Lung stress and strain during mechanical ventilation: any safe threshold?

Rationale: Unphysiologic strain (the ratio between tidal volume and functional residual capacity) and stress (the transpulmonary pressure) can cause ventilator-induced lung damage.

Objectives: To identify a strain-stress threshold (if any) above which ventilator-induced lung damage can occur.

Methods: Twenty-nine healthy pigs were mechanically ventilated for 54 hours with a tidal volume producing a strain between 0.