Daily Respiratory Research Analysis
Three high-impact respiratory studies stood out today: a multinational prospective cohort of 3,860 ECMO-supported COVID-19 patients clarifies mortality predictors and 6-month outcomes; interim U.S. estimates show the 2024–2025 influenza vaccines substantially reduce medically attended flu and hospitalizations; and a multicenter analysis in immunocompromised acute hypoxemic respiratory failure identifies distinct oxygenation-response trajectories that strongly predict intubation and mortality.
Summary
Three high-impact respiratory studies stood out today: a multinational prospective cohort of 3,860 ECMO-supported COVID-19 patients clarifies mortality predictors and 6-month outcomes; interim U.S. estimates show the 2024–2025 influenza vaccines substantially reduce medically attended flu and hospitalizations; and a multicenter analysis in immunocompromised acute hypoxemic respiratory failure identifies distinct oxygenation-response trajectories that strongly predict intubation and mortality.
Research Themes
- Outcomes and prognostication in ECMO for severe respiratory failure
- Real-world vaccine effectiveness for seasonal influenza
- Data-driven personalization of oxygenation strategies in immunocompromised ARF
Selected Articles
1. In-hospital outcomes and 6-month follow-up results of patients supported with extracorporeal membrane oxygenation for COVID-19 from the second wave to the end of the pandemic (EuroECMO-COVID): a prospective, international, multicentre, observational study.
In a 98-center, 21-country prospective cohort (n=3,860) of COVID-19 patients supported with ECMO, in-hospital mortality was 55.9% and largely occurred during ECMO. Older age, pre-ECMO renal failure and vasopressor use, delayed cannulation, and major complications predicted mortality, whereas 99.7% of in-hospital survivors were alive at 6 months despite persistent dyspnea and some cardiac/neurocognitive symptoms.
Impact: This is the largest prospective, multinational ECMO cohort across later pandemic waves, refining risk stratification and underscoring the need for structured post-ECMO follow-up.
Clinical Implications: Use identified predictors (age, pre-ECMO organ failure/vasopressors, cannulation delay, severe complications) for selection, timing, and risk communication; establish multidisciplinary post-ECMO clinics to address persistent dyspnea and neurocognitive/cardiac sequelae.
Key Findings
- In-hospital mortality was 55.9% (2,158/3,860), with 81.2% of deaths occurring during ECMO support.
- Mortality was associated with older age, pre-ECMO renal failure and vasopressor use, longer intubation-to-ECMO interval, and complications (neurologic events, sepsis, bowel ischemia, renal failure, bleeding).
- Of in-hospital survivors (n=1,702), 99.7% were alive at 6 months; persistent symptoms included dyspnea (32%), cardiac (7.8%), and neurocognitive (10.7%) complaints.
Methodological Strengths
- Prospective, multinational, multicenter design with large sample size (n=3,860) across 98 centers in 21 countries
- Adjusted mixed-effects logistic regression identifying independent mortality predictors with external generalizability
Limitations
- Observational design without randomization; residual confounding likely
- Temporal and center-level practice variability across pandemic waves may influence outcomes
Future Directions: Develop validated prognostic tools incorporating timing and complication risks; evaluate standardized cannulation timing strategies and structured post-ECMO rehabilitation to reduce morbidity.
2. Interim Estimates of 2024-2025 Seasonal Influenza Vaccine Effectiveness - Four Vaccine Effectiveness Networks, United States, October 2024-February 2025.
Across four U.S. networks during Oct 2024–Feb 2025, the influenza vaccine reduced medically attended influenza and hospitalizations, with outpatient VE of ~32%–60% in children and 36%–54% in adults, and hospitalization VE of ~63%–78% in children and 41%–55% in adults.
Impact: Timely, multi-network real-world VE estimates inform clinical and public health decisions mid-season, including prioritization and messaging for vaccination.
Clinical Implications: Reinforce age-appropriate influenza vaccination for all eligible persons ≥6 months; communicate that current-season vaccines meaningfully reduce medically attended influenza and hospitalization risk.
Key Findings
- Outpatient VE against any influenza: 32%, 59%, and 60% in children/adolescents across three networks; 36% and 54% in adults across two networks.
- VE against influenza-associated hospitalization: 63% and 78% in children/adolescents; 41% and 55% in adults in two networks.
- Findings support continued seasonal vaccination while influenza viruses circulate locally.
Methodological Strengths
- Multi-network, real-world interim analysis covering outpatient and hospitalization settings
- Age-stratified VE estimates across diverse clinical networks enhancing generalizability
Limitations
- Interim estimates may change as season progresses and circulating strains shift
- Potential residual confounding and differences in testing/healthcare-seeking across networks
Future Directions: Finalize end-of-season VE, subtype-specific effectiveness, and assess waning to guide booster timing and vaccine composition.
3. Escalation of Oxygenation Modalities and Mortality in Critically Ill Immunocompromised Patient With Acute Hypoxemic Respiratory Failure: A Clustering Analysis of a Prospectively Multicenter, Multinational Dataset.
In 1,547 immunocompromised ICU patients with acute hypoxemic respiratory failure, longitudinal clustering of oxygenation modality changes identified three distinct trajectories that strongly predicted invasive ventilation needs and mortality, with one cluster showing extremely high ICU mortality.
Impact: Introduces a data-driven, longitudinal phenotyping of oxygenation responses that may enable early risk stratification and escalation decisions in a vulnerable population.
Clinical Implications: Embedding trajectory-based monitoring can help recognize high-risk patterns early, prompting earlier intubation or adjunctive therapies, and tailoring escalation protocols for immunocompromised patients.
Key Findings
- Three longitudinal clusters of oxygenation strategy changes were identified (A, B, C) with markedly different outcomes.
- Cluster B had 32.9% invasive ventilation requirement and 97% ICU mortality; Cluster C had 37.5% invasive ventilation but only 0.3% ICU mortality.
- Clusters B and C were independently associated with invasive mechanical ventilation after adjustment (OR 9.87 and 19.8).
Methodological Strengths
- Prospective multinational source cohort with large sample size (EFRAIM) and standardized data collection
- Use of nonparametric longitudinal clustering to capture dynamic treatment-response phenotypes
Limitations
- Post hoc analysis without external validation; risk of overfitting
- Potential unmeasured confounding and heterogeneity in oxygenation strategies across centers
Future Directions: Prospective validation of cluster assignment at the bedside, integration into early warning systems, and testing cluster-guided escalation strategies in interventional trials.