Continuous Sustained Low Efficiency Dialysis Research Articles

607. Establishing Pharmacokinetic Profile of β -lactams in Critically Ill Patients on Continuous Sustained Low-efficiency Dialysis (C-SLED)

Abstract Background Critically ill patients have altered pharmacokinetic (PK) due to severity of illness and multi-organ failure. The lack of pharmacokinetic and pharmacodynamic data in Continuous Sustained Low-efficiency Dialysis (C-SLED) further perpetuates the uncertainty of efficacy with current antimicrobial dosing strategies. The objective of this study is to evaluate patient-specific PK of various β-lactams antibiotics in critically ill patients on C-SLED to assess if the current dosing strategy leads to therapeutic drug levels. Methods This prospective observational cohort study was performed at an academic medical center from November 2021 to June 2022. It included patients age > 18 years and on β-lactam antibiotics while on C-SLED. Therapeutic drug monitoring (TDM) was performed by checking two levels (peak and trough). These levels were used to calculate patient-specific elimination rate constant (k), half-life, and the fraction of time above MIC (fT>MIC). Other data collected included demographics, β-lactam regimens, source of infection, microbiology data, mortality on days 7 and 30, and length of stay. Descriptive statistics were used for data analysis. Results There were 11 patients included in the study with a median age of 55 and 82% (n = 9) of patients were male. β-lactam daily regimen was dosed as creatinine clearance (CrCl) > 50mL/min in 71.4% of patients (n = 10), CrCl 30-50 mL/min in 28.5% (n = 4), and < 30mL/min in 0% of patients. An extended infusion dosing strategy was used in 35.6% of patients (n = 5). The therapeutic drug target (50%fT > MIC for penicillins, 60%fT > MIC for cephalosporins, 40%fT > MIC for carbapenems) was achieved in 100% (n=14) of patients. Dose adjustment was not needed in all 14 cases. However, 100%fT > MIC was only achieved in 64% (n=9) patients. The median hospital length of stay was 60 days. Mortality on days 7 and 30 was 9% (n=1) and 27% (n=3), respectively. Conclusion Preliminary analysis shows that β-lactam daily dose based on CrCl of >30mL/min leads to therapeutic drug levels in patients on C-SLED. Disclosures All Authors: No reported disclosures.

Safety of Regional Citrate Anticoagulation for Continuous Sustained Low Efficiency Dialysis (C-SLED) in Critically Ill Patients

Background. Sustained low efficiency dialysis (SLED) is a hybrid therapy that uses a conventional hemodialysis machine to deliver lower solute clearance over prolonged periods of time, typically 8 to 12 hours per treatment, and utilizes the same sodium and bicarbonate concentrations as intermittent hemodialysis. The therapy has been shown to be an effective dialysis mode for the critically ill patient with acute renal failure and hemodynamic instability. At our institution, critically ill patients requiring renal replacement therapy receive SLED on a continuous, 24-hour schedule (C-SLED). The higher dialysis dose with C-SLED compared to continuous venovenous hemodiafiltration (CVVHDF) or traditional SLED would likely alter the prescription needed to provide regional citrate anticoagulation and the incidence of hypernatremia and metabolic alkalosis. Objective. To evaluate the safety of utilizing regional citrate anticoagulation with continuous SLED in critically ill patients who frequently clot the hemofilter and have contraindications to systemic anticoagulation with heparin. We hypothesized that the higher dialysis dose with C-SLED would affect the prescription of citrate anticoagulation and the development of hypernatremia and metabolic alkalosis. Design. We prospectively followed the first 20 patients who received regional citrate anticoagulation on C-SLED for acute renal failure in the intensive care unit. Important outcomes measured included serum sodium, bicarbonate, ionized calcium concentration, serum pH, and PCO2. The number of clotting episodes for each patient while on regional citrate anticoagulation was recorded. Setting. Surgical and medical intensive care units at The University of Texas MD Anderson Cancer Center. Results. In over 2200 hours of continuous dialysis with citrate anticoagulation none of the 20 patients had derangements in the serum sodium or acid base status requiring cessation of regional citrate anticoagulation. In 14 patients, no clotting occurred during 1500 hours of SLED with the citrate infusion. There were eight episodes of hemofilter clotting in six patients during 750 hours of C-SLED. Conclusion. Regional citrate anticoagulation is a safe method of anticoagulation in critically ill patients on continuous SLED.