Are serum cystatin-C-based estimates better than those derived from serum creatinine in critically ill patients?

Aim: To compare serum creatinine (SCr) and serum cystatin C as early marker of acute kidney dysfunction. Methodology: The present cross sectional observation study consisted of eighty- four ICU admitted patients (critical ill). A randomization of patients into 2 groups was done. Patients with normal kidney functions were put in group 1 while those with impaired kidney functions were in group 2. The estimation of serum creatinine (SCr) and serum cystatin C was done. Mann Whitney U and ch- square test was used for statistical inference. Results: In group 1 patients, mean serum creatinine (SCr) was 0.30± 0.21 mg/dl and in group 2 was 0.56±0.41 mg/dl. Serum cystatin C level in group 1patients found to be 0.42±0.17 mg/l and 1.5±0.68 mg/l in group 2 patients. Accuracy for Cys- C was better than SCr (90% vs 67%). Specificity for SCr was 97% whereas for Cys- C was 95%. Sensitivity for Cys-C was 80% while for SCr was 25%. SCr had PPV of 92% and NPV of 61% and for Cys- C it was 93% and 83% respectively. Conclusion: Serum cystatin C found to be better than serum creatinine for the identification of impairment of kidney functions in critically ill patients. Hence, assessment of Cys-C is of great concern in AKI. Key words: Acute renal failure, serum creatinine, serum, renal impairment

Download Full-text

Kidney Biomarkers and Major Adverse Kidney Events in Critically Ill Patients

Kidney360 ◽

10.34067/kid.0003552020 ◽

2020 ◽

pp. 10.34067/KID.0003552020

Author(s):

Alexander H. Flannery ◽

Katherine Bosler ◽

Victor M. Ortiz-Soriano ◽

Fabiola Gianella ◽

Victor Prado ◽

...

Keyword(s):

Prediction Model ◽

Critically Ill ◽

Cystatin C ◽

Critically Ill Patients ◽

Kidney Injury ◽

Clinical Prediction ◽

Serum Cystatin C ◽

Serum Cystatin ◽

Clinical Prediction Model ◽

Major Adverse Kidney Events

Background: Several biomarkers of acute kidney injury (AKI) have been examined for their ability to predict AKI before serum creatinine. Few studies have focused on using kidney biomarkers to better predict major adverse kidney events (MAKE), an increasingly used composite outcome in critical care nephrology research. Methods: Single-center prospective study collecting blood and urine samples from critically ill patients with AKI Kidney Disease: Improving Global Outcomes stage 2 or above, and matched controls from a single, tertiary care intensive care unit. Samples were collected at 24-48 hours after AKI diagnosis (cases) or ICU admission (controls), 5-7 days later, and 4-6 weeks following discharge for AKI patients. The primary outcome of interest was MAKE at hospital discharge (MAKE-DC), consisting of the composite endpoint of death, renal replacement therapy dependence, or a decrease in estimated glomerular filtration to <75% of baseline. Results: Serum/urinary neutrophil gelatinase-associated lipocalin (NGAL), serum/urinary cystatin C, and urinary kidney injury molecule-1 early in the AKI or ICU course were all significantly higher in patients with MAKE-DC compared to those not experiencing MAKE-DC. Additionally, serum/urinary NGAL and serum cystatin C measurements at the first time point remained significantly associated with MAKE events at 3, 6, and 12 months. Serum cystatin C, and to a lesser extent serum NGAL, significantly improved upon a logistic regression clinical prediction model of MAKE-DC (AUROC 0.94 and 0.87 vs. 0.83; p= 0.001 and 0.019, respectively). Patients without MAKE-DC experienced a greater decline in serum NGAL from first to second measurement than those patients experiencing MAKE-DC. Conclusion: Early measures of kidney biomarkers in critically ill patients are associated with MAKE-DC. This relationship appears to be greatest with serum NGAL and cystatin C, which display additive utility to a clinical prediction model. Trending serum NGAL may also have utility in predicting MAKE-DC.

Download Full-text

Estimated Glomerular Filtration Rate Correlates Poorly with Four-Hour Creatinine Clearance in Critically Ill Patients with Acute Kidney Injury

Critical Care Research and Practice ◽

10.1155/2013/406075 ◽

2013 ◽

Vol 2013 ◽

pp. 1-8 ◽

Cited By ~ 4

Author(s):

Christopher J. Kirwan ◽

Barbara J. Philips ◽

Iain A. M. MacPhee

Keyword(s):

Acute Kidney Injury ◽

Renal Function ◽

Glomerular Filtration Rate ◽

Critically Ill ◽

Cystatin C ◽

Critically Ill Patients ◽

Filtration Rate ◽

Kidney Injury ◽

Serum Cystatin C ◽

Serum Cystatin

Introduction.RIFLE and AKIN provide a standardised classification of acute kidney injury (AKI), but their categorical rather than continuous nature restricts their use to a research tool. A more accurate real-time description of renal function in AKI is needed, and some published data suggest that equations based on serum creatinine that estimate glomerular filtration rate (eGFR) can provide this. In addition, incorporating serum cystatin C concentration into estimates of GFR may improve their accuracy, but no eGFR equations are validated in critically ill patients with AKI.Aim.This study tests whether creatinine or cystatin-C-based eGFR equations, used in patients with CKD, offer an accurate representation of 4-hour creatinine clearance (4CrCl) in critically ill patients with AKI.Methods.Fifty-one critically ill patients with AKI were recruited. Thirty-seven met inclusion criteria, and the performance of eGFR equations was compared to 4CrCl.Results.eGFR equations were better than creatinine alone at predicting 4CrCl. Adding cystatin C to estimates did not improve the bias or add accuracy. The MDRD 7 eGFR had the best combination of correlation, bias, percentage error and accuracy. None were near acceptable standards quoted in patients with chronic kidney disease (CKD).Conclusions.eGFR equations are not sufficiently accurate for use in critically ill patients with AKI. Incorporating serum cystatin C does not improve estimates. eGFR should not be used to describe renal function in patients with AKI. Standards of accuracy for validating eGFR need to be set.

Download Full-text