Daily Respiratory Research Analysis
Analyzed 187 papers and selected 3 impactful papers.
Summary
New evidence shows awake prone positioning reduces mortality and intubation in acute hypoxemic respiratory failure, supporting broader bedside adoption. Post‑pandemic influenza surveillance reveals seasonal patterns are re‑converging but with altered lineage ecology and epidemic duration, informing vaccine timing and composition. Human intracranial recordings demonstrate widespread forebrain entrainment to breathing—even under mechanical ventilation—illuminating a neural basis for respiratory interoception with translational implications.
Research Themes
- Noninvasive respiratory support strategies in acute hypoxemic respiratory failure
- Global post‑pandemic influenza dynamics and vaccination policy
- Neural mechanisms of respiratory interoception and brain–lung interactions
Selected Articles
1. Human forebrain neural synchronization and entrainment to breathing during wakefulness, sleep, and external mechanical ventilation.
Intracranial recordings reveal that multiple forebrain regions synchronize with the respiratory cycle across vigilance states, and that external ventilation causally entrains forebrain activity. Entrainment persists without nasal airflow, implying multiple afferent pathways and offering a mechanistic substrate by which slow, deep breathing could modulate emotion and cognition.
Impact: This work uncovers a pervasive neural architecture for respiratory interoception in humans with causal evidence from mechanical ventilation, bridging neuroscience and respiratory physiology and informing neuro‑respiratory interventions.
Clinical Implications: Findings support mechanistic rationales for breath‑based therapies (e.g., slow deep breathing) to influence affect and cognition, and suggest monitoring brain–respiration coupling under mechanical ventilation may inform sedation, delirium prevention, or neurorehabilitation.
Key Findings
- Forebrain oscillations (insula, somatosensory cortex, ACC, amygdala) synchronize with breathing during wakefulness.
- During sleep, coupling weakens but persists in amygdala and hippocampus, suggesting vigilance/memory roles.
- Nasal airflow is not required for coupling, indicating multiple afferent pathways beyond olfactory routes.
- External mechanical ventilation causally entrains forebrain activity; slow deep ventilation recruits more sites.
Methodological Strengths
- Direct human intracranial electrophysiology across behavioral states
- Causal perturbation via external mechanical ventilation demonstrating entrainment
Limitations
- Sample size and implant coverage are constrained to clinical indications for intracranial monitoring
- Generalizability to healthy populations and standardized ventilation settings requires further study
Future Directions: Test whether targeted breathing paradigms modulate specific cognitive/affective outcomes; quantify brain–respiration coupling as a biomarker under sedation/ventilation; map afferent pathways mediating coupling.
The ability of the forebrain to track and integrate respiratory signals, a process known as breathing interoception, is critical for detecting respiratory threats and ensuring survival, yet its neural mechanisms remain largely unknown. Using human intracranial recordings, we identified widespread synchronization between forebrain neural oscillations and breathing rhythms across wakefulness, sleep, and external mechanical ventilation. During wakefulness, localized sites within known interoceptive regions such as insula, somatosensory cortex, anterior cingulate cortex, and amygdala robustly synchronized with breathing, highlighting their critical roles in breathing interoception. During sleep, forebrain synchronization with breathing decreased, while persisting in the amygdala and hippocampus, which may support vigilance and memory consolidation. In contrast to rodents, nasal airflow was not required for this synchronization, implicating multiple afferent pathways in respiratory interoception and possible unique evolutionary changes in humans. When breathing was driven by an external mechanical ventilator, the imposed breathing rhythm directly entrained forebrain activity, indicating a causal link. Notably, ventilator-driven slow, deep breathing entrained more forebrain sites, suggesting a potential mechanism through which breath-based practices might influence emotion and cognition. Together, these findings redefine breathing interoception as a pervasive influence within the forebrain, with implications for understanding disorders of respiratory awareness, emotional regulation, and cognitive health.
2. Global influenza epidemiology after 2020: patterns of circulation, epidemic timing and duration, and implications for vaccination strategies.
Analysis of 500,870 detections (2021–mid‑2025) shows influenza seasonality is re‑converging post‑COVID, with A(H3N2) dominance in 2021/22 and A(H1N1)pdm09 in 2023/24, and B/Victoria almost exclusively. Peak timing aligns again with hemispheric seasons, but epidemic duration and lineage ecology have shifted, supporting latitude‑tailored vaccination schedules and trivalent vaccine consolidation.
Impact: Large‑scale, multi‑year global surveillance clarifies post‑pandemic influenza architecture, directly informing vaccination timing, vaccine composition, and preparedness planning.
Clinical Implications: Adopt latitude‑tailored vaccination schedules, consider trivalent formulations given near‑absence of B/Yamagata, and reinforce surveillance/characterisation capacity to detect shifts in subtype dominance and epidemic duration.
Key Findings
- Global positivity rose from 3.0% (2021) to 23.7% (2024), indicating robust resurgence.
- A(H3N2) dominated 2021/22 and A(H1N1)pdm09 2023/24; influenza B detections were almost exclusively B/Victoria.
- Peak timing re‑aligned with hemispheric seasons, but epidemic duration remained longer at southern latitudes (15–30 weeks).
Methodological Strengths
- Comprehensive WHO FluNet dataset across 120 countries with sentinel and non‑sentinel feeds
- Standardized epidemic timing/duration metrics (75% annual average percentage method) and latitude stratification
Limitations
- Non‑sentinel feeds showed lower characterisation and A‑skew, potentially biasing subtype proportions
- Heterogeneous testing intensity and reporting completeness across regions
Future Directions: Link virologic data with vaccine performance and severe outcomes; refine country‑level, latitude‑specific vaccination calendars; maintain genomic surveillance for emergent lineages.
