From: The future of driving pressure: a primary goal for mechanical ventilation?
▪ 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 [11] ▪ Lung stress: the applied force to lungs during ventilation = transpulmonary pressure [11] ▪ “Baby lung”: the concept that represents the reduced functional lung volume typically observed among patients with ARDS [13] |