Daily Respiratory Research Analysis
Three impactful respiratory studies stood out today: a multi-omics analysis defined metabolomic phenotypes linked to asthma control and inflammation in children; a multicenter cohort found no survival benefit of high-flow nasal oxygen versus conventional oxygen for COVID-19 patients with do-not-intubate orders; and the rollout of nirsevimab prophylaxis markedly reduced PICU burden and costs for severe bronchiolitis. Together, they span precision medicine, acute care decision-making, and populati
Summary
Three impactful respiratory studies stood out today: a multi-omics analysis defined metabolomic phenotypes linked to asthma control and inflammation in children; a multicenter cohort found no survival benefit of high-flow nasal oxygen versus conventional oxygen for COVID-19 patients with do-not-intubate orders; and the rollout of nirsevimab prophylaxis markedly reduced PICU burden and costs for severe bronchiolitis. Together, they span precision medicine, acute care decision-making, and population-level prevention.
Research Themes
- Metabolomic phenotyping and microbiome links in pediatric asthma
- Oxygen therapy strategies in COVID-19 with do-not-intubate orders
- Population impact of RSV monoclonal prophylaxis on PICU burden and costs
Selected Articles
1. Metabotypes are linked to uncontrolled childhood asthma, gut microbiota, and systemic inflammation.
In 92 children with moderate-to-severe asthma, integrated fecal and serum metabolomics identified three metabotypes with distinct lipid signatures, microbiome diversity, diet patterns, and inflammatory profiles. A metabotype enriched in ω-3 fatty acids and acylcarnitines showed better asthma control and lower systemic inflammation, whereas a metabotype with reduced cholesteryl esters/sphingomyelins and lower gut diversity tracked with uncontrolled asthma.
Impact: This study links multi-omic metabolic phenotypes to asthma control and systemic inflammation, offering a data-driven framework to stratify pediatric asthma for precision interventions. It bridges metabolism, diet, microbiota, and clinical outcomes.
Clinical Implications: Metabotyping could guide personalized nutrition (e.g., ω-3 enrichment, reduced sugar), anti-inflammatory strategies, and microbiome-targeted interventions for poorly controlled pediatric asthma. It also identifies biomarkers for risk stratification.
Key Findings
- Three distinct metabotypes emerged from integrated fecal and serum metabolomics in 92 children with moderate-to-severe asthma.
- Metabotype 2 (higher ω-3 fatty acids and acylcarnitines) associated with better asthma control, lower neutrophils and inflammatory markers, longer breastfeeding, and lower sugar intake.
- Metabotype 3 showed highest rates of uncontrolled asthma with decreased serum cholesteryl esters, phosphatidylcholines, sphingomyelins, elevated fecal amino acids, and reduced gut microbiota diversity.
Methodological Strengths
- Integrated multi-omics (fecal and serum targeted metabolomics) with similarity network fusion and spectral clustering
- Correlative analysis with clinical control, diet diaries, microbiota composition, and systemic inflammatory markers
Limitations
- Cross-sectional design limits causal inference
- Modest sample size from a single cohort; external validation needed
Future Directions: Prospective validation of metabotypes as predictive biomarkers, interventional trials targeting diet/microbiome to shift unfavorable metabotypes, and integration with genomics for precision care.
