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??