Stragier A, Wenderickz D, Jadoul M
Rinsing time and disinfectant release of reused
dialyzers: Comparison of formaldehyde, hypochlorite, warexin, and
renalin
Am J Kidney Dis
(Sep) 26:549-553 1995
Dialyzer reuse, while widespread, has come again under question
because of a controversial claim that patients reusing dialyzers
disinfected with Renalin and glutaraldehyde have an increased
risk of mortality (Held et al, AJKD 23: 693, 1994). Stragier
et al studied one potential mechanism: release of residues of
the disinfecting agent after 'adequate rinsing'. They studied
the rinsing time required to eliminate 4 different agents
(formaldehyde, Renalin, bleach, and Warexin), and their in vitro
release after completion of the rinsing process. The agents
were tested in vitro on cuprophane (Renalin), cellulose acetate
(formaldehyde), polysulphone (Renalin), and AN69 (all except
formaldehyde). The principle findings were that the adequate
rinsing time varies for the disinfection agent, and that some of
the agents are released even after adequate rinsing. The rinsing
times were longest for formaldehyde (30-35 min), intermediate for
Renalin (20-25 min), and shortest for bleach and Warexin (7-15
min). The rebound release 30 min after adequate rinsing was the
highest for formaldehyde (6 ppm), intermediate for Renalin, and
low for bleach and Warexin. This study raises questions
concerning the adequacy of current rinsing procedures for
formaldehyde and Renalin.
Additional Comments: Dialyzer reuse is known to alter the
membrane surface properties, causing alterations in middle
molecule
clearance (beta 2 microglobulin), aminoacid loss, and
biocompatibility. This study extends this list to include
adsorption
of disinfectant, with subsequent release. The clinical
consequences
of this phenomenon will require further investigation.
(Star)