Resuscitation

83 (2012) 793–

794

Contents

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Resuscitation

j o

u

r n

a l

h o m

e p a g e

:

w w w . e l s e v i e r . c o m / l o c a t e / r e s u s c i t a t i o n

Editorial

Hospital

care

after

resuscitation

from

out-of-hospital

cardiac

arrest:

The

emperor’s

new

clothes?

The

large

regional

variation

in

outcome

after

treatment

for

out-

of-hospital

cardiac

arrest

(OHCA)

1

has

led

to

efforts

to

develop

and

implement

cardiac

resuscitation

systems

of

care

that

include

interconnected

community,

emergency

medical

services

(EMS)

and

hospital

efforts

to

measure

and

improve

the

process

and

outcome

of

care

for

this

population.

2

Implicit

assumptions

of

these

efforts

are

that

care

provided

for

patients

with

OHCA

is

better

at

some

hos-

pitals

that

receive

such

patients

than

others,

and

that

resuscitated

patients

should

be

preferentially

transported

to

higher-performing

hospitals.

In

this

volume

of

Resuscitation,

two

investigations

describe

whether

the

characteristics

of

receiving

hospitals

are

associated

with

outcome

after

OHCA.

In

a

retrospective

analysis

that

com-

bined

quality

improvement

data

from

the

Cardiac

Arrest

Registry

to

Enhance

Survival

(CARES)

registry

with

administrative

information

about

hospital

characteristics

and

hospitals’

self-report

of

whether

they

use

hypothermia

to

assess

the

relationship,

Cudnik

et

al.

eval-

uated

whether

increasing

hospital

volume

of

OHCA

patients

was

associated

with

improved

survival.

3

They

included

adults

who

had

OHCA

of

presumed

cardiac

etiology,

were

treated

by

EMS,

and

were

directly

transported

to

a

hospital.

The

analysis

used

multi-

level

hierarchical

logistic

regression

to

adjust

for

the

interaction

between

patient-level

factors

with

hospital

characteristics

and

the

association

between

hospital

characteristics

within

different

sites.

A

significant

relationship

was

observed

between

trauma

center

designation

but

not

presence

of

a

coronary

catheterization

labora-

tory

or

the

volume

of

patients

received

and

survival

or

neurologic

outcome

among

all

treated

patients

or

those

with

a

first-recorded

shockable

rhythm.

The

hospital

factor

with

the

largest

treatment

effect

in

this

study

was

self-reported

use

of

hypothermia.

Since

only

a

minor-

ity

of

patients

have

hypothermia

induced

at

hospitals

that

report

that

they

use

it,

4

reported

use

of

hypothermia

may

be

a

surro-

gate

marker

for

other

factors

that

are

associated

with

outcome,

and

attenuate

the

effect

of

hospital

factors

upon

patient

survival

to

discharge.

This

study

restricted

enrollment

to

patients

with

a

cardiac

etiol-

ogy

of

arrest.

There

is

a

twofold

variation

in

the

reported

proportion

of

cardiac

arrests

of

non-cardiac

etiology.

5

There

is

poor

agreement

in

attributing

cause

of

heart

failure

deaths.

6

Information

from

12-

lead

electrocardiogram

does

not

identify

which

patients

among

those

resuscitated

from

OHCA

have

significant

lesions

at

time

of

emergency

catheterization.

7

Assessment

of

the

etiology

of

arrest

is

difficult

to

assess

accurately

in

field.

If

etiology

is

determined

using

hospital

information,

assessing

etiology

is

conditioned

on

survival

to

hospital,

and

analyses

restricted

to

cardiac

etiology

of

arrest

are

susceptible

to

bias.

Thus

the

revised

Utstein

approach

to

comparing

outcomes

after

OHCA

recommended

including

all

treated

patients

rather

than

those

with

a

particular

etiology

or

initial

rhythm.

8

In

another

retrospective

analysis

published

simultaneously

as

the

CARES

work,

Ro

et

al.

evaluated

the

relationship

between

the

annual

volume

of

patients

received

at

hospitals

and

survival

to

discharge

after

cardiac

arrest

of

non-cardiac

etiology

in

a

national

Korean

registry

derived

from

combination

of

ambulance

run

sheets

with

hospital

data

abstracted

by

trained

reviewers.

9

Generalized

additive

modeling

evaluated

for

a

threshold

value

that

discrimi-

nated

between

a

low

and

high

volume

of

patients

received.

Then

multiple

logistic

regression

analysis

evaluated

whether

there

was

an

association

between

the

volume

of

patients

received

and

sur-

vival

to

discharge.

There

was

a

significant

and

important

difference

in

survival

to

discharge

among

patients

transported

to

a

high

vol-

ume

hospital

rather

than

low

volume

hospital

overall

and

within

specific

etiologies

of

arrest.

There

are

several

potential

explanations

why

an

association

between

patient

volume

and

outcome

was

not

observed

in

the

CARES

registry

but

was

in

the

Korean

registry.

The

quality

of

care

may

be

lower

among

CARES

hospitals

than

among

Korean

hospi-

tals,

but

this

seems

unlikely

since

overall

survival

was

greater

in

the

former

than

in

the

latter.