INTRODUCTIONThere remains uncertainty whether global influenza seasonality, viral dynamics and epidemic duration have re-established after 2021.AIMWe describe global circulation patterns of influenza viruses from 2021 to 2025 and discuss implications for prevention and surveillance.METHODSWe analysed World Health Organization (WHO) FluNet sentinel and non-sentinel/not-defined virological data from week 1/2021 to 26/2025, stratifying by latitude, region and season. We calculated influenza positivity rate, proportion of virus (sub)types, typical peak timing and duration of influenza epidemics (applying the 75% annual average percentage method).RESULTSSentinel surveillance in 120 countries reported 500,870 detections in this period; positivity rate rose globally from 3.0% in 2021 to 23.7% in 2024. Type A viruses caused over two-thirds of cases, with variability across WHO Regions and seasons. Among A subtypes, A(H3N2) dominated in 2021/22 and A(H1N1)pdm09 in 2023/24, while all but three influenza B cases were B/Victoria. Epidemic peaks typically occurred from December to March and May to August in northern and southern hemispheres countries, respectively, while tropical countries showed highly heterogeneous timing. The median epidemic duration was ca 10 weeks above 30° north, and it varied between 15 and 30 weeks at more southern latitudes. Non-sentinel/not-defined feeds showed stronger A-skew and lower characterisation.CONCLUSIONInfluenza virus circulation shows convergence toward seasonal architectures described before the COVID-19 pandemic, although changes in lineage ecology and epidemic duration persist. Our results confirm the need for latitude-tailored vaccination schedules, consolidation of trivalent vaccines, and strengthened surveillance to better anticipate changes in influenza circulation and support preparedness.
3. Awake prone positioning reduces mortality, intubation, and hospital stay in acute hypoxemic respiratory failure: a systematic review and meta-analysis of 6,164 patients.
Across 24 studies (6,164 patients), awake prone positioning reduced mortality, intubation, hospital and ICU length of stay, and the need for invasive ventilation, without increasing adverse events. Heterogeneity and possible publication bias warrant cautious interpretation and further high‑quality RCTs.
Impact: Synthesizes multi‑study evidence that a simple, scalable bedside maneuver improves hard outcomes in AHRF, supporting incorporation into care bundles.
Clinical Implications: Implement protocolized awake prone positioning in non‑intubated AHRF with staff training and monitoring; prioritize adherence (e.g., duration per day), patient selection, and safety surveillance while awaiting confirmatory RCTs.
Key Findings
- Mortality reduced with APP (OR 0.60, 95% CI 0.42–0.86).
- Lower intubation risk (OR 0.69) and invasive ventilation use (OR 0.42).
- Shorter hospital stay (−0.70 days) and ICU stay (−2.84 days) without increased adverse events.
Methodological Strengths
- Systematic review/meta‑analysis including RCTs and observational comparators with formal risk‑of‑bias assessment (ROB2/NOS)
- Clinically meaningful hard outcomes (mortality, intubation, LOS) analyzed with random‑effects models
Limitations
- Between‑study heterogeneity and potential publication bias
- Variability in APP protocols (duration, timing), co‑interventions, and patient phenotypes
Future Directions: Large, protocol‑harmonized RCTs to define optimal duration, patient selection, and interaction with HFNC/NIV; pragmatic implementation studies to maximize adherence and safety.
BACKGROUND: Acute hypoxemic respiratory failure (AHRF) is a major cause of morbidity and mortality and often requires advanced respiratory support. Awake prone positioning (APP) has emerged as a simple, low-cost intervention to improve oxygenation in non-intubated patients; however, its clinical effectiveness and safety remain uncertain. AIM: This systematic review and meta-analysis aimed to evaluate the effectiveness and safety of awake prone positioning in non-intubated adult patients with acute hypoxemic respiratory failure. METHODS: A systematic search of PubMed, Scopus, and Web of Science was conducted from database inception to February 2026. Randomized controlled trials and observational comparative studies evaluating APP versus usual care were included. Primary outcomes were mortality, intubation, and length of hospital stay. Secondary outcomes included ICU stay, invasive mechanical ventilation, ICU admission, escalation of respiratory support, time to invasive ventilation, and adverse events. Risk of bias was assessed using ROB 2 for randomized trials and the Newcastle-Ottawa Scale for observational studies. Meta-analysis was performed using a random-effects model. RESULTS: Twenty-four studies involving 6,164 patients were included. APP significantly reduced mortality (OR = 0.60, 95% CI 0.42-0.86, p = 0.005), intubation (OR = 0.69, 95% CI 0.60-0.79, p < 0.00001), length of hospital stay (MD = - 0.70 days, 95% CI - 1.07 to - 0.32, p = 0.0003), ICU stay (MD = - 2.84 days, 95% CI - 5.44 to - 0.24, p = 0.03), and invasive mechanical ventilation (OR = 0.42, 95% CI 0.31-0.58, p < 0.00001). No significant differences were observed in ICU admission, escalation of respiratory support, or adverse events. CONCLUSION: Awake prone positioning was associated with improved clinical outcomes, including reduced mortality, intubation, and hospital stay, without an apparent increase in adverse events. However, these findings should be interpreted cautiously given the observed heterogeneity and potential publication bias. Further high-quality randomized trials are needed to confirm these results.