The Impact of Metabolic Syndrome on Regional Ventilation and Perfusion in ARDS: An Observational Cohort Study Using Electrical Impedance Tomography

Authors: Timothy G. Gaulton, Marcus Victor, Glasiele Alcala, Roberta Ribeiro De Santis Santiago, Florencia Rodriguez Sendic, Yi Xin, Stefano Spina, Cristina Mietto, Lorenzo Berra, and Maurizio Cereda

Acute Respiratory Distress Syndrome (ARDS) is characterised by severe hypoxemia due to heterogeneous alterations in regional ventilation and perfusion. Metabolic syndrome, a highly prevalent condition associated with systemic inflammation and endothelial dysfunction, may influence pulmonary pathophysiology in ARDS. This retrospective cohort study evaluated mechanically ventilated patients with ARDS to determine whether metabolic syndrome affects regional ventilation and perfusion distribution, using electrical impedance tomography following standardised recruitment and PEEP titration protocols. Bayesian regression modelling was applied to adjust for relevant clinical variables.

Among the included patients, those with metabolic syndrome demonstrated a reduction in ventilation distribution to dorsal lung regions, with smaller and less certain changes in perfusion. A trend toward increased ventilation–perfusion mismatch in these regions was observed. Body mass index contributed significantly to the observed differences in ventilation. However, the overall relationship between regional ventilation and perfusion distributions remained similar between groups. These findings suggest that metabolic syndrome may influence regional lung mechanics in ARDS, particularly affecting ventilation distribution, without substantially altering ventilation–perfusion coupling.