Proceedings of The Physiological Society

Europhysiology 2018 (London, UK) (2018) Proc Physiol Soc 41, PCA079

Poster Communications

Effects of high-frequency oscillatory ventilation vs conventional mechanical ventilation on lung function, inflammation and apoptosis in meconium-induced acute lung injury

D. Mokra1,2, P. Mikolka2,1, P. Kosutova2,1, S. Balentova3, M. Kolomaznik2,1, M. Adamkov3, A. Calkovska1

1. Department of Physiology, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Martin, Slovakia. 2. Biomedical Center Martin, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Martin, Slovakia. 3. Department of Histology and Embryology, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Martin, United Kingdom.

Choice of appropriate ventilation mode in severe meconium aspiration syndrome (MAS) is still discussed. Therefore, this study compared short-term effects of high-frequency oscillatory ventilation (HFOV) and conventional mechanical ventilation (CMV) provided by two conventional ventilators on the respiratory parameters, inflammation and lung cell apoptosis in experimental model of MAS to find out which of these modes is superior. Anaesthesized, meconium-instilled New Zealand young rabbits were oxygen-ventilated with HFOV (SLE5000, SLE Ltd., UK; MAS-HFOV, n=7), or with CMV supplied by ventilator SLE5000 (MAS-CMV-S, n=7) or ventilator Aura V (Chirana, Slovakia; MAS-CMV-A, n=7) for 4 hours. Other animals received saline instead of meconium and were CMV-ventilated by ventilator Aura V for 4 hours (VentC, n=7), or served as non-ventilated controls (C, n=6). Blood gases and respiratory parameters were regularly measured. At the end of experiment, left lung was saline-lavaged and protein content, and total and differential cell counts in bronchoalveolar lavage fluid were determined. Wet/dry lung weight ratio as a marker of edema formation was determined. Apoptosis of alveolar and bronchial lung cells was estimated immunohistochemically. Proinflammatory cytokines (TNFα, IL-1β, IL-8) in plasma and lung tissue were detected by enzyme-linked immunosorbent assay. Meconium instillation caused deterioration in gas exchange, neutrophil-mediated inflammation, lung edema formation, and lung cell apoptosis. Gas exchange was slightly enhanced in HFOV than in CMV, but the between-group differences were not significant. No significant differences among the meconium-instilled and HFOV- or CMV-ventilated groups were found in markers of lung edema formation or inflammation. However, higher number of caspase-3 immunoreactive cells in bronchial epithelium in MAS-HFOV group compared to non-ventilated and ventilated controls can indicate higher susceptibility of bronchial cells for apoptosis in HFOV. Both lung-protective ventilations (HFOV and CMV) supplied sufficient gas exchange with comparable impact on the lung, with no clear preference for any of the ventilation modes.

Where applicable, experiments conform with Society ethical requirements