Dynamic Evolution of Lung Ultrasound Phenotypes and Mortality Risk in Shock Patients

Introduction: The lungs possess extensive endothelium, serving as a critical window organ reflecting disease severity and therapeutic response. Lung ultrasound (LUS) captures pulmonary pathophysiological alterations, with distinct phenotypes correlating with disease profiles and time course manifestations. As shock represents the final pathway to mortality, dynamic LUS phenotype changes may reveal prognostic associations.We hope to investigate associations between longitudinal LUS phenotype evolution (assessed over 72hrs) and 30-day mortality in shock.


Methods: 422 shock patients were enrolled (excluded: missing baseline data/observation < 3 days). LUS phenotypes (12-zone protocol) were evaluated at days 0-3. Latent class analysis identified phenotypic classes. Transition matrices analyzed phenotypic evolution. Cox regression assessed mortality risk associations.


Results: Latent class analysis identified 3 phenotypic classes at days 0-1 and 4 classes at days 2-3. Phenotype classification was performed based on distribution characteristics, lesion type, and presence or absence of gravity dependence. Key phenotypes included: (1) Anterior-stable normal (persistent anterior A-lines); (2) Global interstitial-posterior consolidation (diffuse B-lines with posterior consolidation); (3) Anterior normal-posterior consolidation (anterior A-lines with posterior pathologies). Phenotypic transitions demonstrated high stability in Type 1 (89%) and progressive posterior consolidation "fixation" in Type 2 by day 3. Cox regression revealed only day-3 Class 3 (Anterior normal-posterior consolidation) significantly reduced 30-day mortality risk (HR=0.59, 95%CI:0.37-0.96, P=0.034), while no earlier timepoint phenotypes showed prognostic associations (P>0.05 all). This suggests late-stage LUS phenotype evolution, particularly posterior-consolidation patterns within preserved anterior zones, may reflect compensatory adaptations conferring survival advantage in shock.


Conclusions: LUS phenotypes exhibit dynamic evolution with distinct transition patterns. D3-Class3 independently predicts reduced mortality, highlighting late-stage LUS phenotyping as a prognostic tool in shock.