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 the dosing regimen to achieve appropriate plasma concentrations. A total of 27 patients with vancomycin dosing of 1 to 1.5 g based on a weight cutoff 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 that 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 4 hours 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.

中文翻译：

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体外循环心脏手术中万古霉素剂量的调整

本研究旨在评估在接受体外循环 (CPB) 心脏手术的成年患者中预防性使用万古霉素浓度不足的风险因素，并修改给药方案以达到适当的血浆浓度。总共纳入了 27 名万古霉素剂量为 1 至 1.5 g（基于 67 kg 的截断值）的患者，其中只有 13 名（48.15%）在手术结束时万古霉素血浆浓度 > 15 mg/L。多变量逻辑回归分析证实了手术部位闭合时万古霉素浓度 <15 mg/L 的危险因素，表明 CPB 持续时间是一个独立的预测因子。患者 CPB 持续时间 > 4小时的万古霉素浓度显着降低，在体外循环结束和手术闭合时达到目标万古霉素浓度的比例较低。对于 CPB > 4 小时的患者，修改后的给药方案在 CPB 开始后 4 小时添加第二剂 0.5 至 0.75 g，提高了手术闭合时万古霉素浓度的目标实现。综上所述，CPB 持续时间 >4 小时是手术结束时万古霉素浓度不足的危险因素，而我们改进的剂量可以提高万古霉素浓度，以便在接受 CPB 心脏手术的患者中进行预防性使用。在 CPB 开始后 4 小时添加 75 g 提高了手术闭合时万古霉素浓度的目标实现。综上所述，CPB 持续时间 >4 小时是手术结束时万古霉素浓度不足的危险因素，而我们改进的剂量可以提高万古霉素浓度，以便在接受 CPB 心脏手术的患者中进行预防性使用。在 CPB 开始后 4 小时添加 75 g 提高了手术闭合时万古霉素浓度的目标实现。综上所述，CPB 持续时间 >4 小时是手术结束时万古霉素浓度不足的危险因素，而我们改进的剂量可以提高万古霉素浓度，以便在接受 CPB 心脏手术的患者中进行预防性使用。