Importance of Endotoxin Testing in Hemodialysis procedure
Uncountable lives of renal disease patients depend on dialysis procedures, many number of patients worldwide undergo maintenance or long-term hemodialysis. The main Challenges in Hemodialysis is to produce large quantity of high purity water cost effectively and the other challenge which requires attention is occurrence of endotoxin related reactions.
Endotoxin: A pyrogenic substance (lipopolysaccharide) produced by gram-negative bacteria. Endotoxins can cause fever, rigors, hypo tension, organ failure and even death if they get into the circulation.
There is mounting evidence to suggest that exposure to relatively low levels of endotoxin causes chronic inflammation and there is increasing evidence linking inflammation to cardiovascular disease in the general public but the effect of inflammation on rates of mortality and morbidity in haemodialysis patients is still under debate. To be certain that the health of patients is not being compromised, dialysis units should aim to minimise their exposure to any detectable level of
Water used for haemodialysis should meet the requirements of the local specifications for purity.(The European Pharmacopoeia says total viable count <100 cfu/ml and endotoxin level =0.25 IU/ml)
Water treatment systems used in dialysis are a critical factor in the overall care received
by dialysis patients; they also provide one of the greatest hazards to the patients if they
are not functioning properly.
Water used for haemodialysis should be tested routinely to verify the efficacy of the disinfection programme, Disinfection is a less lethal process than sterilization, since it is expected to destroy most recognized pathogenic microorganisms, but not necessarily all those present. Disinfection does not eliminate endotoxin, it is stable, it is not easily destroyed by sanitizers , Only ultra filtration removes endotoxin.
The LAL assay is the method recommended for endotoxin testing by the most Pharmacopoeias, and is widely used the pharmaceutical industry.
All the established techniques (gel-clot, turbidity and chromogenic) for LAL testing can be used for testing water for haemodialysis.
The LAL gel-clot test and Chromogenic Endpoint assay can be performed very easily in a dialysis unit. The suppliers of the LAL reagent will normally provide training in the testing and validation procedures.