Comparison between conventional protective mechanical ventilation and high-frequency oscillatory ventilation associated with the prone position

Abstract

ObjectiveTo compare the effects of high-frequency oscillatory ventilation and conventional protective mechanical ventilation associated with the prone position on oxygenation, histology and pulmonary oxidative damage in an experimental model of acute lung injury.MethodsForty-five rabbits with tracheostomy and vascular access were underwent mechanical ventilation. Acute lung injury was induced by tracheal infusion of warm saline. Three experimental groups were formed: healthy animals + conventional protective mechanical ventilation, supine position (Control Group; n = 15); animals with acute lung injury + conventional protective mechanical ventilation, prone position (CMVG; n = 15); and animals with acute lung injury + high-frequency oscillatory ventilation, prone position (HFOG; n = 15). Ten minutes after the beginning of the specific ventilation of each group, arterial gasometry was collected, with this timepoint being called time zero, after which the animal was placed in prone position and remained in this position for 4 hours. Oxidative stress was evaluated by the total antioxidant performance assay. Pulmonary tissue injury was determined by histopathological score. The level of significance was 5%.ResultsBoth groups with acute lung injury showed worsening of oxygenation after induction of injury compared with the Control Group. After 4 hours, there was a significant improvement in oxygenation in the HFOG group compared with CMVG. Analysis of total antioxidant performance in plasma showed greater protection in HFOG. HFOG had a lower histopathological lesion score in lung tissue than CMVG.ConclusionHigh-frequency oscillatory ventilation, associated with prone position, improves oxygenation and attenuates oxidative damage and histopathological lung injury compared with conventional protective mechanical ventilation.

High Frequency Oscillatory Ventilation in Pediatric Practice: A Single Center Experience in Saudi Arabia

“…As the debate about the value of HFOV in pediatric respiratory failure refractory to conventional means continues, the greater the need to share different experiences from different areas of the world to try to add to our understanding of this unresolved issue. We were able to demonstrate the clear value of HFOV rescue therapy in improving both oxygenation and ventilation as has been described by others from different areas of the world in our study population [1][2][3][4][5]. The majority of our patients had DAD as a pathophysiology, which explained the failure of both oxygenation and ventilation.…”

“…By using HFOV, we recruit diseased lung and improve oxygenation, and to some degree ventilation, by constantly distension using high mean airway pressure (MAP) with tidal volume less than anatomic dead space. Several studies in medical literature have suggested more improvement, mainly in oxygenation and also in ventilation, in patients managed with HFOV when compared to conventional mechanical ventilation (CMV) [1][2][3][4][5]. Despite the wide use in all age groups and many success stories with this mode of HFOV, some newly published studies have described contradicting results.…”