For this study, a previously developed population pharmacokinetic (popPK) model for cefepime (Jonckheere et al., submitted to JAC) was programmed in Rugloop vII, which is a software program to drive an infusion pump. By entering patient data (such as gender, serum creatinine, age and weight) in Rugloop II, a patient-specific dose will be calculated and given to the patient. This concept is known as Target Controlled Infusion (TCI). The aim of this study is to prospectively validate the popPK model using TCI.