Fat emulsions and lung fucntion

IVFE infusion can impair lung function in healthy adults, premature infants, and adults with pre-existing lung injury, and in experimental animals with acute injury. Although all observed IVFE-related lung dysfunction was initially attributed to the temporally associated hyperlipemia, this explanation may in fact be correct only with fat overload syndrome. When serum triglyceride levels are in a more appropriate range, all subsequent studies have shown the same alterations in lung function unrelated to triglyceride increases and indomethacin-related blocking of lung function impairment, despite comparable serum triglyceride increases. Furthermore, our studies with Liposyn demonstrated the most significant increases in serum triglyceride levels, but the smallest PaCO₂ and PaO₂ changes. In general, the lung function abnormalities associated with IVFE infusion have thus been caused by increases in V̇A/Q̇ inequalities. Although elucidation of the relationship between IVFE-related increased PG production and secondary V̇A/Q̇ changes may be of significant physiologic import, the PaO₂ and PaCO₂ changes even with pre-existing lung injury have generally not been of sufficient magnitude to be of much clinical significance. The IVFE-related increases in plasma PG concentrations may, however, still have significant nonpulmonary clinical effects related to known or postulated consequences of increased plasma PG concentrations, including effects on ductus arteriosus patency, retinal and cerebral blood flow, and immune competence.