Assessment of the Different Methods to Predict Equilibrated Kt/V in Pediatric Hemodialysis
Chookiet Kietkajornkul MD*, Prapaipim Thirakhupt MD**, Yupapin Chulamokha MD** Salee Jaiprong BNS**, Sarunya Kitpanich BPH, MSc**
Affiliation : * Nephrology Division, Department of Pediatrics, Queen Sirikit National Institute of Child Health ** Nephrology Division, Department of Pediatrics, Phramongkutklao Hospital
Objectives : To determine the degree of urea rebound in children on hemodialysis and compare the different
calculation models for Kt/V.
Materials and Methods : The present study was performed in 50 hemodialysis sessions of 5 pediatric patients,
2 males and 3 females, aged 5-18 years, who had received hemodialysis for 7-48 months. Blood urea
samples were obtained at the beginning, 70 minutes intradialysis, the end and every 10 minutes for 1 hour
post- dialysis. The compared 6 different models of Kt/V were single pool, Daugirdas, equilibrated, rate
equation, Maduell and Smye method.
Results : Urea rebound was found to be completed at least 60 minutes post- dialysis and mean percentage
value was 30.68 ± 9.663.Mean value of equilibrated Kt/V was 1.442 ± 0.259 while that of single-pool
Kt/V calculated by lnC1/C2 was 1.705 ± 0.252 leading to overestimation of Kt/V by 0.265 ± 0.075.
Mean value calculated by Daugirdas method was 2.083 ± 0.336. Mean values obtained by rate equation,
Maduell and Smye methods were 1.485 ± 0.209, 1.442 ± 0.209 and 1.379 ± 0.343 which differed
from equilibrated Kt/V by 0.086 ± 0.058 (p = 0.002), 0.069 ± 0.063 (p = 0.967) and 0.132 ± 0.132
(p = 0.015), respectively.
Conclusion : Urea rebound in pediatric patients is completed at least 60 minutes after cessasion of hemodialysis.
Kt/V calculated from single-pool is not suitable for children. The Maduell model gives the best correlation
to equilibrated Kt/V when compared to rate equation and Smye models.
Keywords : Hemodialysis, Pediatric, Kt/V, Urea rebound, Urea kinetic models, Adequacy
