Daily Respiratory Research Analysis
Analyzed 190 papers and selected 3 impactful papers.
Summary
A sham-controlled RCT in The Lancet Respiratory Medicine found no benefit of portable concentrator ambulatory oxygen over air for daily physical activity in fibrotic ILD with isolated exertional hypoxemia, challenging routine use. A large systematic review/meta-analysis of real-world data showed high effectiveness and favorable safety of RSV vaccines in older adults but highlighted low uptake and disparities. A multicenter secondary analysis linked elevated ventilatory ratio trajectories in ARDS to subsequent severe late AKI, refining risk stratification.
Research Themes
- Ambulatory oxygen and mobility outcomes in fibrotic interstitial lung disease
- Real-world effectiveness and safety of RSV vaccination in older adults
- Ventilatory ratio trajectories predicting kidney injury in ARDS
Selected Articles
1. Ambulatory oxygen for treatment of exertional hypoxaemia in pulmonary fibrosis (PFOX): a multicentre, randomised, sham-controlled trial.
In a multicentre RCT of 116 participants with fibrotic ILD and isolated exertional hypoxaemia, ambulatory oxygen via portable concentrators did not improve daily step counts versus sham air over 3 months and had no safety differences. Findings question routine prescription and underscore the need for better devices/delivery strategies.
Impact: This high-quality sham-controlled RCT provides definitive evidence against a common supportive intervention and will likely recalibrate guidelines and payer coverage for ambulatory oxygen in fibrotic ILD with isolated exertional desaturation.
Clinical Implications: Avoid routine prescription of portable-concentrator ambulatory oxygen solely for exertional desaturation in fibrotic ILD; assess individual patient-centered outcomes and consider supervised rehabilitation or alternative delivery systems.
Key Findings
- No significant difference in change in mean daily steps at 3 months between ambulatory oxygen and sham air (between-group difference -334 steps; 95% CI -803 to 134).
- No serious adverse events attributable to either intervention; adverse event profiles were similar.
- Results suggest limitations of portable oxygen concentrators for delivering effective oxygen during free-living activity in fibrotic ILD with isolated exertional hypoxaemia.
Methodological Strengths
- Multicentre, randomised, parallel-group, sham-controlled design
- Clinically meaningful free-living activity endpoint (accelerometry-derived steps) with safety monitoring
Limitations
- Relatively modest sample size limits subgroup analyses (e.g., device responsiveness phenotypes)
- Primary activity endpoint assessed at 3 months; durability to 6 months less clear in abstract
Future Directions: Develop and test improved portable oxygen technologies and delivery algorithms; evaluate patient-reported outcomes, dyspnoea, and cardiopulmonary physiology during free-living activity; identify responders via physiological phenotyping.
BACKGROUND: Ambulatory oxygen therapy can be used to treat exertional hypoxaemia during daily life activities in people with fibrotic interstitial lung disease (ILD). However, evidence for its efficacy is scarce. This trial aimed to compare the effects of ambulatory oxygen with ambulatory air on physical activity in daily life over 6 months in people with fibrotic ILD and isolated exertional hypoxaemia. METHODS: This multicentre, parallel-group, randomised, sham-controlled trial was done at seven hospital sites in Australia and Sweden. Eligible participants were aged ≥18 years with fibrotic ILD and isolated exertional hypoxaemia (ie, oxyhaemoglobin saturation [SpO FINDINGS: Between Aug 6, 2019, and Jan 10, 2024, 614 individuals were assessed for eligibility. 116 were randomly assigned to ambulatory oxygen (n=59) or ambulatory air (n=57). 79 (68%) of 116 participants were male and 37 (32%) were female. Mean age was 71 years (SD 10). There was no significant difference between ambulatory oxygen (-271 steps per day, 95% CI -702 to 161) and ambulatory air (64, -377 to 505) for change in mean steps per day at 3 months (-334, -803 to 134). There were no serious adverse events related to study treatments, and no difference between groups for the number or type of adverse events. INTERPRETATION: In people with fibrotic ILD and exertional hypoxaemia, ambulatory oxygen delivered using a portable concentrator did not provide benefits over ambulatory air for physical activity in daily life. Routine prescription of ambulatory oxygen using a portable oxygen concentrator for people with fibrotic ILD with isolated exertional hypoxaemia might not be indicated. These results reinforce the pressing need for innovation in portable oxygen devices to ensure effective oxygen delivery and acceptability to patients. FUNDING: National Health and Medical Research Council (Australia) and Swedish Society of Medicine.
2. Real-world evidence on RSV vaccine uptake, effectiveness, and safety in older adults: a systematic review and meta-analysis.
Across 36 real-world studies (>121.8 million individuals), RSV vaccines in adults ≥60 years were highly effective (~75–80%) against infection, ED/urgent visits, hospitalisation, and severe disease. Uptake was low with disparities, and safety was generally favorable with rare GBS signals reported at ~5–6 per million doses for RSVPreF3+AS01.
Impact: Provides timely post-licensure effectiveness and safety synthesis at population scale, informing policy, equity-focused outreach, and risk–benefit communication for RSV vaccination programs.
Clinical Implications: Scale up RSV vaccination in older adults with targeted outreach to underserved groups; coadministration with influenza/COVID-19 is reasonable; monitor rare neurologic AEs while emphasizing high effectiveness against severe outcomes.
Key Findings
- Uptake among U.S. adults ≥60 years in 2023/24 was 18.0% (95% CI 12.2–25.7), with notable sociodemographic disparities.
- Pooled vaccine effectiveness: 75.3% against lab-confirmed RSV, 76.4% against ED/urgent care, 74.8% against hospitalisation, 79.8% against severe disease.
- Safety signals: rare GBS reports for RSVPreF3+AS01 at ~5.2–6.5 per million doses; overall safety favorable.
