A continuous hemofiltration system using sorbents for hemofiltrate regeneration.

Abstract

Plasma ultrafiltrate obtained by glomerular filtration undergoes tubular modification which leads to the elimination of toxic substances, excess water and electrolytes, and consequently maintains homeostasis. Using normal urine and the substances it contains as a reference, we have developed a wearable device capable of replacing both the renal excretion function and maintaining fluid and electrolyte equilibrium in uremics within acceptable biological limits. Our device includes a hemofilter allowing continuous plasma ultrafiltration and sorbents obtained from a Redy sorbent cartridge to treat 85% of the ultrafiltrate, whereas 15% of this UF is rejected untreated. After calculating the quantity of ultrafiltrate (about 13 l) containing an amount of waste products of metabolism equivalent to 24-h urine elimination, we determined in vitro the amount of sorbent required to eliminate these waste products from the ultrafiltrate (e.g., 20 g of urea/day) and we have evaluated the quantities of other substances which must be replaced using a tailored diet. This extra-corporeal detoxification process was used in a uremic patient who had been on traditional hemodialysis for the past two years. The continuous treatment permitted maintenance of fluid and electrolyte equilibrium at the desired level and allowed rapid improvement of patient clinical status: elimination uf nausea, vomiting, diarrhea and edema, which had previously reappeared during the interdialytic periods, as well as a rapid decrease in heart size as ascites disappeared. In addition, the patient regained sexual drive and the ability to have an erection. In conclusion, traditional hemodialysis and hemofiltration techniques allow intermittent elimination of products retained by the body and reestablish nearly normal fluid and electrolyte balance.(ABSTRACT TRUNCATED AT 250 WORDS)