The Effect of Recruitment Maneuvers on Dead Space in Patients with ARDS: Prospective Observational Study

Objective: Acute Respiratory Distress Syndrome (ARDS) is characterized by severe hypoxemia and heterogeneous lung involvement. Recruitment maneuvers (RMs) and positive end-expiratory pressure (PEEP) titration are commonly employed strategies in lung-protective ventilation to reopen collapsed alveoli and improve oxygenation. However, the effect of these strategies on dead space—a key indicator of ventilation-perfusion mismatch—remains underexplored. This study aimed to investigate the impact of RMs and PEEP titration on dead space in patients with ARDS. Material and Method: This prospective observational study included twelve early-phase ARDS patients. After initial stabilization, each patient underwent a standard RM protocol followed by decremental PEEP titration. Dead space parameters, lung mechanics, blood gases, and hemodynamic variables were measured before and after RM and individualized PEEP titration. Results: A statistically significant reduction in both airway and physiological dead space was observed following RM. PaO₂ and oxygen saturation increased, while arterial pH decreased modestly. Alveolar dead space, compliance, airway pressures, end-tidal CO₂, and hemodynamics did not change significantly. Conclusion: Individualized ventilation strategies with RMs and PEEP may reduce physiological dead space and improve oxygenation in early ARDS without causing significant hemodynamic compromise. These findings suggest that incorporating dead space monitoring could be considered in personalized approaches to help optimize gas exchange and potentially improve clinical outcomes