BACKGROUND: Childhood asthma has been linked to distinct metabolomic profiles. OBJECTIVE: We sought to identify phenotypes (metabotypes) in children with moderate to severe asthma through integrative fecal and serum metabolome analysis. METHODS: Children from the Systems Pharmacology Approach to Uncontrolled Pediatric Asthma cohort with Global Initiative for Asthma treatment step 3 or higher were recruited. Asthma control was defined by the Asthma Control Test and annual exacerbation history. Targeted metabolomic profiling of feces and serum was performed using liquid chromatography and flow injection electrospray ionization-triple quadrupole mass spectrometry. Similarity network fusion integrated fecal and serum metabolome profiles, followed by spectral clustering. Clusters were analyzed for differences in asthma characteristics, food diaries, fecal microbiota composition, and levels of serum inflammatory markers and blood cells. RESULTS: Integrative fecal and serum metabolome analysis of 92 children with moderate to severe asthma (median age, 11.5 years, 34% female) revealed 3 metabotypes. Metabotype 1 had the lowest percentage of allergic rhinitis, with elevated serum ceramides and triglycerides. Metabotype 2 had higher odds of asthma control, the highest percentage of children with 4 or more months of breast-feeding, reduced sugar intake, lowest levels of blood neutrophils and serum inflammatory markers, and elevated serum acylcarnitines and ω-3 fatty acids. Metabotype 3 included the highest percentage of uncontrolled asthma patients, with decreased serum cholesteryl esters, phosphatidylcholines, and sphingomyelins, elevated fecal amino acids, and reduced fecal microbiota diversity. CONCLUSIONS: Metabotypes in children with moderate to severe asthma are linked to asthma control, distinct fecal microbiota, and systemic inflammatory patterns. The findings suggest that metabotyping can be valuable in precision medicine approaches for asthma.
2. High-flow nasal oxygen vs. conventional oxygen therapy in patients with COVID-19 related acute hypoxemic respiratory failure and a do not intubate order: a multicentre cohort study.
Among 226 COVID-19 patients with do-not-intubate orders, high-flow nasal oxygen did not reduce in-hospital mortality versus conventional oxygen (adjusted OR 0.72; 95% CI 0.34–1.54) and was associated with longer hospital stay even after adjustment. These findings question the routine use of HFNO in this specific population.
Impact: This multicenter, adjusted analysis addresses a common but understudied decision—HFNO use in frail COVID-19 patients with DNI orders—and provides outcome data that can change oxygen therapy strategies and resource allocation.
Clinical Implications: For COVID-19 AHRF patients with DNI orders, conventional oxygen may be preferred over HFNO given no survival benefit and longer LOS, emphasizing goals-of-care alignment and resource stewardship.
Key Findings
- No significant difference in in-hospital mortality between HFNO (64%) and COT (71%); adjusted OR 0.72 (95% CI 0.34–1.54).
- HFNO increased hospital length of stay (median 11 vs. 7 days; difference remained significant after adjustment).
- Study focused on a frail cohort (median age 78; 78% CFS 4–9), directly informing care decisions in DNI populations.
Methodological Strengths
- Multicenter cohort assembled from three observational studies with prespecified confounder adjustment
- Clinically relevant endpoints (mortality and LOS) and clear treatment definitions (HFNO vs COT)
Limitations
- Nonrandomized design with potential residual confounding and selection bias
- No patient-centered outcomes (comfort, dyspnea relief) or escalation limitations captured in detail
Future Directions: Prospective pragmatic trials or enriched observational studies to compare symptom relief and care-goals alignment, and cost-effectiveness analyses in DNI populations.
BACKGROUND: High-flow nasal oxygen (HFNO) is frequently used to treat patients with acute hypoxemic respiratory failure (AHRF) due to viral pneumonia, including COVID-19. However, its clinical effect compared to conventional oxygen therapy (COT) remains largely unexplored in patients with a do not intubate (DNI) order. We aimed to assess whether HFNO compared to COT is associated with improved clinical outcomes in hospitalized patients with AHRF due to COVID-19 and a DNI order. METHODS: This analysis included patients with a DNI order and SARS-CoV-2 infection, selected from three observational studies, who were treated with COT only or HFNO. The primary endpoint was in-hospital mortality, the secondary endpoint was hospital length of stay (LOS). The effect of HFNO vs. COT was assessed using multivariable regression, accounting for pre-selected confounders. RESULTS: Between March 2020 and September 2021, 116 patients received HFNO and 110 patients received COT. Median age was 78 [72-83], and 78% of the patients had a Clinical Frailty Scale score of 4 to 9. In-hospital mortality was 64% for HFNO and 71% for COT (p = 0.29), with an adjusted odds ratio of 0.72 (95% confidence interval [0.34-1.54], p = 0.40). Hospital LOS was 11 [6-18] days for HFNO, and 7 [4-12] days for COT (p < 0.001), with a remaining difference after adjusting for confounders (p < 0.01). CONCLUSION: The lack of survival benefit and increased hospital LOS should be taken into account when considering HFNO for patients with a DNI order, suffering from AHRF due to viral pneumonia, like COVID-19. CLINICAL TRIAL REGISTRATION: HFNO-COVID-19 study: DTR, NL9067 (Dutch Trial Registry), registration date: 27-11-2020.
