Effects of different mechanical ventilation methods on morphology of type II alveolar epithelium cell in newborn piglets with acute lung injury

Objective To investigate the effects of 3 different ventilation methods, including conventional mechanical ventilation(CMV), high-frequency oscillatory ventilation(HFOV) and partial liquid ventilation(PLV), on the morphology of type Ⅱ alveolar epithelium cell(ACEⅡ) of newborn piglet with acute lung injury(ALI). Methods Twenty-four less than 3-day-old newborn piglets were enrolled.After ALI was established with saline lavage(38 ℃, 0.035 L/kg), newborn piglets were randomly assigned to 4 study groups: control group(n=6, no ventilation), CMV group(n=6), HFOV group(n=6), and PLV group(n=6, 38 ℃, 0.018 L/kg). Piglets in the 4 groups were sacrificed after being ventilated for 24 hours, and the number, area, density of fluorescence of ACEⅡ were detected. Results Through 24 hours mechanical ventilation, the numbers of ACEⅡ in CMV group, HFOV group and PLV group remained were 30±5, 52±5, 81±7, respectively, while areas of fluorescence were 340.40±47.50, 329.69±124.50, 295.55±109.30, respectively, and there were significant differences among the 3 groups, and the population mean of density of fluorescence had significant difference among the 3 groups.The number of ACEⅡremains was lowest in CMV group compared with HFOV group(P=0.026) and PLV group(P=0.000), and the density of fluorescence of ACEⅡ was lowest in CMV group compared with HFOV group(P=0.001) and PLV group(P=0.002). Conclusions Different mechanical ventilations have various effects for ACEⅡ, and CMV is the most harmful mechanical ventilation on ACEⅡ, while PLV is the least harmful. Key words: Mechanical ventilation; Type Ⅱ alveolar epithelium cell; Morphology; Newborn piglet