The clinical utility of long-term humidification therapy in chronic airway disease

The Role of High Flow Nasal Therapy in Chronic Respiratory Failure

High-flow nasal therapy (HFNT) has an increasing role in the management of acute hypoxic respiratory failure. Due to its tolerable interface and ease of use, its role in chronic hypercapnic respiratory failure (CHRF) is emerging. This article examines the literature to date surrounding the short and long-term mechanisms of HFNT in sleep and wakefulness of CHRF patients. It is likely HFNT will have an increasing role in those patients intolerant of non-invasive ventilation.

Effectiveness, Adherence and Safety of Home High Flow Nasal Cannula in Chronic Respiratory Disease and Respiratory Insufficiency: A Systematic Review

INTRODUCTION

The effectiveness of home high flow nasal cannula (HFNC) for the treatment of chronic respiratory failure in patients with chronic respiratory diseases (CRDs) has not been summarized. We aimed to conduct a systematic review of the effectiveness, adherence, and safety of HFNC in the long-term treatment of patients with chronic respiratory diseases and respiratory failure.

METHODS

A systematic review was conducted. PubMed, Web of science, and SCOPUS were search up to August 2023. Long-term HFNC studies (≥4 weeks) reporting dyspnea; exacerbations, hospitalizations; peripheral oxygen saturation (SpO2), comfort; patient experience, health-related quality of life or partial pressure of carbon dioxide (paCO2) were included.

RESULTS

Thirteen articles (701 patients) based on 10 studies were selected: randomized control trials (n=3), randomized crossover trials (n=2), crossover (n=3) and retrospective (n=2) studies. COPD (n=6), bronchiectasis (n=2), COPD/bronchiectasis (n=1) and ILD (n=1) were the underlined CRDs. HFNC reduced exacerbations when compared to usual care/home respiratory therapies (n=6). Quality of life outcomes were also in favor of HFNC in patients with COPD and bronchiectasis (n=6). HFNC had significant effects on hospitalizations, paCO2, and lung function. Adherence ranged from 5.2 to 8.6h/day (n=5). Three studies reported no events, 3 non-serious events and 2 no differences compared with other home respiratory therapies.

CONCLUSIONS

HFNC seems more effective than usual care or other home respiratory therapies in reducing exacerbations and improving quality of life in patients with COPD and bronchiectasis, while presenting good adherence and being safe. Its apparently superior effectiveness needs to be better studied in future real-world pragmatic trials.

Respiratory support in the emergency department: A systematic review and meta-analysis

BACKGROUND

An estimated 20% of emergency department (ED) patients require respiratory support (RS). Evidence suggests that nasal high flow (NHF) reduces RS need.

AIMS

This review compared NHF to conventional oxygen therapy (COT) or noninvasive ventilation (NIV) in adult ED patients.

METHOD

The systematic review (SR) and meta-analysis (MA) methods reflect the Cochrane Collaboration methodology. Six databases were searched for randomized controlled trials (RCTs) comparing NHF to COT or NIV use in the ED. Three summary estimates were reported: (1) need to escalate care, (2) mortality, and (3) adverse events (AEs).

RESULTS

This SR and MA included 18 RCTs (n = 1874 participants). Two of the five MA conclusions were statistically significant. Compared with COT, NHF reduced the risk of escalation by 45% (RR 0.55; 95% CI [0.33, 0.92], p = .02, NNT = 32); however, no statistically significant differences in risk of mortality (RR 1.02; 95% CI [0.68, 1.54]; p = .91) and AE (RR 0.98; 95% CI [0.61, 1.59]; p = .94) outcomes were found. Compared with NIV, NHF increased the risk of escalation by 60% (RR 1.60; 95% CI [1.10, 2.33]; p = .01); mortality risk was not statistically significant (RR 1.23, 95% CI [0.78, 1.95]; p = .37).

LINKING EVIDENCE TO ACTION

Evidence-based decision-making regarding RS in the ED is challenging. ED clinicians have at times had to rely on non-ED evidence to support their practice. Compared with COT, NHF was seen to be superior and reduced the risk of escalation. Conversely, for this same outcome, NIV was superior to NHF. However, substantial clinical heterogeneity was seen in the NIV delivered. Research considering NHF versus NIV is needed. COVID-19 has exposed the research gaps and slowed the progress of ED research.

[High-flow nasal oxygen therapy and hypercapnic acute respiratory failure]

Humidified high-flow nasal oxygen therapy (HFNO) has, in recent years, come to assume a key role in the management of hypoxemic acute respiratory failure (ARF). While non-invasive ventilation (NIV) currently represents the first-line ventilatory strategy in patients exhibiting hypercapnic ARF, the operating principles and physiological effects of HFNO could be interesting and useful in the initial management of hypercapnic ARF and/or after extubation, particularly in acute exacerbations of chronic obstructive pulmonary disease. Under these conditions, HFNO could be used either alone continuously or in combination with NIV during breaks in spontaneous breathing, depending on the severity and etiology of the underlying hypercapnic ARF.

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.

ERS International Congress 2023: highlights from the Respiratory Intensive Care Assembly

Early career members of Assembly 2 (Respiratory Intensive Care) attended the 2023 European Respiratory Society International Congress in Milan, Italy. The conference covered acute and chronic respiratory failure. Sessions of interest to our assembly members and to those interested in respiratory critical care are summarised in this article and include the latest updates in respiratory intensive care, in particular acute respiratory distress syndrome and mechanical ventilation.

