title: [Evaluation of the adequacy of hemodialysis from the aspect of urea kinetics models].
abstract: BACKGROUND
  One of the widely used indicators of adequacy of haemodialysis (HD) is assessment of the Kt/V of urea (K-dialysis clearance of urea, t-time of haemodialysis, V-distribution volume of urea). Work accomplished in recent years suggests that when the HD is adequate, the value of Kt/V should be 1.5. The objective of the present work was to assess to what extent the so-called adequate value of Kt/V can be influenced by the dietary protein intake and the frequency of HD sessions.
  
  
  RESULTS
  In 15 subjects on regular haemodialysis treatment the kinetics of urea in serum and in the dialyzation fluid was investigated. The protein intake and residual renal function was also recorded. The mean age of the examined subjects was 49 years (28-65 years). For HD treatment capillary dialyzers FOCUS 120H and ALPHA 160H, cuprophan and haemophan membranes with an area of 1.2-1.6 sq.m were used. The period of HD was 4-5 hours. The mean Kt/V value was 1.31 (+/- 0.20) at a normal level of protein catabolism (NPCR): 1.48 (+/- 0.17)g/kg/day. The mean value of the predialysis serum concentration of urea was 28.8 (+/-52)mmol/l. A formula was derived which makes it possible to calculate the adequate value of Kt/V which respects the intensity of the protein metabolism (NPCR which in a stabilized state is identical with the dietary protein intake), body weight (BW), intensity of urea excretion due to residual renal function (U) duration of the dialysis cycle (T is the sum of the dialysis and interdialysis time expressed in days) and the required value of the predialysis serum concentration of urea (CPRE). The relationship between these variables can be expressed by the following formula: [formula: see text] The calculated adequate value of Kt/V in the examined group varied within a wide range from 1.15 to 1.91 (mean value 1.47 +/- 0.25). The assembled results support the idea that an adequate value of Kt/V cannot be expressed by a single figure and that this value must be evaluated on an individual basis with regard to all measurable factors which influence protein metabolism.
authors.affiliation: Hemodialyzacní stredisko MNC, Praha.
authors.forename: O
authors.initials: O
authors.lastname: Schück
authors.forename: J
authors.initials: J
authors.lastname: Kaslíková
mesh_terms: D000328:Adult; D000368:Aged; D004044:Dietary Proteins / Q000008:administration & dosage; D005260:Female; D015312:Hemodialysis Solutions / Q000737:chemistry; D006801:Humans; D007676:Kidney Failure, Chronic / Q000378:metabolism / Q000628:therapy; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D006435:Renal Dialysis; D014508:Urea / Q000378:metabolism*
chemical_list: D004044:Dietary Proteins; D015312:Hemodialysis Solutions; D014508:Urea
vernacular_title: Posuzování adekvátnosti hemodialýzy z hlediska modelování kinetiky mocoviny.