Urea kinetics and clinical evaluation of the haemodialysis patient

Urea kinetic modelling (UKM) was performed on 62 patients in a haemodialysis unit not normally using kinetic methods. Without knowledge of the results, four nephrologists, four nurses and the patients themselves evaluated adequacy of dialysis (eAD) and daily protein intake (eDPI). Thirty-two patients had Kt/V less than 1.0, and 17 patients had Kt/V less than 0.9. Estimated improvement of the efficacy of treatment after the intervention of a physician was minor. Seven patients had a protein catabolic rate (pcr) at less than 0.8 g/kg per day. On average physicians identified five of these. Both nurses and doctors exhibited highly significant correlations between Kt/V and eAD, and between pcr and eDPI, but the correlation coefficients were generally modest (typically below 0.4). When patients evaluated themselves, no significant correlations were found. Examined individually, all four physicians' decisions about eAD correlated better with model-generated decisions than with eAD stated by their colleagues. It is concluded that UKM should be used to secure adequate and more uniform treatment prescription. There is no 'clinical standard' competing with UKM. Nurses make satisfactory evaluations compared to doctors, but the patients are unable to assess the adequacy of their dialysis or diet.