Adaptive Dynamic Subtidal Volume Ventilation (ADSV) Technology: Fluid Dynamic Principles and Physiologic Rationale for Personalized Treatment of Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) imposes regionally heterogeneous, time-dependent alterations in pulmonary mechanics that fundamentally limit conventional ventilation strategies. Fixed-parameter approaches targeting global pressure, volume, or timing thresholds cannot simultaneously address the competing demands of alveolar recruitment and volutrauma prevention, nor can they adapt dynamically to the wide regional variation in compliance, resistance, and expiratory time constants that characterizes the injured lung. These limitations persist across volume-controlled, pressure-controlled, high-frequency oscillatory, and time-controlled ventilation strategies. This article provides a clinically oriented narrative review of the physiologic and fluid-dynamic principles underlying Adaptive Dynamic Subtidal Ventilation (ADSV), an emerging ventilation technology that incorporates a proximal airway device—the Sliding Venturi—that passively modulates subtidal gas delivery in response to evolving respiratory system mechanics. The device utilizes the Bernoulli and Venturi effects to establish a passive pressure–flow feedback mechanism in which downstream respiratory system mechanics influence gas entrainment, delivered subtidal volume, and airway pressure. In the low-compliance (high-elastance) ARDS lung, this may limit gas entrainment and subtidal volume delivery while maintaining distending pressure. As compliance improves, entrainment may increase, permitting larger subtidal volumes at lower pressures. This self-regulating behavior operates on millisecond timescales and adapts to changes in overall respiratory system mechanics. Patient-proximal placement facilitates rapid expiratory venting, potentially reducing circuit-related expiratory resistance and dynamic hyperinflation, although these effects require experimental validation. ADSV therefore provides a fluid-dynamic framework for mechanically responsive subtidal ventilation that may help manage the changing respiratory mechanics associated with ARDS. Bench and computational studies, followed by preclinical and clinical investigations, are needed to characterize device performance, evaluate regional physiological effects, and establish safety and efficacy in ARDS.