O106
THE UTILITY OF DIALYSIS FLUID AUTOFLOW TECHNOLOGY TO REDUCE
CONSUMPTION OF WATER, ACID CONCENTRATE AND BICARBONATE IN A
HAEMODIALYSIS POPULATION
Carlisle G, Croft D, Stoves J
Department of Renal Medicine, Bradford St Luke’s Hospital
INTRODUCTION: Climate change presents a global health threat. Provision of end stage renal
failure services including in-centre haemodialysis accounts for 2% of the overall NHS budget
and produces a significant carbon footprint. Our previous practice has been to choose between
the 500mL/min and 800 mL/min dialysis fluid flow rate settings for patients who are dialysed
using a Fresenius 5008 machine, depending on the prescribed blood flow rate. The Autoflow
facility automatically sets the dialysate flow rate at 1.5 times the blood flow rate, thus for a 400
mL/min blood flow rate a 600 mL/min dialysis fluid flow rate is set automatically (this would
previously have been set manually at 800 mL/min). In addition to reducing the consumption of
water and acid concentrate, the use of Autoflow provides an opportunity to use smaller Bibags
(650g bags in place of 900g bags) for some haemodialysis treatments.
METHODS: Haemodialysis unit staff were informed of the change in practice and shown how
to activate the Autoflow facility. A minimum dialysis fluid flow rate of 500 mL/min was agreed
for patients with blood flow rates of < 330 mL/min, noting a previous finding of reduced
dialysis adequacy when using Autoflow in patients with low prescribed blood flow rates.
Patients who continued to require 900g Bibags (i.e. those who were prescribed a blood flow rate
of 500mL/min and a dialysis treatment time in excess of 4 hours) were identified, and 650g
Bibags were used for all other dialysis prescriptions. The adequacy of haemodialysis treatment
(measured by urea clearance) before and after switchover was compared using a paired t-test.
RESULTS: Following the change in practice there was a 9% reduction in water and acid
concentrate consumption (the latter supplied using a previously installed central acid delivery
system), with projected annual savings of £2,884 (1,140 m3 of water) and £ 2,880 respectively.
The use of smaller Bibags for most haemodialysis treatments provided additional savings of
£5,760, making a total annual cost saving of £11,524. The Centre for Sustainable Healthcare
calculated an associated 3,715 kg CO2 equivalent reduction in greenhouse gas emissions. The
use of Autoflow did not have a significant adverse effect on dialysis adequacy.
CONCLUSION: This study has demonstrated that use of the dialysis fluid Autoflow facility
may reduce the environmental and financial costs of haemodialysis treatment without
compromising dialysis adequacy.