[Clinical evaluation of the Paired Filtration Dialysis in children]

An important challenge for a pediatric nephrologist is to achieve in children the innovations of current adult dialytic technology.

Five children, mean age 14.1 +/- 1.5 yrs, mean weight 31.5 +/- 5.8 kg, mean dialytic age 32 +/- 20 months, were evaluated after a 6-month treatment with paired filtration dialysis (PFD). We used two capillary membranes: a 0.4 m 2 polysulfone hemofilter and a 0.8 m 2 cuprophan dialyzer. There was a reinfusion system (1540 +/- 150 mL/h) between these two filters. QD 500 mL/min and QB 230 +/- 10 mL/min. Ultrafiltration (UF) 2400 mL/h was planned for the hemofilter. At base-line and after 6 months of treatment, in addition, we evaluated routine clinical parameters, and other parameters such as beta2-microglobulin, dialytic adequacy (Kt/V) and nutritional status (dietetic diary). The data were analyzed using the Student's t-test for paired values.

Medium values of small molecules did not demonstrate meaningful variations after 6 months of treatment. The extraction percentage after each session was between 63% phosphorous and 76% for urea, but only 25% for convection. Instantaneous urea clearance after 60 min was 178 +/- 10 mL/min. Dialytic efficiency and nutritional intake were appropriated: Kt/V 1.66 +/- 0.2; PCRn 1.65 +/- 0.2; protein intake 2.2 +/- 0.5 g/kg/die; caloric balance 71.2 +/- 15 Kcal/kg/die; protein balance 0.53 +/- 0.4 g/kg/die; and azotic balance 85.8 +/- 74 mg/kg/die. We confirmed the good depuration capacity from the middle molecules with convective treatments: beta2-microglobulin extraction was 53%. Moreover, in children we found good clinical tolerance to PFD with modest interdialytic symptomatology: headache (8%), hypotension (6%), and cramps and vomiting (<2%). Increased priming of the extracorporeal circuit was not a significant technical problem. The cuprophan membrane has been subsequently replaced with the polysulfone membrane.

We can assert that this technique can also be performed in the pediatric age with similar results as in the adult age: good depuration of the small and averages molecules, good clinical tolerance, and shortening the dialytic sessions.