Antibiotic dosing during sustained low-efficiency dialysis: special considerations in adult critically ill patients.

OBJECTIVE: To address issues of antibiotic dosing during sustained low-efficiency dialysis by using available pharmacokinetic data, intermittent and continuous renal replacement therapy dialysis guidelines, and our experience with sustained low-efficiency dialysis. DATA RESOURCES: Published clinical trials, case reports, and reviews of antibiotic dosing in humans during sustained low-efficiency dialysis. DATA EXTRACTION: A search of electronic databases (MEDLINE, PubMed, and Ovid) was conducted by using key words of extended daily dialysis, sustained low-efficiency dialysis, antibiotics, antimicrobial agents, and pharmacokinetics. MEDLINE identified 32 sustained low-efficiency dialysis articles, and PubMed identified 33 articles. All papers describing antibiotic clearance prospectively in patients were considered for this article. DATA SYNTHESIS: We identified nine original research articles and case reports that determined the impact of sustained low-efficiency dialysis on antibiotic clearance in patients. The blood and dialysate flow rates, duration of dialysis, type of filter, and the pharmacokinetic parameters were extracted from each article. If multiple articles on the same drug were published, they were compared for consistency with the aforementioned dialysis parameters and then compared with forms of continuous renal replacement therapy. Antibiotic clearance by sustained low-efficiency dialysis was determined to be similar or higher than continuous renal replacement therapy therapies. The estimated creatinine clearance during sustained low-efficiency dialysis was approximately 60 mL/min to 100 mL/min depending on the blood and dialysate flow rates and the type of filter used.
CONCLUSIONS: The potential for significant drug removal during an 8-hr-or-longer sustained low-efficiency dialysis session is evident by the limited number of studies available. Because significant amounts of drug may be removed by sustained low-efficiency dialysis combined with altered pharmacokinetic variables in critically ill patients, the risk for suboptimal drug concentrations and pharmacodynamics must be considered. Appropriate dose and calculation of dosing intervals is essential to provide adequate antibiotic therapy in these patients. It is recommended that institutions who utilize sustained low-efficiency dialysis establish dosing guidelines for all pharmacists and physicians to follow to provide consistent delivery of antibiotics at adequate concentrations.