The Impact of IV Fat Emulsion Administration in Acute Lung Injury

Abstract

The aim of this study was to evaluate the effect of parenteral nutrition containing medium- and long-chain triglycerides on the function of the respiratory system and to investigate mechanisms involved in this process. We studied 13 patients with acute respiratory distress syndrome (ARDS), 8 receiving lipid and 5 placebo, and 6 without ARDS, receiving lipid. Bronchoalveolar lavage (BAL) was performed before and 1 hour after administration of lipid or placebo. In patients with ARDS, lipid administration resulted in deterioration of oxygenation (PaO₂/FI_O2: from 129 ± 37 to 95 ± 42), compliance of respiratory system (from 39.2 ± 12 to 33.1 ± 9.2 mL/cm H₂O), and pulmonary vascular resistance (from 258 ± 47 to 321 ± 58 dyne·s·cm^–5). In the BAL fluid of the same group, an increase in total protein and phospholipid concentrations, phospholipase activities, platelet-activating factor and neutrophils, and alterations in BAL lipid profile were observed. No significant changes were observed in the control or in the ARDS-Placebo groups. In conclusion, this study indicates that administration of medium- and long-chain triglycerides in patients with ARDS causes alterations in lung function and hemodynamics. Inflammatory cells, possibly activated by lipids, release phospholipase A₂ and platelet-activating factor, enhancing edema formation, inflammation, and surfactant alterations.