Comprehensive Nursing Pharmacology Q 267
Some institutions will not infuse a fat emulsion, such as Intralipid, into central venous access devices (CVAD) because:
A. Lipid residue may accumulate in the CVAD and occlude the catheter.
B. If the catheter clogs, there is no treatment other than removal and replacement.
C. Lipids are necessary only in the most extreme cases to prevent essential fatty acid (EFA) deficiency
D. Fat emulsions are very caustic.
Correct Answer: A. Lipid residue may accumulate in the CVAD and occlude the catheter.
Occlusion occurs with slow infusion rates and concurrent administration of some medications. A deficiency can quickly develop. Daily essential fatty acids are necessary for constant prostaglandin production. The management of an occluded central line is challenging as the cause of the occlusion is often not known. Most blockages are caused by fibrin clots, therefore the installation of alteplase should be attempted first if the cause of the occlusion is unknown. A blocked line may be due to the precipitation of poorly soluble components in IV solutions such as calcium or certain drugs.
Option B: Infusion of lipids (fat emulsion) especially with TPN, can result in blockage from a gradually thickening deposit of lipid in the line. In these cases, a 70% ethanol instillation may be helpful. Lipid occlusions may be treated with 70 percent ethanol or with 0.1 mmol/mL NaOH.
Option C: Lipids provide essential fatty acids. It is recommended that approximately 4 percent of daily calories be EFAs. The infusion of lipid emulsions allows a high energy supply, facilitates the prevention of high glucose infusion rates, and is indispensable for the supply of essential fatty acids. The administration of lipid emulsions is recommended within ?7 days after starting PN (parenteral nutrition) to avoid deficiency of essential fatty acids.
Option D: Lipids are almost isotonic with blood. Since IV lipids are isotonic and calorically dense, they are a good source of calories for hypermetabolic patients or patients with volume or carbohydrate restrictions. Lipids can provide up to 60% of non-protein calories.