Study on Mechanism of Hyperoxia Through Mechanical Ventilation Induced Lung Injury in Newborn Rabbit / 实用儿科临床杂志

ABSTRACT

Objective To explore the effect of hyperoxia through mechanical ventilation induced lung injury(VILI) in newborn rabbit.Methods One hundred newborn rabbits aged 1-5 days were randomly divided into 4 groups: with 900 mL/L O2 and mechanical ventilation(MV),group A received high peak inspiratory pressure(HPIP),group B received moderate peak inspiratory pressure(MPIP),group C received low peak inspiratory pressure(LPIP),and group D with no mechanical ventilation with room air.There were 30 rabbits in group A,B,C,10 rabbits in D group.All rabbits were killed at 1,3,6 h after trial respectively.Wet-to-dry weight ratio(W/D) of left lung,and white blood cell(WBC)counts in broncho alveolar lavage fluid(BALF) were measured.The changes of lung histopathology were assessed by hematoxylin-eosin(HE) staining and observed under light microscope.Results Compared with group B and C,the group A demonstrated more pulmonary hemorrhage and pulmonary bullae formation,and the WBC and neutrophils counts in BALF increased and the W/D was higher compared with group B and group C.Meanwhile,alveolar epithelial cellⅡ(AECⅡ) hyperplasy transformed to AECⅠ.In group C,AECⅡswelled and lung tissue edema showed obviously,after 6 hours collagen fibers hyperplasia appeared.Part pulmonary atelectasis was obvious in group C.Conclusions HPIP ventilation can increase lung injury induced by hyperoxia in newborn rabbits,but has minimal effects on MPIP and LPIP ventilation.Pulmonary histopathologic changes participate in the newborn rabbit machine ventilation induced lung injury.