Short-term mediating effects of PM2.5 on climate-associated COPD severity

The impact of short-term exposure to environmental factors such as temperature, relative humidity (RH), and fine particulate matter (PM2.5) on chronic obstructive pulmonary disease (COPD) remains unclear. The objective of this study is to investigate PM2.5 as a mediator in the relationship between short-term variations in RH and temperature and COPD severity. A cross-sectional study was conducted on 930 COPD patients in Taiwan from 2017 to 2022. Lung function, COPD Assessment Test (CAT) score, and modified Medical Research Council (mMRC) dyspnea scale were assessed. The mean and differences in 1-day, 7-day, and 30-day individual-level exposure to ambient RH, temperature, and PM2.5 were estimated. The associations between these factors and clinical outcomes were analyzed using linear regression models and generalized additive mixed models, adjusting for age, sex, smoking, and body mass index. In the total season, increases in RH difference were associated with increases in forced expiratory volume in 1 s (FEV1) / forced vital capacity (FVC), while increases in temperature difference were associated with decreases in FEV1 and FEV1/FVC. Increases in PM2.5 mean were associated with declines in FEV1. In the cold season, increases in temperature mean were associated with decreases in CAT and mMRC scores, while increases in PM2.5 mean were associated with declines in FEV1, FVC, and FEV1/FVC. In the warm season, increases in temperature difference were associated with decreases in FEV1 and FEV1/FVC, while increases in RH difference and PM2.5 mean were associated with decreases in CAT score. PM2.5 fully mediated the associations of temperature mean with FEV1/FVC in the cold season. In conclusion, PM2.5 mediates the effects of temperature and RH on clinical outcomes. Monitoring patients during low RH, extreme temperature, and high PM2.5 levels is crucial. Capsule of findings The significance of this study is that an increase in ambient RH and temperature, as well as PM2.5 exposure, were significantly associated with changes in lung function, and clinical symptoms in these patients. The novelty of this study is that PM2.5 plays a mediating role in the association of RH and temperature with COPD clinical outcomes in the short term.

Home high flow nasal cannula for chronic hypercapnic respiratory failure in COPD: A systematic review and meta-analysis

BACKGROUND

Chronic Obstructive Pulmonary Disease (COPD) with chronic hypercapnia is usually treated with non-invasive ventilation (NIV). High flow nasal cannula (HFNC) may be an appropriate alternative. However, the efficacy of HFNC in COPD patients with chronic hypercapnia is yet to be optimally summarized.

METHODS

We conducted a systematic review and meta-analysis using random effects with inverse variance methods. Randomized controlled trials involving adult COPD patients initiated on HFNC for at least one month were included. Outcomes of interest were all-cause mortality, acute exacerbations, hospitalizations, and change in St. George Respiratory Questionnaire (SGRQ). We assessed the risk of bias using ROB 2.0 and assessed the quality of the evidence using GRADE.

RESULTS

We included four randomized trials involving 440 patients. HFNC probably reduces acute exacerbations compared to standard care (RR 0.77 [95 % CI 0.66 to 0.89]; moderate certainty), suggesting 69 fewer acute exacerbations per 1000 patients. HFNC may reduce hospital admissions (RR 0.87 [95 % CI 0.69 to 1.09]; low certainty) and may lower the SGRQ score (MD 8.12 units lower [95 % CI 13.30 to 2.95 lower]; low certainty). However, HFNC may have no effect on mortality (RR 1.22 [95 % CI 0.64 to 2.35]; low certainty).

CONCLUSION

HFNC probably reduces acute exacerbations and might reduce hospital admissions in COPD patients with chronic hypercapnia. However, its effect on mortality is uncertain. Future larger RCTs with longer follow-up periods are recommended to provide more robust evidence on the efficacy of HFNC in patients with COPD.

Long-Term High Flow Nasal Cannula Therapy in Primary and Secondary Bronchiectasis

BACKGROUND

Bronchiectasis is the consequence of chronic bronchial inflammation, inappropriate mucus clearance, bacterial colonization, and recurrent or chronic infection. High flow therapy (HFT) is a type of non-invasive respiratory therapy, usually delivered through a nasal cannula interface (HFNC). It delivers heated and humidified air with a stable fraction of inspired oxygen and a wide range of possible flow rates.

AIM OF THE STUDY

Determine the effectiveness of HFNC as add-on therapy in adult primary and secondary bronchiectasis with frequent acute exacerbations (AEs) and/or hospitalizations.

METHODS

This is a single-center crossover study on long-term home therapy with HFNC in adult bronchiectasis. Pharmacological therapy included pulse therapy with mucolytics and bronchodilators. After one year, all patients were switched to additional HFNC. The temperature range was 31-37 °C. The flow range was 35-60 L/m. FiO₂ was 0.21.

RESULTS

Seventy-eight patients completed the follow-up; 54% were females; the median age was 70 years (IQR 60-76). The etiology of bronchiectasis was mainly post-infective (51%), COPD related (26%), and congenital (11%). AEs at baseline were 2.81 (±2.15). A significant reduction in AEs was observed after 24 months with a mean of 0.45 (±0.66) (f-ratio value 79.703. p-value < 0.00001). No significant difference was observed after HFNC therapy on FEV₁ (2.39 ± 0.87 vs. 2.55 ± 0.82; f-ratio 0.79. p-value 0.45) and FVC (2.73 ± 0.88 vs. 2.84 ± 0.90; f-ratio 0.411. p-value 0.66). A significant reduction in mMRC score was observed after HFNC therapy (2.40 ± 0.81 vs. 0.97 ± 0.97 at 2 months vs. 0.60 ± 0.78 at 24 months; f-ratio value 95.512. p-value < 0.00001).

CONCLUSIONS

HFNC is a well-tolerated add-on therapy for adult bronchiectasis. Dyspnea improved after 2 months and further after 2 years. The exacerbation rate decreased during the 2 years follow-up. No significant difference was observed in lung function.

Cost-Effectiveness of Humidified High-Flow Therapy (HHFT) for COPD Patients on Long-Term Oxygen Therapy

Purpose

Chronic obstructive pulmonary disease (COPD) is the third leading cause of mortality, and is associated with significant respiratory impairment, decreased quality of life, and high health care costs. Recent evidence indicates significant clinical benefit results from adding humidified high-flow therapy (HHFT) to standard long-term oxygen therapy (LTOT) as a home-based therapy in persons with severe COPD. The objective was to evaluate the cost-effectiveness of adding HHFT to standard treatment of COPD patients using LTOT with US healthcare cost estimates.

