KP index at the timing of initiation of dialysis for patients with end-stage renal disease

Hwang, Eui Won; Ji, Suk Bae; Kim, Jin Kuk; Hwang, Seung Duk

Abstract

BACKGROUND: An initiating time of renal replacement therapy (RRT) for patients with end-stage renal disease (ESRD) has great influence on prognosis of the patients, however, there are currently no accurate guidelines for initiation of renal replacement therapy. Traditionally, nephrologists usually initiate RRT on the basis of observation of uremic symptoms and changes of laboratory parameters, such as serum creatinine concentration and/or glomerular filtration rate (GFR). DOQI guidelines suggest weekly Kt/Vurea < 2.0 or nPNA < 0.8 g/kg/day for an objective index of the initiation of dialysis. Then, we designed to formulate KP index {(weekly Kt/Vurea + 2.5 X nPNA) X 1/2} using two indices above as a clinically useful objective index to determine the initiation of RRT for patients with ESRD.
METHODS
Patients with ESRD having the weekly Kt/Vurea index below 3.0 were selected from 186 patients who came to renal unit of Soonchunhyang Bucheon hospital. The patients having the weekly Kt/Vurea index between 1.0 and 2.0 were classified into two groups, KP index > 2.0 and KP index < 2.0. The groups were compared and analyzed via renal function, biochemical index and the number of patients starting a first RRT. Further, the correlations between KP index and other indices were analyzed over all patients. Then, the numbers per group of patients starting RRT were compared after all patients were divided into two groups, one of which is between 1.5 and 2.0 and the other is between 2.0 and 2.5 by weekly Kt/Vurea index and KP index.
RESULTS
The group of KP index < 2.0 indicated significantly lower indices in weekly Kt/Vurea, nPNA (B2) and % LBM (%) than those of the group of KP index > 2.0, while no significant differences between the groups were in serum albumin concentration, serum creatinine concentration, FFEFBM and RRF. And the frequency of patients starting RRT was significantly higher in the group of KP index < 2.0 rather than the group of KP index > 2.0 in statistics. There was a significant correlation between KP index and other indices in all patients. In comparing and analyzing the number of patients starting RRT, weekly Kt/Vurea index did not demonstrate significant differences between two groups of 1.5 < weekly Kt/Vurea < 2.0 and 2.0 < weekly Kt/Vurea < 2.5, but the frequency of patients in the group of 1.5 < KP index < 2.0 was significantly higher than that in the group of 2.0 < KP index < 2.5.
CONCLUSION
It is considered that KP index is an index clinically useful for ESRD patients to determine an appropriate timing for the initiation of RRT, and that the timing should be fixed with regard for other various indices and clinical features for advisable prognosis of the patients. In addition, accurate guideline to determine such an appropriate time needs to be suggested by further new studies.