SCIENTIFIC ARTICLE Lipid Therapy with Two Agents in Ropivacaine-Induced Toxicity: Experimental Study in Swine

Background and objective: Compare hemodynamic changes after ropivacaine-induced toxicity followed by treatment with two lipid emulsions in swine. Methods: Large White pigs were anesthetized with thiopental, followed by intubation, and kept on mechanical ventilation. Hemodynamic vari-ables at rest were recorded with invasive pressure monitoring and pulmonary artery catheterization. After 30 minutes, 7 mg.kg-1 ropivacaine were injected intravenously and new hemodynamic measurements were performed within one minute. The animals were then randomly allocated into three groups and received: 4 mL.kg-1 saline solution, or 4 mL.kg-1 lipid emulsion with long-chain triglycerides, or 4 mL.kg-1 lipid emulsion with long-and medium-chain triglycerides. Hemodynamic changes were reevaluated at 5, 10, 15, 20 and 30 minutes. Results: Ropivacaine-induced toxicity mainly caused a drop in blood pressure and cardiac index without significant changes in vascular resis-tance. Therapy with lipid emulsions restored blood pressure primarily through increased vascular resistance, as cardiac index showed no signifi