The benefits and drawbacks of home oxygen therapy for COPD: what's next?

INTRODUCTION: Home oxygen therapy is one of the few interventions that can improve survival in patients with chronic obstructive pulmonary disease (COPD) when administered appropriately, although it may cause side effects and be an unnecessary burden for some patients. AREAS COVERED: This narrative review summarizes current literature on assessment of hypoxemia, different types of home oxygen therapy, potential beneficial and adverse effects, and emerging research of home oxygen therapy in COPD. A literature search was performed using MEDLINE and EMBASE up to January 2024, with additional articles being identified through clinical guidelines. EXPERT OPINION: Hypoxemia is common in patients with more severe COPD. Long-term oxygen therapy is established to prolong survival in patients with chronic severe resting hypoxemia. Conversely, in the absence of chronic severe resting hypoxemia, home oxygen therapy has an unclear or conflicting evidence base, including for palliation of breathlessness, and is generally not recommended. However, beneficial effects in some patients cannot be precluded. Evidence is emerging on optimal daily duration of oxygen use, role of high-flow and auto-titrated oxygen therapy, improved informed decision-making, and telemonitoring. Further research is needed to validate novel oxygen delivery systems and monitoring tools, and establish longer-term effects of ambulatory oxygen therapy in COPD.

Arterial blood gas analysis or venous blood gas analysis for adult hospitalised patients with respiratory presentations: a systematic review.

BACKGROUND: Identification of hypoxaemia and hypercapnia is essential for the diagnosis and treatment of acute respiratory failure. While arterial blood gas (ABG) analysis is standard for PO2 and PCO2 measurement, venous blood gas (VBG) analysis is increasingly used as an alternative. Previous systematic reviews established that VBG reporting of PO2 and PCO2 is less accurate, but the impacts on clinical management and patient outcomes are unknown. AIMS: This study aimed to systematically review available evidence of the clinical impacts of using ABGs or VBGs and examine the arteriovenous difference in blood gas parameters. METHODS: A comprehensive search of the MEDLINE, Embase and Cochrane Library databases since inception was conducted. Included studies were prospective or cross-sectional studies comparing peripheral ABG to peripheral VBG in adult non-critical care inpatients presenting with respiratory symptoms. RESULTS: Of 15 119 articles screened, 15 were included. No studies were found that examined clinical impacts resulting from using VBG compared to ABG. Included studies focused on the agreement between ABG and VBG measurements of pH, PO2, PCO2 and HCO3 -. Due to the heterogeneity of the included studies, qualitative evidence synthesis was performed. While the arteriovenous difference in pH and HCO3 - was generally predictable, the difference in PO2 and PCO2 was more significant and less predictable. CONCLUSIONS: Our study reinforces the notion that VBG is not comparable to ABG for physiological measurements. However, a key revelation from our research is the significant lack of data regarding the clinical implications of using VBG instead of ABG, a common scenario in clinical practice. This highlights a critical knowledge gap.

Implementing High-Flow Nasal Oxygen Therapy in Medical Wards: A Scoping Review to Understand Hospital Protocols and Procedures.

Acute hypoxemic respiratory failure (ARF) is a common cause for hospital admission. High-flow nasal oxygen (HFNO) is increasingly used as a first-line treatment for patients with ARF, including in medical wards. Clinical guidance is crucial when providing HFNO, and health services use local health guidance documents (LHGDs) to achieve this. It is unknown what hospital LHGDs recommend regarding ward administration of HFNO. This study examined Australian hospitals' LHGDs regarding ward-based HFNO administration to determine content that may affect safe delivery. A scoping review was undertaken on 2 May 2022 and updated on 29 January 2024 to identify public hospitals' LHGDs regarding delivery of HFNO to adults with ARF in medical wards in two Australian states. Data were extracted and analysed regarding HFNO initiation, monitoring, maintenance and weaning, and management of clinical deterioration. Of the twenty-six included LHGDs, five documents referenced Australian Oxygen Guidelines. Twenty LHGDs did not define a threshold level of hypoxaemia where HFNO use was recommended over conventional oxygen therapy. Thirteen did not provide target oxygen saturation ranges whilst utilising HFNO. Recommendations varied regarding maximal levels of inspired oxygen and flow rates in the medical ward. Eight LHGDs did not specify any system to identify and manage deteriorating patients. Five LHGDs did not provide guidance for weaning patients from HFNO. There was substantial variation in the LHGDs regarding HFNO care for adult patients with ARF in Australian hospitals. These findings have implications for the delivery of high-quality, safe clinical care in hospitals.

