EFFECTS OF A COMBINATION OF PRONE POSITIONING AND HIGH-FREQUENCY OSCILLATORY VENTILATION ON BLOOD GAS EXCHANGE IN AN EXPERIMENTAL PIG MODEL OF ACUTE RESPIRATORY DISTRESS SYNDROME

This animal study was conducted in order to verify the effects of combining high-frequency oscillatory ventilation and prone positioning and the order of application of both methods on blood gas exchange in an experimental model of acute respiratory distress syndrome. Forty domestic pigs were used for the study. Saline solution washout was produced by bilateral lung lavage. The lavage process was repeated until adequate impairment of gas exchange (defined as PaO2 < 100 mmHg) 60 min following the last lavage was achieved. Subsequently, lung injury was established and each model was randomized to one of five groups, with differences in the type of mechanical ventilation used (conventional mechanical ventilation in accordance with the principles of protective lung ventilation or high-frequency oscillatory ventilation) and also in the positioning of the experimental model (supine position or mode changing prone and supine positions in a ratio 18: 6 hours). The best oxygenation was achieved in the group prone position + high-frequency oscillatory ventilation. The most favorable combination in terms of carbon dioxide elimination is the high-frequency oscillatory ventilation + prone position. The best results in terms of oxygenation index value were obtained in the combination of a prone position with the high-frequency oscillatory ventilation and in the prone position. In conclusion, by using combinations of prone positioning and high-frequency oscillatory ventilation, one can achieve better blood gas parameters during acute respiratory distress syndrome.