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.

Inclusion Criteria:

• Male or female patients of 18 years of age or older, admitted to the hospital ICU and requiring administration of cefepime as part of their treatment
• Patients within the weight range of 50 -120kg
• Patients with calculated creatinine clearance within the range 15 to > 90 ml/min, allocated to one of three groups as described above.
• Written informed consent, or if not possible surrogate consent, or if not possible declaration for inclusion in an emergency, patient informed consent being signed as soon as possible.
• Patient with an arterial catheter in place for other reason than the current study purpose

Exclusion Criteria:

• Patients displaying acute or chronic renal failure requiring renal replacement therapy
• Pregnancy
• Moribund patients
• Known sensitivity or allergy to cefepime
• Inclusion in another study involving antimicrobial treatment.
• Patient participating in a research for which a period of exclusion is currently required by other study protocol, ethical committee or health authority.
• Patient already previously included in the trial