Pulmonary Hypertension in Interstitial Lung Disease: A Systematic Review and Meta-Analysis.

BACKGROUND: Pulmonary hypertension (PH) is a key complication in interstitial lung disease (ILD), with recent therapeutic advances. RESEARCH QUESTION: What are the diagnostic evaluation, epidemiologic features, associated factors, prognostic significance, and outcome measures in interventional trials for PH in patients with ILD in the current literature? STUDY DESIGN AND METHODS: Ovid MEDLINE, Embase, and CENTRAL databases were searched for original research evaluating PH in participants with ILD of any cause. The definition of PH was based on the investigators' criteria. RESULTS: Three hundred two studies were included, with varying diagnostic evaluations used to define PH. Commonly used diagnostic tests were right heart catheterization (RHC; 56%) and transthoracic echocardiography (TTE; 50%). The pooled prevalence for PH in general populations with ILD was 36% (95% CI, 30%-42%) using RHC and 34% (95% CI, 29%-38%) using TTE. Lower diffusion capacity of the lungs for carbon monoxide, worse oxygenation status, reduced exercise capacity, increased pulmonary artery to aorta ratio and pulmonary artery diameter, and elevated serum brain natriuretic peptide consistently were associated with the presence of PH in at least 60% of reported studies. The presence of PH was associated with increased symptom burden and worse prognosis. Outcome measures in interventional trials of PH in ILD focused on changes in pulmonary vascular hemodynamics and 6-min walk distance. INTERPRETATION: PH is a common complication in ILD with significant health impacts. A standardized definition with prospective evaluation of risk-stratified assessments for PH using identified associated risk factors is warranted. Our findings provide an evidence base for validation as surrogate end points in future PH interventional trials in ILD. TRIAL REGISTRY: International Prospective Register of Systematic Reviews; No.: CRD42021255394; URL: https://www.crd.york.ac.uk/prospero/.

Adaptive multi-interventional trial platform to improve patient care for fibrotic interstitial lung diseases.

BACKGROUND: Fibrotic interstitial lung diseases (fILDs) are a heterogeneous group of lung diseases associated with significant morbidity and mortality. Despite a large increase in the number of clinical trials in the last 10 years, current regulatory-approved management approaches are limited to two therapies that prevent the progression of fibrosis. The drug development pipeline is long and there is an urgent need to accelerate this process. This manuscript introduces the concept and design of an innovative research approach to drug development in fILD: a global Randomised Embedded Multifactorial Adaptive Platform in fILD (REMAP-ILD). METHODS: Description of the REMAP-ILD concept and design: the specific terminology, design characteristics (multifactorial, adaptive features, statistical approach), target population, interventions, outcomes, mission and values, and organisational structure. RESULTS: The target population will be adult patients with fILD, and the primary outcome will be a disease progression model incorporating forced vital capacity and mortality over 12 months. Responsive adaptive randomisation, prespecified thresholds for success and futility will be used to assess the effectiveness and safety of interventions. REMAP-ILD embraces the core values of diversity, equity, and inclusion for patients and researchers, and prioritises an open-science approach to data sharing and dissemination of results. CONCLUSION: By using an innovative and efficient adaptive multi-interventional trial platform design, we aim to accelerate and improve care for patients with fILD. Through worldwide collaboration, novel analytical methodology and pragmatic trial delivery, REMAP-ILD aims to overcome major limitations associated with conventional randomised controlled trial approaches to rapidly improve the care of people living with fILD.

Epidemiology and Prognostic Significance of Cough in Fibrotic Interstitial Lung Disease.

