Renal

replacement

therapy

for

acute

renal

failure

in

children

European

Guidelines

Acute

renal

failure

-LRB-

ARF

-RRB-

is

uncommon

in

childhood

and

there

is

little

consensus

on

the

appropriate

treatment

modality

when

renal

replacement

therapy

is

required

Members

of

the

European

Pediatric

Peritoneal

Dialysis

Working

Group

have

produced

the

following

guidelines

in

collaboration

with

nursing

staff

Good

practice

requires

early

discussion

of

patients

with

ARF

with

pediatric

nephrology

staff

and

transfer

for

investigation

and

management

in

those

with

rapidly

deteriorating

renal

function

Patients

with

ARF

as

part

of

multi-organ

failure

will

be

cared

for

in

pediatric

intensive

care

units

where

there

should

be

access

to

pediatric

nephrology

support

and

advice

The

choice

of

dialysis

therapy

will

therefore

depend

upon

the

clinical

circumstances

location

of

the

patient

and

expertise

available

Peritoneal

dialysis

has

generally

been

the

preferred

therapy

for

isolated

failure

of

the

kidney

and

is

universally

available

Intermittent

hemodialysis

is

frequently

used

in

renal

units

where

nursing

expertise

is

available

and

hemofiltration

is

increasingly

employed

in

the

intensive

care

situation

Practical

guidelines

for

and

the

complications

of

each

therapy

are

discussed

Introduction

Acute

renal

failure

-LRB-

ARF

-RRB-

is

uncommon

in

childhood

but

its

incidence

may

be

increasing

and

modalities

of

treatment

changing

with

an

increasing

number

of

children

being

treated

in

the

intensive

care

unit

-LRB-

ICU

-RRB-

with

multi-organ

failure

Traditionally

children

with

ARF

with

renal

involvement

were

only

treated

with

peritoneal

dialysis

but

extracorporeal

techniques

are

being

increasingly

used

in

ICUs

Members

of

the

European

Pediatric

Dialysis

Working

Group

reviewed

all

modalities

of

renal

replacement

therapy

for

ARF

in

children

and

developed

the

following

guidelines

in

collaboration

with

nursing

staff

during

three

meetings

and

extensive

e-mail

discussion

There

are

no

randomized

trials

of

renal

replacement

treatment

in

children

with

ARF

The

guidelines

are

based

upon

published

reports

and

consensus

opinion

to

emphasize

good

practice

ARF

is

recognized

when

renal

excretory

function

declines

rapidly

Rising

values

of

plasma

urea

and

creatinine

are

usually

accompanied

by

oliguria

-LRB-

ml/kg

per

hour

-RRB-

but

occasionally

patients

may

be

polyuric

The

cause

of

ARF

may

be

pre-renal

intrinsic

or

post-renal

-LRB-

obstructive

-RRB-

problems

and

causes

differ

between

neonates

and

older

children

-LSB-

-RSB-

The

incidence

of

ARF

in

children

is

hard

to

define

as

often

renal

insufficiency

in

the

newborn

and

on

ICUs

is

conservatively

managed

by

ICU

staff

Outside

the

neonatal

period

ARF

is

an

uncommon

condition

accounting

for

referrals

per

million

population

per

year

to

one

regional

pediatric

nephrology

unit

in

the

United

Kingdom

-LSB-

-RSB-

ARF

may

occur

as

isolated

failure

of

the

kidneys

alone

with

other

organ

systems

functioning

normally

or

in

association

with

multiple

organ

failure

The

mortality

of

the

latter

group

is

considerably

higher

especially

with

the

growth

in

pediatric

intensive

care

For

example

the

mortality

in

neonates

and

infants

is

after

cardiac

surgery

for

congenital

heart

defects

-LSB-

-RSB-

but

only

for

children

with

intrinsic

renal

disease

such

as

hemolytic

uremic

syndrome

-LRB-

HUS

-RRB-

in

developed

countries

-LSB-

-RSB-

The

case

mix

in

different

units

treating

ARF

and

hence

mortality

and

morbidity

rates

will

therefore

vary

according

to

local

clinical

activity

and

resources

-LSB-

-RSB-

Many

pediatric

renal

units

will

be

close

to

pediatric

ICUs

-LRB-

PICUs

-RRB-

in

hospitals

that

may

offer

cardiac

surgery

liver

transplantation

and

specialist

treatment

for

metabolic

disorders

oncology

patients

etc.

