Purpose of review: Intravenous lipid emulsions (IVLEs) are an essential component of parenteral nutrition. With the recent incorporation of new lipid emulsions into the Canadian and American market, the clinician responsible for prescribing these lipids should be educated regarding the different fatty acid (FA) profiles of these lipids, as well as their metabolic and functional effects.
Recent findings: New IVLEs contain a mix of soybean oil and olive oil, or a mix of soybean oil, coconut oil, olive oil and fish oil. These new lipid emulsions provide less essential fatty acids (FAs) (linoleic and alpha linolenic acids) than in pure soybean oil, yet incorporation of fish oil into an IVLE may decrease the amount of essential FAs required. Fish oil is a treatment for hypertriglyceridemia, and therefore, IVLEs that include fish oil may decrease serum triglycerides. Historical perspective is that fish oil can be associated with increased bleeding time. Evidence suggests that there is no association between fish oil and increased bleeding in patients, even those who are using anticoagulants. New IVLEs provide less vitamin K than soybean oil alone. Patients, or the parenteral nutrition solutions that include these new IVLEs should be supplemented with vitamin K.
Summary: Canadian and American Guidelines for IVLEs were based on soybean oil. Current practice should be tailored to which IVLE is being prescribed.