Fig. 4

Outcomes in pigs according to end-inspiratory volumes. Mean(± standard deviation) for different variables. Pigs were grouped according to normalized inspiratory volume lower (BELOW), within (WITHIN), or higher (ABOVE) than normal inspiratory capacity and according to outcome: ALIVE (white bars) or DEAD (gray bars). The whole bar indicates a dynamic (coarse stack) and a static component (no pattern). A solid horizontal line represents the average reference value; medium-dashed lines represent mean ± 2 standard deviations reference values, i.e., the lower and upper limits of the variable. Statistical analysis: two-way ANOVA or on ranks, as appropriate (fixed effects: inspiratory volume and outcome). a Total end-inspiratory volume (mL/kg, whole bar) (Inspiratory volume P < 0.001, Outcome P = 0.073, Interaction = 0.067), tidal volume (mL/kg, coarse pattern) (Inspiratory volume P = 0.106, Outcome P = 0.040, Interaction P = 0.908), PEEP volume (mL/kg, no pattern) (Inspiratory volume P < 0.001, Outcome P = 0.306, Interaction P = 0.537). Reference value: inspiratory capacity (CT scan) normalized on body weight. b Total strain (whole bar) (Inspiratory volume P < 0.001, Outcome P = 0.059, Interaction P = 0.245), dynamic strain (coarse pattern) (Inspiratory volume P = 0.536, Outcome P = 0.004, Interaction P = 0.428), static strain (no pattern) (Inspiratory volume P = 0.006, Outcome P = 0.500, Interaction P = 0.438). Reference value: inspiratory capacity (CT scan) on FRC. c Absolute plateau airway pressure (whole bar) (Inspiratory volume P < 0.001, Outcome P = 0.107, Interaction P = 0.970), plateau airway pressure minus PEEP (coarse pattern) (Inspiratory volume P < 0.001, Outcome P < 0.001, Interaction P = 0.437), PEEP (no pattern) (Inspiratory volume P = 0.024, Outcome P = 0.271, Interaction P = 0.723). Reference value: airway pressure at upper inflation point (PV curve). d Total stress (whole bar) (Inspiratory volume P < 0.001, Outcome P = 0.797, Interaction P = 0.344), dynamic stress (coarse pattern) (Inspiratory volume P < 0.001, Outcome P = 0.092, Interaction P = 0.330), static stress (no pattern) (Inspiratory volume P = 0.014, Outcome P = 0.474, Interaction P = 0.756). Reference value: airway pressure reference values multiplied by the ratio of transpulmonary pressure at the upper inflation point (PV curve) to airway pressure at the upper inflation point