Figure 2.

Pressure-volume curve of the respiratory system, depicting all components needed to calculate the mechanical energy transferred from the mechanical ventilator to the respiratory system. The blue area depicts the elastic property of the respiratory system with the respective fraction in the energy formula [ΔV² × (0.5 × E_RS)]. The white area represents the resistive property of the respiratory system, which is associated with the respective fraction in the energy formula [RR × (1+ I:E)/60× I:E × Raw]. The orange area represents the PEEP volume, depicted in the energy formula by ΔV × PEEP. Modified from Tonetti et al. (79).