Patients and Methods

A Markov state-transition model was developed using data from a prospective clinical trial of adding HHFT to standard therapy for persons with severe COPD using LTOT. The analysis was conducted from the US health care system perspective using a 5-year time horizon and 3% discount rate. QALYs and downstream healthcare costs were modeled. One-way and probabilistic sensitivity analyses were used to examine the impact of input parameters on the incremental net monetary benefit (NMB).

Results

Incremental QALYs accrued were 0.058 (2.047 vs 1.989 QALYs for HHFT and standard therapy groups respectively). Incremental total costs were -$3939 ($47,516 vs $51,455 for HHFT and standard therapy groups respectively). Thus, HHFT was the dominant treatment in the analysis, resulting on both better health and lower total costs. Varying utility and cost inputs individually never resulted in NMB approaching 0. Probabilistic analyses indicate that HHFT is cost-effective in 84% of simulations.

Conclusion

Our results indicate that the reductions in acute exacerbations of COPD (AECOPDs) that result from adding HHFT for persons with COPD on LTOT will produce both health benefit (QALYs) and cost savings. Cost savings occur because the HHFT device costs are more than offset by reductions in costly COPD exacerbations. Health care systems and payors can benefit from wider implementation of HHFT with existing treatments.

Home High-Flow Therapy in Patients with Chronic Respiratory Diseases: Physiological Rationale and Clinical Results

High-flow therapy (HFT) is the administration of gas flows above 15 L/min. It is a non-invasive respiratory support that delivers heated (up to 38 °C), humidified (100% Relative Humidity, RH; 44 mg H2O/L Absolute Humidity, AH), oxygen-enriched air when necessary, through a nasal cannula or a tracheostomy interface. Over the last few years, the use of HFT in critically ill hypoxemic adults has increased. Although the clinical benefit of home high-flow therapy (HHFT) remains unclear, some research findings would support the use of HHFT in chronic respiratory diseases. The aim of this review is to describe the HFT physiological principles and summarize the published clinical findings. Finally, we will discuss the differences between hospital and home implementation, as well as the various devices available for HHFT application.

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 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.

Domiciliary High-Flow Nasal Therapy in Primary Ciliary Dyskinesia

We report the case of an adolescent with severe primary ciliary dyskinesia (PCD) phenotype associated with a rare genotype. His clinical condition deteriorated, with daily cough and breathlessness, hypoxemia, and lung function decline. Despite being started on home noninvasive ventilation (NIV), the symptoms progressed to dyspnea at rest and thoracic pain. High-flow nasal cannula (HFNC) was started during the daytime as an adjuvant to NIV, and he was started on regular oral opioids for pain and dyspnea control. There was a clear improvement in comfort and dyspnea and breathing work relief. Additionally, better exercise tolerance was also noted. He is currently on the lung transplant waiting list. We aim to emphasize the benefits of HFNC as an add-on therapy for the management of chronic breathlessness since our patient experienced an improvement in breathing and exercise tolerance. However, there is a paucity of studies regarding domiciliary HFNC, particularly in pediatric age. Therefore, further studies are needed to achieve optimal and personalized care. Close monitoring and frequent reassessment in a specialized center are key to adequate management.

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.

Home High-Flow Nasal Cannula Oxygen Therapy for Stable Hypercapnic COPD: A Randomized Clinical Trial

Rationale: The long-term effects of using a high-flow nasal cannula for chronic hypercapnic respiratory failure caused by chronic obstructive pulmonary disease remain unclear. Objectives: To assess whether long-term high-flow nasal cannula use reduces the number of exacerbations and improves other physiological parameters in patients with chronic hypercapnic respiratory failure caused by chronic obstructive pulmonary disease. Methods: We enrolled 104 participants (aged ⩾40 yr) with daytime hypercapnia (Global Initiative for Chronic Obstructive Lung Disease stages 2-4) receiving long-term oxygen therapy (⩾16 h/d for ⩾1 mo) and randomly assigned them to high-flow nasal cannula/long-term oxygen therapy and long-term oxygen therapy groups. The primary endpoint was the moderate or severe exacerbation rate. We compared changes from baseline in arterial blood gas values, peripheral oxygen saturation, pulmonary function, health-related quality-of-life scores, and the 6-minute-walk test. Measurements and Main Results: High-flow nasal cannula use significantly reduced the rate of moderate/severe exacerbations (unadjusted mean count 1.0 vs. 2.5, a ratio of the adjusted mean count between groups [95% confidence interval] of 2.85 [1.48-5.47]) and prolonged the duration without moderate or severe exacerbations. The median time to first moderate or severe exacerbation in the long-term oxygen therapy group was 25 (14.1-47.4) weeks; this was not reached in the high-flow nasal cannula/long-term oxygen therapy group. High-flow nasal cannula use significantly improved health-related quality of life scores, peripheral oxygen saturation, and specific pulmonary function parameters. No safety concerns were identified. Conclusions: A high-flow nasal cannula is a reasonable therapeutic option for patients with stable hypercapnic chronic obstructive pulmonary disease and a history of exacerbations. Clinical trial registered with www.umin/ac.jp (UMIN000028581) and www.clinicaltrials.gov (NCT03282019).