-LSB-

-RSB-

Other

renal

units

may

be

in

hospitals

that

do

not

have

a

PICU

on

site

and

conversely

there

may

be

hospitals

offering

pediatric

intensive

care

with

no

specialist

pediatric

nephrology

service

Recommendations

All

children

with

ARF

require

discussion

with

a

pediatric

nephrologist

Early

transfer

for

investigation

and

management

is

essential

in

those

with

rapidly

deteriorating

renal

function

or

in

those

with

hemodynamic

or

biochemical

disturbances

-LRB-

good

practice

-RRB-

-LSB-

-RSB-

All

children

with

ARF

as

part

of

multi-organ

failure

require

transfer

to

a

designated

regional

pediatric

ICU

where

there

should

be

access

to

pediatric

nephrology

advice

and

support

-LRB-

good

practice

-RRB-

Rationale

Since

there

are

few

comprehensive

regional

pediatric

nephrology

centers

the

distances

that

families

may

have

to

travel

can

be

considerable

Children

with

acute

renal

impairment

may

be

managed

in

local

hospitals

but

it

is

essential

that

early

referral

is

made

especially

if

children

have

evidence

of

rapidly

deteriorating

renal

function

and

require

an

urgent

histological

diagnosis

to

determine

if

immunosuppressive

therapy

or

other

treatment

is

required

Indications

for

referral

include

oligoanuria

especially

if

associated

with

fluid

overload

hypertension

hyperkalemia

hyponatremia

acidosis

or

the

need

for

blood

transfusion

Dialysis

is

often

accompanied

by

early

nutritional

support

and

pediatric

nephrology

units

should

be

equipped

to

provide

the

necessary

medical

and

nursing

expertise

combined

with

dietetic

and

psychosocial

support

The

latter

support

is

also

important

if

the

child

is

managed

conservatively

Neonates

and

premature

infants

with

ARF

require

transfer

to

a

tertiary

neonatal

unit

with

pediatric

nephrology

team

expertise

Patients

with

ARF

and

multi-organ

failure

require

prompt

transfer

to

a

designated

regional

PICU

The

choice

of

dialysis

therapy

for

ARF

depends

upon

the

clinical

circumstances

patient

location

and

expertise

available

Peritoneal

dialysis

-LRB-

PD

-RRB-

has

generally

been

considered

the

preferred

therapy

if

there

is

isolated

failure

of

the

kidneys

such

as

HUS

It

is

regarded

as

a

simpler

technique

that

is

universally

available

However

hemofiltration

-LRB-

HF

-RRB-

and

hemodiafiltration

-LRB-

HDF

-RRB-

are

increasing

in

popularity

in

PICUs

where

the

facilities

to

perform

hemodialysis

-LRB-

HD

-RRB-

may

not

be

available

HD

may

be

the

preferred

mode

of

treatment

in

more-stable

patients

with

adequate

vascular

access

treated

on

renal

units

where

specialist

nurses

are

available

Although

extracorporeal

techniques

such

as

continuous

venovenous

hemofiltration

-LRB-

CVVH

-RRB-

or

continuous

venovenous

hemodiafiltration

-LRB-

CVVHDF

-RRB-

are

used

quite

frequently

in

adult

ICUs

there

is

still

limited

expertise

in

many

PICUs

Such

techniques

are

very

dependent

on

technology

and

are

more

costly

than

PD

-LSB-

-RSB-

They

are

also

dependent

upon

the

availability

of

appropriate

nursing

expertise

-LSB-

-RSB-

Such

expertise

can

be

developed

and

maintained

in

units

remote

from

the

pediatric

nephrology

center

by

an

outreach

service

using

a

renal

critical

care

nurse

educator

-LSB-

-RSB-

Recommendation

There

is

no

evidence

for

the

optimum

level

of

renal

function

for

starting

renal

replacement

therapy

nor

for

the

optimum

dialysis

modality

Advantages

and

disadvantages

are

listed

in

Table

Consideration

should

be

given

to

establishing

national

and

international

databases

to

collect

these

data

along

with

patient

outcomes

-LSB-

-RSB-

Table

Advantages

and

disadvantages

of

various

modalities

of

renal

replacement

therapy

for

acute

renal

failure

-LRB-

CVVH

continuous

venovenous

hemofiltration

CVVHDF

continuous

venovenous

hemodiafiltration

-RRB-

TypeComplexityUse

in

hypotensionEfficiencyVolume

controlAnticoagulationPeritoneal

dialysisLowYesModerateModerateNoIntermittent

hemodialysisModerateNoHighModerateYesCVVHModerateYesModerateGoodYesCVVHDFHighYesHighGoodYes

