I'm going to assume if you're reading this that you already know what transpulmonary pressure (PL) is and how esophageal manometry works. I'll provide a brief description here, but if you're looking for an in-depth review , I'd recommend a few of the excellent papers already published. The somewhat short version is this: Esophageal manometry is a method for separating the pressure applied across the lung (PL) from that created by the chest wall (PCW). Esophageal pressure is used as a surrogate for pleural pressure (PPl), and subtracting PPl from the airway pressure (PAW) measured by the ventilator equals PL.
PAW - PPl = PL
Ever since the ARDSNet trial highlighted the clinical consequences of overdistending the lung, we've been trying to fine-tune mechanical ventilation strategies. ARDSNet helped highlight the reality that ventilator-induced lung injury (VILI), which is often insidious and all but invisible at the bedside, drives outcomes more than gas-exchange variables that are easy to measure. Since ARDSNet, we've been studying ventilator measures like positive end-expiratory pressure (PEEP) and driving pressure, and specific techniques like recruitment maneuversUnfortunately, we've failed to identify specific mechanical ventilation settings that build on the clinical improvements seen with low tidal volume ventilation.
