[Copper and zinc monitoring in patients on long-term TPN]

The need for oligoelements in patients on parenteral nutrition is not well-defined at this time. This study an attempt to discover the evolution of the serum levels of copper and zinc in patients on long term parenteral nutrition, in order to determine the presence of deficits compared to standard parameters used and discover which pathologies require higher intakes. The evolution of the serum levels of copper and zinc was evaluated, which were determined by atomic absorption spectrophotometry in 57 patients subjected to PNT over a minimum period of 21 days. The determinations were made the day prior to the commencement, on the seventh, fourteenth and twenty-first days. Daily intake was 15.7 mumol of Cu (1 mg) and 45.9 mumol of Zn (3 mg). From the results obtained, it could be concluded that in the patients studied, the incidence of serum levels of copper under normal values was uncommon, that the zinc levels were more varied, although the average value was within normal levels, and underwent a significant increase throughout the study. With regard to the different pathologies, it was observed that patients with severe stress had initially low levels of zinc, which later increased, and that patients who maintained or increased zinc deficits mostly suffered from neoplasias with digestive fistulas.