Jiri Fremuth1, Jiri Kobr2, Katerina Pizingerova2, Lumir Sasek2, Petr Jehlicka2, Jana Zamboryova2, Ondrej Hess3, Jana Vrzalova4, Jaroslav Racek5, Zbynek Tonar6. 1. Pediatric intensive care unit (PICU), Department of Pediatrics, Faculty of Medicine, Charles University of Prague in Pilsen, Pilsen, Czech Republic fremuthj@gmail.com. 2. Pediatric intensive care unit (PICU), Department of Pediatrics, Faculty of Medicine, Charles University of Prague in Pilsen, Pilsen, Czech Republic. 3. Šikl Institute of Pathological Anatomy, Faculty of Medicine, Charles University of Prague in Pilsen, Pilsen, Czech Republic. 4. Central Laboratory of Immunoanalysis, Faculty of Medicine, Charles University of Prague in Pilsen, Pilsen, Czech Republic. 5. Department of Clinical Biochemistry and Hematology, Faculty of Medicine, Charles University of Prague in Pilsen, Pilsen, Czech Republic. 6. Department of Histology and Embryology, Faculty of Medicine, Charles University of Prague in Pilsen, Pilsen, Czech Republic Biomedical Centre, Faculty of Medicine, Charles University of Prague in Pilsen, Pilsen, Czech Republic.
Abstract
BACKGROUND: The aim of this comparative study was to assess the impact of two different settings of tidal volume (Vt) on the function and morphology of the mechanically ventilated lungs during a 12-h period. MATERIALS AND METHODS: A total of 32 animals were randomly divided into two groups. Group A included piglets ventilated with a Vt of 6 ml/kg and group B piglets ventilated with a Vt of 10 ml/kg. Lung functions and pulmonary mechanics were evaluated after 1 and 12 h of mechanical ventilation. Morphological changes of the lung tissue were evaluated at the end of the study. RESULTS: Twelve hours of lower Vt ventilation was associated with the development of respiratory acidosis but minimal histological changes. Higher Vt led to pronounced histological changes in terms of proliferation and apoptosis and a decrease of dynamic compliance, with a trend towards lower oxygenation during the study. CONCLUSION: Mechanical ventilation with a Vt of 6 ml/kg induces minimal histological lung parenchymal changes in terms of proliferation and apoptosis. Positive pressure mechanical ventilation with Vt of 10 ml/kg does not protect lung tissue and induces substantial proliferative and apoptotic changes within the lung parenchyma. Positive pressure mechanical ventilation with Vt of 10 ml/kg does not guarantee protection of healthy pulmonary tissue in the absence of a priming pulmonary insult.
BACKGROUND: The aim of this comparative study was to assess the impact of two different settings of tidal volume (Vt) on the function and morphology of the mechanically ventilated lungs during a 12-h period. MATERIALS AND METHODS: A total of 32 animals were randomly divided into two groups. Group A included piglets ventilated with a Vt of 6 ml/kg and group B piglets ventilated with a Vt of 10 ml/kg. Lung functions and pulmonary mechanics were evaluated after 1 and 12 h of mechanical ventilation. Morphological changes of the lung tissue were evaluated at the end of the study. RESULTS: Twelve hours of lower Vt ventilation was associated with the development of respiratory acidosis but minimal histological changes. Higher Vt led to pronounced histological changes in terms of proliferation and apoptosis and a decrease of dynamic compliance, with a trend towards lower oxygenation during the study. CONCLUSION: Mechanical ventilation with a Vt of 6 ml/kg induces minimal histological lung parenchymal changes in terms of proliferation and apoptosis. Positive pressure mechanical ventilation with Vt of 10 ml/kg does not protect lung tissue and induces substantial proliferative and apoptotic changes within the lung parenchyma. Positive pressure mechanical ventilation with Vt of 10 ml/kg does not guarantee protection of healthy pulmonary tissue in the absence of a priming pulmonary insult.