title: Impairment of surfactant activity and ventilation by proteins in lung edema fluid.
abstract: We investigated the effects of lung edema protein on ventilatory mechanics with special reference to surfactant activity. The edema fluid was obtained from hyperoxia-exposed adult rabbits. In immature newborn rabbits that could not be artificially ventilated at an insufflation pressure of 25 cm H2O, mean tidal volumes of > 27 ml/kg were obtained by supplementation with a natural surfactant (S-alone) or natural surfactant mixed with lung edema fluid (EF), the edema protein-to-surfactant ratio of which was < or = 5.6. A mixture with a ratio of 11.2 (11.2-EF/S), however, decreased the volume to 10.9 ml/kg (P < 0.05 vs S-alone). Surfactant mixed with isolated albumin at a concentration equal to that in 11.2-EF/S decreased the tidal volume to 8.6 ml/kg (NS vs 11.2-EF/S), and with isolated fibrinogen lowered it to 18.1 mg/kg (P < 0.05 vs S-alone). We conclude that lung edema fluid impairs ventilation through surfactant inactivation when the protein-to-surfactant ratio increases, and that albumin and fibrinogen are the main causes of this impairment.
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, School of Medicine, Kanazawa University, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Nitta
authors.forename: T
authors.initials: T
authors.lastname: Kobayashi
mesh_terms: D000418:Albumins / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D001826:Body Fluids / Q000378:metabolism; D005340:Fibrinogen / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*; D011654:Pulmonary Edema / Q000378:metabolism / Q000503:physiopathology*; D011663:Pulmonary Surfactants / Q000378:metabolism*; D011817:Rabbits; D015656:Respiratory Mechanics / Q000502:physiology*; D013990:Tidal Volume / Q000502:physiology
chemical_list: D000418:Albumins; D011506:Proteins; D011663:Pulmonary Surfactants; D005340:Fibrinogen