What is inverse ratio ventilation?

Inverse ratio ventilation is a mechanical ventilation strategy in which the duration of inspiration is extended relative to the duration of expiration. By intentionally shortening the expiration time and lengthening the inspiration time, this technique is employed to enhance oxygenation and improve gas exchange, particularly in conditions like acute respiratory distress syndrome (ARDS).

By prioritizing a longer inspiration phase, inverse ratio ventilation can help recruit collapsed alveoli and improve ventilation-perfusion matching. This approach can also lead to increased mean airway pressure, aiding in the delivery of more oxygen to the lung's surface area.

The other options do not accurately depict the principles of inverse ratio ventilation. Maintaining equal inspiration and expiration times or controlling both equally does not align with the fundamental characteristic of this technique, which actively modifies the ratio in favor of the inspiratory phase. Similarly, increasing expiration time while maintaining inspiration time would counter the goals of this ventilation strategy.