MAINTAINING LOW CONCENTRATIONS OF PLASMA BETA(2)-MICROGLOBULIN THROUGH CONTINUOUS SLOW HEMOFILTRATION

As a first step in the development of a future wearable artificial kid ney, we conducted three forms of treatment with continuous haemofiltra tion (CHF) on a group of 10 patients in an attempt to determine what p lasma values of small molecules and beta(2)-microglobulin (beta(2)-M) could be maintained. In the first system, one ordinary 4-h haemodialys is, followed by 7-day CHF with 51 exchange per day, was repeated. The second system consisted of CHF with 51 exchange/day and thrice weekly slow nocturnal dialysis. The third system used CHF with 101 exchange p er day. The first, second and third systems were used with three, four and four patients, respectively, for at least 4 weeks each. PAN-DX an d FH-66 haemofilters were used eight and three times, respectively, wi th continuous infusion of heparin at 500-700 units/h. In the first sys tem, the pre-CHF plasma beta(2)-M was 45.5 +/- 3.1 mg/l, against a muc h lower 18.8 +/- 1.0 mg/l 4 weeks later. With the second system, this decrease was from 43.5 +/- 5.7 mg/l to 18.1 +/- 1.1 mg/l with 4 weeks treatment, and from 44.7 +/- 3.4 mg/l to 18.1 +/- 1.4 mg/l with 3 week s treatment. Pre-haemodialysis treatment levels of urea nitrogen, plas ma creatinine and uric acid in the first system were greater than ordi nary pre-haemodialysis levels. On the second system, these were kept a t -54 +/- 8.3%, -52.2 +/- 6.7% and -47.6 +/- 4.4% of the ordinary pre- haemodialysis levels, respectively. After 4 weeks on the third system, these same levels were maintained at -32.1 +/- 3.1%, -56.7 +/- 2.1% a nd -59.2 +/- 5.4%, respectively. Although with the first system the se rum Na, Cl and Ca were within the normal range, the pre-dialysis plasm a K concentration was high. Plasma P-i was greater than normal in the first and second systems, but was maintained within the normal range i n the third system.