1. “Put them on the Filter”
Renal Replacement Therapy in ITU
Susanne Young
Aug 04

2. content Indications for RRT Dialysis vs Haemofiltration recap
Variations in RRT
What we need to know!

3. Indications for RRT Uraemia Acidosis Fluid overload Hyperkalaemia
Pericarditis

4. DIALYSIS V FILTRATION Diffusion based solute removal
Convection based water (& sol) rem
Int. 4-6 hrs. Rapid
rate sol/fl loss
“go slow dialysis”
continuous
Usually av access.
BP driven (7l/d)
VV needs extra cor blood pump (16l/d)
Dialysate flows countercurrent
<5000 Da get dragged across

5. DIALYSIS
Aggressive removal of small solutes: Ur, Crn, K, move down concn gradient
Ca, HCO3 moves from dialysate to blood
Fluid removal slower but reduction in solute concentration faster
Replacement fluid not usually given
More risk arterial embolisation

6. FILTRATION Removal of fluid
Filtration itself removes small solutes in roughly the same concentrations as plasma
Removes large solutes
High flow rates would cause hypovolaemia
So, admin of (solute poor) substitution fluid will reduce solute concentration by dilution.

7. Types of RRT SCUF- no replacement fluid, dehydrating
CVVH- replacement solution
CVVHD- replacement and dialysate soln.
CVVHDF
IAVHD

8. SCUF

9. CVVH

10. When are you checking the coag?
HEPARIN
lock the lines at insertion (5000iu/ml) or when not in use.
?Heparin bolus- yes unless contraindicated 50iu/kg
Aim for APR 1.5x normal only. Start at iu/hr (1000iu/ml ALWAYS)
Check at 4hrs then daily

11. How much fluid do you want off
FLUID REMOVAL in CVVH
Patient Fluid removal rate: ml/h, (higher in SCUF) around 100ml/h ballpark AS PER FLUID BALANCE
Replacement fluid flow rate: ml/h, (lower in HD mode)
Blood flow ml/min (120 ususal)
Check U&E at 4hrs

12. What bags do you want me to use
Standard bag composition:
Lactate free if Met Acidosis
More K+ if hypokalaemic 2-4mmol/h.
Now could you fill out the prescription?