Authors (including presenting author) :
NG WLO(1), Wong TY(1), TSUI KL(1), WONG WM(1), LAU CL(1)
Affiliation :
(1)Accident and Emergency Department, Pok Oi Hospital, Hong Kong
Introduction :
Currently in NTWC, estimated glomerular filtration rate (eGFR) is calculated by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) creatinine equation and auto-generated with renal function test. This provides an easy way for renal drug dosage adjustment. However, most of the renal dosage recommendations by pharmaceutical companies are based on creatinine clearance (CrCl) by the Cockcroft-Gault (C-G) formula which is the only calculation method with body weight included. As the CKD-EPI equation is not normalized to body weight, the eGFR of patients with low body weight may not truly reveal the creatinine clearance. This raises our concern as many of the patients in Emergency Medicine Ward (EMW) of Pok Oi Hospital (POH) are elderly patients who possibly require renal dosage adjustment. Therefore, this study aims at comparing the discrepancy between the result of the two different equations in patients admitted to EMW of our Accident and Emergency Department (AED).
Objectives :
Compare and define the discrepancy between CrCl by C-G and eGFR by CKD-EPI in patients admitted to EMW.
Methodology :
A cross-sectional study was conducted. All patients admitted to EMW from July to August 2019 were included. The value of estimated CrCl and eGFR calculated by the C-G formula and the CKD-EPI equation respectively were compared with respect to age and analysed by Paired t-test and the Wilcoxon signed-rank test.
Result & Outcome :
A total of 189 convenient samples were recruited and analysed (n=189). The result of the paired t-test (two-tailed) indicated that there was a significant difference between the value of CrCl by C-G (M=66.57, SD=34.08) and eGFR by CKD-EPI (M=79.16, SD=26.94); t(188)=-9.76, p< 0.05, as well as the Wilcoxon signed-rank test, p< 0.05. The older the age, the larger the discrepancy between the value of CrCl by C-G and eGFR by CKD-EPI would be. The lower the body weight was, the greater the discrepancy was. The eGFR by CKD-EPI tended to overestimate the creatinine clearance among 150 patients who were over 40 years old or body weight less than around 68kg. The study reveals significant discrepancy between the value of CrCl by C-G and eGFR by CKD-EPI in acute care settings especially among elderly patients. The use of the CrCl by C-G is the preferable tool than the eGFR by CKD-EPI for renal dosage adjustment in EMW setting.
