Study Links New Dialysis Technology to Rise in Bleeding
TUESDAY, Oct. 18 (HealthDay News) -- A seemingly innocuous
change in the way that parts of kidney dialysis machines are
sterilized may have adverse health consequences, new research
A recently developed sterilization method called electron beam
(e-beam) sterilization may have caused lower levels of platelets in
the blood of dialysis patients, according to the study. Platelets
help the blood clot. Low levels of platelets, a condition called
thrombocytopenia, can lead to excessive bleeding.
The part of the dialysis machine that is sterilized by e-beam
sterilization is called the dialyzer. The dialyzer is also
sometimes called an artificial kidney. This is the part of the
machine that filters the blood.
"Thrombocytopenia is not widely recognized as a potential dialyzer-related complication," wrote the study authors. But, after observing this complication in 20 people following dialysis, the authors wanted to find the cause.
"In this cohort of patients undergoing hemodialysis in two Canadian provinces in 2009-2010, the use of e-beam sterilized dialyzers was associated with significant thrombocytopenia following dialysis," they wrote.
Results of the study are published in the Oct. 19 issue of the
Journal of the American Medical Association.
Complications related to dialyzers were more common in the 1960s
because the material used to make dialyzers was not as
biocompatible, or well-tolerated by the human body, as the material
Dialyzers made from newer, more biocompatible substances
significantly reduced immunological reactions, so much so that
adverse device reactions to dialysis treatments are uncommon today,
the authors said.
But, in 2009, it was discovered that a woman undergoing dialysis
just before she was scheduled to have a kidney transplant had low
levels of platelets following dialysis. Normally, blood is tested
prior to dialysis, but not after. This particular woman's blood was
taken before and after dialysis because of her scheduled
transplant. Her platelet levels had dropped significantly enough
that her transplant had to be cancelled.
Two days later, the woman returned for another dialysis
treatment. Blood testing revealed that, again, her platelet levels
had dropped during dialysis. After ruling out other potential
causes, her doctors used a dialyzer that had been sterilized with
gamma radiation instead of e-beam sterilization. Gamma radiation
was used to sterilize dialyzers before a switch to e-beam
sterilization occurred in 2009. When the gamma-radiation sterilized
dialyzer was used, the woman experienced no post-dialysis drops in
her platelet counts. She received a kidney transplant a month
The study authors then identified 19 more people who experienced
drops in platelet levels after dialysis with an e-beam sterilized
dialyzer. Once switched back to gamma-radiation sterilized
dialyzers, no drop in platelets was seen. Two people were
inadvertently exposed to an e-beam sterilized dialyzer again, and
had a repeated drop in their blood platelet levels, reported the
The study authors then looked at about 1,700 people undergoing
hemodialysis in British Columbia. Most were undergoing dialysis
with e-beam sterilized dialyzers. The researchers found that e-beam
sterilization was associated with a 3.6-fold increase in the risk
of thrombocytopenia compared to non e-beam sterilized
Similar results were seen when they evaluated platelet levels of
more than 400 dialysis patients in Alberta, the authors said.
It's not yet clear how e-beam sterilization might contribute to
a drop in platelets, said Dr. Jonathan Himmelfarb, director of the
Kidney Research Institute at the University of Washington in
Seattle and author of an editorial in the same journal. In
addition, he said, "We don't yet know if there are any clinical
consequences for patients."
One thing is clear, he said. "Any systematic change in dialysis
procedure should be systematically evaluated," he explained.
"Although hemodialysis has become quite commonplace, we need to
remember that it's still a complex medical procedure and we need to
always be vigilant."
Dr. Robert Provenzano, vice chair of nephrology at St. John
Providence Health System in Detroit, echoed Himmelfarb's concern.
"We need to be cautious about how these products that our blood is
exposed to are sterilized. Sterilization can alter the chemistry of
the dialyzer. It may not be as benign as we thought," he said.
If you're undergoing hemodialysis, Provenzano said you can ask
your center how the dialyzer is sterilized. If it's with e-beam
sterilization, you can ask if it's affecting your platelets. But,
centers can't reasonably screen every patient, he said. Centers
using e-beam sterilization might screen some patients when there is
a problem, he said. Also, some centers re-use dialyzers, which
actually helps avoid some complications and is cost-effective, he
To learn more about dialysis, visit the New York-based
National Kidney Foundation.
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