A Porcine Model of Acute Respiratory Failure with a Continuous Infusion of Oleic Acid

This protocol outlines an acute respiratory distress model utilizing centrally administered oleic acid infusion in Yorkshire pigs. Prior to experimentation, each pig underwent general anesthesia, endotracheal intubation, and mechanical ventilation, and was equipped with bilateral jugular vein central vascular access catheters. Oleic acid was administered through a dedicated pulmonary artery catheter at a rate of 0.2 mL/kg/h. The infusion lasted for 60-120 min, inducing respiratory distress. Throughout the experiment, various parameters including heart rate, respiratory rate, arterial blood pressure, central venous pressure, pulmonary artery pressure, pulmonary capillary wedge pressure, end-tidal carbon dioxide, peak airway pressures, and plateau pressures were monitored. Around the 60 min mark, decreases in partial arterial oxygen pressure (PaO₂) and fraction of oxygen-saturated hemoglobin (SpO₂) were observed. Periodic hemodynamic instability, accompanied by acute increases in pulmonary artery pressures, occurred during the infusion. Post-infusion, histological analysis of the lung parenchyma revealed changes indicative of parenchymal damage and acute disease processes, confirming the effectiveness of the model in simulating acute respiratory decompensation.