953

Introduction: Antibiotics are often administered in patients treated by extracorporeal membrane oxygenation (ECMO) but pharmacokinetics (PKs) of antibiotics during ECMO have not been well defined. Hypothesis: To evaluate vancomycin concentrations in critically ill patients treated with ECMO. Methods: We reviewed all patients who received a continuous infusion (CI) of vancomycin when on ECMO support from January 2011 to May 2012. Vancomycin was given as a 35 mg/kg loading dose in 4-hr, and the infusion doses were adapted to creatinine clearance, CrCL). Drug concentrations were measured at 4 (T1), 12 (T2) and in the first 24 hours (T3) after the onset of therapy. Using a database reporting all patients having this vancomycin regimen, ECMO patients were matched (1:1) with non-ECMO patients according to four criteria: 1) renal function (i.e. same CrCL or both on continuous renal replacement therapy, CRRT); 2) total body weight; 3) Sequential Organ Failure Assessment (SOFA) score; 4) age. Vancomycin concentrations between 20 and 30 µg/ml were considered as adequate. Results: We compared 11 patients treated with ECMO and 11 well matched controls. Mean vancomycin loading (2500 [1610-2975] mg vs. 2450 [1645-3500] mg) and daily doses (1125 [750-3000] vs. 1200 [750-2500] mg) were similar in the two groups. Drug concentrations in ECMO and non-ECMO patients were: 51 [28-71] mcg/mL vs. 45 [37-71] mcg/mL on T1; 23 [16-38] vs. 29 [21-35] mcg/mL on T2; 20 [12-36] vs. 23 [17-28] mcg/mL on T3 (ANOVA, p=0.53). The number of patients with insufficient drug concentrations in ECMO group was 2 on T2 and 4 on T3 when compared to 0 and 1, respectively, in the control group. Conclusions: Vancomycin concentrations in the early phase of therapy were quite similar in patients treated or not with ECMO. Nevertheless, more patients in the ECMO group tended to have insufficient drug concentrations, so that vancomycin doses should be probably increased somewhay in these patients.