How damaged lungs respond differently to life-support breathing machines
Researchers discovered that lungs with pre-existing injury—from disease or chemotherapy—react more severely to mechanical ventilation, the breathing machines that keep critically ill patients alive. The finding could help clinicians adjust ventilator settings for vulnerable patients and reduce complications that extend hospital stays and drive up treatment costs.
Originaltitel: Extracellular matrix remodeling modifies structural responses to ventilator-induced lung injury: a multiscale correlative imaging study.
Lungskador från mekanisk ventilation (VILI) utvecklas snabbare och svårare när lungvävnaden redan är skadad. Svenska och tyska forskare har nu kartlagt varför genom att kombinera 4D-bildbehandling och nanoskala mekaniska mätningar. Studien jämförde friska rattlungor med lungor som först skadats av bleomycin. Resultaten visade att extracellulär matris remodellering förändrar hur lungorna reagerar på injurious ventilation — luftrummen förstorades mest när skada redan fanns. Atomic force microscopy avslöjade region-specifika mekaniska svar, och den rumsliga analysen koplade nanoskala styvhet direkt till klinisk lungmekanik. För intensivvårdsenheter betyder detta att ventilationsstrategier måste anpassas efter lungvävnadens struktur. Regulatoriska myndigheter får empirisk grund för att revidera VILI-riskbedömning. MedTech-företag kan utveckla ventilatoralgoritmer som detekterar matrisförändringar tidigare än dagens metoder.
BACKGROUND: Mechanical ventilation (MV) can induce or exacerbate ventilator-induced lung injury (VILI), particularly in mechanically heterogeneous lungs with pre-existing injury. METHODS: We investigated VILI in a rat model of bleomycin-induced lung injury and compared it with healthy controls using a combined in-vivo and ex-vivo imaging approach. Previously acquired in-vivo data from four-dimensional (4D) phase-contrast synchrotron micro-computed tomography (micro-CT) and forced oscillation measurements showed increased lung elastance and reduced local acinar deformation in bleomycin-induced injured lungs at baseline and after injurious MV. To identify structural and mechanical correlates, we performed automated three-dimensional (3D) pore analysis and atomic force microscopy (AFM) on formalin-fixed, paraffin-embedded lung tissue, complemented by histology and spatial co-registration. RESULTS: Ex-vivo analysis revealed pronounced airspace enlargement after both injurious MV of healthy lungs, and in bleomycin-injured lungs with inflammation and early fibrotic changes, with the strongest cumulative effect in combined bleomycin and VILI. AFM demonstrated region-specific mechanical responses, and correlation analyses linked pore geometry and nanoscale stiffness to in-vivo lung mechanics. Spatial analysis further showed co-localization of VILI-associated airspace damage with injured regions. CONCLUSIONS: Extracellular matrix remodelling modifies the lung's response to injurious mechanical ventilation, with VILI-associated airspace damage preferentially co-localising with regions of pre-existing matrix injury. This multiscale correlative approach provides mechanistic insight into the interplay between lung injury and VILI and informs ventilation strategies in structurally altered lungs.