Choice

of

therapy

Acute

PD

The

main

advantage

of

PD

is

that

it

is

continuous

therapy

that

requires

neither

anticoagulation

nor

vascular

access

and

the

technique

can

be

used

in

hemodynamically

unstable

patients

-LSB-

-RSB-

Acute

PD

can

be

performed

in

units

with

no

HD

expertise

and

is

effective

in

children

of

all

ages

including

neonates

-LSB-

-RSB-

PD

has

been

used

in

treating

acute

pancreatitis

tumor

lysis

syndrome

intoxications

metabolic

diseases

and

other

pathological

conditions

in

children

-LSB-

-RSB-

The

choice

of

PD

as

therapy

has

always

to

be

individualized

balancing

advantages

against

disadvantages

Limitations

in

the

use

of

PD

Inborn

areas

of

metabolism

in

the

newborn

period

lead

to

acute

accumulation

of

neurotoxic

metabolites

that

can

be

better

removed

using

techniques

such

as

CVVHDF

-LSB-

-RSB-

The

latter

technique

requires

good

vascular

access

which

can

still

be

a

major

problem

in

small

children

-LSB-

-RSB-

Newborns

with

respiratory

diseases

even

if

on

ventilatory

treatment

can

be

treated

with

PD

provided

that

the

fill

and

exchange

volumes

are

adapted

to

the

clinical

situation

However

caution

is

necessary

in

neonates

with

necrotizing

enterocolitis

and

older

children

with

suspected

bowel

perforation

-LSB-

-RSB-

Preparation

for

PD

Dialysis

is

only

possible

if

the

access

provides

free

flow

in

and

out

of

the

abdomen

The

choice

is

between

catheters

inserted

at

the

bedside

under

sedation

or

the

placement

of

a

chronic

PD

catheter

by

a

pediatric

surgeon

in

the

operating

theater

or

exceptionally

at

the

bedside

in

the

ICU

The

rigid

Trocath

catheter

with

a

stylet

has

largely

disappeared

and

surgically

placed

Tenckhoff

catheters

are

reported

to

have

fewer

complications

-LSB-

-RSB-

However

small

catheters

for

percutaneous

placement

using

a

Seldinger

technique

are

invaluable

in

providing

acute

PD

rapidly

especially

in

the

neonatal

PICU

-LSB-

-RSB-

Blockage

by

the

omentum

is

always

a

risk

with

PD

catheters

If

the

catheter

is

to

be

placed

surgically

then

consideration

should

be

given

to

partial

omentectomy

-LSB-

-RSB-

In

patients

who

are

having

a

PD

catheter

inserted

under

general

anesthetic

a

cephalosporin

antibiotic

-LRB-

mg/kg

-RRB-

should

be

given

as

a

single

intravenous

dose

up

to

h

prior

to

implantation

of

the

catheter

-LSB-

-RSB-

Any

subsequent

accidental

contamination

should

result

in

the

use

of

prophylactic

antibiotics

e.g.

cefuroxime

mg/l

in

the

dialysate

for

h.

For

catheters

that

are

inserted

percutaneously

prophylactic

antibiotics

e.g.

