convection based crrt의 적절한 처방

1. QA conference: 신장내과
<Convection based CRRT의 적절한 처방>
김 동 기
Division of Nephrology
Seoul National University Hospital

2. CRRT mode: CVVHDF
Vascular access: Internal jugular dual lumen catheter
Replacement solution: 1000mL/hr
Dialysate: 1000mL/hr
BFR: 100mL/min
Patient removal: 120mL/hr
Hemofilter: M60
Anticoagulation: Nafamostat
CRRT set order

3. 1. CRRT mode (SCUF, CVVHD, CVVH, CVHDF)
2. Net patient removal/Hr (Volume status)
3. Target CRRT dose (Replace + Dialysate + Net pt. removal)
4. Hemofilter 선택
5. Anticoagulation
CRRT 처방의 순서

4. CRRT mode

6. Convection: CVVH and CVVHDF
 Convective removal of solute
0
40
80
120
140
Clearance
ml/min
10¹ 102 103 104 105 106
urea, 60 d.
creatinine, 113 d.
vit. B12 , 1355 d.
inulin, 5200 d.
albumin, 55-60K d.
diffusive transport
convective transport
molecular
weight

7. Importance of Convective removal
Pro-inflammatory cytokines
in septic Acute Kidney Injury

8. CVVH (Continuous Veno-Venous Hemofiltration)
Access
Effluent
Return
PRISMA
M100
Replacement
(pre dilution)
CVVHDF (Continuous Veno-Venous HemoDiaFiltration)
1~4 L/hr

9. CVVH (Continuous Veno-Venous Hemofiltration)
Access
Effluent
Return
PRISMA
M100
Dialysate
Replacement
(pre dilution)
CVVHDF (Continuous Veno-Venous HemoDiaFiltration)
1~2 L/hr
1~2 L/hr

10. CRRT dose
(water and solute removal )

11. CRRT dose: 20, 35, 45 mL/hr/Kg?
Ronco et al, Lancet 355: 26-30, 2000
“Up to now, evidence indicate that for treatment of critically ill
patients with AKI, an UF flow of 35 mL/hr/Kg in post dilution
should be delivered”

12. CRRT dose (Clearance) in post-dilution
Freely permeable Urea/Cr
Replace solution: 3 L/hr
BFR: 150 mL/min
UF: 3.1 L/hr
 For freely permeable solutes, Urea & Creatinine (SC=1)
Clearance = Effluent volume
Clearance = 3100 mL/hr,
If Patient wt. is 60Kg, Clearance= 51.6 mL/hr/Kg

13. CRRT dose (Clearance) in post-dilution
UF: 3.1 L/hr (51.7 mL/min)
Replace solution: 3 L/hr
BFR: 150 mL/min (Hct=33%)
BWFR: 100 mL/min
Filtration fraction = UF/BWFR
= 51.7/100 = 51.7%
Filtration fraction >25%
: Blood concentration
Frequent clotting
Membrane performance impairment
Ideal filtration fraction <20%

14. CRRT dose (Clearance) in pre-dilution
 Clearance = Effluent volume X [QBW/(QBW+QR)]
Max BFR of Prisma machine
Impractically high dose of
replacement solution
70 Kg, pre-dilution CVVH
: Replacement sol: 4200mL/hr

15. Post CVVH vs. Pre CVVH vs. CVVHDF
80 Kg, Male, BUN=60 mg/dL, Hct=30%
QB=180 mL/min, QE=3.1 L/hr, Patient removal=100mL/hr
Effluent dose = (3.1 X 1000) / 80 = 38.8 mL/Kg/hr
Urea dose (Actual clearance)
post-CVVH : 38.8 mL/Kg/hr (filtration fraction = 43%)
Pre-CVVH : 29.5 mL/Kg/hr (too low urea clearance)
CVVHDF : 34.1 mL/Kg/hr (Convection +Diffusion)

