Copper, selenium, zinc, and thiamine balances during continuous venovenous hemodiafiltration in critically ill patients.
BACKGROUND
Acute renal failure is a serious complication in critically ill patients and frequently requires renal replacement therapy, which alters trace element and vitamin metabolism.


OBJECTIVE
The objective was to study trace element balances during continuous renal replacement therapy (CRRT) in intensive care patients.


METHODS
In a prospective randomized crossover trial, patients with acute renal failure received CRRT with either sodium bicarbonate (Bic) or sodium lactate (Lac) as a buffering agent over 2 consecutive 24-h periods. Copper, selenium, zinc, and thiamine were measured with highly sensitive analytic methods in plasma, replacement solutions, and effluent during 8-h periods. Balances were calculated as the difference between fluids administered and effluent losses and were compared with the recommended intakes (RI) from parenteral nutrition.


RESULTS
Nineteen sessions were conducted in 11 patients aged 65 +/- 10 y. Baseline plasma concentrations of copper were normal, whereas those of selenium and zinc were below reference ranges; glutathione peroxidase was in the lower range of normal. The replacement solutions contained no detectable copper, 0.01 micromol Se/L (Bic and Lac), and 1.42 (Bic) and 0.85 (Lac) micromol Zn/L. Micronutrients were detectable in all effluents, and losses were stable in each patient; no significant differences were found between the Bic and Lac groups. The 24-h balances were negative for selenium (-0.97 micromol, or 2 times the daily RI), copper (-6.54 micromol, or 0.3 times the daily RI), and thiamine (-4.12 mg, or 1.5 times the RI) and modestly positive for zinc (20.7 micromol, or 0.2 times the RI).


CONCLUSIONS
CRRT results in significant losses and negative balances of selenium, copper, and thiamine, which contribute to low plasma concentrations. Prolonged CRRT is likely to result in selenium and thiamine depletion despite supplementation at recommended amounts.
Surgical Intensive Care Unit and Burns Centre, University Hospital, BH 08.660, CH 1011 Lausanne, Switzerland. mette.berger@chuv.hospvd.ch
Mette M
MM
Berger
Alan
A
Shenkin
Jean-Pierre
JP
Revelly
Eddie
E
Roberts
M Christine
MC
Cayeux
Malcolm
M
Baines
Rene L
RL
Chioléro
D058186:Acute Kidney Injury / Q000097:blood / Q000401:mortality / Q000628:therapy*; D000368:Aged; D003300:Copper / Q000097:blood*; D003422:Critical Care; D018592:Cross-Over Studies; D005260:Female; D017583:Hemodiafiltration / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012643:Selenium / Q000097:blood*; D013831:Thiamine / Q000097:blood*; D015032:Zinc / Q000097:blood*
D003300:Copper; D012643:Selenium; D015032:Zinc; D013831:Thiamine