Abstract PCCLB-59: MORPHOLOGICAL CHANGES FOLLOWING EXPERIMENTAL LUNG RECRUITMENT IN DIFFERENT CHEST WALL ELASTANCE

Abstract

Aims & Objectives: Background: The previous studies have showed the evidence of high-end inspiratory lung stretch lead to diffuse alveolar damage as an impact of the stress and strain during mechanical ventilation. Aims: To observe the morphological changes of the lung tissues and cells following acute experimental lung recruitment. Methods We conduct the experimental study using piglet as animal model of VILI. Nine eligible healthy mixed breed domestic piglets were divided into 2 groups: splinted chest wall (weight 5.680 ± 1.362 kg) and control (weight 6.250 ± 1.121 kg). Animals were anesthetized, paralyzed with supine position and ventilated in pressure control mode with the target tidal volume 4–5 mL/kgBW. After warm saline bronchial lavage, recruitment maneuver was performed in staircase increment-decrement technique. The lung tissues were obtained the morphologic changes by using the modified American Thoracic Society lung injury score. The cellular damages were recognized by detected apoptosis with TUNEL assay. Results Recruitment maneuver was proven improve the oxygenation and maintain the gas exchange in all of groups. The lung tissue infiltrated of neutrophils in alveolar and interstitial space, formation of hyaline membranes and proteinaceous debris filling the airspaces. Apoptosis of the epithelium cells was no statistically significant difference between intervention and control group. The ultra-structure analysis showed that lamellar bodies of pneumocyte type II of control group were intact. The lamellar bodies of pneumocytes type II in intervention group were condensate and forming lumps, some nuclear membrane was rupture. Conclusions There were different changes of lung tissues and cells morphology following lung recruitment in the different chest wall elastance.