Time-Controlled Adaptive Ventilation (TCAV): a personalized strategy for lung protection

Area of Science:

• Critical Care Medicine
• Respiratory Physiology
• Biomedical Engineering

Background:

• Acute respiratory distress syndrome (ARDS) presents significant challenges in mechanical ventilation due to lung heterogeneity.
• Current protective ventilation strategies like low tidal volume (LV_T) and open lung approach (OLA) have limitations in reducing ARDS-related mortality.
• Repetitive alveolar collapse and expansion (RACE) is a key mechanism contributing to ventilator-induced lung injury (VILI).

Purpose of the Study:

• To introduce and describe the Time Controlled Adaptive Ventilation (TCAV) method for applying Airway Pressure Release Ventilation (APRV) mode.
• To present TCAV as an alternative strategy to minimize VILI in ARDS patients by addressing lung heterogeneity.
• To highlight the potential of TCAV to reduce ARDS-related morbidity and mortality.

Main Methods:

• TCAV utilizes a closed-loop system to personalize expiratory duration, tidal volume (V_T), and end-expiratory lung volume (EELV).
• Personalization is achieved by monitoring changes in respiratory system compliance (C_RS) via the expiratory flow curve during passive exhalation.
• The method features a personalized expiratory duration for alveolar stabilization and an extended inspiratory phase for gradual reopening of collapsed lung tissue.

Main Results:

• TCAV aims to minimize alveolar collapse and progressive loss of EELV by personalizing expiratory duration.
• The strategy promotes alveolar stabilization, reducing the time for lung units to collapse between breaths.
• An extended inspiratory phase at fixed inflation pressure facilitates gradual reopening of collapsed lung regions over time.

Conclusions:

• TCAV offers a novel approach to mechanical ventilation in ARDS by adapting to patient-specific lung physiology.
• By minimizing RACE and optimizing lung recruitment, TCAV has the potential to significantly reduce VILI.
• This adaptive strategy may lead to improved outcomes, including reduced morbidity and mortality in ARDS patients.