Concentrations of copper, zinc, manganese, rubidium, and magnesium in thoracic empyemata and corresponding sera

In this study, a number of selected trace elements and clinically relevant parameters were compared between thoracic empyemata and the corresponding s era for a better understanding of the trace element distribution between th ese two compartments. Serum-empyema pairs were obtained from 13 patients an d quantified for selected and essential trace elements, namely copper (Cu), zinc (Zn), manganese (Mn), rubidium (Rb), and magnesium (Mg), by inductive ly coupled plasma-mass spectrometry (ICP-MS). In addition, the concentratio ns of the following clinical laboratory parameters were analyzed by standar d methods: total protein, leukocyte count, lactate dehydrogenase, glucose, pH, and the C-reactive protein. Individual concentrations of the elements determined in the empyemata were frequently higher than in pleural effusions of any other benign or malignan t condition except for Cu. Serum Cu exceeded the normal range (600-1400 mug /kg) in 6 out of 13 patients (median 1410 mug/kg). In the empyemata, Zn con centrations (median 2000 mug/kg) were characteristically higher than in the sera (median 450 mug/kg) and exceeded the upper limit for serum (1200 mug/ kg) in 8 of the 13 patients. Manganese concentrations in the empyemata (med ian 2.7 mug/kg) were also higher compared to corresponding sera, although t hey stayed within the limits considered normal for serum of healthy adults (upper limit 2.9 mug/kg). Rubidium was also moderately higher in most empye mata (median 290 mug/kg) and exceeded the upper limit for serum (560 mug/kg ) in two patients. The median concentration of the essential element magnes ium was higher in the empyemata (23 mg/kg) than in the sera (21 mg/kg). How ever, all serum Mg concentrations except three remained within the normal r ange (17-22 mg/kg). Removal of large amounts of empyematous fluid may deprive the body of trace elements and can cause suboptimal or deficient trace element status and ho meostasis. Recuperation will be accelerated by compensatory supplementation of trace elements. Therefore, selective medication with adequate trace ele ment compounds in patients with thoracic empyema can be generally recommend ed for zinc. The other elements need not necessarily be monitored or substi tuted, because of their stable concentrations in the serum. Rb may have a b iological impact, but deficiency symptoms in man are not clearly defined.