Relationship Between Airway Pressures and Cumulative Fluid Balance in Patients with Acute Respiratory Distress Syndrome: A Prospective Observational Cohort Study

Lung-protective mechanical ventilation using lower airway pressures remains a cornerstone of the management of acute respiratory distress syndrome (ARDS). However, positive pressure ventilation may contribute to positive fluid balance, which has been associated with adverse clinical outcomes. We prospectively enrolled patients with ARDS and collected clinical characteristics and mechanical ventilation parameters during the first 3 days after ARDS onset. The associations between airway pressures and cumulative fluid balance (CFB) were evaluated. The analysis included 287 patients with ARDS, and the all-cause hospital mortality rate was 45.6%. Patients were divided into the positive CFB group (n = 173, 60.3%) and the negative CFB group (n = 114, 39.7%). Compared with patients in the negative CFB group, those in the positive CFB group had a higher risk of organ failure, higher white blood cell counts, higher C-reactive protein levels, more severe hypoxemia, higher peak inspiratory pressures (Ppeak), and higher hospital mortality (all p < 0.05). Multivariable logistic regression analysis showed that higher Ppeak was independently associated with increased odds of positive CFB (adjusted OR, 1.076; p = 0.011). These findings highlight the potential relationship between airway pressures and fluid accumulation during mechanical ventilation in patients with ARDS.