Thrombocytopenia, a disorder in which blood platelets are abnormally low, is linked to an increased risk of bleeding. An investigation published in the October 19 issue of JAMA revealed that dialyzers for hemodialysis that have been sterilized with electron beams increases patients likelihood of developing the disorder.
Background information in the report suggests that:
“Adverse device reactions to hemodialysis treatments are uncommon but can still occur in today’s era of hemodialysis membranes and technology. During hemodialysis treatment, patients are exposed to a variety of components of the dialysis circuit and could have an adverse reaction to blood tubing, dialyzer membranes [used in the dialysis machines], and dialysis solutions.
Thrombocytopenia is not widely recognized as a potential dialyzer-related complication. Following the observation of significant thrombocytopenia among 20 patients undergoing hemodialysis in a single dialysis unit after the introduction of dialyzers sterilized by electron beam (e-beam), a larger investigation was undertaken.”
An investigation was conducted by Mercedeh Kiaii, M.D., F.R.C.P.C., of the University of British Columbia, Vancouver, Canada, and colleagues in order to find out the cause and commonness of thrombocytopenia in individuals undergoing hemodialysis between April 2009 and November 2010 in southern Alberta and British Columbia. They performed a retrospective analysis of patients’ historic, laboratory, and dialyzer data before carrying out conversions to e-beam dialyzers. They then conducted an analysis of platelet counts with prospective pre- and post-dialysis collections before and after the change from e-beam to non-e-beam sterilized dialyzers in September 2009.
They defined significant thrombocytopenia as a post-dialysis treatment platelet count of less than 100 x 103/µL and a reduction of over 15% in post-dialysis platelet count.
Researchers obtained data from 80% of British Columbian patients who underwent hemodialysis in community and hospital-based facilities, i.e. 1,706 from 2,146 hemodialysis patients and from 425 patients from Alberta. 1,411 (83%) of the 1,706 patients from British Columbia were undergoing dialysis where the membranes were sterilized using e-beam. Of the 1,411 patients, 11.4% (n=194) had platelet counts of less than 100 x 103/µL after dialysis, 23.4% (n=400) had a decrease in platelet count by over 15% post-dialysis, and 7.2% (n=123) met both criteria.
The found similar ratios from patients in Alberta who were undergoing dialysis using a polysulfone e-beam sterilized dialyzer made by a different manufacturer, 10.8% (n=46) had platelet counts of less than 100 x 103/µL after dialysis, 32.0% (n=156) of patients had a decrease in platelet count by more than 15% post-dialysis, and 7.3% (n=31) met both criteria.
In multivariate examination adjusting for dialysis and patient history characteristics, they discovered that use of an e-beam sterilized dialyzer was connected with a 2.5 times higher risk of considerable thrombocytopenia.
The researchers explain:
“Overall, among 1,784 patients, there were significant reductions in postdialysis thrombocytopenia following the change to use of non-e-beam sterilized dialyzers, such that 120 patients (6.7 percent) had platelet counts of less than 100 x 103/µL; 167 patients (9.4 percent) had decreases in platelet counts of greater than 15 percent; and 38 patients (2.1 percent) met both criteria.
Our study highlights 2 important points in the care of patients undergoing hemodialysis. First, dialyzer reactions such as thrombocytopenia can occur even with the use of current technologically advanced dialyzer membranes and devices. Second, these reactions may be overlooked with current routine predialysis blood work. Hemodialysis unit protocols and guidelines might consider adding postdialysis blood counts to routinely performed blood work when new dialyzers are introduced to help identify possible dialyzer-associated adverse effects.”
They add that biologically, it is possible that e-beam sterilization could activate alterations in platelets in numerous ways, although none have been exhaustively analyzed.
Commenting on the discoveries of this investigation, Jonathan Himmelfarb, M.D., of the University of Washington, Seattle, writes in an associated article that:
“This systematic, multifaceted study clearly demonstrated a robust association of thrombocytopenia risk with use of e-beam sterilization of dialyzers. It is also an exemplary model for investigating other problems that can affect patient safety during complex procedures such as dialysis. Several recently published single-patient case reports also have implicated e-beam sterilization as a possible cause of dialysis-induced thrombocytopenia.
Written by Grace Rattue