Haemodialysis and the Environment
(We can and must do more)
The Geelong Experiment
Haemodialysis is NOT environmentally friendly
Haemodialysis, in a word, ‘rapes’ the environment.
1. Haemodialysis uses massive amounts of water
This may not be a major issue in some regions but, in Australia, and in particular in Geelong which lives in perpetual drought from a geographical ‘rain-shadow’, water is a precious resource and the wanton and profligate waste of it is unacceptable. Haemodialysis is water hungry.
For a standard Fresenius, Gambro, Braun or other ‘single-pass’ HD system running on a 500-600ml/minute dialysate flow rate, this amounts to 30 litres water use for every hour of dialysis.
In Australia, where the average conventional HD patient has 4.5 hours of dialysis, that amounts to 135 litres per dialysis.
But … That is just the water that makes it through the water filtration system! Back up a minute …
Mains water is used to provide the purified water for dialysis but it first has to be turned from clean, potable, mains water into dialysis-grade water for dialysate preparation.
After a series of particulate and carbon filtration (chlorine-removing) processes, the now-filtered and chlorine-free water is put through a reverse osmosis (RO) system.
RO’s remove any salts and impurities remaining in the ‘now-filtered and chlorine-free water’ and ‘reject’ these salts and impurities to the drain with only AAMI or, preferably, European grade pure water passing on to make the dialysate.
Though more efficient systems are available, most dialysis services use smaller RO machines (less efficient) and older models than the latest and most efficient systems (cost reasons).
As such, in most commonly used RO systems in dialysis, about 2/3rd of the presented water is ‘rejected’ and 1/3rd passes on to the dialysis machine to ‘make’ dialysate.
Do your mathematics …
130 litres is 1/3rd of the water
That means 260 litres is rejected – even before any water gets to the dialysis system
So … now we have 130 + 260 = 390 litres for each dialysis
BUT …
The machines need to be ‘primed’ before us and ‘rinsed’ after use
That uses the best part of another 100+ litres per dialysis
Add some more ‘lost’ by carelessness – not switching off – and the allowing of between-session bypass
AND … ~500+ litres water is used for each and every dialysis
Multiply that by each dialysis patient in the program Multiply that x 3 treatments for each per week Multiply that x 52 weeks in each year
And … that is the amount of water used
BUT …
Back to the reject water for a moment – and remember, it is 2/3rd of all the water used
Reject water accounts for ~330 litres/treatment
and reject water is really nice water!
Reject water passes all US EPA and WHO standards for potable water – even its’ conductivity … essentially, the salt concentration … falls well within EPA and WHO limits for drinking water...
Yet, we throw it away!
WHY?
Because until now
we have simply not thought to use it
Current systems and dialysis practices are water-wasteful.
New systems are coming – sorbent based and water-sparing – but until they do … and the US FDA processes alone will ensure a protracted wait … current processes are simply ‘guzzling’ water.
Even when new systems ARE available and prove reliable and cost-effective (more time), it will take years for a transition to occur.
So … water use at high water flow rates will remain main-stream practice for many years to come.
Meanwhile, countries like Australia – the driest continent on earth – and places like Geelong, among the driest in the driest, water use is a critical daily community problem. The same will likely apply in parts of the US – the south-west in particular – so the steps we have taken in Geelong are more widely applicable than in my own parched dialysis service. So …
In 2005, we took steps to minimize our water use We now re-use >100,000 litres of water a week within our medium sized (113 patient) dialysis service
The Geelong reject water re-use program
We published our data and systems in Hemodialysis International 2008 and 2009 and in an American Journal of Kidney Disease editorial 2008 … see below … creating in the process the 1st known peer-review literature on water conservation in haemodialysis.
1. Agar JWM*, Simmonds RE, Knight R, Magoffin J. Simple but essential new water-conservation practices for home-based dialysis services. Hemodialysis International. 12(2): 121. March 2008.
2. Agar JWM*, Simmonds RE, Knight R, Magoffin J. Simple but essential new water-conservation practices for facility-based dialysis services. Hemodialysis International. 12(2) 120-121. March 2008.
3. Agar JWM*, Simmonds RE, Magoffin J, Hinton T. Reusing the reject water at the R/O with a revert-to-mains alarm system in nocturnal home hemodialysis. Hemodialysis International. 12(2): 121. March 2008.
4. Agar JWM. Recycling Dialysis Wastewater: ‘The Elephant in the Room’. (Requested Editorial): Am J Kid Dis. 52(1):10-12. March 2008.
5. Agar JWM, Simmonds RE, Knight R. Using water wisely: New, essential and affordable water conservation practices for both facility and home hemodialysis. Hemodialysis International. (13(1): 35-39, January 2009.
All reject water at all facility-based services and in all homes in our home-based nocturnal haemodialysis service now recyle and/or re-use all reject water for a range of purposes* …
*NB: Australian services do not currently have NxStage® … all home patients use single-pass systems
In-centre dialysis services · The generation of steam for the sterilization of all hospital instruments and other sterile materials · The provision of water for some janitor services and ward areas for toilet flushing · Hospital grounds landscaping and gardens
Satellite dialysis facilities · Trucked water for community sporting facilities (football, cricket, bowls, golf) · School playgrounds and gardens · Aged care gardens
In 23/30 home NHHD patients · Animal water troughs · Garden and domestic uses (laundry/toilet)
In 7/30 home NHHD patients · An innovative recycling/re-presentation system to the RO has reduced home patient water uses by 82%
2. Haemodialysis uses significant power
Power is needed for both the dialysis machine and for the reverse osmosis process that ensures water standards are kept to the European standard – which is a significantly cleaner/tighter standard than the US AAMI standard.
The recent (2004/5) application of state and federal reimbursement programs to encourage alternative power uses – in particular solar and wind power – have made the application of solar power to dialysis services a practical and cost-attractive proposition.
So …
In 2010, we installed, trialed and later published the first known solar-assisted dialysis program at our 4 station home haemodialysis training centre
This study has been recently published in the Clinical Journal of the American Society of Nephrology
See …
Agar JWM … Solar-assisted Hemodialysis.CJASN.2012:7(2);310-314. February 2012.
The program is now being extended to offer out home dialysis patients the option of the installation of solar assisted power (~ 9 x 175kWh panels) at the time of home transfer
3. Haemodialysis creates mountains of medical waste
The ‘disposable’ one-use nature of haemodialysis consumables – Australia, along with most others, abandoned dialyser re-use in the late 1980’s or early 1990’s – has created, along with other medical waste from other hospital and clinic sources, a mountain of problematic waste.
Though as yet we have no answer for this problem, it is one that we believe industry must tackle and consider and we would encourage an creative approach to this problem from dialysis companies.
My vision for a greener future for dialysis can be found in a paper recently published in Hemodialysis International
See …
Agar JWM … Personal Viewpoint: Hemodialysis – water, power and waste disposal. Re-thinking our environmental responsibilities. Hemodialysis International. 16 (1); 6-10. January 2012.
Authored by Prof John Agar. Copyright © 2012 |