion and reduce the risk of transmission. Different measures should be put in field based on setting, patient's clinical characteristics, urgency and indications of bronchoscopy. The use of this technique in SARS-CoV-2 patients is reported primarily for removal of airway plugs and for obtaining microbiological culture samples. In mechanically ventilated patients with SARS-CoV-2, bronchoscopy is commonly used to manage complications such as hemoptysis, atelectasis or lung collapse when prone positioning, physiotherapy or recruitment maneuvers have failed. Further indications are represented by assistance during percutaneous tracheostomy. Continuous positive airway pressure, non-invasive ventilation support and high flow nasal cannula oxygen are frequently used in patient affected by Coronavirus Disease-2019 (COVID-19): management of patients' airways and ventilation strategies differs from bronchoscopy indications, patient's clinical status and in course or required ventilatory support. Sedation is usually administered by the pulmonologist (performing the bronchoscopy) or by the anesthetist depending on the complexity of the procedure and the level of sedation required. Finally, elective bronchoscopy for diagnostic indications during COVID-19 pandemic should be carried on respecting rigid standards which allow to minimize potential viral transmission, independently from patient's COVID-19 status. This narrative review aims to evaluate the indications, procedural measures and ventilatory strategies of bronchoscopy performed in different settings during COVID-19 pandemic.

Effect of sequential high-flow nasal cannula oxygen therapy and non-invasive positive-pressure ventilation in patients with difficult weaning from mechanical ventilation after extubation on respiratory mechanics

Background

Patients with difficult weaning who undergo mechanical ventilation are more likely to be at risk of reintubation and the sequential use of oxygen therapy after extubation is a concern for clinicians. Therefore, the aim of the present study was to compare the effects of transnasal high-flow nasal cannula (HFNC) oxygen therapy and non-invasive positive-pressure ventilation (NIV) on respiratory mechanics in patients with difficult weaning.

Methods

The present study was a single-center, retrospective, observational study. Twenty-nine patients with difficult weaning off invasive mechanical ventilation from the Department of Critical Care Medicine, The First Affiliated Hospital of Guangzhou Medical University, from December 2018 to April 2021, were included. Within 48 h after extubation, alternate respiratory support with HFNC and NIV was provided. Relevant indicators were recorded after each support mode had been maintained for at least 60 min. These included esophageal pressure (Pes), gastric pressure (Pga), transdiaphragmatic pressure (Pdi), pressure-time product of Pes (PTPes), pressure-time product of Pga (PTPga), pressure-time product of Pdi (PTPdi), ratio of the PTPdi to the PTPes (PTPdi/PTPes), and ratio of the Pes to the Pdi (Pes/Pdi), diaphragmatic electromyogram (EMGdi), percentage of esophageal pressure coefficient of variation (CVes%),diaphragmatic electromyogram coefficient of variation (CVEMG),inspiratory time (Ti), expiratory time (Te) and respiratory cycle time (Ttot).

Results

Of the 29 patients included, 22 were males and 7 were females [age: 63.97±15.34 years, Acute Physiological and Chronic Health Estimation II (APACHE II) score: 18.00±5.63]. The CVes% and the Pes/Pdi were significantly higher in patients with NIV than HFNC using 40 L/min, CVes%: 9 (−6, 20) vs. −7 (−23, 6) and Pes/Pdi: 0.17 (−0.1, 0.53), vs. −0.12 (−0.43, 0.08) (P<0.05). The remaining indicators were not statistically different.

Conclusions

The sequential NIV and HFNC can be tolerated in patients with such difficult weaning off mechanical ventilation after extubation, and more patients tend to choose HFNC subjectively. Compared with HFNC, NIV reduces the work of adjunctive respiratory muscle, but the patient’s Pes dispersion is high when NIV is used, and it is necessary to pay attention to patient–ventilator coordination in clinical practice. We recommend alternating HFNC and NIV during the sequential respiratory therapy after extubation.

Impact of Body Mass Index and Initial Respiratory Support on Pediatric Subjects in Acute Respiratory Failure

BACKGROUND

It is unknown how the initial choice of respiratory support by pediatric ICU providers contributes to outcomes of nonintubated obese children with respiratory failure. We hypothesized that body mass index and the type of initial respiratory support applied are associated with poor clinical outcomes in patients who carry respiratory failure-associated diagnoses.

