title: On the crucial ventilatory setting adjustment from two- to one-lung ventilation.
abstract: Lung mechanics, histology, oxygenation and type-III procollagen (PCIII) mRNA were studied aiming to evaluate the need to readjust ventilatory pattern when going from two- to one-lung ventilation (OLV). Wistar rats were assigned to three groups: the left lung was not ventilated while the right lung received: (1) tidal volume (V(T))=5 ml/kg and positive end-expiratory pressure (PEEP)=2 cm H(2)O (V5P2), (2) V(T)=10 ml/kg and PEEP=2 cm H(2)O (V10P2), and (3) V(T)=5 ml/kg and PEEP=5 cm H(2)O (V5P5). At 1-h ventilation, V5P2 showed hypoxemia, alveolar collapse and impaired lung function. Higher PEEP minimized these changes and prevented hypoxemia. Although high V(T) prevented hypoxemia and maintained a higher specific compliance than V5P2, a morphologically inhomogeneous parenchyma and higher PCIII expression resulted. In conclusion, the association of low V(T) and an adequate PEEP level could be useful to maintain arterial oxygenation without inducing a possible inflammatory/remodeling response.
authors.affiliation: Laboratory of Respiration Physiology, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, RJ, Brazil. hcidrini@gmail.com
authors.forename: Halina C
authors.initials: HC
authors.lastname: Ferreira
authors.forename: Flavia
authors.initials: F
authors.lastname: Mazzoli-Rocha
authors.forename: Denise P
authors.initials: DP
authors.lastname: Momesso
authors.forename: Cristiane S N B
authors.initials: CS
authors.lastname: Garcia
authors.forename: Giovanna M C
authors.initials: GM
authors.lastname: Carvalho
authors.forename: Roberta M
authors.initials: RM
authors.lastname: Lassance-Soares
authors.forename: Luiz F M
authors.initials: LF
authors.lastname: Prota
authors.forename: Marcelo M
authors.initials: MM
authors.lastname: Morales
authors.forename: Débora S
authors.initials: DS
authors.lastname: Faffe
authors.forename: Alysson R
authors.initials: AR
authors.lastname: Carvalho
authors.forename: Patricia R M
authors.initials: PR
authors.lastname: Rocco
authors.forename: Walter A
authors.initials: WA
authors.lastname: Zin
mesh_terms: D000818:Animals; D008297:Male; D011175:Positive-Pressure Respiration / Q000379:methods*; D012123:Pulmonary Ventilation / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D015656:Respiratory Mechanics / Q000502:physiology*; D013990:Tidal Volume