UNKNOWN TRACE-ELEMENT ADMINISTRATION IN TRAUMA AND BURN PATIENTS

Recommended trace element doses during parenteral nutrition have been revised many times and increased, especially in surgical patients. Blood products are known to provide significant amounts of trace elements under certain circumstances. In intensive care patients cristalloids and colloids are also given in large amounts. This study aimed at determining the magnitude of the unrecognized trace element administrations after major bums and/or trauma. Fifteen patients burnt 36 +/- 11 % (xBAR +/- SD) of body surface area, aged 34 +/- 8 years, admitted to the Bums Centre and 11 trauma patients with an Injury Severy Score of 29 +/- 6 points, aged 40 +/- 13 years, admitted to the surgical Intensive Care Unit in a Swiss University Hospital. Prospective study of intakes and urinary excretion from the first post-injury day (D1) to D7. Copper and zinc were analyzed by flame atomic absorption spectrophotometry, and selenium by fluorimetry. The actual trace element administrations were much larger than those prescribed in the 3 groups of patients, and were significantly above the most recent parenteral recommended daily allowance = RDA (2,3 times RDA for copper, 5 times for selenium and zinc in Group 2, which received the largest i.v. supplements). There greatest provision of the 3 elements was by the blood products (packed red cells and frozen plasma) and by the albumin solutions (0.5 mg . L-1 Cu, 90 mug . L-1 Se and 2.1 mg . L-1 Zn in the 20 % solutions). During the resuscitation phase, cristalloids provided a significant amount of copper (0.14 mg . L-1 NaCl 0.9 %, none in dextrose) and zinc (0.3 mg . L-1 of any cristalloid), whereas selenium was not dectected. No case of toxicity was observed. In intensive care settings, the unknown amounts of trace elements administred by the i.v. route are significant and often above the RDA during the first post-injury week, but have no deleterious effects. This shows that there is a wide safety margin for the short term prescription of increased amounts of trace elements, and the recommended parenteral doses will probably be upgraded for burn and trauma patients.