Impact of high-flow oxygen therapy during exercise in idiopathic pulmonary fibrosis: a pilot crossover clinical trial

Pulmonary rehabilitation in idiopathic pulmonary fibrosis

PURPOSE OF REVIEW

This review synthesizes the expanding evidence for pulmonary rehabilitation that has led to its recommended inclusion in the holistic care of people with idiopathic pulmonary fibrosis (IPF), as well as discussing strategies that may maximize and sustain benefits.

RECENT FINDINGS

Pulmonary rehabilitation is an effective intervention leading to significant improvements in exercise tolerance, symptoms, and quality of life for people with IPF. Improvements in symptoms and quality of life can persist longer term, whereas functional capacity does not; therefore, strategies to preserve functional capacity are an important area of research. Referral early in the disease course is encouraged to promote longer lasting effects. Evidence that high-intensity interval training may optimize benefits of exercise training is emerging. Supplemental oxygen is frequently used to manage exercise-induced desaturation, although its use as an adjunct therapy requires more evidence.

SUMMARY

Current evidence strongly supports the inclusion of pulmonary rehabilitation in the standard holistic care of IPF, with early participation encouraged. Further research is needed to establish the optimal exercise strategies, modalities and adjunct therapies that enhance outcomes of pulmonary rehabilitation and promote longer lasting effects.

Enhancing exercise tolerance in interstitial lung disease with high-flow nasal cannula oxygen therapy: A randomized crossover trial

BACKGROUND AND OBJECTIVE

Interstitial lung disease (ILD) is characterized by dyspnoea on exertion and exercise-induced hypoxaemia. High-flow nasal cannula (HFNC) therapy reduces the respiratory workload through higher gas flow and oxygen supplementation, which may affect exercise tolerance. This study aimed to examine the effects of oxygen and gas flow rates through HFNC therapy on exercise tolerance in ILD patients.

METHODS

We conducted three-treatment crossover study. All ILD patients performed the exercises on room air (ROOM AIR setting: flow, 0 L/min; fraction of inspired oxygen [FiO2], 0.21), HFNC (FLOW setting: flow 40 L/min, FiO2 0.21), and HFNC with oxygen supplementation (FLOW + OXYGEN setting: flow 40 L/min, FiO2 0.6). The primary endpoint was the endurance time, measured using constant-load cycle ergometry exercise testing at a peak work rate of 80%.

RESULTS

Twenty-five participants (10 men, 71.2 ± 6.7 years) were enrolled. The increase in exercise duration between the ROOM AIR and FLOW was 46.3 s (95% CI, -6.1 to 98.7; p = 0.083), and the FLOW and FLOW + OXYGEN was 91.5 s (39.1-143.9; p < 0.001). The percutaneous oxygen saturation (SpO2) at rest was significantly higher with the FLOW + OXYGEN setting than with the ROOM AIR and FLOW settings, and the difference persisted during exercise. At equivalent time points during exercise, the SpO2 with the FLOW setting was significantly higher than that with the ROOM AIR setting.

CONCLUSION

Oxygen supplementation in HFNC therapy improved exercise tolerance and SpO2. We found that gas flow alone did not improve exercise tolerance, but improved SpO2 during exercise.

An additional mechanism enhancing exercise tolerance in interstitial lung disease with high-flow nasal cannula

See related article

Oxygen therapy for exercise capacity in fibrotic interstitial lung disease: A systematic review and meta-analysis of randomised controlled trials

BACKGROUND

Fibrotic interstitial lung disease (fILD) is characterised primarily by impaired lung function and quality of life. The present study investigated whether oxygen therapy could improve exercise capacity among patients with fILD.

METHODS

Previously published randomised controlled trials (RCTs) were surveyed. A systematic review and meta-analysis was conducted to evaluate the effectiveness of oxygen therapy in improving the exertional capacity of patients with fILD. The primary outcome was peripheral oxygen saturation (SpO2) during exercise. The effects of oxygen therapy on fatigue, dyspnoea, heart rate, and exercise duration or distance were also analysed.

