Hypothermia was shown to attenuate ventilator-induced lung injury due to large tidal volumes. It is unclear if the protective effect of hypothermia is maintained under less injurious mechanical ventilation in animals without previous lung injury. Tracheostomized rats were randomly allocated to non-ventilated group (group C) or ventilated grou ps of normothermia (group N) and mild hypothermia (group H). After two hours of mechanical ventilation with inspiratory fraction of oxygen 1.0, respiratory rate 60 min-1 , tidal volume 10 ml·kg-1 , positive end-expiratory pressure (PEEP) 2 cm H 2 O or immediately after tracheostomy in non-ventilated animals inspiratory pressures were recorded, rats were sacrificed, pressure-volume (PV) curve of respiratory system constructed, bronchoalveolar lavage (BAL) fluid and aortic blood samples obtained. Group N animals exhibited a higher rise in peak inspiratory pressures in comparison to group H animals. Shift of the PV curve to right, higher total protein and interleukin- 6 levels in BAL fluid were observed in normothermia animals in comparison with hypothermia animals and non-ventilated controls. Tumor necrosis factor- α was lower in the hypothermia group in comparison with normothermia and non-ventilated groups. Mild hypothermia attenuated changes in respiratory system mechanics and modified cytokine concentration in bronchoalveolar lavage fluid during low lung volume ventilation in animals without previous lung injury., P. Dostál, M. Šenkeřík, R. Pařízková, D. Bareš, P. Živný, H. Živná, V. Černý., and Obsahuje bibliografii
The objective of our study was to assess the influence of mechanical ventilation on healthy body organs. Fifteen piglets (aged 6 weeks, 19-27 kg) were anesthetized, instrumented, and divided into three groups: Group A - spontaneously breathing, group B - mechanically ventilated with tidal volume 6 ml/kg, and group C - ventilated with tidal volume 10 ml/kg for 12 hours. The parameters of lung, heart, liver and kidney functions neurohumoral regulation and systemic inflammatory reaction were recorded initially (time-1) and after 12 hours (time-12) of mechanical ventilation. At the onset of experiment (time-1) the levels of soluble adhesive molecules were higher (CAM; P<0.01), glomerular filtration index and free water clearance were lower (P<0.05) in both ventilated groups than in group A. Right ventricle myocardial performance index was higher (RIMP; P<0.05) in group C when compared with group A. Levels of CAM (P<0.05) and creatinine clearance (P<0.01) were higher, free water clearance was lower (P<0.05) in group C when compared to group B. At time-12 the RIMP (P<0.05) and levels of CAM were increased (P<0.01), creatinine clearance was decreased (P<0.05) in both ventilated groups compared to the same parameter at time-1. Ventilation index was higher (P<0.05), and hypoxemic index was lower (P<0.01) in group C when compared to group B. In conclusion, this study showed that mechanical ventilation induced changes compatible with early inflammatory response in healthy animals. Higher tidal volumes had detrimental effect on ventilatory parameters, reduced myocardial performance and potentiated adverse reaction of other organs., J. Kobr ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy