Sequential evaluations of trace elements in patients receiving parenteral nutrition.

BACKGROUND/AIMS: To evaluate alterations of serum trace element (TE) levels in critically ill patients receiving parenteral nutrition (PN) including the recommended doses of TEs.

METHODOLOGY

Measurements of serum levels of TEs such as zinc, iron, copper, manganese and iodine were performed on the day before, and two and four weeks after, administration of PN.

RESULTS

Forty-six patients who received PN from October 2007 to August 2009, were enrolled. All patients received 100µmol (6.5mg) zinc, 35µmol (2mg) iron, 5µmol (0.3mg) copper, 1µmol (0.05mg) manganese and 1µmol (0.13mg) iodine as the recommended daily doses. There were no significant differences in the serum levels of iron, copper and manganese among the three measurement points. On the other hand, there were significant differences in the serum levels of zinc (p<0.001), triiodothyronine (T3) (p=0.010) and unbound T3 (p=0.006) among the three points, but not for thyroxine (T4) and unbound T4.

CONCLUSIONS

The recommended doses of TEs are justified for critically ill patients in terms of constant serum levels, except for zinc and iodine.