A fiber widely used in dialysis machines breaks down with age, causing severe and possibly fatal reactions in kidney patients, according to an April 26 report in the Journal of the American Medical Association . The findings arose from a 1996 case, in which seven patients who underwent dialysis on the same day at an Alabama hospital suffered vision and hearing loss, confusion, and other neurological symptoms. All seven underwent dialysis on cellulose acetate dialyzers manufactured in April 1985. Two other patients treated on newer machines had no symptoms.
Cellulose acetate is a fiber used to filter blood as it is pumped into the patient s body.
It is generally considered safe, but researchers found that the fiber s chemical properties change with age and that the chemical byproduct leaks into the patient s blood. According to an Associated Press interview with Joseph C. Hutter, an FDA chemical engineer and lead author of the study, new dialysis machines must now carry a date of manufacture. FDA is developing shelf-life standards for dialyzers and has recommended that dialysis centers check with manufacturers before using old dialyzers.