Korean Journal of Nephrology 1998;17(2):243-249.

악성종양환자에서 유도한 크레아티닌 청소율 계산식

서기현 , 김혜영 , 이윤하 , 허우성 , 김윤구 , 김대중 , 박근칠 , 박찬형 , 오하영

Abstract

Evaluation of renal function was required in can- cer patients treated with drugs which were nephro- toxic or excreted by the kidney. In the clinical set- ting, the measured creatinine clearance(MCC) was commonly used method of predicting glomerular filt- ration rate. But, there were many potential sources of error in measurement of creatinine clearance, such as incornplete urine collections, inaccurate time reco- rdings, or analytical errors. Then, Cockcroft and Gault devised formula to estimate creatinine cleara- nce in adult males in 1976. Many cancer patients have diminished muscle mass due to nutritional sta- tus and edematous condition, which may lead to substantial underproduction of creatinine and overe- stimation of creatinine clearance. The purposes of this study were to compare and evaluate the corre- lation between estimated creatinine clearance(ECC) by the Cockcroft-Gault formula and measured crea- tinine clearance(MCC) from 24-hour urine collection in cancer patients and to develop new formula(new estimated creatinine clearance, ECCn) from these cancer patients. We analyzed 1411 samples from 798 cancer patie- nts. Using creatinine excretion(age, weight, and sex corrected+ standard deviation) as an index of comp- leteness of collection, 997 samples were accepted as adequate urine eollection. The correlation between ECC and MCC was excellent(r=0.85, P<0.001). But the differences between ECC and MCC were signifi- cant(P<0.05). We developed new formula by regre- ssion from random sampled 249 samples, and com- pared the correlations among ECC, MCC, and ECCn in other 748 samples. There were no significant dif- ferences between MCC and ECCn(P>0.05). In the cli- nical setting, dose adjustments of nephrotoxic drugs are not necessary if MCC is over 50mVmin. We expect that MCC is over 50mVmin if ECC or ECCn is over 60ml/rnin in this study. We conclude that Cockcroft-Gault s formula is applicable in cancer patient for dose adjustments of nephrotoxic drugs, but new forrnula is more accurate in predicting MCC than Cockcroft-Gault' s formula in cancer patients. Ccr= (230 - age) x (wt kg) // 144 xScr(mg/dl) (for male). Ccr= (165 - age)x (wt kg) // 120xScr(mg/dl) (for female)