Korean Journal of Nephrology 1994;13(3):478-488.

Urea Kinetic Modeling의 임상적 응용

최규복 , 정성애 , 홍영선 , 윤견일

Abstract

Background
To evaluate the adequacy of hemo- dialysis in patients with chronic renal failure, the KT/V urea has been used as a guideline on the Dose of Dialysis. But the UKM was frequently influenced by errors in measuring blood flow and dialysis time, in sampling technic and in BUN analysis. And practically it was not feasible to avoid above errors which resulted in inappropriate deviation of urea distribution volume (UKM vol) from Anthropometric volume. We tried to correct the deviation of UKM vol after the UKM in 22 patients undergoing regular hemodialysis (12 males, 10 females), and then performed dialysis prescription, and finally evaluated the validity of that prescription. Methods .: We recorded dialysis time and measured body weight and BUN before and after hemodialysis. On the next dialysis, predialysis body weight and BUN were measured. Also we calculated residual renal func- tion, recirculation of blood in arteriovenous fistula and bloodside In-Vivo clearance of dialyzer. Initially we performed the UKM by using blood-side In-Vivo clear- ance with TherAps program (single-pool variable vol- ume model, Cobe laboratories) to obtain the Profile 1 and 2. The Profile 1 include Anthropometric volume and KT/V urea. In the Profile 2, UKM vol, KT/V urea (UKM-KT/V) and protein catabolic rate (PCR) were included. When the difference between UKM vol and Anthropometric volume (Vol-Dev) exceeded the acceptable range ( -15%-+15%), we tried to correct the Profile 2. If corrected, profile 2 was calculated. But if not, only profile 1 was calculated. The UKM-KT/V was compared with the KT/V urea calculated by percent reduction of urea (PRU) (PRU-KT/V) as an index. According to the method of profile composition for dialysis prescription, two uncorrected profile 2 were used in Group 1, two profile 2 of which one was corrected in Group 2, and profile 1 and 2 regardless of correction in Group 3. Result:. 1) Among 44 cases of the UKM, Vol-Dev exceeded the acceptable range in 21 cases (48%) and 11 cases of them (52%) was corrected. 2) Uncorrected group (23 cases) and corrected group (before and after correction) showed no significant dif- ferences in Vol-Dev, KT/V ratio, degree of recirculation, blood-side dialyzer clearance and in dialyzer KoA. 3) The SD of Vol-Dev was decreased from 23.44 to 9 .86 after profile correction. 4) Corrected and uncorrected groups showed highly significant positive correlations between UKM-KT/V and PRU-KT/V (r=0.95 & r=0.98; p<0.000) (2-tail prob.). 5) Between In-Vivo clearance and effective clearance, uncorrected group showed strong positive correlation (r =0.94, p<0,000) but corrected group did not (2-tail prob.). 6) KT/V urea deviation, pre- and post-BUN deviation from prescribed value, and Vol-Dev had no significant differences among 3 Groups. And pre- and post-BUN and KT/V urea had no significant differences between measured and prescribed value within each group. 7) In 11 cases of the UKM performed after prescription, there were positive correlation between pre-BUN or post-BUN deviation and NPCR deviation from prescribed value (r=0.76, p<0.01; r=0.55, p<0. 05) (1-tail prob). Conclusion '. If the Vol-Dev exceeds the acceptible range, there is the possibilities of errors. In unavoidable situation it maybe feasible to use corrected profile for dialysis preseription. So, we can lessen the frequency of the UKM and make prescription more easily by correction of the Profile.