Optimising positive end-expiratory pressure in acute respiratory distress syndrome: a narrative review of approaches to titration.

Positive end-expiratory pressure (PEEP) is a fundamental component of mechanical ventilation in patients with acute respiratory distress syndrome (ARDS). However, identifying the optimal PEEP remains a clinical challenge owing to the heterogeneity of lung injury and the resulting regional variability in mechanical properties. A variety of techniques have been proposed to guide individualised PEEP titration, each based on distinct physiological principles and associated with specific advantages and limitations. Among these, oxygenation-based titration remains the most commonly applied method, although its limitations are well recognised. Alternative strategies, including compliance-guided methods, driving pressure (ΔP) minimisation, and oesophageal pressure-guided ventilation, are gaining attention but require further validation. Imaging modalities, ranging from conventional chest radiography to advanced tools such as chest CT, electrical impedance tomography, and lung ultrasound, provide valuable insights into alveolar recruitment and can support more precise PEEP adjustment. This narrative review critically evaluates current approaches to PEEP titration in ARDS, emphasising the integration of physiological and imaging-based strategies to optimise lung recruitment while minimising ventilator-induced lung injury. An integrative strategy that combines physiological assessment, imaging, and continuous monitoring offers the greatest potential to individualise PEEP. Ongoing technological and clinical advances are likely to further improve the feasibility and effectiveness of personalised PEEP titration in critical care.