Non-invasive Diagnostics of Iron Deficiency in Surgical Patients by Measuring Zinc Protoporphyrin-IX

In patients fitting the inclusion criteria Zinc protoporphyrin will be measured non-invasively as proxy for iron deficiency. Results will be compared to ZnPP reference values measured via HPLC and with spectroscopical measurements performed on whole blood as well as with blood values (HB, MCH, MCV, ferritin, CRP, transferrin saturation, soluble transferrin receptor) assessed during clinical routine.