Bouzas Lorena, Hermida Jesus, Tutor J Carlos
Laboratorio Central, Hospital Clínico Universitario, Santiago de Compostela, Spain.
Clin Lab. 2004;50(3-4):187-91.
We studied the effect of analytical inaccuracy on the determination of gentamicin for estimation of the recommended dose regime (RDR) using the Abbottbase Pharmacokinetic System programme (PKS). The study was carried out in a group of 26 adult patients, determining their serum levels of gentamicin (Cmin and one hour after completing infusion, C1h) and these concentrations were processed using the PKS in order to establish the RDR (dose, posologic interval and infusion time) for each patient. Various simulations were made for each patient, adding and subtracting the clinically acceptable error (CAE) once, twice and three times to the experimentally determined Cmin and the estimated Cmax. The simulated dose regime (SDR) was calculated for each patient. The number of cases in which the SDR differed from the RDR were determined, and also the percentage of variation of the SDR with respect to the RDR. A highly significant correlation was found between C1h and the estimated Cmax (r = 0.941, p < 0.001). A statistically significant difference (p < 0.05) and a clinically significant difference were found between both populations of concentrations, and so the simulations were carried out using the estimated Cmax. A frequency of change of 29.87% was recorded in the RDR, and inaccuracies of +/- CAE in the Cmin and Cmax led to changes of the RDR in 21.2% of the cases studied. A higher frequency of change in the RDR was observed in additive-type simulations for Cmax, with this change mainly affecting the dose, and in subtractive-type simulations for Cmin, with this change affecting both the dose and the posologic interval. An inaccuracy of the order of +/- CAE in the serum concentrations of gentamicin (both for Cmin and Cmax) frequently led to changes in the RDR, thus requiring precise and accurate concentration results, particularly in the case of Cmin. For this reason, we would suggest the convenience of using a previous moment in the time concentration level in the monitoring of gentamicin instead of Cmin, which would be determined with greater imprecision and inaccuracy.
我们使用雅培基础药代动力学系统程序（PKS）研究了分析误差对庆大霉素测定的影响，以评估推荐剂量方案（RDR）。该研究在26名成年患者中进行，测定他们的血清庆大霉素水平（Cmin以及输注结束后1小时的C1h），并使用PKS对这些浓度进行处理，以便为每位患者确定RDR（剂量、给药间隔和输注时间）。对每位患者进行了各种模拟，将临床可接受误差（CAE）分别加、减一次、两次和三次到实验测定的Cmin和估计的Cmax上。计算每位患者的模拟剂量方案（SDR）。确定SDR与RDR不同的病例数，以及SDR相对于RDR的变化百分比。发现C1h与估计的Cmax之间存在高度显著相关性（r = 0.941，p < 0.001）。在两组浓度之间发现了统计学显著差异（p < 0.05）和临床显著差异，因此使用估计的Cmax进行模拟。记录到RDR的变化频率为29.87%，Cmin和Cmax中±CAE的误差导致在所研究的病例中有21.2%的RDR发生变化。在Cmax的加法型模拟中观察到RDR的变化频率更高，这种变化主要影响剂量，而在Cmin的减法型模拟中，这种变化影响剂量和给药间隔。庆大霉素血清浓度（Cmin和Cmax）中±CAE量级的误差经常导致RDR的变化，因此需要精确准确的浓度结果，特别是在Cmin的情况下。因此，我们建议在监测庆大霉素时，使用浓度水平时间上更早的时刻比使用Cmin更方便，因为Cmin的测定精度和准确性较低。