cefuroxime

mg/l

should

be

added

to

the

dialysis

fluid

unless

the

patient

is

on

systemic

treatment

Heparin

units/l

should

be

prescribed

to

prevent

catheter

blockage

with

fibrin

This

is

generally

maintained

for

the

first

h

and

longer

if

the

PD

fluid

remains

slightly

bloodstained

-LSB-

-RSB-

PD

prescription

This

needs

to

be

individualized

according

to

patient

size

and

condition

Automated

PD

machines

are

the

preferred

method

for

delivering

the

individualized

dialysis

prescription

and

accurately

measuring

ultrafiltration

-LSB-

-RSB-

Such

machines

are

now

available

that

can

deliver

dialysis

volumes

accurately

down

to

ml

with

increments

Although

such

machines

now

have

improved

accuracy

of

ultrafiltration

measurements

the

dead

space

of

the

tubing

can

reduce

dialysis

efficiency

A

manual

PD

set

can

be

used

using

burettes

that

can

accurately

measure

inflow

and

outflow

with

the

PD

fluid

warmed

appropriately

-LSB-

-RSB-

With

manual

sets

attempts

should

be

made

to

maintain

a

closed

drainage

system

which

can

help

reduce

the

frequency

of

peritoneal

contamination

-LSB-

-RSB-

Such

manual

PD

sets

are

commercially

available

for

neonatal

patients

Choice

of

dialysis

solution

The

choice

of

dialysis

solution

will

depend

upon

the

weight

blood

pressure

and

hydration

status

of

the

child

bearing

in

mind

the

need

to

create

nutritional

space

as

part

of

the

management

strategy

-LSB-

-RSB-

The

general

principle

is

to

commence

with

the

lowest

concentration

of

glucose

solution

possible

-LRB-

-RRB-

with

stepwise

increments

Care

is

needed

if

glucose

solution

is

required

as

-LRB-

-RRB-

rapid

ultrafiltration

can

occur

-LRB-

especially

in

infants

-RRB-

and

-LRB-

-RRB-

hyperglycemia

may

develop

-LRB-

especially

in

septic

and

multi-organ

failure

patients

-RRB-

leading

to

hyperosmolarity

and

loss

of

effective

ultrafiltration

Icodextrine

solutions

need

a

longer

dwell

time

to

obtain

significant

ultrafiltration

and

so

are

rarely

indicated

in

ARF

Lactate-containing

dialysis

solutions

are

likely

to

be

replaced

by

bicarbonate

solutions

which

are

being

evaluated

in

chronic

PD

The

routine

use

of

bicarbonate

solutions

should

be

considered

in

neonates

or

in

patients

with

reduced

lactate

metabolism

or

with

lactic

acidosis

-LSB-

-RSB-

Practical

points

Patients

should

be

connected

and

automated

PD

or

manual

cycles

started

immediately

after

catheter

implantation

Heparin

-LRB-

units/l

-RRB-

should

be

added

to

the

dialysis

fluid

to

prevent

fibrin

deposition

and

to

improve

peritoneal

solute

permeability

-LSB-

-RSB-

but

it

can

be

absorbed

and

care

is

needed

in

patients

with

coagulation

disorders

Dialysis

fill

volumes

of

ml/kg

-LRB-

-RRB-

should

be

used

initially

depending

on

the

body

size

and

cycle

in

and

out

until

the

dialysate

becomes

clear

A

PD

program

with

dwells

should

be

used

during

the

first

h.

