The invention relates to a system and a method for monitoring at least one blood parameter of the blood from a predetermined patient, with an access device for setting up access to the patient's blood, a removal device for removing an amount of blood in order to obtain a blood sample, a blood analysis device for analysing the blood sample, and a calculation device for calculating drug parameters of a drug to be administered to the patient as well as a supply device for supplying the drug having the calculated drug parameters. The system identifies the blood samples using bar codes, as a result of which there are no errors when assigning the blood to be analysed to the respective patient.