Brondén B, Eyjolfsson A, Blomquist S, Dardashti A, Ederoth P, Bjursten H. Evaluation of cystatin C with iohexol clearance in cardiac surgery.
Acta Anaesthesiol Scand 2011;
55:196-202. [PMID:
21226861 DOI:
10.1111/j.1399-6576.2010.02361.x]
[Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND
Post-operative renal dysfunction after cardiac surgery is not uncommon and can lead to adverse outcome. The ability to accurately monitor renal function is therefore important. Cystatin C is known to be a sensitive marker of the glomerular filtration rate (GFR), but it has not been fully evaluated in cardiac surgery. Iohexol clearance is considered a reliable reference method for the determination of GFR. The aim of this study is to, for the first time, evaluate the diagnostic accuracy of plasma cystatin C compared with iohexol clearance in cardiac surgery.
METHODS
Twenty-one patients scheduled for elective coronary artery bypass grafting were prospectively enrolled in the study. Before surgery and on the second post-operative day, an iohexol clearance was performed. Plasma cystatin C, plasma creatinine and plasma C-reactive protein were determined before surgery and on the first, second, third and fifth post-operative day. Estimated creatinine and cystatin C clearances were determined.
RESULTS
Post-operative cystatin C and 1/cystatin C correlated strongly to iohexol clearance (r=-0.90 and 0.86) and so did creatinine and 1/creatinine (r=-0.83 and 0.78). Estimated creatinine clearance differed from iohexol clearance (P<0.01), whereas estimated cystatin C clearance did not differ from iohexol clearance (P=0.81). No correlation was found between C-reactive protein and cystatin C.
CONCLUSION
This study indicates that clearance estimations based on cystatin C are more accurate compared with estimations based on creatinine in determining GFR in cardiac surgery. Cystatin C has, in this study population, a stronger correlation to iohexol clearance than creatinine.
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