3. Nirsevimab prophylaxis on pediatric intensive care hospitalization for severe acute bronchiolitis: a clinical and economic analysis.
Over six consecutive seasons, universal neonatal nirsevimab prophylaxis halved PICU burden for severe bronchiolitis: PICU admission proportion dropped from 17.6% to 8.5%, length of stay decreased (4.4 to 3.3 days), and annual PICU costs fell from €210,105 to €121,044, with similar patient profiles and RSV predominance.
Impact: This real-world pre–post analysis quantifies PICU-level clinical and economic benefits of universal nirsevimab implementation, informing policy, capacity planning, and budgeting for RSV seasons.
Clinical Implications: Health systems can anticipate reduced PICU admissions and costs with universal nirsevimab, supporting broader adoption, equitable access, and reallocation of winter critical care resources.
Key Findings
- PICU admission proportion for bronchiolitis decreased from 17.6% (2022–2023) to 8.5% (2023–2024) after universal nirsevimab prophylaxis.
- Median PICU length of stay shortened from 4.4 days to 3.3 days with similar patient characteristics and RSV predominance (83% vs 77%).
- Annual PICU cost for severe bronchiolitis dropped from €210,105 to €121,044 without altering return on investment.
Methodological Strengths
- Six-season time frame with pre–post comparison capturing roll-out effects
- Concurrent reporting of clinical (admissions, LOS) and economic outcomes
Limitations
- Single-center, observational before–after design susceptible to secular trends and confounding (virus circulation, healthcare behavior)
- No individual-level vaccination coverage linkage or formal cost-effectiveness modeling
Future Directions: Multi-center evaluations with coverage-adjusted analyses and formal cost-effectiveness studies; assessment of equity in access and spillover effects on non-RSV bronchiolitis.
BACKGROUND: Severe acute viral bronchiolitis is a common cause of admissions to pediatric intensive care units (PICUs), resulting in a significant organizational burden each winter. The recent introduction of generalized neonatal prophylactic therapies using Nirsevimab, a monoclonal antibody targeting the respiratory syncytial virus (RSV), has significantly reduced consultations and hospitalizations. However, its impact on the medico-economic aspects of the PICU remains poorly defined. METHODS: We analyzed all infants admitted to our unit for severe acute bronchiolitis over six consecutive epidemic periods (September to March) and examined the effect of Nirsevimab generalized prophylaxis on PICU admissions during the 2023-2024 period. RESULTS: Between 2018 and 2024, 572 out of, 3728 infants under 6 months of age were admitted to the PICU for severe acute bronchiolitis during six epidemic periods. The average percentage of infants with bronchiolitis admitted to the PICU was 15.3% (95% CI 14.2-16.5), with a net decrease during the 2023-2024 period (8.5%) compared to the 2022-2023 period (17.6%). Patients' characteristics were similar, as were the supporting therapies. The causes of bronchiolitis were identical, with 83% and 77% secondary to RSV. PICU duration was significantly reduced during the last period from 4.4 days (95% CI 3.8-5.9) to 3.3 days (95% CI 2.6-4). The medico-economic impact was significant, with a cost reduction for acute severe viral bronchiolitis PICU total stays from €210,105 to €121,044 per annual epidemic without a change in the return on investment. CONCLUSIONS: The introduction of generalized neonatal prophylaxis with Nirsevimab significantly impacts the burden of severe acute bronchiolitis in the PICU.