大面积烧伤早期应用阿米卡星后水疱液中药物浓度的动态变化

Dynamic changes of blister fluid amikacin concentration after its early-stage administration in severely burned patients

目的调查阿米卡星在烧伤早期患者水疱液中的动态变化特征,探讨抗生素的合理应用时机。方法20名严重烧伤早期患者,根据烧伤后用药时间的不同分为4组:A组(烧伤后3～4h用药,n=5),B组(烧伤后10h用药,n=5),C组(烧伤后20h用药,n=5),D组(烧伤后30h用药,n=5),每名患者在30min内单剂匀速静脉滴注阿米卡星400mg,并于给药后0.25～7h分别抽取水疱液。利用荧光偏振免疫法测定每份标本浓度。结果严重烧伤患者静脉滴注阿米卡星后其渗入水疱液中的浓度有一个先升高再下降的过程,其中15min后即可测得一定浓度,1～2h达到高峰;伤后10h内静脉滴注者,15min后其水疱液中的浓度可达4.96±1.60μg/ml;A、B两组0.25～4h各时相的药物浓度数值明显高于C、D组(P<0.05)。D组中常规用量的阿米卡星在水疱液中的浓度难以达到理想的抑菌水平。结论烧伤早期阿米卡星,创面渗出液、水疱液中的药物浓度就越高,伤后10h以内用药在理论上可获得更好的抗感染效果。

Objective To determine the adequate timing of antibiotics application in severely burned patients by observing the dynamic changes of amikacin in blister fluid during early postburn stage.Methods Twenty patients in early stage of sever burns were divided into 4 groups（n=5）according to the timing of amikacin administration,namely at 3-4 h（group A）,10 h（group B,20 h（group C）,and 30 h（group D）postburn.Amikacin was administered intravenously via a single dose of 400 mg within 30 min,and at the time points of 0.25 to 7 h after completion of the infusion,the blister fluid was collected from each patient for determination of amikacin concentration with fluorescence polarization immunoassay.Results Fifteen minutes after intravenous administration,amikacin could be detected in the blister fluid,reaching the highest level at 1-2 h after administration followed by gradual declination.In group B,blister fluid amikacin concentration reached 4.96±1.60 μg/ml 15 min after administration,and at the subsequent time points until 4 h,amikacin concentration was significantly higher in groups A and B than in groups C and D（P〈0.05）.Amikacin concentration in the blister fluid in group D was not sufficient for effective antibacterial therapy.Conclusion Amikacin administration in the early postburn stage may ensure higher amikacin concentration in the blister fluid and wound exudate.Better antibacterial effect can be expected when amikacin is applied within the initial 10 h postburn.