a) If a patient requires antimicrobial therapy for a proven or suspected infection at the time of CRRT initiation or at any time receiving CRRT, they are eligible for inclusion. If cefazolin is part of the empiric or definitive treatment regimen, it will be mixed in the CRRT solution(s) and administered via a continuous infusion to obtain pharmacokinetic and safety data of administering cefazolin via the CRRT solution and infection treatment related data. For this indication, pharmacokinetic and safety data will be obtained for the duration the patient receives cefazolin via the CRRT solution(s) for the proven or suspected infection as dictated by the primary team caring for the patient.

b) If a patient is deemed a candidate for CRRT and requires therapy with any anti-microbial for a proven or suspected infection not requiring cefazolin as part of the anti-microbial drug regimen, administration of cefazolin via the CRRT solution(s) will occur to solely obtain pharmacokinetic and safety data. For this indication, pharmacokinetic and safety data will be obtained for a 72-96-hour duration.

c) If a patient is deemed a candidate for CRRT and does not require any anti-microbial therapy, administration of cefazolin via the CRRT solution(s) will occur to solely obtain pharmacokinetic and safety data. For this indication, pharmacokinetic and safety data will be obtained for a 72-96-hour duration.

Mixing cefazolin into the CRRT solution(s) for delivery as a continuous infusion

Therapeutic serum cefazolin levels. Serum samples will be obtained at specified intervals during the course of CRRT for cefazolin concentration determination.