title: Short courses of mechanical ventilation with high-O2 levels in elderly rat lungs.
abstract: OBJECTIVE
  To evaluate the effects of mechanical ventilation (MV) of high-oxygen concentration in pulmonary dysfunction in adult and elderly rats.
  
  
  METHODS
  Twenty-eight adult (A) and elderly (E), male rats were ventilated for 1 hour (G-AV1 and G-EV1) or for 3 hours (G-AV3 and G-EV3). A and E groups received a tidal volume of 7 mL/kg, a positive end-expiratory pressure of 5 cm H2O, respiratory rate of 70 cycles per minute, and an inspiratory fraction of oxygen of 1. We evaluated total protein content and malondialdehyde in bronchoalveolar lavages (BAL) and performed lung histomorphometrical analyses.
  
  
  RESULTS
  In G-EV1 animals, total protein in BAL was higher (33.0±1.9 µg/mL) compared with G-AV1 (23.0±2.0 µg/mL). Upon 180 minutes of MV, malondialdehyde levels increased in elderly (G-EV3) compared with adult (G-AV3) groups. Malondialdehyde and total proteins in BAL after 3 hours of MV were higher in elderly group than in adults. In G-EV3 group we observed alveolar septa dilatation and significative increase in neutrofiles number in relation to adult group at 60 and 180 minutes on MV.
  
  
  CONCLUSIONS
  A higher fraction of inspired oxygen in short courses of mechanical ventilation ameliorates the parameters studied in elderly lungs.
authors: Department of Preventive Medicine, UNIFESP, Sao Paulo, SP, Brazil.
authors: Sâmia Santos
authors: SS
authors: Cavassani
authors: Virginia Berlanga Campos
authors: VB
authors: Junqueira
authors: Juliana Britto
authors: JB
authors: Moraes
authors: Karen Kristina
authors: KK
authors: Luzo
authors: Claudeny Matos Assis
authors: CM
authors: Silva
authors: Maciel
authors: M
authors: Barros
authors: Márcia
authors: M
authors: Marinho
authors: Ricardo Santos
authors: RS
authors: Simões
authors: Itamar Souza
authors: IS
authors: Oliveira-Júnior
mesh_terms: D000818:Animals; D001992:Bronchoalveolar Lavage Fluid; D006612:High-Frequency Ventilation / Q000379:methods*; D008168:Lung / Q000737:chemistry / Q000166:cytology*; D008297:Male; D008315:Malondialdehyde / Q000032:analysis; D023421:Models, Animal; D010100:Oxygen / Q000008:administration & dosage*; D011175:Positive-Pressure Respiration; D051381:Rats; D017208:Rats, Wistar; D013990:Tidal Volume; D013997:Time Factors
chemical_list: D008315:Malondialdehyde; D010100:Oxygen