New parallel-flow hemodialyzer (Argonne type)

Abstract

A new pumpless, parallel flow hemodialyzer was first described by Lavender et al. in 1968. The design was modified and used for hemodialysis by Kokumai et al. in 1972. This improved disposable parallel flow hemodialyzer (FA-11) was 33×6×6cm in overall dimensions. The dry weight of the dialyzer was 480g. A plastic screen mesh for membrane support was placed inside cuprophan dialysis tube (45×260 mm). Seventy layers of this tubing sets were stacked to construct a FA-11 dialyzer with effective surface area of 11, 340 cm2 • The priming volume was 50 ml at 0 mmHg transmembrane pressure. FA-11 dialyzer was used for 47 hemodialysis on 15 patients with chronic renal failure and compared with the standard two layers Kiil and EX 03 dialyzer regarding those preformance. Performance of FA-11 dialyzer was as follows. The average BUN dialysance in FA-11 dialyzer was highest followed by EX 03, standard Kiil, and in uric acid dialysance F A-11 dialyzer was more effective than standard Kiil. No significant difference of the extraction rate of various substance was found between FA-H and EX-03, but they were better than those by standard Kiil. The average weight loss during dialysis at negative pressure 200mmHg was 130g/h in FA-H. In order to obtain the same amount of body weight reduction, negative pressure in dialysate had to be doubled in FA-11 as compared with standard Kiil. FA-11 dialyzer was compact, presterilized, disposable and simple for operation. The internal resistance to blood flow was quite low, which allows higher blood flow rates when used without a blood pump. The priming volume in dialyzer and residual blood volume at the end of dialysis were very small. If FA-11 dialyzer should be manufactured in automation and become inexpensive this dialyzer will be more useful for clinical hemodialysis.