Variations of serum magnesium and zinc after surgery, and postoperative fatigue.

Changes in serum zinc and magnesium can be induced by stress from circumstances such as traumatic injury or inflammation. This present study involved 58 patients admitted for a variety of surgical abdominal interventions. After surgery, serum magnesium showed a minor increase on d 3 and d 9 (P < 0.05) and a return to initial levels on d 27 and d 45 after surgery. On the ninth postoperative day there was a significant decrease in serum zinc. On d 45, serum zinc concentrations increased to normal values. There was an inverse correlation between serum and dynamometric variables and fatigue. The relation between serum magnesium and zinc was in agreement with other studies; these changes might be due, at least in part, to stress. Surgical trauma increases corticosteroids, which affect the homeostasis of magnesium and zinc. In conclusion, increases in fatigue were accompanied by decreases in serum zinc and increases of serum magnesium. This suggests that these elements are implicated, directly or indirectly, in fatigue mechanisms, and therefore their measurement may be used as a guide to the status of fatigue in patients after surgery.