Regional pulmonary blood flow during partial liquid ventilation in normal and acute oleic acid-induced lung-injured piglets

Objective: To determine the spatial distribution of pulmonary blood flow in three groups of piglets: partial liquid Ventilation in normal piglets, par tial liquid ventilation during acute lung injury, and conventional gas vent ilation during acute lung injury. Design: Prospective randomized study. Setting: A university medical school laboratory approved for animal researc h. Subjects: Neonatal piglets. Interventions: Regional pulmonary blood flaw was studied in 21 piglets in t he supine position randomized to three different groups: a normal group tha t received partial liquid ventilation (Normal-PLV) and two acute lung injur y groups that received an oleic acid-induced lung injury: partial liquid ve ntilation during acute lung injury (OA-PLV) and conventional gas ventilatio n during acute lung injury (OA-Control). Acute lung injury was induced by i nfusing oleic acid (0.15 mL/kg iv) over 30 mins. Partial liquid ventilation was instituted with perflubron (LiquiVent, 30 mL/kg) after 30 mins in the Normal-PLV and OA-PLV groups. Measurements and Main Results: Arterial and venous blood gases, hemodynamic s, and pulmonary mechanics were measured every 15 mins throughout the hour- long study. Pulmonary blood flow was assessed by fluorescent microsphere te chnique at baseline and after 30, 45, and 60 mins. In the Normal-PLV piglet s, pulmonary blood flow decreased from baseline (before injury or partial l iquid ventilation) in the most dependent areas of the lung (F ratio = 3.227 ; p < .001). In the OA-PLV piglets, pulmonary blood flow was preserved over time throughout the lung (F ratio = 1.079; p = .38). In the OW-Control pig lets, pulmonary blood flow decreased in the most dependent areas of the lun g and increased from baseline in less dependent slices over time (F ratio = 2.48; p = .003). Conclusions: The spatial distribution of regional pulmonary blood flow is p reserved during partial liquid ventilation compared with gas ventilation in oleic acid-induced lung injury.