▪ Driving pressure (DP): the change in airway pressure during a tidal breath.|
◦ DP = Pplat − PEEP
◦ Crs = Vt/(Pplat − PEEP) = Vt/DP
◦ DP = Vt/Crs
Thus, DP represents the tidal volume corrected for the patient’s respiratory system compliance.
*Transpulmonary driving pressure (DPL): DPL represents dynamic stress that takes into account the chest wall elastance whereas DP represents total (dynamic plus static) stress.
◦ DPL = (Pplat − PEEP) − (plateau esophageal pressure − end-expiratory esophageal pressure)
▪ Static compliance of the respiratory system (Crs): the compliance measured during periods without gas flow. Crs is strongly correlated with the volume of the baby lung [13, 14]
▪ Cyclic lung strain: the magnitude of lung deformation (change of volume) during each ventilator cycle 
▪ Lung stress: the applied force to lungs during ventilation = transpulmonary pressure 
▪ “Baby lung”: the concept that represents the reduced functional lung volume typically observed among patients with ARDS