Intermittent alveolar overdistension for 30 or 240 minutes does not produce acute lung injury in normal pig lung.

Background: The objective is to study whether alveolar overdistension can induce acute lung injury in pigs as assessed by analysis of respiratory and histological parameters and inflammatory markers.

Materials And Methods: Experimental study, using mixed-breed pigs. Animals were assigned to one of the following groups: Control Group (CG) (n = 5), applying mechanical ventilation with tidal volume (Vt) of 10 ml/kg, respiratory rate (RR) of 18 bpm, and FiO2 of 1 for 240 min; High Vt for 30 min (HVt-30) Group (n = 5), applying ventilation with Vt of 50 ml/kg and RR of 8 bpm and FiO2 of 1 for 30 min, followed by ventilation as in the CG for a further 210 min; and HVt-240 Group (n = 5), applying ventilation with Vt of 50 ml/kg, RR of 8 bpm, and FiO2 of 1 for 240 min.