Influence of the Lung Recruitment Potential on the Response to Two Positive End-Expiratory Pressure (PEEP) Titration Strategies in Patients With Acute Respiratory Distress Syndrome (ARDS)
Acute Respiratory Distress Syndrome (ARDS) is characterized by severe hypoxemia and diffuse alveolar collapse, often requiring invasive mechanical ventilation. Non-individualized mechanical ventilation settings can cause ventilator-induced lung injury (VILI). Positive end-expiratory pressure (PEEP) prevents alveolar collapse, but its effect varies among individuals. The recruitment-to-inflation (R/I) ratio evaluates bedside lung recruitment potential. This pilot study aims to compare two individualized PEEP titration strategies-one guided by the best static respiratory compliance and another guided by transpulmonary pressure via an esophageal balloon-and evaluate how baseline lung recruitment potential alters the early physiological responses to these interventions. Both strategies are preceded by an identical, standardized pressure-controlled initial lung recruitment maneuver to establish a baseline recruitment state.
• Diagnosis of moderate or severe Acute Respiratory Distress Syndrome (ARDS) according to the Berlin definition: acute onset, bilateral opacities not fully explained by heart failure or fluid overload, and Partial pressure of oxygen in arterial blood/Fraction of inspired oxygen \<= 200 mmHg with Positive End-Expiratory Pressure (PEEP) \>= 5 cmH2O.
• ARDS duration \< 36 hours since fully meeting Berlin consensus criteria.
• Relative hemodynamic stability: absence of refractory shock, defined as norepinephrine dose \<= 0.5 mcg/kg/min.