The purpose is to investigate daptomycin pharmacokinetics in critically ill patients with suspected or verified bacteremia with Gram-positive cocci undergoing combined continuous hemodiafiltration at a filtration rate of 35ml/kg/h and to establish a dose recommendation for continuous hemodiafiltration at a filtrate rate of 35ml/kg/h.

Inclusion Criteria:

• male or female of 18 years or older
• females: negative pregnancy test
• Hospitalisation in the medical ICU
• High suspicion or evidence of Gram-positive infections requiring antibiotic therapy
• Subjects receiving standard antibiotic treatment for Gram-positive infection
• Evidence of renal failure
• Clinical necessity for continuous renal replacement therapy
• Written informed consent signed by the patient or a next of kin and an independent physician in case the patient is not able to sign.

Exclusion Criteria:

• Skeletal muscle disorders or CPK levels of > 2 x ULN
• History of hypersensitivity to the drug
• Participation in another study
• Subjects with a history of muscle disease
• Patients with severe liver function impairment (Child C)
• Life expectancy of less than 5 days