The use of transpulmonary pressure to set optimal positive end-expiratory pressure: A case report

The airway pressure generated by the mechanical ventilator does not distinguish the pressure generated within the lung from that which may be present outside of the lung. True lung pressure is transpulmonary pressure, which represents the actual movement of the lung (airway pressure - pleural pressure = transpulmonary pressure). Theoretically, if the pressure outside of the lung at end-exhalation was higher than the Positive End-expiratory Pressure (PEEP) set on the ventilator, the result would be atelectasis, and with subsequent breaths would place the patient at high risk of atelectrauma. This case is an example of how estimating transpulmonay pressure can assist the clinician to optimally set PEEP in a mechanically ventilated patient.