Use of electron-beam sterilized hemodialysis membranes and risk of thrombocytopenia.

CONTEXT

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.

OBJECTIVE

To determine the prevalence and etiology of thrombocytopenia in hemodialysis populations of 2 Canadian provinces (British Columbia and Alberta).

DESIGN, SETTING, AND PARTICIPANTS: A cohort study of patients undergoing hemodialysis in British Columbia (n = 1706) and southern Alberta (n = 425) between April 1, 2009, and November 30, 2010. Retrospective analyses of historical patient, laboratory, and dialyzer data predating conversion to e-beam dialyzers were undertaken, with prospective collection of predialysis and postdialysis platelet counts before and after the change from e-beam to non-e-beam sterilized dialyzers in September 2009.

MAIN OUTCOME MEASURE

Significant thrombocytopenia, defined a priori as postdialysis treatment platelet count of less than 100 × 10(3)/μL and a postdialysis decrease in platelet count of more than 15%.

RESULTS

Among 1706 patients undergoing hemodialysis in British Columbia, 1411 (83%) were undergoing hemodialysis with e-beam sterilized dialyzers. Of 1706 patients, 194 (11.4%; 95% CI, 9.9%-12.9%) had postdialysis platelet counts of less than 100 × 10(3)/μL; 400 (23.4%; 95% CI, 21.5%-25.5%) had postdialysis decreases in platelet counts of more than 15%; and 123 (7.2%; 95% CI, 6.0%-8.6%) met both criteria. Among 425 patients in Alberta undergoing dialysis with polysulfone, e-beam sterilized dialyzers made by a different manufacturer, 46 (10.8%; 95% CI, 8.1%-14.3%) had platelet counts of less than 100 × 10(3)/μL; 156 (32.0%; 95% CI, 27.6%-36.7%) had decreases in platelet counts of more than 15%; and 31 (7.3%; 95% CI, 5.1%-10.3%) met both criteria. In multivariable analysis adjusting for patient and dialysis history characteristics, a significant association was observed between using an e-beam sterilized dialyzer and risk of significant thrombocytopenia (odds ratio [OR], 2.52; 95% CI, 1.20-5.29; P = .02). Compared with use of e-beam sterilized dialyzers, following the change to use of non-e-beam sterilized dialyzers, among 1784 patients, significant reductions were observed in postdialysis thrombocytopenia (120 patients [6.7%; 95% CI, 5.6%-8.0%; P < .001] had platelet counts of <100 × 10(3)/μL; 167 patients [9.4%; 95% CI, 8.1%-10.8%; P < .001] had decreases in platelet counts of >15%; and 38 patients [2.1%; 95% CI, 1.5%-2.9%; P < .001] met both criteria). Using generalized estimating equation modeling for repeated data with binary outcome, after adjusting for patient characteristics, the odds of significant thrombocytopenia were higher during the use of e-beam sterilized dialyzers than with use of non-e-beam sterilized dialyzers (OR, 3.57; 95% CI, 2.54-5.04; P < .001).

CONCLUSION

In this cohort of patients undergoing hemodialysis in 2 Canadian provinces in 2009-2010, the use of e-beam sterilized dialyzers was associated with significant thrombocytopenia following dialysis.