METHODS

This is a retrospective analysis of de-identified patient data obtained from the Virtual PICU System database (2009-2018). We included subjects 2-18 y old who received bi-level positive airway pressure/CPAP or high-flow nasal cannula as the initial respiratory support and were assigned respiratory failure-associated diagnoses (ie, acute hypoxic respiratory failure). The study population was divided into 2 body mass index percentile groups, underweight/healthy weight (< 85th percentile) and overweight/obese (≥ 85th percentile), and subjects were evaluated for the following outcomes: endotracheal intubation requirement, medical and physical PICU length of stay, and mortality scores.

RESULTS

A total of 1,721 subjects were included: 1,091 (63.4%) underweight/healthy weight and 630 (36.6%) overweight/obese. Body mass index percentile was not associated with the initial respiratory support utilized (odds ratio 0.961 [95% CI 0.79-1.17], P = .73). Multivariable logistic regression analysis demonstrated that the odds of requiring endotracheal intubation (odds ratio 1.60 [95% CI 1.10-2.35], P = .02) were significantly higher in overweight/obese subjects initially placed on high-flow nasal cannula. Body mass index and bi-level positive airway pressure/CPAP therapy were both positively associated with medical and physical PICU length of stay, Pediatric Risk of Mortality Score 3 (PRISM3) scores, and Pediatric Index of Mortality 2 (PIM2) scores when separate multivariable models were fit for these 4 response variables.

CONCLUSIONS

The selection of respiratory support may place overweight/obese pediatric patients at higher risk for endotracheal intubation. Due to methodological limitations, we were unable to draw conclusions about the initial approach to the respiratory management of overweight/obese pediatric patients. Further investigation may be warranted.

The effect of high flow nasal oxygen therapy in intensive care units: a systematic review and meta-analysis

BACKGROUND

High flow nasal oxygen (HFNO) therapy has been widely used in intensive care units (ICU); however, its efficacy remains inconclusive. This systematic review and meta-analysis aimed to compare the efficacy of HFNO therapy with th at of alternative noninvasive oxygen therapies such as conventional oxygen therapy (COT) and noninvasive ventilation (NIV) in ICU.

METHODS

A Pubmed, Embase, Web of Science, Cochrane Library database search was performed in March 2020. Results: The meta-analysis ultimately included 17 clinical studies. Compared with the overall effect of COT and NIV, HFNO was associated with a low incidence of pneumonia (95% CI: 0.6-0.99, P = 0.04) and improvement in lowest pulse oxygen saturation (SpO₂) during oxygenation (95% CI: 0.02-1.61; P = 0.04). However, no differences were detected in the following outcomes: length of ICU stay, the rate of intubation or reintubation, mortality at day 28, hospital mortality, and SpO₂ at the end of oxygen therapy (all P > 0.05).

CONCLUSIONS

In adult patients in ICU, HFNO may improve oxygenation and decrease pneumonia rate without affecting the length of ICU stay, intubation or reintubation rate, mortality, and SpO₂ at the end of oxygen therapy.

High flow nasal oxygen for acute type two respiratory failure: a systematic review

Background: Acute type two respiratory failure (AT2RF) is characterized by high carbon dioxide levels (PaCO 2 >6kPa). Non-invasive ventilation (NIV), the current standard of care, has a high failure rate. High flow nasal therapy (HFNT) has potential additional benefits such as CO 2 clearance, the ability to communicate and comfort. The primary aim of this systematic review is to determine whether HFNT in AT2RF improves 1) PaCO 2, 2) clinical and patient-centred outcomes and 3) to assess potential harms. Methods: We searched EMBASE, MEDLINE and CENTRAL  (January 1999-January 2021). Randomised controlled trials (RCTs) and cohort studies comparing HFNT with low flow nasal oxygen (LFO) or NIV were included. Two authors independently assessed studies for eligibility, data extraction and risk of bias. We used Cochrane risk of bias tool for RCTs and Ottawa-Newcastle scale for cohort studies. Results: From 727 publications reviewed, four RCTs and one cohort study (n=425) were included. In three trials of HFNT vs NIV, comparing PaCO 2 (kPa) at last follow-up time point, there was a significant reduction at four hours (1 RCT; HFNT median 6.7, IQR 5.6 - 7.7 vs NIV median 7.6, IQR 6.3 - 9.3) and no significant difference at  24-hours or five days. Comparing HFNT with LFO, there was no significant difference at 30-minutes. There was no difference in intubation or mortality. Conclusions: This review identified a small number of studies with low to very low certainty of evidence. A reduction of PaCO 2 at an early time point of four hours post-intervention was demonstrated in one small RCT. Significant limitations of the included studies were lack of adequately powered outcomes and clinically relevant time-points and small sample size. Accordingly, systematic review cannot recommend the use of HFNT as the initial management strategy for AT2RF and trials adequately powered to detect clinical and patient-relevant outcomes are urgently warranted.

