title: Impact of mechanical ventilation and fluid load on pulmonary glycosaminoglycans.
abstract: The combined effect of mechanical ventilation and fluid load on pulmonary glycasaminoglycans (GAGs) was studied in anaesthetized rats ((BW 290±21.8 (SE)g) mechanically ventilated for 4h: (a) at low (∼7.5mlkg(-1)) or high (∼23mlkg(-1)) tidal volume (V(T)) and zero alveolar pressure; (b) at low or high V(T) at 5cmH(2)O positive end-expiratory pressure (PEEP); (c) with or without 7mlkg(-1)h(-1) intravenous infusion of Phosphate Buffer Solution (PBS). Compared to spontaneous breathing, GAGs extractability decreased by 52.1±1.5% and 42.2±7.3% in not-infused lungs mechanically ventilated at low V(T) or at high V(T) and PEEP, respectively. In contrast, in infused lungs, GAGs extractability increased by 56.1±4.0% in spontaneous ventilation and PEEP and up to 81.1% in all mechanically ventilated lungs, except at low V(T) without PEEP. In the absence of an inflammatory process, these results suggest that PEEP was protective at low but not at high V(T) when alveolar structures experience exceedingly high stresses. When combined to mechanical ventilation, fluid load might exacerbate edema development and lung injury.
authors.affiliation: Dept. Surgical and Morphological Sciences, University of Insubria, Varese, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Moriondo
authors.forename: Cristiana
authors.initials: C
authors.lastname: Marcozzi
authors.forename: Francesca
authors.initials: F
authors.lastname: Bianchin
authors.forename: Marcella
authors.initials: M
authors.lastname: Reguzzoni
authors.forename: Paolo
authors.initials: P
authors.lastname: Severgnini
authors.forename: Marina
authors.initials: M
authors.lastname: Protasoni
authors.forename: Mario
authors.initials: M
authors.lastname: Raspanti
authors.forename: Alberto
authors.initials: A
authors.lastname: Passi
authors.forename: Paolo
authors.initials: P
authors.lastname: Pelosi
authors.forename: Daniela
authors.initials: D
authors.lastname: Negrini
mesh_terms: D000818:Animals; D001825:Body Fluid Compartments; D045604:Extracellular Fluid / Q000502:physiology; D018495:Fluid Shifts; D006025:Glycosaminoglycans / Q000378:metabolism*; D008168:Lung / Q000378:metabolism; D008297:Male; D010953:Plasma Volume / Q000502:physiology; D011175:Positive-Pressure Respiration / Q000379:methods*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D012121:Respiration, Artificial / Q000009:adverse effects* / Q000145:classification; D013990:Tidal Volume; D055397:Ventilator-Induced Lung Injury / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology*
chemical_list: D006025:Glycosaminoglycans