지속성 외래 복막투석환자에서 요소 동력학 모형 (Urea Kinetic Modeling)과 크레아티닌 청소율을 이용한 투석의 적절도 평가에 관한 연구

Abstract

It is hardly an exaggeration to state that adequacy of dialysis and it assesment are at present the most important issues in the management of end-stage renal disease. There is a need to find a balance between underdialysis, which leads by definition to excess morbidity and mortality, and overdialysis, which is best defined as any dialysis in excess of that dose at which the social and economic burden of the therapy is continuing to increase without there being significant, verifiable, incremental medical benefit for the patient. Urea kinetic modeling has become the accepted method by which to determine the hemodialysis prescription, but what indices of adequacy for CAPD exist? Until recently, the standard CAPD prescription has been quite empiric. Recent reports evaluating urea kinetic modeling as a useful predictor of CAPD outcome are conflicting and several studies have suggested that a weekly creatinine clearance of 40~50 L/1.73㎡probably results in adequate dialysis. This study was performed to evaluate the relationship between weekly Kt/V, normalized protein catabolic rate (NPCR), weekly standardized creatinine clearance (SCCr) and serum albumin and also to evaluate whether the urea kinetic modeling or creatinine kinetics have relationship with the clinical status presenting the adequacy of CAPD. Clinical status was assessed by two methods, one using the score system based on the subjective symptoms and laboratory findings (CS I) and the other scored by the attending phsician (CS II). The patients were divided into three groups, poor, intermediate, and good, according to the CS I and II. Total 154 patients who were clinically stabile and free from peritonitis in the preceeding 2 months were analyzed and the following results were obtained. 1) The patients were 89 men and 65 women, age 47.0 years, and mean duration of CAPD before study was 24.3 months. The BUN, serum creatinine, serum albumin, and hematocrit were 55.4±16.2mg/dl, 12.7±4.0mg/dl, 4.0±0.5g/dl, and 26.4±6.2%. The weekly Kt/V, NPCR and SCCr were 1.95±0.43,0.94±0.21g/kg/ day, and 62.6±24.1L/wk/1.73M2. 2) Positive correlation was observed between weekly Kt/V and NPCR(Kt/V=1.21×NPCR=0.91, r=0.53).And also, there was a weak correlation between weekly Kt/V and SCCr(Kt/V=0.008×SCCr+1.44, r=0.45).But weekly Kt/V, NPCR, and SCCr did not show any corre-lation with the serum albumin concentration. 3) Significant difference was observed among poor, intermediate, good group (16.9±1.9,21.0±1.2, 25.6±1.2)in terms of total score in CS I. But no correlation was noted between total score by CSI and other parameters (weekly Kt/V, NPCR,SCCr, and serum albumin).There was no significant difference among three groups in terms of weekly Kt/V and serum albumin (1.96±0.53,1.92±0.38, 2.02±0.44, 4.0±0.7, 4.0±0.5, 4.1±0.5g/dl)in CS I.Athough SCCr was elevated in good group, there was no significant difference among three groups (60.7±17.5, 60.0±22.3, 69.2±30.5L/wk/1.73m2) in CS I. No significant difference was noted among three out come groups in terms of weekly Kt/V(2.01 0.45, 1091±0.46, 1.98±0.40)in CS II. But, SCCr was significantly different between poor and good group (54.2±11.2, 70.0±30.4L/wk/1.73m2)and intermediate and good group (59.3±19.5, 70.0±30.4L/wk/17.3m2)(p<0.05)in CS II. And significant differ-ence was observed between poor and intermediate group (3.6±0.7, 4.1±0.5g/dl), and poor and good group (3.6±0.7, 4.2±0.4g/dl)in terms of serum albumin, respective-ly (p<0.05)in CS II. In conclusion, a positive correlation between weekly Kt/V and NPCR, and a weak correlation between weekly Kt/V and SCCr was observed in CAPD patients. No significant correlations were found between serum albumin concentration and other parameters (weekly Kt/V, NPCR, SCCr). The weekly Kt/V values were not any different between poor, intermediate and good groups both in CS I. However, SCCr and serum albumin levels were significantly higher in good group compared to the poor group, especially when assessed by physician sccring system (CSLL). Thus, based on this study, creatinine clearance and serum albumin appear to be more sensitive predictors of clinical status of CAPD patients than Kt/V. But further prospective studies and parameters which can define the exact clinical status are required to evaluate the adequacy of CAPD.