Climate-mediated air pollution associated with COPD severity

Air pollution has been reported to be associated with chronic obstructive pulmonary disease (COPD). Our study aim was to examine the mediating effects of air pollution on climate-associated health outcomes of COPD patients. A cross-sectional study of 117 COPD patients was conducted in a hospital in Taiwan. We measured the lung function, 6-min walking distance, oxygen desaturation, white blood cell count, and percent emphysema (low attenuation area, LAA) and linked these to 0-1-, 0-3-, and 0-5-year lags of individual-level exposure to relative humidity (RH), temperature, and air pollution. Linear regression models were conducted to examine associations of temperature, RH, and air pollution with severity of health outcomes. A mediation analysis was conducted to examine the mediating effects of air pollution on the associations of RH and temperature with health outcomes. We observed that a 1 % increase in the RH was associated with increases in forced expiratory volume in 1 s (FEV₁), eosinophils, and lymphocytes, and a decrease in the total-lobe LAA. A 1 °C increase in temperature was associated with decreases in oxygen desaturation, and right-, left-, and upper-lobe LAA values. Also, a 1 μg/m³ increase in PM_2.5 was associated with a decrease in the FEV₁ and an increase in oxygen desaturation. A 1 μg/m³ increases in PM₁₀ and PM_2.5 was associated with increases in the total-, right-, left, upper-, and lower-lobe (PM_2.5 only) LAA. A one part per billion increase in NO₂ was associated with a decrease in the FEV₁ and an increase in the upper-lobe LAA. Next, we found that NO₂ fully mediated the association between RH and FEV₁. We found PM_2.5 fully mediated associations of temperature with oxygen saturation and total-, right-, left-, and upper-lobe LAA. In conclusion, climate-mediated air pollution increased the risk of decreasing FEV₁ and oxygen saturation and increasing emphysema severity among COPD patients. Climate change-related air pollution is an important public health issue, especially with regards to respiratory disease.

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.

Hospital Cost Savings for Sequential COPD Patients Receiving Domiciliary Nasal High Flow Therapy

Purpose

To estimate the 5-year budget impact to Aotearoa New Zealand (NZ) hospitals of domiciliary nasal high flow (NHF) therapy to patients with chronic obstructive pulmonary disease (COPD) who require long term oxygen therapy.

Methods

Hospital admission counts along with length of stay were obtained from hospital records of 200 COPD patients enrolled in a 12-month randomized clinical trial of NHF in Denmark, both over a 12-month baseline and then in the study period while on randomized treatment (control or NHF). NZ costings from similar COPD patients were estimated using data from Middlemore Hospital, Auckland and were applied to the Danish trial. The budget impact of NHF was estimated over the predicted 5-year lifetime of the device when used by patients sequentially.

Results

Fifty-five of 100 patients in the NHF group and 44 of 100 patients in the control group were admitted to hospital with a respiratory diagnosis during the baseline year. They had 108 admissions in the treatment group vs 89 in the control group, with 632 vs 438 days in hospital, and modeled annual costs of $9443 vs $6512 per patient, respectively. During the study period there were 38 vs 44 patients with 67 vs 80 admissions and 302 vs 526 days in hospital, at a modeled annual cost of $6961 vs $9565 per patient respectively. Taking into account capital expenditure and running costs, this resulted in cost savings of $5535 per patient-year (95% CI, -$36 to -$11,034). With 90% usage over the estimated five-year lifetime of the NHF device, amortized capital costs of $594 per year and annual running costs of $662, we estimate a 5-year undiscounted cost saving per NHF device of $18,626 ($16,934 when discounted to net present value at 5% per annum). There would still be annual cost savings over a wide range of assumptions.

Conclusion

Domiciliary NHF therapy for patients with severe COPD has the potential to provide substantial hospital cost savings over the five-year lifetime of the NHF device.

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.

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.

The effect of domiciliary high flow nasal cannula treatment on dyspnea and walking distance in patients with interstitial lung disease - A pilot study

INTRODUCTION

Interstitial Lung Diseases (ILD) affect the lung parenchyma and are often complicated by respiratory failure (RF) and impaired physical activity. High Flow Nasal Cannula (HFNC) has proved effective in other disease entities with RF. The aim of this study is to investigate the effect of domiciliary HFNC in ILD on dyspnea and walking distance.

METHODS

A 6 weeks cross-over study with domiciliary HFNC-treatment/6 weeks' observation in ILD-patients requiring ambulatory oxygen therapy or with newly prescribed (within 12 months) long term oxygen therapy. Patients were advised to use HFNC 8 h/day, recommended night-time use. Body phletysmography; 6-min walk test (6MWT) including BORG-score, oxygen saturation (SO2) at start, minimum SO2 and time to recovery after 6MWT; arterial blood gasses; modified Medical Research Council (mMRC)-score; quality of life, by the St George Respiratory Questionnaire (SGRQ) and QoS, by the Richards-Campbell Sleep Questionnaire (RCSQ) were investigated at baseline; six weeks and 12 weeks.

RESULTS

10 patients were included; one later withdrew consent. Patients used HFNC between 8-<1 h/day. There were no differences in lung function; blood gasses; SGRQ or RCSQ over the observational period). Walking distance improved significantly (393-441 m p = 0.049) as did time to recovery (3.4-2-2 min, p = 0.001). When correcting for HFNC use (hours/day) significant improvement was also seen in mMRC-score (p = 0.035) and minimum saturation during 6MWT (p = 0.01).

CONCLUSION

Despite a very heterogenous group and no effect on quality of life and -sleep, the study indicates an improvement in dyspnea and physical ability of HFNC in ILD patients.

Cost-Effectiveness of Domiciliary High Flow Nasal Cannula Treatment in COPD Patients with Chronic Respiratory Failure

PURPOSE

To evaluate the cost-effectiveness of long-term domiciliary high flow nasal cannula (HFNC) treatment in COPD patients with chronic respiratory failure.

PATIENTS AND METHODS

A cohort of 200 COPD patients were equally randomized into usual care ± HFNC and followed for 12 months. The outcome of the analysis was the incremental cost per quality-adjusted life-year (QALY) gained, and the analysis was conducted from a healthcare sector perspective. Data on the patients' health-related quality of life (HRQoL), gathered throughout the trial using the St. George's Respiratory Questionnaire (SGRQ), was converted into EQ-5D-3L health state utility values. Costs were estimated using Danish registers and valued in British pounds (£) at price level 2019. Scenario analyses and probabilistic sensitivity analyses were conducted to assess the uncertainty of the results.

RESULTS

The adjusted mean difference in QALYs between the HFNC group and the control group was 0.059 (95% CI: 0.017; 0.101), and the adjusted mean difference in total costs was £212 (95% CI: -1572; 1995). The analysis resulted in an incremental cost-effectiveness ratio (ICER) of £3605 per QALY gained. At threshold values of £20.000-30.000 per QALY gained, the intervention had an 83-92% probability of being cost-effective. The scenario analyses all revealed ICERs below the set threshold value and demonstrated the robustness of the main result.

