What is the absolute harmful threshold of end-inspiratory transpulmonary pressure associated with dangerous lung strain?

What is the absolute harmful threshold of end-inspiratory transpulmonary pressure associated with dangerous lung strain?

• A. 40 cm H2O
• B. 15 cm H2O
• C. 10 cm H2O
• D. 27 cm H2O

Answer: (D)

End-inspiratory transpulmonary pressure is the distending pressure across the lung at the end of inspiration, reflecting the net force trying to expand the lung when airway pressure and chest wall recoil act together. When this pressure reaches about 27 cm H2O, the risk of alveolar overdistension—and thus volutrauma and lung injury—increases markedly. That’s why keeping end-inspiratory transpulmonary pressure around or below the mid-20s to ~27 cm H2O is aimed for in ventilator management. Values well above this, such as around 40 cm H2O, carry a higher injury risk, while much lower values (10–15 cm H2O) are safer but may indicate underdistension depending on lung mechanics.

End-inspiratory transpulmonary pressure is the distending pressure across the lung at the end of inspiration, reflecting the net force trying to expand the lung when airway pressure and chest wall recoil act together. When this pressure reaches about 27 cm H2O, the risk of alveolar overdistension—and thus volutrauma and lung injury—increases markedly. That’s why keeping end-inspiratory transpulmonary pressure around or below the mid-20s to ~27 cm H2O is aimed for in ventilator management. Values well above this, such as around 40 cm H2O, carry a higher injury risk, while much lower values (10–15 cm H2O) are safer but may indicate underdistension depending on lung mechanics.