title: Effects of high-frequency oscillatory ventilation on oleic acid-induced lung injury in sheep.
abstract: High-frequency oscillatory ventilation (HFOV) is a possible mechanical method for open lung strategies. The aim of this study was to examine whether HFOV has a beneficial effect on oleic acid-induced lung injury, with emphasis on changes in extravascular lung water. Thirteen anesthetized sheep prepared with a lung lymph fistula and vascular catheters for monitoring were randomly allocated to two experimental groups. In experiment 1, sheep (n = 6) were ventilated using conventional mechanical ventilation [CMV; 10 ml/kg of tidal volume, 70% oxygen, and positive end-expiratory pressure (PEEP) of 6 cmH(2)O after oleic acid administration (0.08 ml/kg)]. In experiment 2, sheep (n=7) were ventilated using HFOV (frequency=15 Hz, stroke volume=120 ml, mean airway pressure=15 cmH(2)O) after administration of the same dose of oleic acid as in experiment 1. Observation was continued for 4 h after oleic acid administration, then bronchoalveolar lavage (BAL) was performed and the lung wet-to-dry weight ratio was determined. Compared with CMV, HFOV significantly improved the deteriorated oxygenation during the late phase (2-4 h) of oleic acid-induced lung injury without any deterioration effects on pulmonary or systemic hemodynamics. HFOV showed significantly reduced lung lymph protein clearance, which paralleled significant decreases in wet-to-dry ratios and neutrophil counts in BAL fluid in the HFOV group. These findings suggest that HFOV could contribute to decreased lung lymph filtration in pulmonary microcirculation and improved oxygenation following oleic acid-induced lung injury in sheep.
authors.affiliation: Department of Anesthesiology and Resuscitation, Shinshu University School of Medicine, 3-1-1 Asahi Matsumoto, 390-8621, Matsumoto, Japan.
authors.forename: Rikimaru
authors.initials: R
authors.lastname: Nakagawa
authors.affiliation: First Department of Internal Medicine, Shinshu University School of Medicine, 3-1-1 Asahi Matsumoto, 390-8621, Matsumoto, Japan. tomonobu@hsp.md.shinshu-u.ac.jp.
authors.forename: Tomonobu
authors.initials: T
authors.lastname: Koizumi
authors.affiliation: Department of Anesthesiology and Resuscitation, Shinshu University School of Medicine, 3-1-1 Asahi Matsumoto, 390-8621, Matsumoto, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Ono
authors.affiliation: First Department of Internal Medicine, Shinshu University School of Medicine, 3-1-1 Asahi Matsumoto, 390-8621, Matsumoto, Japan.
authors.forename: Sumiko
authors.initials: S
authors.lastname: Yoshikawa
authors.affiliation: First Department of Internal Medicine, Shinshu University School of Medicine, 3-1-1 Asahi Matsumoto, 390-8621, Matsumoto, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Tsushima
authors.affiliation: Department of Anesthesiology and Resuscitation, Shinshu University School of Medicine, 3-1-1 Asahi Matsumoto, 390-8621, Matsumoto, Japan.
authors.forename: Tetsutarou
authors.initials: T
authors.lastname: Otagiri
mesh_terms: D000818:Animals; D001794:Blood Pressure; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D002245:Carbon Dioxide / Q000097:blood; D002302:Cardiac Output; D004195:Disease Models, Animal; D006612:High-Frequency Ventilation; D008168:Lung / Q000378:metabolism* / Q000503:physiopathology; D055370:Lung Injury / Q000139:chemically induced / Q000378:metabolism / Q000503:physiopathology / Q000517:prevention & control*; D008196:Lymph / Q000378:metabolism; D020556:Neutrophil Infiltration; D019301:Oleic Acid; D010100:Oxygen / Q000097:blood; D011175:Positive-Pressure Respiration; D011506:Proteins / Q000378:metabolism; D011652:Pulmonary Circulation; D012756:Sheep; D013997:Time Factors
chemical_list: D011506:Proteins; D002245:Carbon Dioxide; D019301:Oleic Acid; D010100:Oxygen