In the present study, in critically ill patients with suspected infection undergoing application of antibiotics, CD64 and inflammatory plasma markers will be determined on days 1 to 4.~CD64 expression on the surface of neutrophils will be determined by fluorescence activated cell sorter (FACS) and with a new bedside test (LeukoDx).~The purpose of the study is to clarify:~Is CD64 expression on neutrophils associated with effective antibiotic therapy in critically ill adult patients at risk of sepsis?~Is CD64 expression associated with distinct plasma parameters of inflammation?~Do the results of the gold standard CD64 determination by FACS correlate with those of a new bedside test (LeukoDx)?
The purpose of the study is to find out whether CD64 expression on neutrophils measured by a new bedside test (LeukoDx) within 30 minutes is associated with effective antibiotic therapy in critically ill adult patients at risk of sepsis.