Dependence of lung injury on inflation rate during low-volume ventilation in normal open-chest rabbits
Articolo
Data di Pubblicazione:
2004
Citazione:
Dependence of lung injury on inflation rate during low-volume ventilation in normal open-chest rabbits / E. D'Angelo, M. Pecchiari, M. Saetta, E. Balestro, J. Milic Emili. - In: JOURNAL OF APPLIED PHYSIOLOGY. - ISSN 8750-7587. - 97:1(2004), pp. 260-268. [10.1152/japplphysiol.01175.2003]
Abstract:
Lung mechanics and morphometry were assessed in two groups of nine normal open-chest rabbits mechanically ventilated (MV) for 3-4 h at zero end-expiratory pressure (ZEEP) with physiological tidal volumes (Vt; 11 ml/kg) and high (group A) or low (group B) inflation flow (44 and 6.1 ml x kg(-1) x s(-1), respectively). Relative to initial MV on positive end-expiratory pressure (PEEP; 2.3 cmH(2)O), MV on ZEEP increased quasi-static elastance and airway and viscoelastic resistance more in group A (+251, +393, and +225%, respectively) than in group B (+180, +247, and +183%, respectively), with no change in viscoelastic time constant. After restoration of PEEP, quasi-static elastance and viscoelastic resistance returned to control, whereas airway resistance, still relative to initial values, remained elevated more in group A (+86%) than in group B (+33%). In contrast, prolonged high-flow MV on PEEP had no effect on lung mechanics of seven open-chest rabbits (group C). Gas exchange on PEEP was equally preserved in all groups, and the lung wet-to-dry ratios were normal. Relative to group C, both groups A and B had an increased percentage of abnormal alveolar-bronchiolar attachments and number of polymorphonuclear leukocytes in alveolar septa, the latter being significantly larger in group A than in group B. Thus prolonged MV on ZEEP with cyclic opening-closing of peripheral airways causes alveolar-bronchiolar uncoupling and parenchymal inflammation with concurrent, persistent increase in airway resistance, which are worsened by high-inflation flow
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
Airway-parenchymal coupling; Lung mechanics; Parenchymal inflammation; Recruitment-derecruitment of lung units; Viscoelasticity
Elenco autori:
E. D'Angelo, M. Pecchiari, M. Saetta, E. Balestro, J. Milic Emili
Link alla scheda completa: