Proportional assist ventilation (PAV) is a mode in which the medical ventilator guarantees the percentage of work regardless of changes in pulmonary compliance and resistance.

The medical ventilator varies the tidal volume and pressure based on the patient's work of breathing. The amount it delivers is proportional to the percentage of assistance it is set to give.

PAV, like NAVA, supports both resistive and elastic work of breathing in proportion to the patient's inspiratory effort.