Shorter

cycles

can

be

considered

initially

if

hyperkalemia

needs

urgent

treatment

The

program

should

be

adjusted

with

increasing

dwell

times

and

cycle

fill

volume

-LRB-

if

no

leakage

problems

-RRB-

until

the

desired

fill

volume

-LRB-

-RRB-

is

achieved

with

adequate

ultrafiltration

and

biochemical

control

-LSB-

-RSB-

High

intraperitoneal

pressure

-LRB-

IPP

-RRB-

can

be

a

problem

in

the

first

days

after

surgical

catheter

insertion

The

measurement

of

IPP

may

limit

the

risk

of

leakage

when

the

fill

volumes

are

being

increased

and

allow

optimized

pain

management

but

is

not

yet

in

routine

use

-LSB-

-RSB-

Inflow/outflow

pain

on

PD

usually

diminishes

with

time

Tidal

dialysis

is

an

alternative

-LSB-

-RSB-

and

bicarbonate

dialysis

should

be

considered

-LSB-

-RSB-

The

amount

of

ultrafiltration

that

is

prescribed

will

partly

depend

upon

the

volume

of

oral

nasogastric

or

total

parenteral

nutrition

that

is

required

combined

with

fluid

for

drugs

Ultrafiltration

may

not

be

enough

without

the

use

of

or

glucose

solutions

The

clinical

biochemical

and

nutritional

status

of

the

patient

should

be

assessed

regularly

in

conjunction

with

an

experienced

renal

dietitian

-LSB-

-RSB-

Optimal

nutrition

is

necessary

to

avoid

a

catabolic

state

and

associated

production

of

blood

urea

nitrogen

and

uremic

products

Rationale

Patients

with

ARF

need

constant

assessment

while

on

PD

and

adequacy

should

be

judged

in

terms

of

clinical

status

ultrafiltration

achieved

and

biochemical

parameters

particularly

urea

creatinine

and

bicarbonate

levels

-LSB-

-RSB-

Although

a

link

between

the

dialysis

dose

and

the

outcome

of

adult

patients

in

ARF

has

been

established

-LSB-

-RSB-

there

are

no

guidelines

as

to

what

constitutes

adequate

PD

in

a

child

with

ARF

The

aim

is

to

deliver

maximum

clearance

to

compensate

for

the

catabolic

stress

Complications

of

acute

PD

Leakages

can

be

a

difficult

problem

and

are

mostly

due

to

a

leakage

around

the

catheter

The

incidence

can

be

reduced

by

proper

surgical

technique

when

using

a

Tenkhoff

catheter

-LSB-

-RSB-

or

resuturing

around

a

percutaneous

catheter

Fibrin

glue

injected

into

the

catheter

tunnel

is

a

technique

under

evaluation

-LSB-

-RSB-

Poor

drainage

due

to

mechanical

blockage

or

catheter

migration

is

all

too

common

Flushing

the

catheter

and

preventing

fibrin

accumulation

by

increasing

the

heparin

dosage

and/or

urokinase

is

suggested

initially

-LSB-

-RSB-

A

plain

abdominal

X-ray

is

rarely

justified

as

repeated

poor

drainage

will

require

catheter

relocation

If

available

a

laparoscopic

technique

may

be

used

to

correct

poor

drainage

or

replace

the

malfunctioning

catheter

-LSB-

-RSB-

Hernias

can

be

a

problem

in

neonates

and

infants

particularly

males

They

do

not

usually

require

interruption

of

PD

and

can

be

repaired

electively

by

laparoscopic

or

direct

measures

when

the

child

's

clinical

condition

has

improved

or

stabilized

Peritonitis

remains

a

constant

threat

especially

if

there

has

been

a

lot

of

manipulation

of

the

catheter

The

standard

features

of

cloudy

PD

fluid

require

urgent

attention

-LSB-

-RSB-

Continuous

extracorporeal

techniques

Continuous

arteriovenous

hemofiltration

-LRB-

CAVH

-RRB-

has

largely

been

replaced

by

pumped

CVVH

and

CVVHDF

particularly

in

ICUs

-LSB-

-RSB-

Such

continuous

renal

replacement

therapies

-LRB-

CRRT

-RRB-

have

expanded

the

possible

role

of

blood

purification

in

the

management

of

critically

ill

patients

However

there

is

a

lack

of

randomized

trials

in

patients

with

sepsis

and

a

recent

analysis

failed

to

show

a

benefit

for

hemofiltration

-LSB-

-RSB-

Studies

in

adult

ICU

patients

have

shown

a

lower

mortality

in

patients

treated

with

CRRT

compared

with

intermittent

HD

However

a

recent

meta-analysis

of

studies

before

concluded

that

the

evidence

was

insufficient

to

draw

strong

conclusions

regarding

the

mode

of

renal

replacement

therapy

for

ARF

in

the

critically

ill

-LSB-

-RSB-

A

recent

randomized

trial

in

adult

ICU

patients

showed

a

significant

survival

advantage

when

the

intensity

of

ultrafiltration

was

increased

-LSB-

-RSB-

Practical

guidelines

for

prescription

Since

the

concentration

of

solutes

in

the

filtrate

is

the

same

as

in

the

plasma

biochemistry

is

controlled

by

removing

large

volumes

of

filtrate

and

replacing

it

with

electrolyte-containing

fluid

-LRB-

HF

replacement

fluid

-RRB-

As

most

solutes

are

distributed

within

the

extracellular

and

intracellular

fluid

compartments

-LRB-

total

body

water

-RRB-

the

exchange

volume

of

filtration

necessary

to

control

biochemistry

relates

to

total

body

water

Clinical

