Essential fatty acid deficiency may complicate total parenteral nutrition (TPN). Which of the following statements are true?

B. Fat-free parenteral nutrition results in the appearance of plasma abnormalities, indicating essential fatty acid deficiency, within 7 to 10 days of initiation

D. Following initiation of fat-free parenteral nutrition, dry, scaly skin associated with a maculopapular rash indicates essential fatty acid deficiency.

 DISCUSSION: Biochemical evidence of essential fatty acid deficiency may occur as early as 7 to 10 days following initiation of fat-free parenteral nutrition. The decrease in arachidonic acid in plasma and the appearance of the abnormal eicosatrienoic acid may yield the earliest indication of prostaglandin deficiency; it is not absolute. Decreased intraocular pressure, another early indication of prostaglandin deficiency, may appear as soon as 7 days following initiation of fat-free parenteral nutrition. While my current practice is to give at least 500 ml. of 10% lipid emulsion daily to provide 20% to 25% of total calories to support hepatic protein synthesis, as little as 4% to 6% of total daily calories as fat prevents essential fatty acid deficiency. Practically, this may be undertaken by the administration of 500 ml. of 10% lipid three times weekly. The appearance of eicosatrienoic acid and a decrease in arachidonic acid, and a change in ratio, is not essential to the diagnosis of essential fatty acid deficiency, but this plasma abnormality is often present.