Rationale: Cough is a key symptom in patients with fibrotic interstitial lung disease (ILD). Objective: This study evaluated the prevalence, longitudinal change, associations, and prognostic significance of cough severity in patients with fibrotic ILD. Methods: We included consecutive patients with idiopathic pulmonary fibrosis (IPF) and non-IPF fibrotic ILD who completed the 100mm-Cough Severity Visual Analog Scale (VAS) from the prospective multi-center Canadian Registry for Pulmonary Fibrosis. Baseline cough severity and associations with patient demographics and clinical factors were determined. Relationships between baseline cough severity and health outcomes were evaluated. Measurements and Main Results: Patients with IPF (n=1061) had higher median baseline cough severity than those with non-IPF fibrotic ILD (n=2825) [24 vs 20mm, p<0.001], with worse cough associated with gastroesophageal reflux disease for both cohorts. Worse cough severity was independently associated with worse health-related quality of life at baseline, larger annualized decline in DLCO, development of disease progression, and reduced transplant-free survival in both IPF and non-IPF fibrotic ILD cohorts. The IPF cohort (2.2mm, 95% CI 1.6-2.9mm) had larger annualized increments in cough severity compared to the non-IPF fibrotic ILD cohort (1.1mm, 95% CI 0.8-1.4mm; p=0.004). There was no difference in worsening cough over time comparing those receiving and not receiving ILD-targeted therapy or with and without lung function decline. Conclusion: Cough is common in patients with IPF and non-IPF fibrotic ILD, with increasing cough severity over time irrespective of ILD-targeted therapy. Patient-reported cough severity has prognostic implications on health-related quality of life, disease progression, and survival in fibrotic ILD.

Navigating the COVID-19 pandemic: Experiences and self-management approaches adopted by people with interstitial lung disease.

BACKGROUND: People with interstitial lung disease (ILD) were deemed more vulnerable to the SARS-CoV-2 virus and isolated as a means of reducing risk of infection. This study examined the impact of the pandemic on daily life, psychological wellbeing and access to healthcare and identified approaches undertaken to remain safe. METHODS: Four specialist clinics in tertiary centres in Australia (Victoria: two sites; New South Wales: one site; Western Australia: one site) recruited patients with ILD during an 8-week period from March 2021. Semi-structured telephone interviews were conducted with transcripts analysed using principles of grounded theory. RESULTS: Ninety participants were interviewed between April and December 2021. Participants were predominantly female, former smokers with an average age of 66 years. IPF and connective tissue-ILD being the most common subtypes. Five main themes were identified: vulnerability reduced social interaction and isolation, access to healthcare services and support, staying active, emotional and psychological impact. Self-management strategies included staying active both physically and mentally. DISCUSSION: Self-management was key to managing the impact of the pandemic. In combination with advances in technology, implementation of strategies for monitoring wellbeing and support for self-management provides an opportunity to leverage the lessons learnt to ensure a more individualised model of care for people with ILD.

Prognostic factors associated with mortality in acute exacerbations of idiopathic pulmonary fibrosis: A systematic review and meta-analysis.

BACKGROUND: Acute exacerbations of idiopathic pulmonary fibrosis (AE-IPF) increases mortality risk, but which factors increase mortality is unknown. We aimed to perform a prognostic review of factors associated with mortality in patients with IPF. STUDY DESIGN: and methods: We searched MEDLINE, EMBASE, and CINAHL for studies that reported on the association between any prognostic factor and AE-IPF. We assessed risk of bias using the QUIPS tool. We conduced pairwise meta-analyses using REML heterogeneity estimator, and GRADE approach to assess the certainty of the evidence. RESULTS: We included 35 studies in our analysis. We found that long-term supplemental oxygen at baseline (aHR 2.52 [95 % CI 1.68 to 3.80]; moderate certainty) and a diagnosis of IPF compared to non-IPF ILD (aHR 2.19 [95 % CI 1.22 to 3.92]; moderate certainty) is associated with a higher risk of death in patients with AE-IPF. A diffuse pattern on high resolution computed tomography (HRCT) compared to a non-diffuse pattern (aHR 2.61 [95 % CI 1.32 to 2.90]; moderate certainty) is associated with a higher risk of death in patients with AE-IPF. We found that using corticosteroids prior to hospital admission (aHR 2.19 [95 % CI 1.26 to 3.82]; moderate certainty) and those with increased neutrophils (by % increase) in bronchoalveolar lavage (BAL) during the exacerbation is associated with a higher risk of death (aHR 1.02 [1.01 to 1.04]; moderate certainty). INTERPRETATION: Our results have implications for healthcare providers in making treatment decisions and prognosticating the clinical trajectory of patients, for researchers to design future interventions to improve patient trajectory, and for guideline developers in making decisions about resource allocation.

Self-management interventions for people with pulmonary fibrosis: a scoping review.

