A comparison of CKD-EPI estimated glomerular filtration rate and measured creatinine clearance in recently admitted critically ill patients with normal plasma creatinine concentrations.
BACKGROUND
The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) estimated glomerular filtration rate (eGFR) has been widely integrated into clinical practice. Although useful in screening for CKD, its' application in critically ill patients with normal plasma creatinine concentrations remains uncertain. The aim of this study was to assess the performance of CKD-EPI eGFR in comparison to creatinine clearance (CLCR) in this setting.


METHODS
This prospective observational study was performed in a tertiary level, university affiliated intensive care unit (ICU). Study participants had to have an expected ICU length of stay > 24 hours, a plasma creatinine concentration < 121 μmol/L, and no history of prior renal replacement therapy or CKD. CKD-EPI eGFR was compared against 8-hour measured urinary CLCR. Data capture occurred within 48 hours of admission.


RESULTS
One hundred and ten patients (n = 110) were enrolled in the study. 63.6% were male, the mean age was 50.9 (16.9) years, 57.3% received invasive mechanical ventilation, and 30% required vasopressor support. The mean CLCR was 125 (45.1) ml/min/1.73 m(2), compared to a CKD-EPI eGFR of 101 (23.7) ml/min/1.73 m(2) (P < 0.001). Moderate correlation was evident (r = 0.72), although there was significant bias and imprecision (24.4 +/- 32.5 ml/min/1.73 m(2)). In those patients with a CKD-EPI eGFR between 60-119 ml/min/1.73 m(2) (n = 77), 41.6% displayed augmented renal clearance (CLCR ≥ 130 ml/min/1.73 m(2)), while 7.8% had a CLCR < 60 ml/min/1.73 m(2).


CONCLUSIONS
These data suggest CKD-EPI eGFR and measured CLCR produce significantly disparate results when estimating renal function in this population. Clinicians should consider carefully which value they employ in clinical practice, particularly drug dose modification.
Burns, Trauma, and Critical Care Research Centre, The University of Queensland, Royal Brisbane and Womens Hospital, Butterfield Street, Herston 4029, Queensland, Australia. andrew_udy@health.qld.gov.au.
Andrew A
AA
Udy
Fraser J A
FJ
Morton
Sallyanne
S
Nguyen-Pham
Paul
P
Jarrett
Melissa
M
Lassig-Smith
Janine
J
Stuart
Rachel
R
Dunlop
Therese
T
Starr
Robert J
RJ
Boots
Jeffrey
J
Lipman
D001315:Australia / Q000453:epidemiology; D003404:Creatinine / Q000097:blood*; D003422:Critical Care / Q000706:statistics & numerical data*; D016638:Critical Illness; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data; D007677:Kidney Function Tests / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012016:Reference Values; D051436:Renal Insufficiency, Chronic / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D003404:Creatinine