CONCLUSION

This is the first cost-effectiveness study on domiciliary HFNC in Europe. The findings demonstrate that long-term domiciliary HFNC treatment is very likely to be a cost-effective addition to usual care for COPD patients with chronic respiratory failure. The results must be interpreted in light of the uncertainty associated with the indirect estimation of health state utilities.

What Are the Effects of Meteorological Factors on Exacerbations of Chronic Obstructive Pulmonary Disease?

Chronic obstructive pulmonary disease (COPD) is one of the greatest global public health challenges. Acute exacerbations of COPD lead to the accelerated deterioration of lung function, reduced quality of life, a higher number of hospitalizations, and increased mortality. The factor causing the exacerbation is usually an infectious agent, but the impact of environmental factors is being studied more thoroughly. Among them, meteorological factors are the least examined. Multiple studies have shown that lower temperatures during the cold season, as well as sudden temperature changes regardless of the season, have the most significant negative effect on patients with COPD. However, higher temperatures, especially during summer heatwaves, can also cause COPD exacerbation and it is expected that this will be an even more important health problem in the future considering climate changes. The effects of other meteorological factors on acute exacerbation of COPD, such as atmospheric pressure, solar radiation, rainfall, wind speed, and humidity are far less investigated and opposing results have been obtained in different studies. Thus, there is a need for further research in this area that would result in clinical recommendations and public health interventions that could decrease the global burden of COPD.

The role of high-flow nasal therapy in bronchiectasis: a post hoc analysis

High-flow nasal therapy (HFNT) is a gas delivery system that provides heated and humidified air or supplemental oxygen by nasal cannula. The role of HFNT in airways disease has primarily focused on COPD. Studies in patients with COPD have demonstrated improvement in quality-of-life scores and reduced acute exacerbations with HFNT use [1, 2].

High-flow nasal therapy significantly reduces exacerbation rates and improves quality of life in patients with stable bronchiectasis. High-flow nasal therapy is therefore a potential treatment option for patients with bronchiectasis.https://bit.ly/2JFXuQc

The Obese Patient: Facts, Fables, and Best Practices

The prevalence of obesity continues to rise worldwide, and anesthesiologists must be aware of current best practices in the perioperative management of the patient with obesity. Obesity alters anatomy and physiology, which complicates the evaluation and management of obese patients in the perioperative setting. Gastric point-of-care ultrasound (PoCUS) is a noninvasive tool that can be used to assess aspiration risk in the obese patient by evaluating the quantity and quality of gastric contents. An important perioperative goal is adequate end-organ perfusion. Standard noninvasive blood pressure (NIBP) is our best available routine surrogate measurement, but is vulnerable to greater inaccuracy in patients with obesity compared to the nonobese population. Current NIBP methodologies are discussed. Obese patients are at risk for wound and surgical site infections, but few studies conclusively guide the exact dosing of intraoperative prophylactic antibiotics for them. We review evidence for low-molecular-weight heparins and weight-based versus nonweight-based administration of vasoactive medications. Finally, intubation and extubation of the patient with obesity can be complicated, and evidence-based strategies are discussed to mitigate danger during intubation and extubation.

Variability in tracheal mucociliary transport is not controlled by beating cilia in lambs in vivo during ventilation with humidified and nonhumidified air

Mucociliary transport in the respiratory epithelium depends on beating of cilia to move a mucus layer containing trapped inhaled particles toward the mouth. Little is known about the relationship between cilia beat frequency (CBF) and mucus transport velocity (MTV) in vivo under normal physiological conditions and when inspired air is dry or not fully humidified. This study was designed to use video-microscopy to simultaneously measure CBF and MTV in the tracheal epithelium through an implanted optical window in mechanically ventilated lambs. The inspired air in 6 animals was heated to body temperature and fully saturated with water for 4 hours as a baseline. In another series of experiments, 5 lambs were ventilated with air at different temperatures and humidities and the mucosal surface temperature was monitored with infrared macro-imaging. In the baseline experiments, during ventilation with fully humidified air at body temperature, CBF remained constant, mean 13.9 ± 1.6 Hz but MTV varied considerably between 0.1 and 26.1 mm/min with mean 11.0 ± 3.9 mm/min, resulting in a maximum mucus displacement of 34.2 µm/cilia beat. Fully humidified air at body temperature prevented fluctuations in the surface temperature during breathing indicating a thermodynamic balance in the airways. When lambs were ventilated with dryer air, the mucosal surface temperature and MTV dropped without a significant change in CBF. When inspired air was dry, mainly latent heat (92%) was transferred to air in the trachea, reducing the surface temperature by 5 °C. Reduced humidity of the inspired air lowered the surface temperature and reduced MTV in the epithelium during ventilation.

High-flow nasal cannula oxygen versus conventional oxygen for hypercapnic chronic obstructive pulmonary disease: A meta-analysis of randomized controlled trials

INTRODUCTION

Low-concentration oxygen is an established way for the treatment of chronic obstructive pulmonary disease (COPD) with Type II respiratory failure. Hypercapnia can complicate both COPD exacerbations and stable COPD. Treating with noninvasive ventilation (NIV) can reduce carbon dioxide tension in arterial (PaCO₂ ) in hypercapnic COPD. As an open system, high-flow nasal cannula oxygen (HFNC) is easy to tolerate and use. More researches are needed to focus on how HFNC is used to treat COPD patients with hypercapnic respiratory failure.

METHODS

The Cochrane Library, Medline, EMBASE, and CINAHL database were retrieved from inception to October 2019. Eligible trials were clinical randomized controlled trials comparing the effects of HFNC and conventional oxygen on hypercapnic COPD patients. Two researchers assessed the quality of each study and extracted the data into RevMan 5.3 independently. The primary outcome was PaCO₂ and the secondary outcome was PaO₂ .