experience

has

shown

that

a

turnover

of

approximately

of

body

weight

in

h

is

usually

adequate

for

CVVH

The

extracorporeal

circuit

requires

good

central

venous

access

usually

via

a

dual-lumen

catheter

to

allow

the

high

blood

flows

necessary

to

prevent

clotting

in

the

hemofilter

Suggested

catheter

sizes

in

French

gauge

-LRB-

FG

-RRB-

are

Patient

size

-LRB-

kg

-RRB-

Vascular

dual-lumen

-LRB-

cm

-RRB-

dual-lumen

-LRB-

cm

-RRB-

or

larger

dual-lumen

-LRB-

cm

-RRB-

For

neonates

a

dual-lumen

catheter

may

be

adequate

and

access

can

be

obtained

via

the

umbilical

vein

-LSB-

-RSB-

A

single-lumen

catheter

using

a

single

needle

for

CVVHD

in

very

low

birth

weight

infants

has

also

been

described

-LSB-

-RSB-

but

this

method

may

be

compromised

by

high

recirculation

rates

with

most

available

systems

However

the

smaller

the

access

the

greater

the

problems

-LSB-

-RSB-

It

is

possible

to

consider

placing

two

small

single-lumen

catheters

in

different

central

veins

A

low

blood

flow

rate

high

hematocrit

and

high

plasma

protein

concentration

will

limit

the

rate

at

which

filtration

can

occur

and

solutes

-LRB-

particularly

of

higher

molecular

weight

-RRB-

are

removed

For

a

given

blood

flow

rate

pre-dilution

results

in

higher

clearance

of

solutes

than

does

post-dilution

-LSB-

-RSB-

but

at

the

expense

of

greater

use

of

replacement

fluid

-LRB-

approximately

more

-RRB-

Pre-dilution

has

the

potential

for

extending

filter

life

As

with

HD

the

blood

volume

in

the

extracorporeal

circuit

should

be

less

than

of

the

patient

's

circulatory

volume

Blood

flows

of

ml/kg

per

min

or

of

circulating

blood

volume

prevents

excessive

hemoconcentration

in

the

filter

Automated

machines

with

appropriate

accuracy

for

children

are

recommended

for

delivering

the

CRRT

prescription

safely

-LSB-

-RSB-

and

have

replaced

pump-assisted

hemofiltration

using

volumetric

pumps

-LSB-

-RSB-

To

achieve

a

exchange

of

total

body

water

in

h

an

appropriate

filter

should

be

selected

with

a

surface

area

of

no

more

than

the

surface

area

of

the

patient

Suggested

maximum

filtration

rates

are

Patient

size

-LRB-

kg

-RRB-

Maximum

filtration

rate

-LRB-

ml/h

-RRB-

Under

post-dilution

conditions

the

filtration

rate

should

never

exceed

one-third

of

the

blood

flow

Several

filter

materials

are

now

available

Synthetic

membranes

have

replaced

cellulose

acetate

as

they

are

more

biocompatible

causing

less

complement

reaction

and

anticoagulation

needs

The

synthetic

polysuphone

membranes

are

also

thought

to

aid

convective

clearance

of

solutes

through

solute

drag

-LSB-

-RSB-

A

variety

of

replacement

fluids

are

available

such

as

lactate

bicarbonate

and

buffer-free

solutions

Bicarbonate

or

buffer-free

solutions

should

be

used

in

young

infants

and

those

intolerant

of

lactate

If

a

commercially

available

bicarbonate

solution

were

freely

available

then

this

would

be

the

solution

of

choice

Careful

monitoring

of

electrolytes

glucose

and

phosphate

is

essential

as

the

constituents

vary

between

the

solutions

Anticoagulation

The

goals

of

anticoagulation

are

to

prevent

clotting

of

the

circuit

and

maintain

adequate

clearances

with

minimal

risk

to

the

patient

Heparin

is

the

standard

anticoagulant

in

Europe

but

the

choice

of

dosage

will

depend

upon

the

patient

's

coagulation

status

adequacy

of

blood

flow

and

blood

viscosity

In

most

patients

heparin

should

be

administered

as

an

initial

bolus

-LRB-

maximum

units/kg

-RRB-

at

the

time

of

connection

to

the

extracorporeal

circuit

followed

by

a

continuous

infusion

of

units/kg

per

hour

The

activated

clotting

time

-LRB-

ACT

-RRB-

or

whole

blood

activated

partial

thromboplastin

time

-LRB-

aPPT

-RRB-

are

usually

used

to

monitor

treatment

The

optimal

ACT

during

hemofiltration

is

s

The

aPPT

should

be

between

and

times

the

respective

baseline

value

Some

patients

can

be

treated

without

heparin

in

the

circuit

-LSB-

-RSB-

In

those

patients

who

are

severely

thrombocytopenic

or

where

there

is

suspected

heparin-induced

thrombocytopenia

alternative

treatment

with

prostaglandin

infusions

or

recombinant

hirudin

-LSB-

-RSB-

a

direct

thrombin

inhibitor

can

be

considered

-LSB-

-RSB-

Regional

anticoagulation

with

citrate

has

been

favored

by

some

centers

-LSB-

-RSB-

Sodium

citrate

chelates

ionized

calcium

necessary

for

the

coagulation

cascade

and

systemic

anticoagulation

is

avoided

by

infusing

calcium

through

a

separate

central

line

The

disadvantages

include

the

possibility

of

various

acidbase

and

electrolyte

disturbances

including

hypernatremia

hypocalcemia

and

metabolic

alkalosis

Adjustment

of

the

prescription

