Karen Mak R.N. (Team Leader) Renal Dialysis Centre Hong Kong Sanatorium & Hospital
- Renal Transplantation - Peritoneal Dialysis - Extracorporeal Therapy
Extracorporeal Therapy It is the procedure in which blood is taken from the patient s circulation to have a process applied to it before it is returned back to the circulation.
Renal Support in Critical Care Setting Continuous Renal Replacement Therapy -CAVH,CVVH -CAVHD,CVVHD
Renal Support in Critical Care Setting Intermittent -Haemodialysis (HD) -On-line Haemodiafiltration (HDF)
Different between IHD & CRRT Intermittent HD/ HDF It is inexpensive and has the convenience of scheduled downtime that allows the patient to be available for out-ofunit activity. Continuous RRT It allows fluid removal with minimal hemodynamics instability and provide consistent solute control
Clarity of Terminology Treatment Modality Indication CRF AKI Terms Intermittent CRRT (Continuous) Hybrid (Extended) Modality HD ONLINE HDF CVVHDF SLEDD-f Solute Removal Fluid Removal Diffusion + Convection Ultrafiltration Treatment Time 4 to 5 hours 4 to 5 hours 24 hours 6 to 18 hours Frequency (Week) 2-3 x 2-3 x 7 x 6 x Vascular Access Fistula/Graft/Catheter Fistula/Graft/Catheter Temp. Catheter Temp. Catheter QB (ml/min.) 300-500 300-500 100-350 100 350 Dialysate Fluid Bicarbonate Bicarbonate Lactate/Bicarbonate Bicarbonate QD (ml/min.) 500 800 500 800 16.6 33.3 100 200 QF (low volume) - < 15 L/ treatment < 35 ml/h/kg < 35 ml/h/kg QF (high volume) - > 15 L/ treatment > 35 ml/h/kg > 35 ml/h/kg Infusate - ONLINE Pre-packed ONLINE Water Treatment Yes Yes No Yes
On-line Haemodiafiltration (HDF)
Haemodiafiltration HD + HF = HDF - A combination of dialysis and haemofiltration A treatment designed to remove accumulated metabolic products from blood by a combination of diffusive and convective transport through a semipermeable membrane of high-flux type.
Haemodiafiltration HD + HF = HDF - High clearance in middle /high molecular weight waste products Fluid is removed by ultrafiltration and the volume of filtered fluid exceeding the desired weight loss is replaced by sterile, pyrogenfree infusion solution. HDF provides a better elimination of highermolecular weight solutes than HD.
Molecular Weights
On-line HDF ONLINE Haemodiafiltration (On-line HDF) is a treatment modality which uses ultrapure dialysate produced by the dialysis machine as a substitution fluid. This allows the exchange of large amounts of fluid during the treatment, thereby achieving a dialysis which more closely resembles the natural function of the kidney.
Advantage of on-line technique - On-line production of infusion fluid - More physiological buffer - Composition can be modified easily - Temperature can be modified easily - Cost savings - Space to storage of commercial fluid bag, avoiding an environmental burden - No additional workload
On-line HDF technique is not complex!
Therapy System able to provides unlimited quantities of highly pure physiological substitution fluid prepared ONLINE from dialysis fluid.
Dilutional Methods
Technical and Clinical Considerations
Post dilution HDF - Post-dilution is the most efficient mode of HDF for clearing middle and large molecular weight substances.
Post dilution HDF - High extracorporeal blood flow rates (typically >350 ml/min) - A reliable vascular access (ideally an arteriovenous fistula with a flow rate >600mL/min) - An ability to achieve adequate anticoagulation throughout the procedure and the absence of any condition that increases blood viscosity (high haematocrit, cryoglobulinaemia and gammopathies).