RESULTS

Four RCTs with 329 patients were included. The research results indicated that PaCO₂ in the HFNC group was similar to the conventional oxygen group. No significant difference were observed in PaCO₂ (MD -0.98, CI: -2.67 to 0.71, Z = 1.14, p = 0.25) and PaO₂ (MD -0.72, CI: -6.99 to 5.55, Z = 0.23, p = 0.82) between the HFNC group and conventional oxygen group.

CONCLUSIONS

Our meta-analysis showed no difference in PO₂ and PCO₂ between the HFNC and conventional oxygen. But we should treat this conclusion with caution because the number of studies and participants is small and, there is heterogeneity in the PaO₂ and PCO₂ measurements between stable and AECOPD.

The Mechanisms of Benefit of High-Flow Nasal Therapy in Stable COPD

High-flow nasal therapy (HFNT) is a unique system that delivers humidified, heated oxygen-enriched air via nasal cannula at high flow rates. It is a promising therapy for chronic obstructive pulmonary disease (COPD) patients. Several studies have examined the physiologic effects of this therapy in the patient population and have revealed that it improves mucociliary clearance, reduces nasopharyngeal dead space, and subsequently increases CO₂ washout. It also improves alveolar recruitment and gas exchange. These mechanisms may explain the promising results observed in recently published studies that examined the role of HFNT in stable COPD patients.

Development in PaCO2 over 12 months in patients with COPD with persistent hypercapnic respiratory failure treated with high-flow nasal cannula-post-hoc analysis from a randomised controlled trial

INTRODUCTION

Persistent hypercapnic failure in chronic obstructive pulmonary disease (COPD) is associated with poor prognosis. Long-term home non-invasive ventilation is recommended for patients with PaCO2 >7.0 kPa. Domiciliary high-flow nasal cannula (HFNC) reduces PaCO2 in short-term studies. This post-hoc analysis examines the effect of HFNC on PaCO2 levels, exacerbations and admissions in patients with COPD with persistent hypercapnic and hypoxic failures.

METHODS

The original trial included 74 long-term oxygen-treated patients (31 HFNC treated/43 controls) with persistent hypercapnic failure (PaCO2 >6 kPa) who completed the 12-month study period. Baseline data included age, sex, blood gases, exacerbations and hospital admissions in the previous year. Data on blood gases were also recorded at 6 and 12 months for all patients. In addition, acute changes in blood gases after 30 min of HFNC use at site visits were examined, as were exacerbations and hospital admissions during study.

RESULTS

Patients were comparable at baseline. After 12 months there was a 1.3% decrease in PaCO2 in patients using HFNC and a 7% increase in controls before HFNC use on site (p=0.003). After 30 min of HFNC at visits PaCO2 changed significantly, with comparable reductions, at 0, 6 and 12 months, including for controls who tried HFNC at study end (p<0.001). The exacerbation rate increased, compared with 12 months prestudy, by 2.2/year for controls (p<0.001) and 0.15/year for HFNC-treated patients (p=0.661). Hospital admission rates increased in the control group,+0.3/year from prestudy (p=0.180), And decreased by 0.67/year (p=0.013)for HFNC-treated patients.

CONCLUSION

This post-hoc analysis indicates that HFNC stabilises patients with COPD with persistent hypoxic and hypercapnic failures, in terms of PaCO2, exacerbations and number of hospitalisations, whereas those not receiving HFNC worsened. This suggests that HFNC is a possible treatment for patients with persistent hypercapnic COPD.

Tolerability and Safety of High-Flow Nasal Therapy in Patients Hospitalized with an Exacerbation of COPD

BACKGROUND

The effect of high-flow nasal therapy (HFNT) in individuals with an exacerbation of chronic obstructive pulmonary disease (COPD) and hypercapnia is not well studied. We assessed patient tolerance and impact of air-gas therapy delivered by humidified HFNT (20-35 L/min) on gas exchange in hypercapnic COPD patients during hospitalization for COPD exacerbation. We hypothesized that HFNT use would be safe and well tolerated in individuals hospitalized for COPD exacerbation regardless of the degree of hypercapnia.

METHODS

Patients hospitalized for a COPD exacerbation were included if they were hypercapnic (arterial partial pressure of carbon dioxide [PaCO2] > 45 mmHg), ≥ 10 pack-year history, and agreed to treatment with HFNT, along with daily arterial blood gas (ABG) samples and bedside spirometry. They were placed on a HFNT system following admission for at least 3 days with an air-gas blend to maintain a flow rate between 20-35 L/min and fraction of inspired oxygen (FiO2) titrated to keep oxygen saturation (SaO2) values > 90%. Patient tolerance of HFNT and evidence of clinical deterioration as defined by worsening hypoxia or hypercapnia was the primary endpoint.

RESULTS

Ten consecutive patients participated in the study. The patients had frequent prior exacerbations, were hypercapnic, dyspneic, and gas trapped. Participants received an air-gas flow rate (median [interquartile range (IQR)] 25 (IQR 20-30) L/min and FiO2 of 30 (IQR 30-30) %. There was no increase in PaCO2- levels (p = 0.26) or dyspnea (Borg scale, p= 0.52) while using HFNT. No patient discontinued HFNT, had further decompensation, required non-invasive ventilation or intubation during the study period.

CONCLUSION

In a pilot study, patients experiencing a severe COPD exacerbation were able to tolerate continuous HFNT safely regardless of degree of hypercapnia.

Use of Humidified High Flow Nasal Oxygen in Community Palliative Care: A Case Report

Breathlessness is a distressing symptom that is often seen in palliative care patients with respiratory failure and it can make care in the home setting difficult. Humidified High Flow Nasal Oxygen is a relatively new intervention for respiratory failure, but it has not been researched greatly in a palliative care setting. One device with the capacity to deliver high flow humidified oxygen to spontaneously breathing patients is the myAIRVO2 humidifier.1 The myAIRVO2 is a humidifier with an integrated flow generator that delivers warmed and humidified respiratory gases to a spontaneously breathing patient.1 The following case report describes how the technology was used at home for symptom control in a 76 year old patient with severe chronic obstructive pulmonary disease with associated pulmonary hypertension. The patient was successfully discharged from hospital and managed at home using high-flow nasal oxygen for approximately one month up until his death. In this last month of life, he reported that he was more comfortable on high-flow nasal oxygen than on traditionally-administered oxygen. Humidified High Flow Nasal Oxygen is potentially beneficial to aid in symptom control for palliative care patients in an inpatient and community setting.

