Daily Respiratory Research Analysis
Three studies stand out today: a prospective meta-trial of six randomized studies shows inhaled nebulized unfractionated heparin in hospitalized COVID-19 patients reduced intubation and mortality without bleeding; universal nirsevimab immunization in Tuscany dramatically cut RSV hospitalizations and PICU admissions in infants; and a large multicenter cohort found admission anemia (especially <9 g/dL) predicts worse in-hospital outcomes in severe AECOPD, while polycythemia did not.
Summary
Three studies stand out today: a prospective meta-trial of six randomized studies shows inhaled nebulized unfractionated heparin in hospitalized COVID-19 patients reduced intubation and mortality without bleeding; universal nirsevimab immunization in Tuscany dramatically cut RSV hospitalizations and PICU admissions in infants; and a large multicenter cohort found admission anemia (especially <9 g/dL) predicts worse in-hospital outcomes in severe AECOPD, while polycythemia did not.
Research Themes
- Inhaled anticoagulant therapy for viral respiratory failure
- Population-level RSV prevention via universal nirsevimab
- Hematologic risk stratification in severe AECOPD
Selected Articles
1. Efficacy of inhaled nebulised unfractionated heparin to prevent intubation or death in hospitalised patients with COVID-19: an investigator-initiated international meta-trial of randomised clinical studies.
A pre-specified, prospective meta-trial pooling six randomized studies (n=478) found inhaled nebulized unfractionated heparin significantly reduced intubation or death (OR 0.43) and in-hospital mortality (OR 0.26) among hospitalized but non-intubated COVID-19 patients, with no pulmonary or systemic bleeding. The finding supports inhaled UFH as a safe, adjunctive therapy in severe viral respiratory disease.
Impact: Prospective, pre-specified integration of randomized trials demonstrating mortality benefit without bleeding risk is rare in inhaled therapies and has direct practice implications for managing severe respiratory infections.
Clinical Implications: Consider inhaled nebulized UFH as an adjunct in hospitalized, non-intubated COVID-19 patients at risk of deterioration, with appropriate protocols for dosing and delivery; the safety profile suggests minimal bleeding risk even in respiratory failure settings.
Key Findings
- Intubation or death reduced with inhaled UFH vs standard care (OR 0.43; p=0.001).
- In-hospital mortality reduced (OR 0.26; p<0.001) with inhaled UFH.
- No pulmonary or systemic bleeding events observed in the UFH group across six RCTs and six countries.
Methodological Strengths
- Prospective, a priori meta-trial design integrating randomized clinical studies.
- Consistent efficacy across international multicenter settings with safety monitoring.
Limitations
- Heterogeneity in UFH dosing and nebulization methods across contributing trials.
- Focused on COVID-19; generalizability to other severe viral pneumonias requires direct testing.
Future Directions: Head-to-head RCTs versus standard care in broader viral pneumonias and dose-optimization trials; implementation studies to define delivery protocols and patient selection.
BACKGROUND: Inhaled nebulised unfractionated heparin (UFH) has a strong rationale as a treatment for severe respiratory infections, including COVID-19, due to its antiviral, anti-inflammatory, and anti-coagulant properties, which may prevent viral entry, lung injury progression, and pulmonary thrombosis. We aimed to evaluate the efficacy of inhaled nebulised UFH to prevent intubation or death in hospitalised COVID-19 patients. METHODS: In this prospective, a priori set up and defined, collaborative meta-trial of six randomised clinical studies, adult hospitalised but not intubated COVID-19 patients were randomly assigned to inhaled nebulised UFH on top of standard of care or standard of care alone. The dose and method of nebulisation was specific to each study. The primary outcome was intubation or death, assessed at the longest follow-up after randomisation. The meta-trial was registered at ClinicalTrials.gov ID NCT04635241. FINDINGS: Between June 2020 and December 2022, 478 patients from 10 hospitals in six countries (Argentina, Brazil, Egypt, Indonesia, Ireland and USA) were enrolled. The odds ratio (OR) for intubation or death was 0.43 (0.26-0.73, p = 0.001); the OR for in-hospital mortality was 0.26 (0.13-0.54, p < 0.001) with inhaled nebulised UFH compared to standard of care alone. There were no safety issues reported, including no instances of pulmonary or systemic bleeding in the nebulised UFH group. INTERPRETATION: In patients hospitalised but not intubated for COVID-19, inhaled nebulised UFH prevented intubation and reduced mortality, without causing pulmonary or systemic bleeding. FUNDING: The Sponsor of the meta-trial was the INHALE-HEP Collaborative Research Group (CRG); investigators of each contributing study were members of the INHALE-HEP CRG. No funding was received for the meta-trial. The Brazilian study was funded by The J.R. Moulton Charity Trust. The Irish study was funded by a Grant from Science Foundation Ireland to Cúram, the SFI's Centre for Research in Medical Devices (Research Centre Award Reference: 13/RC/2073).
2. Public health impact of nirsevimab and reduction of RSV hospitalisation in all infants: early real-world data from Tuscany (Italy) in the 2024-25 RSV season.
With ~90% coverage, universal nirsevimab immunization in Tuscany reduced RSV-related hospitalizations by 82.1% and PICU admissions by 85.2% among infants during the 2024–25 season, with consistent benefits in both in-season and out-of-season birth cohorts. This real-world evidence supports universal infant immunization policies.
Impact: Demonstrates a large real-world, season-wide reduction in severe RSV outcomes under universal immunization, informing policy decisions beyond clinical trials.
Clinical Implications: Health systems should prioritize universal infant nirsevimab programs ahead of RSV season, including those born from April onward, to reduce hospital and PICU burden; monitoring infrastructure should track coverage and outcomes.
