| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Istituto di Fisiologia Umana I, Università di Milano, 20133 Milan; Dipartimento di Medicina Clinica e Sperimentale, Università di Padova, 35128 Padua, Italy; and Meakins-Christie Laboratories, McGill University, Montreal, Quebec, Canada H2X 2P2
Submitted 3 November 2003 ; accepted in final form 10 March 2004
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·kg–1·s–1, respectively). Relative to initial MV on positive end-expiratory pressure (PEEP; 2.3 cmH2O), 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.
lung mechanics; viscoelasticity; recruitment-derecruitment of lung units; airway-parenchymal coupling; parenchymal inflammation
This article has been cited by other articles:
|
|
 |
|
  E. D'Angelo, A. Koutsoukou, P. D. Valle, G. Gentile, and M. Pecchiari Cytokine release, small airway injury, and parenchymal damage during mechanical ventilation in normal open-chest rats J Appl Physiol, January 1, 2008; 104(1): 41 - 49. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. B. Drummond and J. Milic-Emili Forty years of closing volume Br. J. Anaesth., December 1, 2007; 99(6): 772 - 774. [Full Text] [PDF]
|
|
|
|
|
|
H. C. Yalcin, S. F. Perry, and S. N. Ghadiali Influence of airway diameter and cell confluence on epithelial cell injury in an in vitro model of airway reopening J Appl Physiol, November 1, 2007; 103(5): 1796 - 1807. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Moriondo, P. Pelosi, A. Passi, M. Viola, C. Marcozzi, P. Severgnini, V. Ottani, M. Quaranta, and D. Negrini Proteoglycan fragmentation and respiratory mechanics in mechanically ventilated healthy rats J Appl Physiol, September 1, 2007; 103(3): 747 - 756. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. A. Shore Obesity and asthma: lessons from animal models J Appl Physiol, February 1, 2007; 102(2): 516 - 528. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. D'Angelo, M. Pecchiari, and G. Gentile Dependence of lung injury on surface tension during low-volume ventilation in normal open-chest rabbits J Appl Physiol, January 1, 2007; 102(1): 174 - 182. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. D'Angelo, M. Pecchiari, P. D. Valle, A. Koutsoukou, and J. Milic-Emili Effects of mechanical ventilation at low lung volume on respiratory mechanics and nitric oxide exhalation in normal rabbits J Appl Physiol, August 1, 2005; 99(2): 433 - 444. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
