Effects of cardio-pulmonary bypass on vancomycin plasma concentration decay.
Effects of cardio-pulmonary bypass on vancomycin plasma concentration decay.
复制标题
心肺转流对万古霉素血浆浓度衰减的影响。
作者：
P. Miglioli;F. Merlo;E. Grabocka;R. Padrini
该研究的目的是调查体外循环（CPB）引起的万古霉素血清水平可能发生的变化。 10 名接受过需要 CPB 的心脏手术的心脏病患者（7 名男性，3 名女性，年龄在 56 至 81 岁之间）参加了这项研究。麻醉前60 min静脉滴注万古霉素（15 mg·kg-1），给药后（0、0.5、1、6、8 h）、CPB开始后（0、5、30、60 min）和主动脉钳夹后（0、5、30、60、120 min）适当时间采集血样。通过荧光偏振免疫测定法测定药物血清浓度。将 CPB 期间测量的浓度-时间曲线下面积 (AUC) 与通过将两室药代动力学模型拟合到 CPB 前后获得的药物浓度而在相同时间间隔内推断的 AUC 进行比较。开始 CPB 5 分钟后，万古霉素血清水平平均下降 40.9%，并在接下来的 60 分钟内稳定低于预期值。在同一时间间隔内，测量的 AUC 比预期的 AUC 低 31.7%。在任何情况下，血清水平均未低于最常见病原体的 MIC (1-2 mg l-1)。主动脉松开时，血清水平略有反弹，但在接下来的 120 分钟内往往仍低于预期浓度。总之，在体外循环期间，万古霉素血清水平总是下降，但在所采用的剂量（15 mg kg-1）下，仍保持在抗菌预防的潜在有效范围内。
The objective of the study was to investigate possible changes in vancomycin serum levels induced by cardio-pulmonary bypass (CPB). Ten cardiac patients (seven males, three females, aged between 56 and 81), who underwent cardiac surgery requiring CPB, took part in the study. Vancomycin (15 mg kg-1) was intravenously infused over 60 min before anaesthesia and blood samples were taken at appropriate times after drug administration (0, 0.5, 1, 6, 8 h), after starting CPB (0, 5, 30 and 60 min) and after aortic unclamping (0, 5, 30, 60, 120 min). Drug serum concentrations were determined by means of a fluorescence polarization immunoassay. The area under the concentration-time curve (AUC) measured during CPB were compared with the AUC extrapolated in the same interval by fitting a two-compartment pharmacokinetic model to drug concentrations obtained before and after CPB. Five minutes after starting CPB vancomycin serum levels decreased, on average, by 40.9% and remained steadily lower than the expected values over the next 60 min. In the same interval, the measured AUC was 31.7% lower than the expected AUC. In no instance did serum levels fall below the MIC for most common pathogens (1-2 mg l-1). At aortic unclamping serum levels slightly rebounded but tended to remain lower than the expected concentrations over the next 120 min. In conclusion, during CPB vancomycin serum levels invariably decreased but, at the dose employed (15 mg kg-1), remained in a potentially effective range for antimicrobial prophylaxis.