Thrombocytopenia (PLT) as an independent predictor may influence ARDS progression through dual mechanisms: impaired endothelial repair due to platelet deficiency exacerbates alveolar-capillary leakage, while platelet-derived mediators such as serotonin and PF4 directly enhance pulmonary vasoconstriction and neutrophil extracellular trap (NET) formation [40]. Here, PF4 is linked to acute respiratory distress syndrome.