A narrative review on trans-nasal pulmonary aerosol delivery

The use of trans-nasal pulmonary aerosol delivery via high-flow nasal cannula (HFNC) has expanded in recent years. However, various factors influencing aerosol delivery in this setting have not been precisely defined, and no consensus has emerged regarding the optimal techniques for aerosol delivery with HFNC. Based on a comprehensive literature search, we reviewed studies that assessed trans-nasal pulmonary aerosol delivery with HFNC by in vitro experiments, and in vivo, by radiolabeled, pharmacokinetic and pharmacodynamic studies. In these investigations, the type of nebulizer employed and its placement, carrier gas, the relationship between gas flow and patient’s inspiratory flow, aerosol delivery strategies (intermittent unit dose vs continuous administration by infusion pump), and open vs closed mouth breathing influenced aerosol delivery. The objective of this review was to provide rational recommendations for optimizing aerosol delivery with HFNC in various clinical settings.

High Flow Through Nasal Cannula in Stable and Exacerbated Chronic Obstructive Pulmonary Disease Patients

BACKGROUND

High-Flow through Nasal Cannula (HFNC) is a system delivering heated humidified air-oxygen mixture at a flow up to 60 L/min. Despite increasing evidence in hypoxemic acute respiratory failure, a few is currently known in chronic obstructive pulmonary disease (COPD) patients.

OBJECTIVE

To describe the rationale and physiologic advantages of HFNC in COPD patients, and to systematically review the literature on the use of HFNC in stable and exacerbated COPD patients, separately.

METHODS

A search strategy was launched on MEDLINE. Two authors separately screened all potential references. All (randomized, non-randomized and quasi-randomized) trials dealing with the use of HFNC in both stable and exacerbated COPD patients in MEDLINE have been included in the review.

RESULTS

Twenty-six studies have been included. HFNC: 1) provides heated and humidified airoxygen admixture; 2) washes out the anatomical dead space of the upper airway; 3) generates a small positive end-expiratory pressure; 4) guarantees a more stable inspired oxygen fraction, as compared to conventional oxygen therapy (COT); and 5) is more comfortable as compared to both COT and non-invasive ventilation (NIV). In stable COPD patients, HFNC improves gas exchange, the quality of life and dyspnea with a reduced cost of muscle energy expenditure, compared to COT. In exacerbated COPD patients, HFNC may be an alternative to NIV (in case of intolerance) and to COT at extubation or NIV withdrawal.

CONCLUSION

Though evidence of superiority still lacks and further studies are necessary, HFNC might play a role in the treatment of both stable and exacerbated COPD patients.

Characteristics and outcome of patients set up on high-flow oxygen therapy at home

Background:

High-flow oxygen therapy (HFOT) is increasingly used for acute respiratory failure. Few data support its use at home for the treatment of chronic respiratory failure. Our aim was to report the pattern of the use of long-term HFOT in our center and the outcome of patients setup on long-term HFOT.

Methods:

A retrospective monocentric study including all patients setup on long-term HFOT between January 2011 and April 2018 in Rouen University Hospital was carried out. Patients were divided into two groups, patients with hypoxemic respiratory failure treated with nasal HFOT (nHFOT) and tracheotomized patients treated with tracheal HFOT (tHFOT).

Results:

A total of 71 patients were established on long-term HFOT. Out of these 43 (61%) were included in the nHFOT group and 28 (39%) were included in the tHFOT group. In the nHFOT group, underlying respiratory diseases were interstitial lung disease (n = 15, 35%), pulmonary hypertension (n = 12, 28%), lung cancer (n = 9, 21%), and chronic airway disease (n = 7, 16%). In the tHFOT group, the number of admissions for exacerbation decreased by −0.78 per year (–2 to 0) (p = 0.045). In total, 51 (72%) patients were discharged to their homes and 20 (28%) went to a post-acute re-enablement facility. Median survival following HFOT was 7.5 months. Survival was significantly lower in the nHFOT group with a median survival of 3.6 months whereas median survival was not reached in the tHFOT group (p < 0.001). Monthly costs associated with home delivery of HFOT were €476 (296–533) with significant differences in costs between the nHFOT group of €520 (408–628) and costs in the tHFOT group of €296 (261–475) (p < 0.001).

Conclusions:

The use of long-term HFOT allows very severe patients to be discharged at a reasonable cost from acute care facilities.

The reviews of this paper are available via the supplementary material section.

High-Flow Nasal Cannula Oxygen Therapy Can Be Effective for Patients in Acute Hypoxemic Respiratory Failure with Hypercapnia: a Retrospective, Propensity Score-Matched Cohort Study

BACKGROUND

Usually, high-flow nasal cannula (HFNC) therapy is indicated for de novo acute hypoxemic respiratory failure (AHRF). Although only a few researches have examined the effectiveness of HFNC therapy for respiratory failure with hypercapnia, this therapy is often performed under such conditions for various reasons. We investigated the effectiveness of HFNC therapy for AHRF patients with hypercapnia compared to those without hypercapnia.

METHODS

All consecutive patients receiving HFNC therapy between January 2012 and June 2018 at a university hospital were enrolled and classified into nonhypercapnic and hypercapnic groups. We compared the outcomes of both groups and adjusted the outcomes with propensity score matching.

RESULTS

A total of 862 patients were enrolled, of which 202 were included in the hypercapnic group. HFNC weaning success rates were higher, and intensive care unit (ICU) and hospital mortality was lower in the hypercapnic group than in the nonhypercapnic group (all P < 0.05). However, no statistical differences in HFNC weaning success (adjusted P = 0.623, matched P = 0.593), ICU mortality (adjusted P = 0.463, matched P = 0.195), and hospital mortality (adjusted P = 0.602, matched P = 0.579) were noted from the propensity-adjusted and propensity-matched analyses. Additionally, in the propensity score-matched subgroup analysis (according to chronic lung diseases and causes of HFNC application), there was also no significant difference in outcomes between the two groups.