Any

formula

for

the

prescription

of

HF

is

at

best

an

approximation

or

starting

point

as

the

needs

will

be

determined

by

many

unmeasured

variables

such

as

the

rate

of

solute

production

nutritional

intake

and

the

actual

volumes

of

the

extracellular

fluid

and

intracellular

fluid

compartments

If

only

fluid

removal

is

required

then

relatively

low

rates

of

filtration

are

needed

often

referred

to

as

slow

continuous

ultrafiltration

-LRB-

SCUF

-RRB-

There

will

be

negligible

solute

removal

under

these

circumstances

Correction

of

uremia

and

electrolyte

disturbance

requires

the

turnover

of

large

volumes

per

kilogram

of

fluid

typically

of

the

order

of

of

body

weight

per

day

for

post-dilution

and

for

pre-dilution

-LRB-

approximately

ml/kg

per

hour

-RRB-

In

catabolic

patients

the

clearances

achieved

with

standard

CVVH

may

not

be

sufficient

Solute

removal

may

be

increased

by

attempting

high-volume

exchange

but

this

may

be

limited

by

the

practical

problems

of

pediatric

patients

with

limitations

of

vascular

access

and

hemoconcentration

in

the

filter

In

these

cases

small

solute

clearances

can

be

maximized

by

establishing

diffusive

mass

transport

via

a

dialysis

circuit

This

can

be

performed

with

CVVHDF

or

without

an

additional

major

ultrafiltration

component

-LRB-

CVVHD

-RRB-

CVVHDF

latter

technique

requires

an

additional

pump

to

achieve

separate

control

of

the

dialysate

in

and

outflow

and

of

the

replacement

fluid

flow

CVVH

substitution

fluid

bags

can

be

used

as

dialysis

fluid

Dialysis

fluid

flow

should

be

times

the

blood

flow

if

maximal

efficacy

is

desired

This

setting

requires

frequent

manual

bag

exchanges

and

continuous

supervision

of

the

system

For

practical

purposes

the

HD

component

can

be

added

for

several

hours

per

day

to

a

CVVH

regimen

CVVHD

has

recently

been

recommended

as

the

method

of

choice

for

the

treatment

of

inborn

errors

of

metabolism

since

it

supplies

maximal

clearance

of

ammonium

and

other

neurotoxic

metabolites

When

CVVHD

is

unavailable

large

volume

turnover

of

body

water

with

CVVH

will

provide

the

next

best

therapy

Rates

of

up

to

ml/kg

per

hour

have

been

reported

-LSB-

-RSB-

If

possible

the

blood

pump

speed

also

needs

to

be

increased

When

high

turnover

and

blood

flow

rates

are

in

use

patients

should

be

carefully

monitored

for

hypothermia

hypokalemia

and

circulatory

failure

Hypothermia

may

need

to

be

treated

with

an

external

warming

blanket

and

hypokalemia

will

require

replacement

Blood

flow

should

not

be

increased

if

the

patient

develops

cardiovascular

instability

CVVH

and

extracorporeal

membrane

oxygenation

In

the

authors

experience

the

best

results

are

achieved

when

pre-diluted

fully

automated

CVVH

is

used

attached

to

the

venous

-LRB-

outflow

from

patient

-RRB-

side

of

the

extracorporeal

membrane

oxygenation

-LRB-

ECMO

-RRB-

circuit

This

appears

to

reduce

problems

of

shunting

blood

around

the

oxygenator

and

overcomes

the

problems

of

the

increased

hematocrit

that

may

be

associated

with

ECMO

It

also

reduces

the

complications

of

excessive

fluid

and

solute

clearances

with

a

free

flow

when

systemic

hemofilters

are

used

in

line

with

the

ECMO

circuit

When

using

CVVH

in

the

suggested

configuration

the

pigtails

provide

access

with

very

little

resistance

causing

the

arterial

and

venous

pressure

alarms

to

activate

and

shut

down

the

circuit

Therefore

three-way

taps

are

used

to

create

more

resistance

to

flow

into

and

out

of

the

CVVH

circuit

When

treating

neonatal

patients

the

ECMO

circuit

increases

the

extracorporeal

blood

volume

very

significantly

Therefore

the

blood

pump

speed

should

be

calculated

taking

into

account

the

patient

's

blood

volume

and

the

priming

volume

of

the

ECMO

circuit

Complications

of

continuous

extracorporeal

techniques

Complications

of

continuous

extracorporeal

techniques

are

described

in

reference

-LSB-

-RSB-

Hypotension

Hemofiltration

is

most

commonly

used

in

sick

septic

children

many

of

whom

will

be

on

pressor

therapy

Indeed

the

need

for

pressor

agents

gives

a

poorer

prognosis

-LSB-

-RSB-

Care

should

have

been

taken

to

minimize

the

amount

of

blood

in

the

extracorporeal

circuit

and

blood

priming

of

the

HF

circuit

may

be

necessary

at

the

outset

Fluid

removal

is

obviously

adjusted

according

to

the

patient

's

clinical

state

during

the

treatment

Clotting

of

the

filter

and

lines

This

is

one

of

the

commonest

complications

and

again

is

related

to

the

patient

's

changing

clinical

status

and

problems

with

anticoagulation

This

complication

occurred

in

of

patients

treated

with

CVVH

in

a

local

audit

-LRB-

B.

