Continuous intra-tracheal gas insufflation during mechanical ventilation in juvenile piglets with acute lung injury induced by endotoxin / 中华急诊医学杂志

ABSTRACT

Objective To evaluate the effects of continuous intra-tracheal gas insufflation (TGI) during mechanical ventilation for protecting the juvenile piglets with acute lung injury (ALI) induced by endotoxin. Method Twelve healthy juvenile piglets were anesthetized and mechanically ventilated at 2 cmH2O PEEP with 10 cmH2O peak inspiration pressure. The piglets were challenged with lipopolysaccharide (LPS) and randomly (random number) assigned to two groups (n = 6 each): (1) piglets treated with mechanical ventilation alone (group MV) and (2) piglets treated with TGI by continuous airway flow of 2 L/min (group TGI). FiO2 was set at 0.4 to avoid oxygen toxicity, and the piglets were continuously monitored with an oxygen analyzer. Results Tidal volume, ventilation efficacy index and mean airway pressure were significantly improved in piglets of TGI group (P < 0.01 or P < 0.05). Four hours after ALI, pH decreased to below 7.20 in piglets of MV group, and was higher in piglets of TGI group (P < 0.01). Similarly, PaCO2 was stable and was significantly lower in piglets of TGI group than that in piglets of MV group (P < 0.01). PaO2 and PaO2/FiO2 increased in piglets of TGI group (P < 0.05). There were no significant differences in heart rate, respiraaatory rate, mean arterial pressure, central venous pressure, dynamic lung compliance and mean resistance of airway between two groups. Lung histopathological changes showed severe inflammation,and intra-alveolar hemorrhage and interstitial patchy hemorrhage were ameliorated and the lungs were more homogenously expanded in piglets of TGI group. Conclusions Continuous TGI during MV can significantly improve gas exchange and ventilation efficacy, and may provide a better treatment for acute lung injury.