Alveolar overdistension as a cause of lung injury: differences among three animal species.
This study analyses characteristics of lung injuries produced by alveolar overdistension in three animal species. Mechanical ventilation at normal tidal volume (10 mL/Kg) and high tidal volume (50 mL/Kg) was applied for 30 min in each species. Data were gathered on wet/dry weight ratio, histological score, and area of alveolar collapse. Five out of six rabbits with high tidal volume developed tension pneumothorax, and the rabbit results were therefore not included in the histological analysis. Lungs from the pigs and rats showed minimal histological lesions. Pigs ventilated with high tidal volume had significantly greater oedema, higher neutrophil infiltration, and higher percentage area of alveolar collapse than rats ventilated with high tidal volume. We conclude that rabbits are not an appropriate species for in vivo studies of alveolar overdistension due to their fragility. Although some histological lesions are observed in pigs and rats, the lesions do not appear to be relevant.
Intensive Care Unit, Hospital Universitario Virgen de las Nieves, 18014 Granada, Spain. mjgardel@telefonica.net
Manuel
M
García-Delgado
Inés
I
Navarrete-Sánchez
Virginia
V
Chamorro-Marín
Juan Carlos
JC
Díaz-Monrové
Javier
J
Esquivias
Enrique
E
Fernández-Mondéjar
D000818:Animals; D008168:Lung / Q000033:anatomy & histology / Q000503:physiopathology*; D055370:Lung Injury / Q000503:physiopathology*; D011030:Pneumothorax / Q000503:physiopathology; D011175:Positive-Pressure Respiration / Q000379:methods; D011650:Pulmonary Alveoli / Q000033:anatomy & histology / Q000503:physiopathology; D011817:Rabbits; D051381:Rats; D017208:Rats, Wistar; D012121:Respiration, Artificial; D015656:Respiratory Mechanics; D013045:Species Specificity; D013552:Swine; D013990:Tidal Volume