Tattersall J E, Doyle S, Greenwood R N, Farrington K
Lister Renal Unit, Stevenage, Hertfordshire, UK.
Nephrol Dial Transplant. 1994;9(7):749-52.
Urea kinetic modelling (UKM) has been proposed as a tool for auditing the adequacy of CAPD and a total fractional daily urea cleared volume (Kt/V) of 0.25 suggested as the minimum adequate level. At the start of CAPD the kidneys contribute significantly to the total clearance and Kt/V often falls below 0.25 as renal function declines. We performed 3-monthly UKM measurements in 56 CAPD patients. These results were used to individualize exchange volume and frequency in an attempt to achieve a Kt/V > 0.25 and compensate for declining renal function in all patients over a study period of 1 year. The mean Kt/V was maintained over 0.29 over the study period. During this time the residual renal component of Kt/V fell significantly from 0.09 (SD +/- 0.07) to 0.06 +/- 0.08 (P < 0.001) while the dialysis component increased significantly from 0.20 +/- 0.05 to 0.24 +/- 0.05 (P < 0.005). This was achieved by increasing the mean daily exchange volume from 8.12 +/- 1.22 to 10.39 +/- 2.68 litres (P < 0.001). After a year, 15 patients had Kt/V < or = 0.25 despite maximum practical exchange volumes. Twelve patients dropped out of the study due to death (4), transplantation (2), and transfer to haemodialysis (6 patients, of whom 4 had frank uraemic toxicity). In most CAPD patients it is possible to compensate for declining renal function by increasing exchange volume, at least over 1 year. However, CAPD was unable to provide Kt/V > 0.25 in 40% of patients, despite individualization of the dialysis prescription.
尿素动力学建模（UKM）已被提议作为评估持续性非卧床腹膜透析（CAPD）充分性的一种工具，并且建议每日尿素清除总量分数（Kt/V）达到0.25作为最低充分水平。在CAPD开始时，肾脏对总清除率有显著贡献，随着肾功能下降，Kt/V常常低于0.25。我们对56例CAPD患者进行了每3个月一次的UKM测量。这些结果被用于个体化调整透析液交换量和频率，以期在1年的研究期内使所有患者的Kt/V>0.25，并补偿肾功能的下降。在研究期间，平均Kt/V维持在0.29以上。在此期间，Kt/V中残余肾功能部分从0.09（标准差±0.07）显著降至0.06±0.08（P<0.001），而透析部分则从0.20±0.05显著增至0.24±0.05（P<0.005）。这是通过将平均每日交换量从8.12±1.22升增至10.39±2.68升实现的（P<0.001）。1年后，尽管已达到最大实际交换量，仍有15例患者的Kt/V≤0.25。12例患者因死亡（4例）、移植（2例）以及转至血液透析（6例患者，其中4例有明显的尿毒症毒性）而退出研究。在大多数CAPD患者中，至少在1年内通过增加交换量有可能补偿肾功能的下降。然而，尽管对透析处方进行了个体化调整，仍有40%的患者无法使Kt/V>0.25。
