crrt terminology
TRANSCRIPT
CRRT TERMINOLOGY
Stefano Picca, MDDept. of Nephrology and Urology, Dialysis Unit“Bambino Gesù” Pediatric Research Hospital
ROMA, Italy
6th International Conference on Pediatric Continuous Renal Replacement TherapyRome,Italy. 2010, April 8-10
Bellomo, Ronco, Mehta, AJKD,1996
…everchanging array of names and abbreviations…
…lack of standardization… creates unnecessary confusion…prevents accurate comparisons and multicenter research, and is scientifically undesirable…
CRRT modalities…
Gibney N, Kimmel PL, Lazarus M, 2000
CRRT NOMENCLATURE
PHYSICAL PRINCIPLE TREATMENT DURATION
CONVECTION(ultrafiltration)
DIFFUSION(dialysis)
CONVECTION+
DIFFUSION
A B
P
A B
from Ricci et al, 2009
SCUF
Slow Continuous UltraFiltration
•Venovenous Circuit•Slow ultrafiltration•No substitution fluid
DEFINITIONS (1)
Filtrate collecting device
CVVH (postdilution)
Continuous VenoVenous Hemofiltration
•Venovenous Circuit•High ultrafiltration•Substitution fluid
DEFINITIONS (2)
Filtrate collecting device
Replace-ment fluid
CVVH (predilution)
Continuous VenoVenous Hemofiltration
•Venovenous Circuit•High ultrafiltration•Substitution fluid
DEFINITIONS (3)
Filtrate
Replace-ment fluid
Replace-ment fluid
CVVHD
Continuous VenoVenous HemoDialysis
•Venovenous Circuit•Dialysate (diffusion)•Low ultrafiltration (convection) , usually BW loss•No substitution fluid
DEFINITIONS (4)
Filtrate-Diaysate
Dialysate
CVVHDF
Continuous VenoVenous HemoDiaFiltration
•Venovenous Circuit•Dialysate (diffusion)•High ultrafiltration (convection)•Substitution fluid
DEFINITIONS (5)
Replace-ment fluid
Filtrate-Diaysate
Dialysate
DEFINITIONS: flows in children (6)
Replace-ment fluid
Filtrate-Diaysate
Dialysate
Qb: blood flow(from 10 ml/kg/min
in infants to 150-200 ml/min in
adolescents)
Qd: dialysate flow(from 200 to 5000 ml/h)
Quf: ultrafiltration rate(2000 ml/1.73 m2/h or?)
MISCELLANEOUS TECHNIQUES: HYBRID (1)
• Sustained Low Efficiency Dialysis (SLED)• Sustained Low Efficiency Daily Dialysis (SLEDD)• Prolonged Intermittent Daily RRT (PDIRRT)• Extended Dialysis (ED)• Extended Daily Dialysis (EDD)• Extended Daily Dialysis with filtration (EDDf)
In adults:• Reduced blood flow (100-200 ml/min)• Reduced dialysate flow (100-200 ml/min)• 10-12 hours a day
MISCELLANEOUS TECHNIQUES: HYBRID (2)
from Baldwin, 2009
Adapted from Ronco, 2006
high-volume hemofiltration:
In adults, claimed to be more efficient in:
• mediators removal
• hemodynamics
• improvement of immune dysfunction
MISCELLANEOUS TECHNIQUES (3)
“MAXIMAL”(?) EFFICIENCY IN CVVHADULT-CHILD-NEONATE
BW
(kg)
TBW
(l)
Qb
(ml/min)
UF/h
(=K urea)
(l/h)
K urea per liter of TBW
(l/h)
NEONATENEONATE 3 2.4 30 0.25 0.10
CHILDCHILD 25 15 80 1.2 0.08
ADULTADULT 70 42 150 2.5 0.05
PUBMED, March 2010:• CVVHD-hemodiafiltration: 58 post-2000
papers• 40/58 use the acronym CVVHD
incorrectly• 15/40 incorrect definition in nephrology
journals• 15/40 incorrect definition in IC journals
Word: a speech sound or series of speech sounds that symbolizes and communicates a meaning usually without being divisible into smaller units capable of
independent use. Merrian-Webster on line, 2010 (www.merriam-webster.com)
CV
VH
D
CHP
CPFA
CAVHDF
HVHF
CVVHDFCAVH
CRRTPE
SLEDD
CVVHDCVVH
CAVHD
CV
VH
DF
SLE
D
CRITICAL NEPHROLOGIST IN CRITICAL SITUATION
…and dialysis??