Harvey

unpublished

observations

-RRB-

Other

potential

complications

of

bleeding

anticoagulation

toxicity

and

infections

appear

to

be

minimal

Air

embolism

is

a

rare

but

preventable

complication

of

extracorporeal

circuits

and

is

greatly

reduced

with

the

proper

use

of

automated

machinery

Intermittent

HD

The

advantages

and

limitations

of

intermittent

HD

are

described

in

reference

-LSB-

-RSB-

Advantages

The

main

advantage

of

HD

is

the

relatively

rapid

removal

of

uremic

toxins

and

ultrafiltration

of

fluid

This

makes

the

technique

well

suited

for

acute

situations

Limitations

HD

is

not

a

continuous

therapy

and

it

requires

good

vascular

access

as

with

HF

A

purified

water

supply

is

also

required

as

well

as

anticoagulation

which

should

always

be

minimized

The

technique

might

not

be

applicable

for

hemodynamically

unstable

patients

Often

the

major

limiting

factor

is

the

availability

of

expert

nursing

staff

-LSB-

-RSB-

especially

in

the

ICU

-LSB-

-RSB-

Practical

guidelines

for

prescription

HD

is

only

possible

with

good

vascular

access

provided

either

by

a

double-lumen

HD

catheter

or

a

single-lumen

catheter

of

sufficient

diameter

to

achieve

flows

for

single-needle

dialysis

Catheter

lengths

vary

from

cm

for

neonates

to

cm

for

large

adolescents

Bloodline

choice

depends

on

the

priming

-LRB-

extracorporeal

-RRB-

volume

which

traditionally

has

not

exceeded

of

the

blood

volume

-LRB-

approximately

ml/kg

-RRB-

Dialyzer

choice

depends

on

the

priming

volume

and

maximum

flow

rate

with

a

surface

area

that

should

not

exceed

the

child

's

surface

area

and

with

a

urea

clearance

between

and

ml/kg

per

min

There

is

no

evidence

for

dialyzer

choice

in

pediatric

practice

but

meta-analysis

in

adult

patients

with

ARF

suggested

synthetic

membranes

conferred

a

significant

survival

advantage

over

cellulose-based

membranes

but

with

no

similar

benefit

for

recovery

of

renal

function

-LSB-

-RSB-

Bloodline

priming

is

usually

performed

with

isotonic

saline

Small

babies

anemic

patients

and

those

in

an

unstable

cardiocirculatory

condition

require

priming

with

albumin

or

blood

HD

catheter

care

After

the

session

the

catheter

should

be

flushed

with

isotonic

saline

and

filled

with

undiluted

heparin

-LRB-

IU/ml

-RRB-

with

volumes

according

to

manufacturer

's

recommendations

-LRB-

usually

marked

on

the

catheter

itself

-RRB-

HD

prescription

The

first

session

should

not

exceed

h

but

the

standard

time

is

usually

h.

Longer

sessions

are

advisable

to

avoid

too-rapid

ultrafiltration

and

disequilibrium

syndrome

All

children

should

be

dialyzed

using

volume-controlled

machines

and

with

bicarbonate

dialysate

The

blood

pump

rate

is

usually

ml/kg

per

min

but

depends

upon

the

catheter

and

patient

size

-LSB-

-RSB-

The

ultrafiltration

target

should

not

exceed

ml/kg

per

min

for

acute

patients

who

should

be

carefully

monitored

for

hypovolemia

and

hypotension

Sodium

profiling

is

rarely

used

in

pediatric

HD

practice

Anticoagulation

is

usually

with

heparin

-LRB-

IU/kg

per

session

including

initial

bolus

-RRB-

Reinfusion

is

usually

performed

with

isotonic

saline

Complications

occurring

during

acute

HD

For

hypotension

the

ultrafiltration

should

be

switched

off

and

isotonic

saline

infused

into

the

venous

line

until

the

blood

pressure

normalizes

additional

albumin

ml/kg

might

be

helpful

Hypertension

is

treated

according

to

standard

hypertension

protocols

available

elsewhere

-LSB-

-RSB-

Disequilibrium

syndrome

is

now

a

rare

event

with

adequate

control

of

ultrafiltration

and

stepwise

reduction

of

uremic

toxins

Hypoglycemia

should

not

occur

with

the

use

of

glucose-containing

dialysis

fluid

In

cases

of

anemia

transfusions

are

avoided

unless

patient

symptomatic

Erythropoietin

may

be

given

intravenously

at

the

end

of

dialysis

-LRB-

IU/kg

-RRB-

to

maintain

hemoglobin

levels

Medications

The

clearance

of

drugs

on

HD

or

during

CRRT

needs

to

be

considered

Reference

should

be

made

to

standard

texts

-LSB-

-RSB-

O O O O B I I O O O O B B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O B O O O O O O O O O O B O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

acute renal failure
peritoneal dialysis
hemofiltration
hemodialysis
guidelines