High flow nasal oxygen for acute type two respiratory failure: a systematic review

Background: Acute type two respiratory failure (AT2RF) is characterized by high carbon dioxide levels (PaCO 2 >6kPa). Non-invasive ventilation (NIV), the current standard of care, has a high failure rate. High flow nasal therapy (HFNT) has potential additional benefits such as CO 2 clearance, the ability to communicate and comfort. The primary aim of this systematic review is to determine whether HFNT in AT2RF improves 1) PaCO 2, 2) clinical and patient-centred outcomes and 3) to assess potential harms. Methods: We searched EMBASE, MEDLINE and CENTRAL  (January 1999-January 2021). Randomised controlled trials (RCTs) and cohort studies comparing HFNT with low flow nasal oxygen (LFO) or NIV were included. Two authors independently assessed studies for eligibility, data extraction and risk of bias. We used Cochrane risk of bias tool for RCTs and Ottawa-Newcastle scale for cohort studies. Results: From 727 publications reviewed, four RCTs and one cohort study (n=425) were included. In three trials of HFNT vs NIV, comparing PaCO 2 (kPa) at last follow-up time point, there was a significant reduction at four hours (1 RCT; HFNT median 6.7, IQR 5.6 - 7.7 vs NIV median 7.6, IQR 6.3 - 9.3) and no significant difference at  24-hours or five days. Comparing HFNT with LFO, there was no significant difference at 30-minutes. There was no difference in intubation or mortality. Conclusions: This review identified a small number of studies with low to very low certainty of evidence. A reduction of PaCO 2 at an early time point of four hours post-intervention was demonstrated in one small RCT. Significant limitations of the included studies were lack of adequately powered outcomes and clinically relevant time-points and small sample size. Accordingly, systematic review cannot recommend the use of HFNT as the initial management strategy for AT2RF and trials adequately powered to detect clinical and patient-relevant outcomes are urgently warranted.

Physiological Effects of High-Flow Nasal Cannula Therapy and Its Use in Acute Cardiogenic Pulmonary Edema

High-flow nasal cannula (HFNC) is an open oxygen delivery system, which provides heated and humidified oxygen at a high flow (up to 60 L/min). This effect can improve mucociliary function, airway clearance, and level of comfort to the patient. It can provide controlled and adequate fraction of inspired oxygen (FiO₂) between 21% and 100%. Generation of end-expiratory pressure helps in carbon dioxide washout, reduction of anatomical dead space, and recruitment of collapsed alveoli, ultimately improving tissue oxygenation.

The use of HFNC in acute hypoxemic respiratory failure, post-extubation period, pre-intubation period, respiratory infection, and obstructive airway disease has been extensively studied, but there are very few studies regarding its use in cardiogenic pulmonary edema. This review provides the current understanding of the physiological effect of HFNC and its application in acute cardiogenic pulmonary edema (ACPE). We conducted a literature search on PubMed using appropriate terms and reviewed relevant articles published within the last 10 years. We found that initial therapy with HFNC in ACPE patients can improve oxygenation and respiratory rate. HFNC can potentially be an alternative to non-invasive positive-pressure ventilation in terms of initial oxygen therapy in patients with ACPE. There is a need for larger prospective studies to evaluate and develop guidelines to consider the use of HFNC in patients with ACPE. We also highlight the fact that if there is no improvement in arterial blood gas parameters after HFNC therapy, initiation of invasive ventilation should not be delayed.