End-Expiratory transpulmonary pressure is calculated as which of the following?

End-Expiratory transpulmonary pressure is calculated as which of the following?

• A. Paw - PEEP
• B. Pes - PEEP
• C. Pplat - Pes
• D. PEEP - Pes

Answer: (D)

End-expiratory transpulmonary pressure is the distending pressure across the lung at the end of expiration. It’s found by taking the airway pressure at end-expiration (which is the PEEP when the airway is not actively flowing) and subtracting the pleural pressure, approximated by esophageal pressure. So end-expiratory transpulmonary pressure = PEEP − Pes. This tells you how much positive pressure is actively distending the lung tissue at the end of expiration, which helps assess the risk of collapse versus overdistension as you adjust PEEP. Using other formulas would reflect different moments or conditions: for example, end-inspiratory transpulmonary pressure uses plateau pressure minus Pes, while Paw minus PEEP would not reflect the actual distending pressure at end-expiration because Paw at that instant equals PEEP.

End-expiratory transpulmonary pressure is the distending pressure across the lung at the end of expiration. It’s found by taking the airway pressure at end-expiration (which is the PEEP when the airway is not actively flowing) and subtracting the pleural pressure, approximated by esophageal pressure. So end-expiratory transpulmonary pressure = PEEP − Pes. This tells you how much positive pressure is actively distending the lung tissue at the end of expiration, which helps assess the risk of collapse versus overdistension as you adjust PEEP.

Using other formulas would reflect different moments or conditions: for example, end-inspiratory transpulmonary pressure uses plateau pressure minus Pes, while Paw minus PEEP would not reflect the actual distending pressure at end-expiration because Paw at that instant equals PEEP.