Inadequate antibiotic dosing in patients receiving sustained low efficiency dialysis

Background Patients requiring SLED are often critically ill and/or hemodynamically unstable, and often need antibiotic therapy for life-threatening infections. Antibiotic dosing recommendations for intermittent hemodialysis and continuous renal replacement therapy are not appropriate for SLED and there is substantial concern for under dosing. Objective To characterize the adequacy of antibiotic dosing during SLED. Setting: Inpatient adult acute care hospital. Methods A retrospective chart review was performed for the period of October 2010 to August 2013 to identify patients who received SLED and at least one of the selected antibiotics: cefepime, daptomycin, piperacillin/tazobactam, meropenem, and vancomycin. Dosing regimens were evaluated each day the patient was receiving one of these antibiotics concurrently with SLED. The administered antibiotic dosing regimens were defined as "adequate" or "inadequate" based on recommendations available in the literature. Main outcome measure The percentage of adequate antibiotic days for each antibiotic. Results Antibiotic regimens were evaluated for a total of 51 patients: 35 (69%) with acute kidney injury, 16 (31%) with end-stage renal disease, mean SLED duration 9.3 ± 1.7 h. The total percent of adequate antibiotic days were: vancomycin 86%, cefepime 62%, daptomycin 58%, meropenem 35%, and piperacillin/tazobactam 20%. Under dosing accounted for 63% of the days antibiotic dosing was considered inadequate. Conclusion: Antibiotic dosing was frequently inadequate, especially for antibiotics requiring more frequent dosing, suggesting a high potential for subtherapeutic levels during the majority of time critically ill patients are requiring SLED.