Modification of vancomycin dosing in cardiac surgery with cardiopulmonary bypass.

This study aims to assess the risk factors for insufficient vancomycin concentrations for its prophylactic use in adult patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) and to modify dosing regimen to achieve appropriate plasma concentrations. A total of 27 patients with vancomycin dosing of 1 to 1.5 g based on weight cut-off of 67 kg were included, of which only 13 (48.15%) had vancomycin plasma concentration > 15 mg/L at surgical closure. Risk factors of vancomycin concentration < 15 mg/L at surgical site closure were confirmed by multivariate logistic regression analysis, which showed CPB duration was an independent predictor. Patients with CPB duration > 4 hours had significantly lower vancomycin concentrations and lower proportion in achieving target vancomycin concentration at the end of CPB and surgical closure. For patients with CPB > 4 hours, the modified dosing regimen that a second dose of 0.5 to 0.75 g added at 4th hour since the onset of CPB, improved the target achievement of vancomycin concentration at surgical closure. Taken together, CPB duration > 4 hours was the risk factor for insufficient vancomycin concentration at surgical closure, while our modified dosing could improve the vancomycin concentrations for its prophylactic use in patients undergoing cardiac surgery with CPB. This article is protected by copyright. All rights reserved.