CONCLUSION

In AHRF with underlying conditions, HFNC therapy might be helpful for patients with hypercapnia. Large prospective and randomized controlled trials are required for firm conclusions.

High Flow Nasal Therapy Use in Patients with Acute Exacerbation of COPD and Bronchiectasis: A Feasibility Study

The efficacy and feasibility of high flow nasal therapy (HFNT) use in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and bronchiectasis is unknown. We performed a single-center, single-arm prospective observational study in patients with AECOPD, documented bronchiectasis, pH ≥ 7.35, respiratory rate (RR) ≥ 26 breaths/minute despite receiving maximal medical treatment and oxygen via face mask up to 10 L/m. Patients received HFNT (Airvo 2, Fisher & Paykel) at a gas flow of 50 L/min and FIO₂ adjusted to maintain SpO₂ ≥92%. Dyspnea, rated by Borg scale, RR, arterial blood gases and mucus production (ranging from 1 to 3) were collected before and 1 h after starting HFNT and then every 24 h for 3 days. Tolerance was measured using a visual analogic scale (VAS). Fifteen patients were enrolled. After 24 h, patients showed a significant improvement in dyspnea score [Borg scale from 6.7 ± 1.4 to 4.1 ± 1.3 (p<.001)]; RR decreased from 29.6 ± 2.7 breaths/min to 23.2 ± 2.9 breaths/min (p<.001); pCO2 significantly decreased after 24 h [58.4 ± 13 vs. 51.7 ± 8.2 (p=.003)] while quantity of mucus production increased [(1.1 ± 0,6 vs. 2.4 ± 0.7, p<.001)]. No patient received invasive or noninvasive mechanical ventilation. Overall VAS score for HFNT tolerance was 6.5. HFNT was effective in improving dyspnea score, decreasing RR, improving gas exchange, and increasing mucus production in patients with AECOPD and coexisting bronchiectasis. Moreover, no safety concerns on its use were detected. Nevertheless, due to the single-arm design, the effect of HFNT could not be isolated from standard pharmacological treatment due to the study design.

Clinical Evidence of Nasal High-Flow Therapy in Chronic Obstructive Pulmonary Disease Patients

Nasal high-flow therapy (NHFT) is an upcoming treatment for chronic obstructive pulmonary disease (COPD) patients. It supplies heated, humidified, and, desirably, oxygen-enriched air through a nasal cannula at flow rates up to 60 L/min. Several studies examined the effect of NHFT in COPD patients, but a clear overview is lacking. The present review aimed to give an overview of the clinical evidence of NHFT in 3 aspects of COPD care: long-term use in stable COPD patients, use for treatment of COPD exacerbations, and use during exercise therapy in COPD. For each topic, a specific literature search was performed up to December 9, 2019. Studies show promising results, with most evidence for its long-term use in hypoxemic COPD patients that frequently exacerbate, and very limited evidence for its use during COPD exacerbations or as a worthwhile adjunct to exercise training. More evidence is therefore needed to know how to incorporate NHFT in standard clinical practice.

Nasal High Flow Use in COPD Patients with Hypercapnic Respiratory Failure: Treatment Algorithm & Review of the Literature

Nasal high flow (NHF) therapy has recently gained attention as a new respiratory support system and is increasingly being utilized in every day clinical practice. Recent studies suggest that it may also be effective in patients with hypercapnia and suggest NHF as a possible alternative for patients who cannot tolerate standard noninvasive ventilation. The present review discusses the mechanisms of action that make NHF potentially suitable for chronic obstructive pulmonary disease (COPD) patients and evaluates the current evidence of NHF use for treatment of stable hypercapnic COPD patients as well as acute hypercapnic exacerbation of COPD. An algorithm is also proposed for the clinical application of NHF in patients with acute hypercapnic exacerbation of COPD, based on current literature.

Domiciliary high-flow treatment in patients with COPD and chronic hypoxic failure: In whom can we reduce exacerbations and hospitalizations?

INTRODUCTION

Domiciliary High-flow, humidified, nasal cannula (HFNC) is a possible add-on in patients with chronic respiratory diseases. This post-hoc study investigates benefit of HFNC in subgroups of advanced COPD patients with chronic hypoxic failure on reduction of exacerbations and hospitalizations.

METHODS

One hundred patients were randomized to HFNC in a previous trial. Subgroups with 0-1 (N = 32) respectively two or more (2+) (N = 68) exacerbations 12 months pre-study were investigated. Changes in number of exacerbations and hospitalizations pre- and in study were analyzed, corrected for HFNC days with HFNC.

RESULTS

Patients were comparable at baseline. Exacerbations increased in subgroup 0-1 (p = 0.01) and decreased in subgroup 2+ (p = 0.03). Correcting for HFNC days no correlation was seen in subgroup 0-1 (p = 0.08), but in subgroup 2+ (p<0.001). Number of hospitalizations increased in subgroup 0-1 (p = 0.01) with no change in days of hospitalization (p = 0.08). Number and days of hospitalization decreased in subgroup 2+ (p = 0.002 resp. 0.025). Correcting for HFNC days no correlation was found in number or days of hospitalization in subgroup 0-1 (p = 0.48 and p = 0.65). Positive correlation was found in subgroup 2+ (both p<0.001).

CONCLUSION

In patients with advanced COPD, chronic hypoxic failure and two or more exacerbations per year, HFNC significantly reduced exacerbations and hospitalizations.

Add-on interventions during pulmonary rehabilitation

Both pulmonary rehabilitation (PR) and chronic obstructive pulmonary disease (COPD) are generic terms and it increasingly becomes clear that rehabilitation programmes need to be tailored to the complexity and circumstances of the individual patient. Indeed, PR is described as a comprehensive, individualized intervention based on thorough assessment of identifiable treatable traits. The current review summarizes ongoing developments regarding additional interventions and tools to facilitate PR and improve outcomes in patients with a chronic respiratory disease.