Ultrastructural study of alveolar epithelial type II cells by high-frequency oscillatory ventilation.

Alveolar epithelial type II cells (AECIIs) containing lamellar bodies (LBs) are alveolar epithelial stem cells that have important functions in the repair of lung structure and function after lung injury. The ultrastructural changes in AECIIs after high-frequency oscillatory ventilation (HFOV) with a high lung volume strategy or conventional ventilation were evaluated in a newborn piglet model with acute lung injury (ALI). After ALI with saline lavage, newborn piglets were randomly assigned into five study groups (three piglets in each group), namely, control (no mechanical ventilation), conventional ventilation for 24 h, conventional ventilation for 48 h, HFOV for 24 h, and HFOV for 48 h.

High frequency oscillatory ventilation versus conventional ventilation in a newborn piglet model with acute lung injury.

Background: High frequency oscillatory ventilation (HFOV) is considered a protective strategy for human lungs. This study was designed to define microscopic structural features of lung injury following HFOV with a high lung volume strategy in newborn piglets with acute lung injury.

Methods: After acute lung injury with saline lavage, newborn piglets were randomly assigned to 5 study groups (6 in each group): control (no mechanical ventilation), conventional mechanical ventilation for 24 hours, conventional ventilation for 48 hours, HFOV for 24 hours, and HFOV for 48 hours.