Daily Respiratory Research Analysis
A large UK multicenter RCT (UK-ROX) found that conservative oxygen therapy targeting SpO2 88–92% did not reduce 90-day mortality in mechanically ventilated ICU patients. An international prospective registry showed balloon pulmonary angioplasty (BPA) improves hemodynamics and functional status in chronic thromboembolic pulmonary hypertension, with complication predictors identified. A systematic review/meta-analysis links long-term ambient air pollution exposure to adverse adult lung function, r
Summary
A large UK multicenter RCT (UK-ROX) found that conservative oxygen therapy targeting SpO2 88–92% did not reduce 90-day mortality in mechanically ventilated ICU patients. An international prospective registry showed balloon pulmonary angioplasty (BPA) improves hemodynamics and functional status in chronic thromboembolic pulmonary hypertension, with complication predictors identified. A systematic review/meta-analysis links long-term ambient air pollution exposure to adverse adult lung function, reinforcing prevention policies.
Research Themes
- Oxygen targets and harm minimization in critical care ventilation
- Interventional therapy outcomes for chronic thromboembolic pulmonary hypertension
- Environmental exposures and long-term adult lung function
Selected Articles
1. Conservative Oxygen Therapy in Mechanically Ventilated Critically Ill Adult Patients: The UK-ROX Randomized Clinical Trial.
In 16,500 ventilated ICU patients across 97 UK ICUs, targeting SpO2 88–92% reduced supplemental oxygen exposure by 29% but did not lower 90-day all-cause mortality versus usual care. Secondary outcomes (ICU/hospital stay, organ support–free days, and other mortality time points) were also not significantly different.
Impact: This definitive, large RCT directly informs oxygen titration strategies in critical care, showing no mortality benefit of conservative SpO2 targets in ventilated patients.
Clinical Implications: Routine targeting of SpO2 88–92% to minimize oxygen exposure should not be adopted to reduce mortality in mechanically ventilated adults; clinicians can individualize targets while avoiding both hypoxemia and unnecessary hyperoxia.
Key Findings
- Conservative oxygen therapy reduced supplemental oxygen exposure by 29% versus usual care.
- No significant difference in 90-day all-cause mortality (35.4% vs 34.9%; adjusted risk difference 0.7 percentage points, 95% CI -0.7 to 2.0; P=0.28).
- No significant differences in ICU/hospital length of stay, days alive and free from organ support at 30 days, or mortality at other time points.
Methodological Strengths
- Large, multicenter pragmatic randomized clinical trial with 16,500 participants across 97 ICUs
- Clear prespecified oxygen saturation targets and adjusted analyses
Limitations
- Open-label design and potential variability in adherence to SpO2 targets
- Findings may not generalize to non-ventilated ICU patients or specific subgroups requiring different oxygen strategies
Future Directions: Identify subgroups that may benefit from different oxygenation targets (e.g., severe ARDS, ischemic injuries), test individualized oxygen strategies, and evaluate patient-centered outcomes beyond mortality.
2. Balloon Pulmonary Angioplasty for Chronic Thromboembolic Pulmonary Hypertension: Results of an International Multicenter Prospective Registry.
Among 484 analyzed patients from 18 centers, median 5 BPA sessions over ~5 months yielded substantial hemodynamic and functional improvement: mean pulmonary artery pressure decreased by 15 mm Hg (≈38%), pulmonary vascular resistance fell by 332 dyn·s·cm−5, 6-minute walk distance increased by 49 m, and WHO functional class improved. Female sex, Europe/US region, pulmonary hypertension medications, and higher baseline PVR predicted complications; experienced centers achieved greater PVR reductions.
Impact: This largest prospective international BPA registry confirms meaningful hemodynamic and functional gains and clarifies complication risk factors, guiding patient selection, procedural planning, and center development.
Clinical Implications: BPA is an effective option for inoperable CTEPH with real-world improvements in mPAP, PVR, exercise capacity, and WHO class; risk stratification (e.g., baseline PVR, sex) and center experience are crucial to optimizing safety and outcomes.
Key Findings
- Median 5 BPA sessions over a median 4.9 months led to a 15 mm Hg (≈38%) decrease in mPAP.
- Pulmonary vascular resistance decreased by 332 dyn·s·cm−5 and 6-minute walk distance increased by 49 m; WHO functional class improved.
- Female sex, Europe/US region, use of pulmonary hypertension medications, and higher baseline PVR independently predicted complications; greater PVR reduction at more experienced centers.
Methodological Strengths
- Prospective, international, multicenter registry capturing real-world practice
- Standardized hemodynamic and functional endpoints with multivariable analyses
Limitations
- Observational design without randomized comparator; potential selection and center-related biases
- Heterogeneity in procedural details and regional practice patterns
Future Directions: Randomized or rigorously matched comparative studies versus medical therapy and surgical endarterectomy, standardized BPA protocols, and longitudinal assessment of survival, right ventricular remodeling, and quality of life.
3. Exposure to long-term ambient air pollution and lung function in adults: a systematic review and meta-analysis.
Across 27 included studies (12 meta-analyzed), long-term exposure (≥1 year) to ambient air pollutants (PM2.5, PM10, NO2, O3) was associated with adverse adult lung function, with evidence suggesting lower FEV1, FVC, and FEV1/FVC. The certainty of evidence was generally low, but the direction of effect was consistent, emphasizing the importance of air quality mitigation.
Impact: This synthesis consolidates evidence that long-term ambient air pollution adversely affects adult lung function, informing population-level prevention and regulatory policies.
Clinical Implications: Clinicians should incorporate environmental exposure history when assessing unexplained lung function decline and advocate for pollution mitigation; at-risk adults may benefit from exposure reduction strategies.
Key Findings
- Systematic review identified 27 studies; 12 contributed to meta-analysis of long-term pollution and lung function.
- Long-term exposure to PM2.5/PM10 and gaseous pollutants (NO2, O3) was associated with lower FEV1, FVC, and FEV1/FVC.
- Despite low-certainty evidence and heterogeneity, results consistently indicate adverse effects, underscoring air quality mitigation.
Methodological Strengths
- Comprehensive multi-database search with predefined inclusion criteria
- Use of random-effects models to account for between-study heterogeneity
Limitations
- Low certainty due to heterogeneity in exposure assessment, outcomes, and confounding control
- Only 12 studies were meta-analyzed, limiting precision of pooled estimates
Future Directions: Large prospective cohorts with standardized exposure and spirometry protocols, integration of personal exposure metrics, and causal inference methods to strengthen certainty and guide policy.