RESULTS

Fourteen RCTs involving 370 patients were included. Oxygen therapy improved SpO2 during exercise (mean difference, MD = 6.26 %), exercise duration (MD = 122.15 s), fatigue (standard mean difference, SMD = -0.30), and dyspnoea (MD = -0.75 Borg score units). High-flow oxygen systems tended to be more effective than low-flow systems in improving exercising SpO2, duration, fatigue, dyspnoea, and heart rate. High-flow nasal cannulas (HFNCs) yielded better outcomes regarding SpO2 and fatigue than did high-flow Venturi masks (MD = 1.60 % and MD = -1.19 Borg score units, respectively). No major adverse events were reported.

CONCLUSION

The evidence from RCTs supports the short-term use of oxygen supplementation to improve SpO2, exercise capacity, fatigue, and dyspnoea among patients with fILD. Further analyses demonstrates that HFNCs yield more favourable outcomes, yet not reaching statistical significance except for improving SpO2 and fatigue. However, the long-term effects of oxygen therapy on quality of life and mortality remain unclear.

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.

Pulmonary fibrosis: Is stem cell therapy the way forward?

Pulmonary fibrosis, a chronic and fatal lung disease affecting millions of people worldwide, is characterized by the scarring of lung tissue, thereby impairing oxygen exchange between the lungs and blood. The etiology of pulmonary fibrosis is multifactorial, involving environmental exposures, comorbidities, and genetic mutations. Current pharmacological treatments can only slow the disease progression, and lung transplantation is limited by donor availability and complications. Stem cell therapy has emerged as a potential alternative treatment for pulmonary fibrosis, in which stem cells modulate the inflammatory response, differentiate into lung epithelial cells, secrete growth factors and extracellular matrix components, and enhance vascularization and tissue regeneration. Various sources of stem cells, such as endogenous lung stem cells, embryonic stem cells, induced pluripotent stem cells, and mesenchymal stem cells, have been investigated in animal models and human trials. Various delivery routes, such as intravenous injection, intratracheal instillation, and inhalation, have been tested for safety and efficacy. However, several challenges and limitations remain to be overcome, such as high costs, ethical issues, immunological compatibility, cell survival and homing, and long-term outcomes. Further research is needed to optimize the protocols and parameters in stem cell therapy for pulmonary fibrosis, and to evaluate the clinical benefits and risks for patients.

Automated O2 Titration Alone or With High-Flow Nasal Cannula During Walking Exercise in Chronic Lung Diseases

BACKGROUND

Exercise-induced O2 desaturation contributes to dyspnea and exercise intolerance in various respiratory diseases. This study assessed whether automated O2 titration was superior to fixed-flow O2 to improve exertional dyspnea and walking exercise endurance. We also aimed at evaluating possible additive effects of high-flow nasal cannula coupled with automated O2 titration on these outcomes.

METHODS

Subjects with chronic respiratory diseases and exercise-induced desaturation performed a 3-min constant-speed shuttle test (CSST) and an endurance shuttle walking test (ESWT) with either (1) fixed-flow O2, (2) automated O2 titration targeting an SpO2 of 94% (± 2%), and (3) automated O2 titration + high-flow nasal cannula according to a randomized sequence. The main outcome was Borg dyspnea score at the end of the 3-min CSST. Secondary outcomes included endurance time and dyspnea during ESWT and oxygenation status during exercise.

RESULTS

Ten subjects with COPD, 10 with interstitial lung disease, 5 with pulmonary hypertension, and 3 with cystic fibrosis completed the study. Compared to fixed-flow O2, automated O2 titration did not reduce dyspnea at the end of the 3-min CSST. Endurance time during the ESWT was prolonged with automated O2 titration (mean difference 298 [95% CI 205-391] s, P < .001), and dyspnea at isotime was reduced. No further improvement was noted when high-flow nasal cannula was added to automated O2 titration. Compared to fixed-flow O2, O2 flows were higher with automated O2 titration, resulting in better oxygenation.

CONCLUSIONS

Automated O2 titration was superior to fixed-flow O2 to alleviate dyspnea and improve exercise endurance during the ESWT in subjects with a variety of chronic respiratory diseases. Adding high-flow nasal cannula to automated O2 titration provided no further benefits.

IPF Respiratory Symptoms Management - Current Evidence

Idiopathic pulmonary fibrosis (IPF) is a progressive, chronic disease of the lungs which is characterized by heavy symptom burden, especially in the last year of life. Despite recently established anti-fibrotic treatment IPF prognosis is one of the worst among interstitial lung diseases. In this review available evidence regarding pharmacological and non-pharmacological management of the main IPF symptoms, dyspnea and cough, is presented.