title: The Effects of Prone Position Ventilation on Experimental Mild Acute Lung Injury Induced by Intraperitoneal Lipopolysaccharide Injection in Rats.
abstract: BACKGROUND
  The benefits of prone position ventilation are well demonstrated in the severe forms of acute respiratory distress syndrome, but not in the milder forms. We investigated the effects of prone position on arterial blood gases, lung inflammation, and histology in an experimental mild acute lung injury (ALI) model.
  
  
  METHODS
  ALI was induced in Wistar rats by intraperitoneal Escherichia coli lipopolysaccharide (LPS, 5 mg/kg). After 24 h, the animals with PaO2/FIO2 between 200 and 300 mmHg were randomized into 2 groups: prone position (n = 6) and supine position (n = 6). Both groups were compared with a control group (n = 5) that was ventilated in the supine position. All of the groups were ventilated for 1 h with volume-controlled ventilation mode (tidal volume = 6 ml/kg, respiratory rate = 80 breaths/min, positive end-expiratory pressure = 5 cmH2O, inspired oxygen fraction = 1) RESULTS: Significantly higher lung injury scores were observed in the LPS-supine group compared to the LPS-prone and control groups (0.32 ± 0.03; 0.17 ± 0.03 and 0.13 ± 0.04, respectively) (p < 0.001), mainly due to a higher neutrophil infiltration level in the interstitial space and more proteinaceous debris that filled the airspaces. Similar differences were observed when the gravity-dependent lung regions and non-dependent lung regions were analyzed separately (p < 0.05). The BAL neutrophil content was also higher in the LPS-supine group compared to the LPS-prone and control groups (p < 0.05). There were no significant differences in the wet/dry ratio and gas exchange levels.
  
  
  CONCLUSIONS
  In this experimental extrapulmonary mild ALI model, prone position ventilation for 1 h, when compared with supine position ventilation, was associated with lower lung inflammation and injury.
authors.affiliation: Pulmonary Research Laboratory, Hospital Universitário da Universidade Federal de Juiz de Fora, Av. Eugênio do Nascimento - s/nº, Dom Bosco, Juiz de Fora, MG, 36038-330, Brazil.|Center of Reproductive Biology, Universidade Federal de Juiz de Fora, Juiz de Fora, MG, Brazil.
authors.forename: Aydra Mendes Almeida
authors.initials: AM
authors.lastname: Bianchi
authors.affiliation: Pulmonary Research Laboratory, Hospital Universitário da Universidade Federal de Juiz de Fora, Av. Eugênio do Nascimento - s/nº, Dom Bosco, Juiz de Fora, MG, 36038-330, Brazil.|Center of Reproductive Biology, Universidade Federal de Juiz de Fora, Juiz de Fora, MG, Brazil.
authors.forename: Maycon Moura
authors.initials: MM
authors.lastname: Reboredo
authors.affiliation: Pulmonary Research Laboratory, Hospital Universitário da Universidade Federal de Juiz de Fora, Av. Eugênio do Nascimento - s/nº, Dom Bosco, Juiz de Fora, MG, 36038-330, Brazil.|Center of Reproductive Biology, Universidade Federal de Juiz de Fora, Juiz de Fora, MG, Brazil.
authors.forename: Leda Marília Fonseca
authors.initials: LM
authors.lastname: Lucinda
authors.affiliation: Pulmonary Research Laboratory, Hospital Universitário da Universidade Federal de Juiz de Fora, Av. Eugênio do Nascimento - s/nº, Dom Bosco, Juiz de Fora, MG, 36038-330, Brazil.|Center of Reproductive Biology, Universidade Federal de Juiz de Fora, Juiz de Fora, MG, Brazil.
authors.forename: Fernando Fonseca
authors.initials: FF
authors.lastname: Reis
authors.affiliation: Pulmonary Research Laboratory, Hospital Universitário da Universidade Federal de Juiz de Fora, Av. Eugênio do Nascimento - s/nº, Dom Bosco, Juiz de Fora, MG, 36038-330, Brazil.|Center of Reproductive Biology, Universidade Federal de Juiz de Fora, Juiz de Fora, MG, Brazil.
authors.forename: Manfrinni Vinícius Alves
authors.initials: MV
authors.lastname: Silva
authors.affiliation: Pulmonary Research Laboratory, Hospital Universitário da Universidade Federal de Juiz de Fora, Av. Eugênio do Nascimento - s/nº, Dom Bosco, Juiz de Fora, MG, 36038-330, Brazil.
authors.forename: Maria Aparecida Esteves
authors.initials: MA
authors.lastname: Rabelo
authors.affiliation: Laboratory of Respiration, Department of Internal Medicine, Universidade Federal do Ceará, Fortaleza, CE, Brazil.
authors.forename: Marcelo Alcantara
authors.initials: MA
authors.lastname: Holanda
authors.affiliation: Pulmonary Research Laboratory, Hospital Universitário da Universidade Federal de Juiz de Fora, Av. Eugênio do Nascimento - s/nº, Dom Bosco, Juiz de Fora, MG, 36038-330, Brazil.
authors.forename: Júlio César Abreu
authors.initials: JC
authors.lastname: Oliveira
authors.affiliation: Hospital Universitario de Getafe, Madrid, Spain.|CIBER de Enfermedades Respiratorias, Madrid, Spain.|Universidad Europea, Madrid, Spain.
authors.forename: José Ángel
authors.initials: JÁ
authors.lastname: Lorente
authors.affiliation: Pulmonary Research Laboratory, Hospital Universitário da Universidade Federal de Juiz de Fora, Av. Eugênio do Nascimento - s/nº, Dom Bosco, Juiz de Fora, MG, 36038-330, Brazil. bvallepinheiro@gmail.com.|Center of Reproductive Biology, Universidade Federal de Juiz de Fora, Juiz de Fora, MG, Brazil. bvallepinheiro@gmail.com.
authors.forename: Bruno do Valle
authors.initials: Bdo V
authors.lastname: Pinheiro
mesh_terms: D055371:Acute Lung Injury / Q000097:blood / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control*; D000818:Animals; D004195:Disease Models, Animal; D007274:Injections, Intraperitoneal; D008070:Lipopolysaccharides; D008168:Lung / Q000473:pathology* / Q000503:physiopathology; D008297:Male; D020556:Neutrophil Infiltration; D011014:Pneumonia / Q000097:blood / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control*; D011175:Positive-Pressure Respiration / Q000009:adverse effects / Q000379:methods*; D016684:Prone Position; D017208:Rats, Wistar; D056152:Respiratory Rate; D016683:Supine Position; D013990:Tidal Volume; D055397:Ventilator-Induced Lung Injury / Q000097:blood / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control*
chemical_list: D008070:Lipopolysaccharides; C482199:lipopolysaccharide, E coli O55-B5
keywords: Acute respiratory distress syndrome; Experimental model; Prone position; Ventilator-induced lung injury