Daily Respiratory Research Analysis
A multicenter randomized trial in pediatric critical care found that high-flow nasal cannula (HFNC) was non-inferior to CPAP for acutely ill children but not after extubation, where CPAP performed better and HFNC was associated with higher 180-day mortality. A quasi-experimental analysis of Ontario’s 2023 wildfire smoke episodes showed sharp, short-term increases in asthma-related emergency visits. A cross-sectional breathomics study using portable micro–gas chromatography achieved high diagnost
Summary
A multicenter randomized trial in pediatric critical care found that high-flow nasal cannula (HFNC) was non-inferior to CPAP for acutely ill children but not after extubation, where CPAP performed better and HFNC was associated with higher 180-day mortality. A quasi-experimental analysis of Ontario’s 2023 wildfire smoke episodes showed sharp, short-term increases in asthma-related emergency visits. A cross-sectional breathomics study using portable micro–gas chromatography achieved high diagnostic performance for COPD, asthma, and PRISm, suggesting point-of-care screening potential.
Research Themes
- Non-invasive respiratory support strategies in pediatric critical care
- Acute respiratory impacts of wildfire smoke exposure
- Point-of-care breathomics for early detection of chronic respiratory diseases
Selected Articles
1. High-flow nasal cannula therapy versus continuous positive airway pressure for non-invasive respiratory support in paediatric critical care: the FIRST-ABC RCTs.
In two pragmatic multicenter RCTs, HFNC was non-inferior to CPAP for time to liberation from respiratory support in acutely ill children and required less sedation, but non-inferiority was not demonstrated post-extubation. Notably, 180-day mortality was higher with HFNC after extubation.
Impact: This is the first large head-to-head RCT program clarifying where HFNC is acceptable versus where CPAP should be preferred in pediatric critical care, with a mortality signal in the post-extubation setting.
Clinical Implications: Use HFNC as acceptable first-line support for acutely ill children requiring non-invasive support, but favor CPAP in the immediate post-extubation period given higher 180-day mortality observed with HFNC.
Key Findings
- In acutely ill children (step-up RCT), HFNC met non-inferiority vs CPAP for time to liberation (median 52.9 h vs 47.9 h; adjusted HR 1.03).
- HFNC reduced sedation use (27.7% vs 37%) and shortened acute hospital stay (13.8 vs 19.5 days).
- Post-extubation (step-down RCT), non-inferiority was not shown and 180-day mortality was higher with HFNC (5.6% vs 2.4%; adjusted OR 3.07).
Methodological Strengths
- Pragmatic multicenter randomized non-inferiority design with master protocol covering two clinical scenarios.
- Comprehensive outcomes including 180-day mortality, resource use, comfort, and cost-effectiveness.
Limitations
- Unblinded interventions may introduce performance bias.
- Heterogeneous pediatric population with varied diagnoses and illness severity.
Future Directions: Identify predictors of HFNC failure, validate protocolized post-extubation strategies, and investigate causes of increased mortality in the HFNC post-extubation group.
2. Impact of the 2023 wildfire smoke episodes in Ontario, Canada, on asthma and other health outcomes: an interrupted time-series analysis.
Two June 2023 wildfire smoke episodes in Ontario led to sharp increases in asthma-related ED visits, peaking at a 23.6% rise at a 1-day lag and persisting up to 5 days for the first episode. Effects were more sustained in adults; no clear effects were detected for other respiratory or cardiovascular outcomes.
Impact: Provides quasi-experimental, population-level evidence that wildfire smoke acutely exacerbates asthma, informing public health alerts, resource allocation, and protective interventions.
Clinical Implications: Health systems should pre-position asthma management resources during smoke episodes and target adults for sustained risk, with messaging on indoor air quality, filtration, and timely controller/reliever use.
Key Findings
- Asthma-related ED visits increased by 23.6% (95% CI 13.2–34.9%) at a 1-day lag, persisting up to 5 days after the first smoke episode.
- The later, more intense smoke episode had a reduced effect on asthma visits, suggesting behavioral adaptation or other modifiers.
- No detectable effects on other respiratory or cardiovascular outcomes; effects were brief in children and more sustained in adults.
Methodological Strengths
- Interrupted time-series with triangulation using case-crossover and multiple data sources.
- Province-wide real-time syndromic and administrative datasets enabling robust population inference.
Limitations
- Ecological design may be subject to residual confounding and exposure misclassification.
- ED visits may not capture outpatient exacerbations or medication uptitration.
Future Directions: Evaluate protective measures (e.g., HEPA filtration, masks, targeted outreach) and quantify heterogeneity of effect by comorbidity, socioeconomic status, and indoor air quality.
3. Exhaled volatile organic compounds as novel biomarkers for early detection of COPD, asthma, and PRISm: a cross-sectional study.
Using portable micro–gas chromatography, breath VOC panels combined with machine learning distinguished COPD, asthma, and PRISm with high AUCs (e.g., COPD vs healthy AUC 0.92; PRISm vs healthy AUC 0.78). Results support rapid, point-of-care screening for chronic respiratory diseases, including identification of PRISm.
Impact: Demonstrates a deployable, scalable diagnostic approach using portable devices and VOC panels that can accelerate early detection of COPD and PRISm, where early intervention may change trajectories.
Clinical Implications: Breathomics with portable micro-GC could complement spirometry to pre-screen individuals for COPD/asthma/PRISm, enabling targeted confirmatory testing and earlier management.
Key Findings
- Identified distinct VOC panels: 9 VOCs (COPD vs healthy), 9 (PRISm vs healthy), 5 (asthma vs healthy), 5 (COPD vs asthma), 7 (PRISm vs asthma).
- Best models: Random forest for COPD vs healthy (AUC 0.92±0.01) and asthma vs healthy (AUC 0.81±0.02); SVC for PRISm vs healthy (AUC 0.78±0.01); logistic regression for asthma vs PRISm (AUC 0.74±0.02) and asthma vs COPD (AUC 0.92±0.01).
- Portable micro-GC enabled rapid breath analysis, supporting feasibility for point-of-care screening.
Methodological Strengths
- Use of portable micro-GC enabling real-world, rapid breath sampling and analysis.
- Multiple machine-learning algorithms with comparative AUC reporting across disease pairs.
Limitations
- Cross-sectional design without external validation limits causal inference and generalizability.
- Modest sample sizes in some groups (e.g., asthma n=66, PRISm n=72) may affect stability of feature selection.
Future Directions: Prospective external validation, longitudinal assessment for progression to COPD, and integration with clinical workflows as a pre-screen prior to spirometry.