BACKGROUND: The most effective method for encouraging self-management in individuals with pulmonary fibrosis (PF) is unclear. This review aimed to identify common self-management components, the outcome measures used and the impact of these components in PF. METHODS: A scoping review was conducted according to the Joanna Briggs Institute Manual for Evidence Synthesis using Medline, Embase, PsychInfo, CINAHL and the Cochrane Central Register of Controlled Trials. Eligible studies included those with educational, behavioural or support components aimed at facilitating self-management among adults with PF and employed quantitative and/or qualitative methods. RESULTS: 87 studies were included. Common self-management components included education (78%), managing physical symptoms (66%) and enhancing psychosocial wellbeing (54%). Components were predominantly delivered in a pulmonary rehabilitation setting (71%). No studies tested a PF-specific self-management package. Common outcome measures were 6-min walk distance (60%), St George's Respiratory Questionnaire (37%) and the Medical Research Council Dyspnoea scale (34%). Clinically significant improvements in these outcomes were seen in ≥50% of randomised controlled trials. Qualitative data highlighted the importance of healthcare professional and peer support and increased confidence in managing PF. CONCLUSION: Self-management components are commonly incorporated into pulmonary rehabilitation programmes rather than being offered as standalone packages. Future research should focus on testing PF-specific self-management packages and employ standardised outcome assessments that include self-efficacy and health-related behaviours.

Predicting New-onset Exertional and Resting Hypoxemia in Fibrotic Interstitial Lung Disease.

Rationale: Hypoxemia in fibrotic interstitial lung disease (ILD) indicates disease progression and is of prognostic significance. The onset of hypoxemia signifies disease progression and predicts mortality in fibrotic ILD. Accurately predicting new-onset exertional and resting hypoxemia prompts appropriate patient discussion and timely consideration of home oxygen. Objectives: We derived and externally validated a risk prediction tool for both new-onset exertional and new-onset resting hypoxemia. Methods: This study used ILD registries from Canada for the derivation cohort and from Australia and the United States for the validation cohort. New-onset exertional and resting hypoxemia were defined as nadir oxyhemoglobin saturation < 88% during 6-minute-walk tests, resting oxyhemoglobin saturation < 88%, or the initiation of ambulatory or continuous oxygen. Candidate predictors included patient demographics, ILD subtypes, and pulmonary function. Time-varying Cox regression was used to identify the top-performing prediction model according to Akaike information criterion and clinical usability. Model performance was assessed using Harrell's C-index and goodness-of-fit (GoF) likelihood ratio test. A categorized risk prediction tool was developed. Results: The best-performing prediction model for both new-onset exertional and new-onset resting hypoxemia included age, body mass index, a diagnosis of idiopathic pulmonary fibrosis, and percent predicted forced vital capacity and diffusing capacity of carbon monoxide. The risk prediction tool exhibited good performance for exertional hypoxemia (C-index, 0.70; GoF, P = 0.85) and resting hypoxemia (C-index, 0.77; GoF, P = 0.27) in the derivation cohort, with similar performance in the validation cohort except calibration for resting hypoxemia (GoF, P = 0.001). Conclusions: This clinically applicable risk prediction tool predicted new-onset exertional and resting hypoxemia at 6 months in the derivation cohort and a diverse validation cohort. Suboptimal GoF in the validation cohort likely reflected overestimation of hypoxemia risk and indicated that the model is not flawed because of underestimation of hypoxemia.

Treatable traits: a comprehensive precision medicine approach in interstitial lung disease.

Interstitial lung disease (ILD) is a diverse group of inflammatory and fibrotic lung conditions causing significant morbidity and mortality. A multitude of factors beyond the lungs influence symptoms, health-related quality of life, disease progression and survival in patients with ILD. Despite an increasing emphasis on multidisciplinary management in ILD, the absence of a framework for assessment and delivery of comprehensive patient care poses challenges in clinical practice. The treatable traits approach is a precision medicine care model that operates on the premise of individualised multidimensional assessment for distinct traits that can be targeted by specific interventions. The potential utility of this approach has been described in airway diseases, but has not been adequately considered in ILD. Given the similar disease heterogeneity and complexity between ILD and airway diseases, we explore the concept and potential application of the treatable traits approach in ILD. A framework of aetiological, pulmonary, extrapulmonary and behavioural and lifestyle treatable traits relevant to clinical care and outcomes for patients with ILD is proposed. We further describe key research directions to evaluate the application of the treatable traits approach towards advancing patient care and health outcomes in ILD.

Telerehabilitation in pulmonary diseases.

