Blood urea nitrogen, middle molecules and uremic morbidity in hemodialyzed patients

Abstract

The adequacy of dialysis remains debatable. We compared the morbidity in our hemodialyzed patients according to predialysis blood urea nitrogen (BUN) levels, on the one hand, and to calculated middle molecule clearance (MMC = residual creatinine clearance + vitamin B12 clearance of the dialyzer), on the other hand. Patients with systemic diseases or with residual creatinine clearances above 3 ml/min were excluded. Fifty-one patient, incorporated into the same dialysis schedule, were studied during a follow-up of six to 30 months. Analyses of the data were conducted in the following two ways: Analysis A compared patients with BUN = 115 ± 12 mg/dl (n = 26) to patients with BUN = 85 ± 9 mg/dl (n = 25), while analysis B compared patients with MMC = 37 ± 8 (n = 26) to patients with MMC = 16 ± 5 (1/week; n = 25). In analysis A, both groups of patients had comparable MMC; in analysis B, both groups of patients had similar BUN. The following parameters were recorded: creatinine clearance, age, sex, weight, mortalities, hepatitis, pericarditis, bacterial infection, gastrointestinal diseases, duration of hospitalization, iPTH levels, motor nerve conduction velocity, blood pressure, hematologic values, number of transfusions. Among all these parameters, only the need for transfusions was higher in patients with higher BUN (24.8 v 14.4 units/patient/year, P < .001) for similar hematocrit. Lower MMC was associated with significantly higher morbidity (2.12 v 1.33 recorded complications/patient/year, P < .05), as well as with longer hospitalization (15.5 v 5.3 days/patient/year, P < .001). In our experience, overall morbidity was better correlated with the loss in MMC than with BUN levels, except for the need for transfusions. Monitoring of motor nerve conduction velocity did not seem useful for detecting underdialysis.SCOPUS: NotDefined.jinfo:eu-repo/semantics/publishe