Key Findings
- RSV-related hospitalizations decreased by 82.1% among eligible infants in 2024–25 vs the mean of 3 prior seasons.
- PICU admissions decreased by 85.2% with universal nirsevimab coverage ~90%.
- Effects were consistent for infants born during the RSV season and those born before the season.
Methodological Strengths
- Season-wide real-world assessment with pre- vs multi-season comparator.
- High immunization coverage enabling robust population-level inference.
Limitations
- Single tertiary hospital; potential referral and secular trend biases.
- Retrospective design without individual-level confounder adjustment.
Future Directions: Multicenter population-based evaluations with individual-level linkage (e.g., vaccination status, comorbidities) and cost-effectiveness analyses to guide national rollout and scheduling.
Real-world evidence on the public health impact of nirsevimab across a full RSV season in Italy is currently lacking, particularly with respect to hospitalisations and admissions to paediatric intensive care units (PICU), and only limited data are available worldwide. This study aimed to evaluate, in a real-world setting, the public health impact of nirsevimab on RSV-related hospitalisations and PICU admissions in Tuscany. This observational retrospective study included all children under one year of age experiencing their first RSV season, i.e., those born between April and March of the 2021-22, 2022-23, 2023-24, and 2024-25 seasons, who were hospitalised at the Meyer Children's Hospital, a tertiary regional paediatric hospital in Tuscany, for respiratory symptoms with RSV confirmed via real-time PCR testing. Starting November 1st 2024, Nirsevimab was offered to all infants born between 1 April, 2024, and 31 March, 2025. The percentage reduction in RSV-related hospitalisations was calculated by comparing the number of hospitalisations observed in 2024/25 with the mean number recorded across the three preceding RSV seasons. Immunization coverage reached around 90%. During the 2024-2025 RSV season, RSV-related. hospitalisations decreased by 82.1% among infants eligible for immunization, by 83.2% among those born during the RSV season, and by 81.5% among those born before the season. PICU admissions decreased by 85.2%, 84.0%, and 86.8%, respectively, in the same groups. High coverage of nirsevimab immunization substantially reduced RSV-related hospitalisations among infants in Tuscany during the 2024-2025 season. The consistent benefits observed across both in-season and out-of-season birth cohorts support a universal immunization program for all infants, including those born from April onward, in Italy. What is Known: • RSV is the leading cause of infant hospitalisations for lower respiratory tract infections, especially in those ≤12 months. Real-world data on season-wide nirsevimab public health impact in Italy were lacking.. What is New: • Universal nirsevimab immunisation in Tuscany led to an 82.1% reduction in RSV-related hospitalisations and 85.2% in PICU admissions in infants eligible for immunization. Findings support universal over selective immunisation to protect all infants entering their first RSV season.
3. Hemoglobin and clinical outcomes of in-hospital patients with severe acute exacerbation of chronic obstructive pulmonary disease: a multicenter cohort study.
In a prospective multicenter cohort of 9,660 inpatients with severe AECOPD, admission anemia—especially Hb <9 g/dL—was associated with higher risks of in-hospital mortality, invasive ventilation, and ICU admission, whereas polycythemia showed no adverse association. Admission hemoglobin may serve as a pragmatic prognostic biomarker to guide risk stratification and care intensity.
Impact: Large, multicenter, prospective data provide actionable thresholds for a common, inexpensive biomarker in a high-burden condition, enabling immediate bedside risk stratification.
Clinical Implications: Screen for and correct anemia in severe AECOPD admissions; consider enhanced monitoring and early escalation (e.g., respiratory support planning, ICU triage) when Hb <9 g/dL; polycythemia alone should not prompt escalation.
Key Findings
- Among 9,660 severe AECOPD inpatients, admission anemia correlated with increased adverse in-hospital outcomes versus normal Hb.
- Hemoglobin <9 g/dL identified a subgroup at particularly high risk for mortality, invasive ventilation, and ICU admission.
- Polycythemia was not associated with worse in-hospital outcomes.
Methodological Strengths
- Prospective enrollment across 10 medical centers with large sample size.
- Clinically meaningful composite outcomes with pragmatic categorization by admission Hb.
Limitations
- Observational design limits causal inference and residual confounding cannot be excluded.
- Details on multivariable adjustments and subgroup analyses are limited in the abstract.
Future Directions: Interventional trials testing anemia correction strategies in severe AECOPD and external validation across diverse health systems; integrate Hb into risk scores for triage.
BACKGROUND: Hemoglobin is one of the most common laboratory tests for hospitalized patients, and both anemia and polycythemia are common comorbidities in severe acute exacerbation of chronic obstructive pulmonary disease (AECOPD). However, limited evidence focuses on the predictive value of anemia or polycythemia for in-hospital adverse outcomes of severe AECOPD. METHODS: The patients hospitalized for severe AECOPD were prospectively enrolled from 10 medical centers in China. They were categorized into three groups: anemia, normal, and polycythemia, based on their hemoglobin levels on-admission. The adverse outcomes which included all-cause in-hospital mortality, invasive ventilation, and intensive care unit (ICU) admission. RESULTS: A total of 9,660 AECOPD inpatients were included. The cohort identified a significant association between anemia and adverse outcomes when compared to the normal group (5.20% vs. 2.80%, CONCLUSION: While there is no effect of polycythemia on adverse outcomes in severe AECOPD inpatients, anemia on-admission, particularly <9 g/dL, is associated with a heightened risk of adverse outcomes, which may serve as an effective biomarker of poor prognosis among inpatients with severe AECOPD.