PURPOSE OF REVIEW: Telerehabilitation is an alternative delivery model for pulmonary rehabilitation, an evidence-based nonpharmacological intervention, in people with chronic pulmonary disease. This review synthesizes current evidence regarding the telerehabilitation model for pulmonary rehabilitation with an emphasis on its potential and implementation challenges, as well as the clinical experiences from the COVID-19 pandemic. RECENT FINDINGS: Different models of telerehabilitation for delivering pulmonary rehabilitation exist. Current studies comparing telerehabilitation to centre-based pulmonary rehabilitation primarily focus on the evaluation in people with stable chronic obstructive pulmonary disease, which demonstrated equivalent improvements in exercise capacity, health-related quality of life and symptoms with improved programme completion rates. Although telerehabilitation may improve access to pulmonary rehabilitation by addressing travel burden, improving schedule flexibility and geographic disparity, there are challenges of ensuring satisfaction of healthcare interactions and delivering core components of initial patient assessment and exercise prescription remotely. SUMMARY: Further evidence is needed on the role of telerehabilitation in various chronic pulmonary diseases, as well as the effectiveness of different modalities in delivering telerehabilitation programmes. Economic and implementation evaluation of currently available and emerging models of telerehabilitation in delivering pulmonary rehabilitation are needed to ensure sustainable adoption into clinical management for people with chronic pulmonary disease.

Understanding patient experience of chronic cough in interstitial lung disease.

Rationale: Chronic cough is a common symptom in patients with interstitial lung disease (ILD), negatively contributing to health-related quality of life. Despite this, there is limited information and understanding on the experience of this group of patients with chronic cough. This study aimed to explore the symptom experiences for chronic cough in patients with ILD to identify its characteristics and impacts. Methods: A qualitative study using semi-structured telephone interviews was undertaken in 16 adults with a diagnosis of ILD of any type and severity. Patients were recruited from a quaternary referral centre in Melbourne, Australia. Interviews were transcribed verbatim and coded by two researchers using thematic analysis. Results: Patients (age range: 39-87 years, forced vital capacity: 53-107% predicted and diffusing capacity of the lung for carbon monoxide: 28-89% predicted) experienced a spectrum of cough severity and characteristics, including both dry and productive coughs. The impact of chronic cough included physical symptoms, social and emotional difficulties, and interference with work and vocational participation. Management strategies used to relieve cough included mucolytics, opiates, throat lozenges, warm drinks, pacing, breath control, relaxation exercises, movement, continuous positive airways pressure and supplemental oxygen. Patients expressed a need for further information and education regarding chronic cough, including its triggers and management. Conclusions: This study highlights the experience and significance of chronic cough in patients with ILD. The nature and severity of chronic cough in patients with ILD appears to be more heterogeneous than previously described, with physical, social and emotional impacts contributing to symptom burden.

Understanding the telehealth experience of care by people with ILD during the COVID-19 pandemic: what have we learnt?

INTRODUCTION: The COVID-19 pandemic resulted in a rapid transformation of health services. This study aimed to understand the experiences of healthcare by people with interstitial lung disease (ILD), to inform future service delivery. METHODS: Four specialist clinics in tertiary centres in Australia (Victoria:2 sites; New South Wales: 1 site; Western Australia: 1 site) recruited patients with ILD during an 8-week period from March 2021. Participants completed a COVID-specific questionnaire focused on health-related experiences during 2020. RESULTS: Ninety nine (65% of 153) participants completed the questionnaire. 47% had idiopathic pulmonary fibrosis or connective tissue disease-associated ILD, 62% were female and the average age was 66 years. Whilst 56% rated their overall health in 2020 as the same as months prior, 38% indicated a worsening in health attributed to reduced physical activity and fear of contracting the virus. Access to healthcare professionals was 'good' in 61%, and 'fair-to-poor' for 37% due to missed respiratory assessments, with telehealth (mainly telephone) being perceived as less effective. 89% had contact with respiratory physicians, 68% with general practitioners, predominantly via telephone, with few video consultations. High satisfaction with care was reported by 78%, with lower satisfaction attributed to delays in assessments, disruption to usual services such as pulmonary rehabilitation, and dissatisfaction with telehealth. CONCLUSION: People with ILD were generally satisfied with their care during 2020, however reduced access to healthcare professionals was challenging for those experiencing a deterioration in health. Telehealth was largely well received but did not always meet the needs of people with ILD particularly when unwell.