Department of Clinical Pharmacology, Christchurch Hospital, Christchurch, New Zealand.
Ann Clin Biochem. 2013 Nov;50(Pt 6):546-57. doi: 10.1177/0004563213492320. Epub 2013 Sep 17.
It is unclear which renal function equation, employing an isotope dilution mass spectrometry (IDMS)-aligned creatinine assay, best predicts gentamicin clearance.
The performances of the Cockcroft-Gault, Modification of Diet in Renal Disease (MDRD) Study and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations for predicting gentamicin clearances were assessed retrospectively in 240 patients treated with gentamicin during 2011-2012, when the local creatinine assay was IDMS-aligned. Comparisons were based on the percentage within 30% of gentamicin clearance (P 30) and the root-mean-square error (RMSE) of each equation. Gentamicin clearance was calculated from plasma concentrations using a one-compartment model.
The Cockcroft-Gault equation and the CKD-EPI equation corrected for individual body surface area (BSA) were associated with the highest P 30 (69% and 67%, respectively) and lowest RMSE (39 and 36 mL/min, respectively) in the 240 patients. Correction for individual BSA improved the performances of the MDRD Study and CKD-EPI equations in patients with body mass indices <18.5 or ≥30 kg/m(2). The equations systematically underestimated gentamicin clearance as gentamicin clearance increased, with performance being inferior with gentamicin clearance ≥90 versus <90 mL/min.
The CKD-EPI equation corrected for individual BSA, and the Cockcroft-Gault equation, provided the best estimates of gentamicin clearance. The CKD-EPI and MDRD Study equations should be corrected for individual BSA at the extremes of body size, if used for guiding gentamicin therapy. The performances of the equations were inferior in patients with higher values of gentamicin clearance.
目前尚不清楚哪种基于同位素稀释质谱法（IDMS）校准的肌酐检测的肾功能方程能够更好地预测庆大霉素清除率。
本研究回顾性分析了 2011 年至 2012 年期间接受庆大霉素治疗的 240 例患者，当时采用的是 IDMS 校准的肌酐检测方法，评估了 Cockcroft-Gault、改良肾脏病饮食研究（MDRD）方程和慢性肾脏病流行病学合作（CKD-EPI）方程预测庆大霉素清除率的性能。基于每个方程预测的庆大霉素清除率的 30%以内的百分比（P30）和均方根误差（RMSE）进行比较。采用一室模型计算庆大霉素清除率。
在 240 例患者中，Cockcroft-Gault 方程和校正了个体体表面积（BSA）的 CKD-EPI 方程与最高的 P30（分别为 69%和 67%）和最低的 RMSE（分别为 39 和 36ml/min）相关。在 BMI<18.5 或≥30kg/m2的患者中，校正 BSA 改善了 MDRD 方程和 CKD-EPI 方程的性能。随着庆大霉素清除率的增加，这些方程系统地低估了庆大霉素清除率，当庆大霉素清除率≥90 与<90ml/min 时，表现更差。
校正了个体 BSA 的 CKD-EPI 方程和 Cockcroft-Gault 方程能够更好地预测庆大霉素清除率。如果要指导庆大霉素治疗，应在体型极端的情况下校正 CKD-EPI 和 MDRD 方程的个体 BSA。在庆大霉素清除率较高的患者中，这些方程的性能较差。
