Relationship between airway pressure and the distribution of gas-liquid interface during partial liquid ventilation in the oleic acid lung injury model: fluorine-19 magnetic resonance imaging study.
OBJECTIVE
To elucidate the relationship between airway pressure (Paw) and the distribution of gas-liquid interface d ring partial liquid ventilation (PLV).


METHODS
Prospective, controlled study.


METHODS
A research laboratory at a university medical center.


METHODS
Ten Japanese white rabbits.


METHODS
Ten rabbits were tracheostomized and mechanically ventilated (F(IO2) = 1.0, tidal volume = 40 mL, respiratory rate = 25 breaths/min) under general anesthesia. In the oleic acid lung injury group (n = 5), oleic acid (0.10-0.12 mL/kg) was intravenously administered to make a lung injury model. When PaO2 became <100 torr (13.3 kPa), 15 mL/kg of perflubron was instilled into the endotracheal tube, and PLV was performed for 60 mins. In the control group, PLV was performed for 60 mins without any insult to the lung. After animals were killed under deep anesthesia, Paw was set at 0, 5, 10, 15, 20, 25, 30 cm H2O and fluorine-19 magnetic resonance imaging was performed. Pressure-volume relationship was investigated using proton magnetic resonance imaging.


RESULTS
Gas-liquid interface reduces fluorine-19 magnetic resonance signal. The total lung fluorine-19 signal intensity was reduced by the Paw above the lower inflection point on the pressure-volume curve, and severe lung injury interfered with establishing gas-liquid interface, especially in the dependent region, even during PLV.


CONCLUSIONS
Paw above the lower inflection point on the pressure-volume curve established gas-liquid interface dose dependently during PLV, and severe lung injury with low compliance could cause difficulty in the establishment of gas-perflubron interface, especially in the dependent lung region.
Uchida
T
T
Department of Anesthesiology and Critical Care Medicine, Tokyo Medical and Dental University School of Medicine, Japan. uchida.mane.@tmd.ac.jp
Makita
K
K
Nakazawa
K
K
Yokoyama
K
K
D000818:Animals; D001826:Body Fluids; D005461:Fluorine; D008171:Lung Diseases / Q000139:chemically induced / Q000473:pathology / Q000503:physiopathology* / Q000628:therapy*; D008279:Magnetic Resonance Imaging; D019301:Oleic Acid / Q000008:administration & dosage; D011446:Prospective Studies; D011669:Pulmonary Wedge Pressure; D011817:Rabbits; D012121:Respiration, Artificial
D005461:Fluorine; D019301:Oleic Acid