AN AUTOMATIC CONTROLLED HEMOFILTRATION SYSTEM AND THE CLINICAL EVALUATION

Abstract

We have developed an automatic hemofiltration system in order to operate easily and to equalize UFR with substitution rate precisely. The system consists of two 2-chamber roller pumps, a level controller and a filter. 2-chamber roller pump (1) has two functions: delivering blood to the filter and producing negative pressure to facilitate UFR. Ultrafiltrated was transported into a level controller which regulated performance of two chamber roller pump (2). Two chamber roller pump (2) was for delivering substitution fluid into the venous line and for draining ultrafiltrate at same rate.
An extra ultrafiltrate was drained via the level controller by flow meter.
PMMA hollow fiber dialyzer (Toray A-1) was used as a filter. Blood flow and ultrafiltration rate were 50-300ml/min and 10-110ml/min, respectively. Discrepancy between graduated total UF except an extra UF and total substituion fluid was less than 2% when a venous pressure below 150mmHg. In vivo, sieving coefficient for urea, creatinine, inorganic phosphate and uric acid were 1.08±0.26mg/dl, 1.10±0.22mg/dl, 1.09±0.28mg/dl, 0.91±0.20mg/dl, respectively. Plasma clearance for 99.96±14.5ml/min, 98.48±13.54ml/min, 96.21±15.39ml/min, 79.40±14.46ml/min, respectively.
An exchange of body fluid between 18 and 20L was sufficient to remove metabolic wastes with regard to urea and creatinine.
Two patients were treated with only hemofiltration for nine months. Other two patients were treated with hemofiltration and hemodialysis alternately.
Their clinical course were not eventful. Disequilibrium syndrome, such as hypotension, crump, nausea and vomiting scaresely occurred during hemofiltration. Plasma triglyceride and cholesterol levels significantly decreased inspite of moderate increases in BUN and serum creatinine, after three to nine months hemofiltration period. Hemofiltration therapy seems to have some superior effects to regular hemodialysis therapy.