The

accuracy

of

the

data

in

each

reg-

istry

may

differ

as

CARES

performs

limited

data

verification

at

the

source

whereas

staff

of

the

Korean

registry

visit

participating

hos-

pitals

and

review

medical

records

to

identify

information

related

to

covariate

and

outcome.

It

seems

plausible

that

bias

and

confound-

ing

in

CARES

data

may

reduce

the

likelihood

of

identifying

whether

differences

in

care

are

associated

with

differences

in

survival.

Prior

studies

provide

conflicting

evidence

regarding

the

influ-

ence

of

hospital

factors

on

survival

after

OHCA.

A

Japanese

study

that

included

more

10,000

patients

showed

that

OHCA

patients

transported

to

critical

cardiac

care

hospitals

had

improved

1-month

survival

compared

with

patients

transported

to

hospitals

without

specialized

facilities

(6.7%

versus

2.8%,

p

<

0.001,

adjusted

odds

ratio

3.39,

p

<

0.001).

10

A

Swedish

study

of

almost

4000

OHCA

patients

reported

marked

variability

in

hospital

outcomes

after

adjusting

for

pre-hospital

factors,

with

survival

varying

from

14%

to

42%

in

differ-

ent

centres.

11

Similarly

a

recent

Australian

study

of

2706

patients

who

were

transported

to

hospital

with

return

of

a

spontaneous

cir-

culation

found

that

survival

to

hospital

discharge

was

significantly

greater

in

patients

transported

to

hospitals

with

24

h

interventional

cardiology

facilities,

with

the

best

survival

in

major

trauma-level

hospitals.

12

A

US

study

of

109,739

patients

who

received

intensive

0300-9572/$

–

see

front

matter ©

2012 Elsevier Ireland Ltd. All rights reserved.

http://dx.doi.org/10.1016/j.resuscitation.2012.03.034

794

Editorial

/

Resuscitation

83 (2012) 793–

794

care

in

hospital

indicated

that

hospital

teaching

status,

size

and

urban

location

were

associated

with

outcome

in

patients

resusci-

tated

from

in-hospital

and

out-of-hospital

cardiac

arrest.

13

Conversely,

a

North

American

study

of

4087

patients

with

OHCA

reported

increased

rates

of

survival

among

patients

resuscitated

from

OHCA

who

were

treated

at

larger

hospitals

capable

of

inva-

sive

cardiac

procedures

but

this

effect

was

not

independent

of

pre-hospital

factors.

14

How

should

variation

in

outcome

after

hospitalization

for

post-

resuscitation

care

be

interpreted

in

the

context

of

factors

associated

with

variations

in

outcomes

of

other

conditions?

Variation

in

out-

comes

after

hospitalization

for

acute

myocardial

infraction

has

been

associated

with

hospitals’

teaching

status,

15

urban

location,

16

geographic

region,

17

safety

net

status,

18

and

institutional

culture.

19

Additional

work

is

necessary

to

understand

and

improve

the

varia-

tion

in

process

and

outcome

after

OHCA

as

has

been

done

for

acute

myocardial

infarction.

There

are

multiple

examples

throughout

the

field

of

medicine

of

the

positive

correlation

between

greater

provider

experience

or

procedural

volume

for

complex

diagnoses

or

procedures

and

better

patient

outcome.

20

The

relationship

between

volume

and

outcome

is

complex.

Procedural

volume

is

an

identifiable

surrogate

marker

for

a

number

of

patient,

physician,

and

systems

variables

that

have

an

impact

on

outcome

but

are

difficult

to

quantify

individually.

Despite

inconsistent

evidence

of

a

relationship

between

the

volume

of

patients

a

hospital

receives

after

cardiac

arrest

and

their

subsequent

survival,

we

believe

that

it

would

be

premature

to

conclude

that

implementation

of

regional

cardiac

resuscita-

tion

systems

of

care

will

not

improve

process

and

outcome.

We

recommend

that

future

efforts

to

evaluate

the

effect

of

regional-

ization

in

this

population

should

include

all

patients

regardless

of

the

putative

etiology

of

their

arrest,

and

should

be

consistent

with

the

Utstein

approach.

Until

such

an

evaluation

has

been

com-

pleted,

it

seems

reasonable

to

preferentially

transport

patients

who

have

been

resuscitated

from

OHCA

to

a

facility

with

trauma

center

designation

and

other

facilities

to

enable

use

goal-directed

ther-

apies

including

therapeutic

hypothermia,

primary

percutaneous

coronary

intervention,

together

with

comprehensive

neurological

assessment

and

therapy

regardless

of

the

volume

of

patients

with

OHCA

that

the

hospital

receives

annually.

Indeed,

the

emperor

is

wearing

clothes.

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Dion

Stub

Alfred

Hospital,

Baker

Heart

and

Diabetes

Institute,

Melbourne,

Australia

Graham

Nichol

∗

University

of

Washington-Harborview

Center

for

Prehospital

Emergency

Care,

Seattle,

WA,

United

States

∗

Corresponding

author.

E-mail

address:

[e-mail]

(G.

Nichol)

29

March

2012