High-frequency oscillatory ventilation combined with partial liquid ventilation in experimental lung injury: effects on lung cell apoptosis

OBJECTIVE: To investigate the effects of high-frequency oscillatory ventilation (HFOV) and partial liquid ventilation (PLV) on apoptosis of lung tissue induced by steam inhalation injury in rabbit. DESIGN: A prospective, randomized, controlled, multiple-group study. SETTING: An animal research laboratory centre in a university burns centre. SUBJECTS: New Zealand rabbits (n = 32; 2.25 ± 0.25 kg) of either sex. INTERVENTIONS: The animals were ventilated by HFOV with a mean airway pressure of 10 cm H(2)O, a frequency of 10 Hz, an amplitude of 20 cm H(2)O, an inspiratory:expiratory ratio of 1:1, and an FiO(2) of 1.0. After the induction of acute lung injury (ALI) by steam inhalation, the animals were randomly divided into four groups: CMV, HFOV, CMV + PLV, HFOV + PLV group. Then they were ventilated for 4 h by CMV, HFOV, CMV + PLV and HFOV + PLV, respectively. After the experimental period, cell apoptosis and apoptosis indexes in the lung tissue were assessed with TUNEL FragELTM (Fragment End Labeling). RESULTS: Lung tissue apoptosis indexes in HFOV group and HFOV + PLV group were lower than that of in CMV group and CMV + PLV group; between-group comparison had significant difference (P < 0.01). HFOV + PLV group showed lowest apoptosis indexes. CONCLUSION: HFOV combined with PLV can suppress lung tissue apoptosis induced by steam inhalation.