Methodological Strengths
- Prospective protocol (PROSPERO) with repeated monthly searches and random-effects meta-analyses
- Very large aggregated population across multiple countries and healthcare systems
Limitations
- Observational real-world designs susceptible to residual confounding and misclassification
- Heterogeneity in case definitions, data sources, and follow-up windows across studies
Future Directions: Evaluate durability, booster strategies, subgroup effectiveness (e.g., immunocompromised), and continued pharmacovigilance for neurologic events; address uptake disparities via targeted implementation research.
BACKGROUND: Vaccines to prevent respiratory syncytial virus (RSV)-associated lower respiratory tract disease in older adults have become available in recent years. We investigated RSV vaccine uptake, effectiveness, and safety signals in older adults reported in post-licensure real-world studies. METHODS: For this systematic review and meta-analysis, we conducted 11 monthly searches (between November 5, 2024, and November 10, 2025) in Ovid Medline, Embase, and Global Health databases. Meta-analyses, using random-effects modelling, were performed for uptake, effectiveness, and safety signals. PROSPERO registration: CRD42025643585. FINDINGS: A total of 3900 studies were identified, of which 36 were included, published between December 22, 2023, and October 28, 2025, and covering over 121.8 million individuals across the United States, United Kingdom, Italy, Australia, Czech Republic, Switzerland, France, Canada, and Israel. In the United States, RSV vaccine uptake among adults aged ≥60 years during the 2023/24 RSV season was 18.0% (95% confidence interval (CI): 12.2-25.7; ten studies), varying by clinical and socio-demographic subgroups. Among adults aged ≥60 years, pooled estimates of vaccine effectiveness were 75.3% (95% CI: 73.7-76.9; three studies) against any laboratory-confirmed RSV-positive infection, 76.4% (95% CI: 74.2-78.5; four studies) against RSV-related emergency department or urgent care visits, 74.8% (95% CI: 66.8-82.9; six studies) against RSV-related hospital admissions, and 79.8% (95% CI: 68.1-91.5; four studies) against severe RSV-associated disease. Following vaccination, Guillain-Barré syndrome (GBS) was reported in two studies with between 5.2 and 6.5 cases per one million doses for RSVPreF3+AS01 ( INTERPRETATION: RSV vaccine uptake in older adults was low globally with substantial disparities between sociodemographic and clinical subgroups. Our study showed a favourable safety profile and high effectiveness of the RSV vaccines, highlighting the value of wide implementation of these vaccines. FUNDING: There was no funding for the study.
3. Association between ventilatory ratio and subsequent development of severe late acute kidney injury in acute respiratory distress syndrome.
In 3007 ARDS patients from ARDS/PETAL trials, higher baseline ventilatory ratio and a persistently higher VR trajectory were independently associated with severe late AKI occurring 2–7 days after ARDS onset. Latent class modeling identified a high-VR class with ~2.5-fold increased AKI risk.
Impact: Links a bedside ventilation efficiency metric to kidney injury risk, supporting integrated heart–lung–kidney monitoring and potentially informing early renal-protective strategies in ARDS.
Clinical Implications: Incorporate VR trends into early risk stratification for AKI in ARDS; prompt nephroprotective measures (fluid stewardship, nephrotoxin avoidance) and consider VR-targeted ventilatory adjustments to mitigate dead space/excess drive.
Key Findings
- Baseline ventilatory ratio independently associated with severe late AKI (OR 1.712; 95% CI 1.096–2.674).
- Patients developing severe late AKI exhibited a higher VR trajectory over time (mixed-effects estimate 0.23; p<0.001).
- Latent class mixed modeling identified a high-VR trajectory class with increased AKI risk (OR 2.55; 95% CI 1.02–6.41).
Methodological Strengths
- Large multicenter patient-level secondary analysis spanning seven RCT datasets
- Robust longitudinal modeling (mixed-effects, latent class) adjusting for confounders
Limitations
- Observational secondary analysis cannot prove causality; residual confounding possible
- AKI defined within 2–7 days; applicability beyond this window requires validation
Future Directions: Prospective validation of VR-guided AKI risk tools; interventional studies testing ventilatory strategies that lower VR to reduce kidney injury; integration with kidney biomarkers.
OBJECTIVE: To investigate the association of a dead space ventilation index, namely ventilatory ratio (VR), with subsequent development of severe late acute kidney injury (AKI). DESIGN: Multicenter retrospective study. Secondary analysis of individual patient-level data from seven ARDS Network and PETAL Network randomized controlled trials. SETTING: Critically ill patients with ARDS. PATIENTS: We compared patients who developed severe AKI (stage II or III) more than two days but no longer than seven days following ARDS onset ("severe late AKI" group) with patients who did not develop severe late AKI ("no severe late AKI" group). INTERVENTIONS: None. MAIN VARIABLES OF INTEREST: VR, severe late AKI. RESULTS: Of 3007 patients with ARDS included in the study, 376 (12.5%) developed severe late AKI. Baseline VR was independently associated with severe late AKI development [odds ratio (OR) 1.712, CI 1.096-2.674, p = 0.018)]. An adjusted linear mixed effects model revealed that trajectory of VR was higher in patients who developed severe late AKI than those who did not (estimate = 0.23, p < 0.001). Adjusted latent class mixed modeling identified two distinct trajectories of VR evolution over time, class 1 with lower trajectory over time, and class 2 with higher trajectory, which was independently associated with an increased risk of severe late AKI (OR 2.55, 95% CI 1.02-6.41, p = 0.046) compared to class 1. CONCLUSIONS: In ARDS, baseline value of VR was independently associated with severe late AKI, while its trajectory was significantly higher in patients who developed severe late AKI than those who did not.