Post dilution HDF
Pre-dilution HDF - Pre-dilution HDF is the most appropriate modality for cases with HCT, TP, BFR and tight dose of heparin or heparin free thus avoid complication (e.g. TMP and filter clotting)
Pre-dilution HDF - The blood is diluted with substitution fluid prior entry into the dialyser and before plasma water is removed by UF, thus lower risk of hemoconcentration - Higher the degree of pre-dilution, the lower the clearance of small solutes
Pre-dilution HDF
HDF versus HD
Small /middle solute clearance Dialysis-related amyloidosis Marginally lower serum albumin Lower triglycerides and higher HDL- cholesterol Hemodynamic stability Anemia / EPO requirement Nutritional status Quality of Life Mortality rate
Safety
Factors affecting safety of ONLINE HDF: Water Treatment System ~ Ultrapurity of water feeding HDF machine ~ Ultrapure dialysate as standard for ONLINE HDF Hemodiafiltration machine ~ Microbiological monitoring of dialysis/ Substitution fluid
Water Treatment System Tap water contains a lot of harmful products e.g. Bacterial, Endotoxin To prepare sufficiently pure water for dialysate to meet the recommended standard by the Association for the Advancement of Medical Instrumentation (AAMI).
Tap water Water Treatment System Product water (R.O. water) mixed up with dialysate conc. Dialysate passed through additional filters Substitution fluid
Water Quality - Colony Count ~ R.O. water used to prepare dialysate: <100 cfu/ml ~ Dialysate used to prepare Dialysis: <200 cfu/ml ~ Substitution fluid used to prepare on-line Haemodiafiltration: <10 ¹ cfu/ml
Water Quality -Bacterial Endotoxin ~ R.O. water for Haemodialysis/Haemodiafiltration / On-line Haemodiafiltration: <0.25 EU/ml ~ Dialysate for Routine Haemodialysis /Haemodiafiltration: <0.25EU/ml ~ Substitution fluid for On-line Haemodiafiltration: <0.03EU/ml
Implementation of On-line Haemodiafiltration In HKSH
- 1 st case in 2005. - Post dilution - Convection volume equivalent to 20% of the total blood volume processed.
- 20% of dialysis patient carry out on-line HDF at 2013. - Otherwise High-Flux Dialysis.
- Age: 66-89 (mean age 80 ±2.5) - Duration: 3-60 Months - Blood flow rate: 150-350ml/min - Post dilution: 70% (9 30 liter) - Pre dilution: 30% (22 64 liter)
- All patient were on EPO treatment achieving a mean Haemoglobin level of 10.93 + 1.34g/dl. - The mean serum Albumin level was 39.34 + 4.43 g/l.
- Adequacy of dialysis in terms of percentage urea reduction was 72.5 + 6.93 %. - Weekly KT/V (Watson s formula) value of more than 3.2 with a median weekly KT/V of 3.21.
Reference Centre for Health Prevention. Infection Control Guideline on Nephology Service in Hong Kong. Issue Date: 18 th March 2010. Available at :http://www.chp.gov.hk/files/pdf/infection_control_guideline_on_neph rology_service _in_hong_kong. pdf F. Pizzarelli and Q. Maggiore et al. Clinical perspectives of on-line haemodiafiltration Nephrol Dial Transplant 1998; 13: 34 37 1. James E. Tattersall, Richard A Ward on behalf of the EUDIAL group* Online haemodiafiltration: definition, dose quantification and safety revisited Nephrol. Dial. Transplant. 2013; 28 (3): 542-550. 2. Marshall. MR. et al. Sustained low-efficiency daily diafiltration (SLEDDf) for critically ill patients requiring renal replacement therapy: towards an adequate therapy. Nephrol. Dial. Transplant. 2004 Apr; 19(4):877-84.
Acknowledgement Zoe Hung, Senior Business Manager, Fresenius Medical Care Hong Kong Ltd. Katherine Koo, Clinical Resource Specialist, Fresenius Medical Care Hong Kong Ltd. Andy Chan, Sales Supervisor, Acute Therapies, Gambro Hong Kong Ltd.
Thank You