Author(s)

Leopoldo Muniz da Silva, Pedro Thadeu Galvão Vianna, Mariana Takaku, Glênio Bittencourt Mizubuti, Yara Marcondes Machado Castiglia

Department of Anaesthesiology, Botucatu School of Medicine, S?o Paulo State University (UNESP), S?o Paulo, Brazil.

Introduction: The utility of estimates of glomerular filtration rate based on creatinine and cystatin C serum levels to assess renal function in older surgical patients remains to be determined. Objective: To determine whether 2h-creatinine clearance (CrCl-2h) can be an adequate substitute for glomerular filtration rate estimates obtained by measuring serum cystatin C and creatinine in the elderly at preoperation. Methods: A total of 102 consecutive elder patients undergoing pre-anesthesia evaluation for routine surgeries were included. Study subjects were allocated into three groups: Group 1 (G1)—hypertensive diabetic patients, Group 2 (G2)—hypertensive patients, and Group 3 (G3)—non-hypertensive and non-diabetic patients. Two-hour urine collection was performed and CrCl-2h adjusted for ultrasonic residual bladder volume was estimated. GFR was estimated based on creatinine and cystatin C serum levels. Bland-Altman analysis was used to compare methods. Results: The mean difference between the evaluated methods and CrCl-2h was <15 mL·min^-1·1.73 m^-2 for Cys-GFR, and >20 mL·min^-1·1.73 m^-2 for Cr-GFR in all groups. CrCl-2h adjusted for ultrasonic residual bladder volume did not differ from non-adjusted CrCl-2h in none of the groups. Conclusion: Two-hour creatinine clearance was not an adequate substitute for GFR estimates based on creatinine and cystatin C serum levels in older patients at preoperation. The ultrasonic assessment of residual bladder volume had no significant influence on the calculation of two-hour creatinine clearance.

Renal Function; Creatinine Clearance; Cystatin C; Elderly

L. da Silva, P. Galvão Vianna, M. Takaku, G. Mizubuti and Y. Machado Castiglia, "Two-Hour Creatinine Clearance and Glomerular Filtration Rate Estimated from Serum Cystatin C and Creatinine in the Elderly to Preoperative Period," Open Journal of Nephrology, Vol. 3 No. 4, 2013, pp. 184-188. doi: 10.4236/ojneph.2013.34032.