Pharmacy Service, Division of Medicines, Hospital Clinic de Barcelona, Barcelona, Catalunya, Spain.
Pharmacy Service, Division of Medicines, Hospital Clinic de Barcelona, Barcelona, Catalunya, Spain
Eur J Hosp Pharm. 2024 Oct 25;31(6):543-549. doi: 10.1136/ejhpharm-2023-003738.
24-hour urine creatinine clearance (ClCr 24 hours) remains the gold standard for estimating glomerular filtration rate (GFR) in critically ill patients; however, simpler methods are commonly used in clinical practice. Serum creatinine (SCr) is the most frequently used biomarker to estimate GFR; and cystatin C, another biomarker, has been shown to reflect GFR changes earlier than SCr. We assess the performance of equations based on SCr, cystatin C and their combination (SCr-Cyst C) for estimating GFR in critically ill patients.
Observational unicentric study in a tertiary care hospital. Patients with cystatin C, SCr and ClCr 24 hours measurements in ±2 days admitted to an intensive care unit were included. ClCr 24 hours was considered the reference method. GFR was estimated using SCr-based equations: Chronic Kidney Disease Epidemiology Collaboration based on creatinine (CKD-EPI-Cr) and Cockcroft-Gault (CG); cystatin C-based equations: CKD-EPI-CystC and CAPA; and Cr-CystC-based equations: CKD-EPI-Cr-CystC. Performance of each equation was assessed by calculating bias and precision, and Bland-Altman plots were built. Further analysis was performed with stratified data into CrCl 24 hours <60, 60-130 and ≥130 mL/min/1.73 m.
We included 275 measurements, corresponding to 186 patients. In the overall population, the CKD-EPI-Cr equation showed the lowest bias (2.6) and best precision (33.1). In patients with CrCl 24 hours <60 mL/min/1.73 m, cystatin-C-based equations showed the lowest bias (<3.0) and CKD-EPI-Cr-CystC was the most accurate (13.6). In the subgroup of 60≤ CrCl 24 hours <130mL/min/1.73 m, CKD-EPI-Cr-CystC was the most precise (20.9). However, in patients with CrCl 24 hours ≥130mL/min/1.73 m, cystatin C-based equations underestimated GFR, while CG overestimated it (22.7).
Our study showed no evidence of superiority of any equation over the others for all evaluated parameters: bias, precision and Lin's concordance correlation coefficient. Cystatin C-based equations were less biased in individuals with impaired renal function (GFR <60 mL/min/1.73 m). CKD-EPI-Cr-CystC performed properly in patients with GFR from 60-130 mL/min/1.73 m and none of them were accurate enough in patients ≥130 mL/min/1.73 m.
24 小时尿肌酐清除率（ClCr24 小时）仍然是评估危重症患者肾小球滤过率（GFR）的金标准；然而，在临床实践中通常使用更简单的方法。血清肌酐（SCr）是最常用的估计 GFR 的生物标志物；另一种生物标志物胱抑素 C 已被证明比 SCr 更早反映 GFR 变化。我们评估了基于 SCr、胱抑素 C 及其组合（SCr-Cyst C）的方程在评估危重症患者 GFR 中的表现。
这是一项在三级护理医院进行的观察性单中心研究。纳入了在重症监护病房（ICU）住院并在±2 天内接受了胱抑素 C、SCr 和 ClCr24 小时测量的患者。ClCr24 小时被认为是参考方法。使用基于 SCr 的方程估计 GFR：基于肌酐的慢性肾脏病流行病学合作研究（CKD-EPI-Cr）和 Cockcroft-Gault（CG）；基于胱抑素 C 的方程：CKD-EPI-CystC 和 CAPA；以及基于 Cr-CystC 的方程：CKD-EPI-Cr-CystC。通过计算偏倚和精度评估每个方程的性能，并绘制 Bland-Altman 图。进一步对 CrCl24 小时<60、60-130 和≥130 mL/min/1.73 m 的分层数据进行了分析。
我们纳入了 275 次测量，对应 186 名患者。在总体人群中，CKD-EPI-Cr 方程的偏倚最低（2.6），精度最好（33.1）。在 CrCl24 小时<60 mL/min/1.73 m 的患者中，胱抑素 C 基于方程的方程显示出最低的偏倚（<3.0），并且 CKD-EPI-Cr-CystC 是最准确的（13.6）。在 60≤CrCl24 小时<130mL/min/1.73 m 的亚组中，CKD-EPI-Cr-CystC 是最精确的（20.9）。然而，在 CrCl24 小时≥130mL/min/1.73 m 的患者中，胱抑素 C 基于方程低估了 GFR，而 CG 高估了 GFR（22.7）。
我们的研究没有证据表明任何方程在所有评估参数（偏倚、精度和 Lin 的一致性相关系数）上都优于其他方程。在肾功能受损（GFR<60 mL/min/1.73 m）的个体中，胱抑素 C 基于方程的偏倚较小。在 GFR 为 60-130 mL/min/1.73 m 的患者中，CKD-EPI-Cr-CystC 表现良好，而在 GFR≥130 mL/min/1.73 m 的患者中，没有一种方法足够准确。
