8q: a patient who was on total parenteral nutrition developed scaling dermatitis after 4 weeks . which can be the probable cause of his symptoms ?
a. linoleic acid deficiency
b. zinc deficiency
c. vitamin defiiciency
d. glucose intolerance
answer: a . linoleic acid deficiency . one of the important complication of total parenteral nutrition is essential fatty acids deficiency .
Essential fatty acids deficiency. The lack of linoleic acid leads to dermatitis,
hair loss and impaired wound healing. Clinical evidence of fatty acid deficiency
appears after one or two months of parenteral nutrition without lipid
administration but biochemical evidence may be detected much earlier consisting
in an increasing quotient between eicosatrienoic and arachidonic acids above
0.425. This syndrome was reported mostly in North American patients since fat
emulsions were introduced late in the USA. Initially some authorities
recommended the weekly administration of 1000 to 1500 ml of a 10% fat
emulsion to prevent fatty acid deficiency. This practice, however, has largely
been abandoned in favour of the daily administration of 20% fat emulsions to
cover from 30 to 60% of the daily caloric requirements.