16. Target of CRRT indices in CVVHDF mode
 Target CRRT dose (clearance) of CVVHDF mode
40 mL/hr/Kg (BFR with filtration fraction <20%)
Clearance = replacement + dialysate + net pt removal
Filtration fraction (filter 내에 남는 water의 분획)=
Actual UF volume [replacement sol + net patient removal]
BWFR [BFR X (100-Hct)/100] + Replacement sol

17. Clinical practice in CVVHDF mode
 67 Kg, male, septic AKI, UO=0, CXR: congestion (+)
BUN/Cr 66/7.5, Hct 30%
IV infusion=3L/day (TPN, NS, inotropics, antibiotics)
1. Define target volume removal
target I&O= -1 L/day
net fluid to be removed = 4 L/day (170 mL/hr)

18. Clinical practice
 67 Kg, male, septic AKI, UO=0, CXR: congestion (+)
BUN/Cr 66/7.5, Hct 30%
IV infusion=3L/day (TPN, NS, inotropics, antibiotics)
2. Set fixed effluent volume target to achieve
clearance of 40 mL/hr/Kg
40 mL/hr/Kg X 67 Kg = 2670 mL/hr
- Replacement fluid : 1250mL/hr
- Dialysate : 1250mL/hr
- Net patient removal : 170 mL/hr

19. UF: 2670 mL/hr (44.5 mL/min)
Dialysate solution: 1250 mL/hr
BFR: φ mL/min (Hct=30%)
BWFR: 0.7 X φ mL/min
Filtration fraction =
actual UF from plasma
3. Set proper BFR that achieve filtration fraction
= 20% to minimize clotting and maximize
convective removal via pre-dilution replacement
Replace solution
: 1250 mL/hr
(20.8 mL/min) Actual UF from plasma: replace + net pt removal
: 1420 mL/hr (23.6 mL/min)
BWFR + replacement
Target Filtration fraction = 0.2 =
23.6 mL/min [actual UF from plasma]
0.7 X φ mL/min [BWFR] + 20.8 mL/min [replacement sol.]
BFR (φ) = 140 mL/min

20. CRRT mode: CVVHDF
Vascular access: Internal jugular dual lumen catheter
Replacement solution: 1250mL/hr
Dialysate: 1250mL/hr
BFR: 140mL/min
Patient removal: 170mL/hr
Hemofilter: ?
CRRT order

21. CRRT Hemofilter

22. CRRT Hemofilter (SNUH)
M60 M100 HF1000 ST60 ST100
Surface area (m2) 0.6 0.9 1.15 0.6 0.9
Material AN69 PAES AN69
Surface Charge Negative Neutral Neutral
(polyethlene imine surface treatment)
Priming volume (mL) 90 107 128 90 107
UF coefficient
(mL/hr/mmHg)
15 25 27 15 25
Range of BFR 50-180 75-400 75~400? 50-180 75-400
Sieving coefficient
(QB=100, QUF=20)
Urea / Creatinine 1 1 1 1 1
Vit B12 0.95 0.95 1 0.95 0.95
Inulin 0.96 0.95 1 0.96 0.95
Myoglobin 0.55 0.55 0.12 0.55 0.55
Albumin <0.01 <0.01 0.01 <0.01 <0.01
Sterilization ETO ETO ETO ETO ETO

23. M100 vs. HF1000

24. CRRT mode: CVVHDF
Vascular access: Internal jugular dual lumen catheter
Replacement solution: 1250mL/hr
Dialysate: 1250mL/hr
BFR: 140mL/min
Patient removal: 170mL/hr
Hemofilter: M100 or M60
CRRT order

25. 1. CRRT mode: 환자의 질환에 따른 mode의 결정
2. Target dose (40mL/hr/Kg in CVVHDF)를 정한 후 이를
충족시킬 수 있는 dialysate 및 replacement solution
volume 을 결정해야 함
3. Clotting이 억제되고 solute removal을 최대한 많이 할
수 있는 BFR을 ideal filtration fraction (20% 이하)을 통
하여 구해야 함
4. 환자의 질환에 따른 적절한 hemofilter의 선택
Summary

26. Thank you for your attention