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Currents
in Emergency Cardiovascular Care
Volume 16
Number 4 Winter 2005-2006
The 5 major changes in the 2005 guidelines
are these:
1. Emphasis on, and recommendations to
improve, delivery of effective
chest
compressions.
2005 (New):
Effective chest compressions produce blood
flow during CPR.The
guidelines
note the following about chest
compressions during CPR:
To give effective chest
compressions, all rescuers should push hard
and push fast.
Compress the chest at a rate of about 100
compressions per minute for all victims
except
newborns).
Allow the chest to
recoil (return to normal position)
completely after each
compression, and
use approximately equal compression and
relaxation times.
Try to limit
interruptions in chest compressions. Every
time you stop chest
compressions,
blood flow stops.
2. A single compression-to-ventilation ratio
for all single rescuers for all
victims (except
newborns)
2005
(New):
The
AHA recommends a compression-to-ventilation
ratio of 30:2 for all lone
(single) rescuers to use for all victims
from infants (excluding newborns)
to
adults.
This
recommendation applies to all lay rescuers
and to all healthcare providers who
perform 1-rescuer CPR.
The science experts
wanted to simplify CPR information so that
more rescuers
would learn,
remember, and perform better CPR. They also
wanted to ensure that
all rescuers would
deliver longer series of uninterrupted chest
compressions.
Although research has
not identified an ideal
compression-to-ventilation ratio, the
higher
the compression-to-ventilation ratio, the
more chest compressions are given
in a series
during CPR. This change should increase
blood flow to the heart, brain,
and other vital
organs.
During the first
minutes of VF SCA, ventilation (ie, rescue
breaths) is probably not
as
important as compressions. Ventilation,
however, is important for victims of
hypoxic arrest
and after
the first minutes of any arrest.
3. Recommendation that each rescue breath be
given over 1 second and
should produce
visible chest rise
2005
(New):
Each
rescue breath should be given over 1 second
(Class IIa). This
recommendation applies to all rescuers. Each
rescue breath
should make
the chest rise
rescuers should be able to see the chest
rise). All rescuers should give the
recommended number of rescue breaths. All
rescuers should avoid delivering too many
breaths (more than the number recommended)
or breaths that are too large or too
forceful.
During CPR, blood flow to the lungs is
much less than normal, so the victim needs
less ventilation than normal.
Rescue breaths can safely be given in 1
second. In
fact, during cycles of CPR, it is
important to limit the time used to deliver
rescue
breaths to reduce interruptions in
chest compressions.
Rescue breaths given
during CPR increase pressure in the chest.
This pressure
reduces the amount of blood that
refills the heart and in turn reduces the
blood flow
generated by the next group of
chest compressions.
For all of these
reasons, hyperventilation (too many breaths
or too large a volume
is not necessary, and may be
harmful because it can actually reduce the
blood
flow generated by chest
compressions. In addition, delivery of large
and forceful
breaths may cause gastric inflation
and its complications.
4. A new recommendation that single
shocks, followed by immediate CPR,
be used to
attempt defibrillation for VF cardiac
arrest. Rhythm checks
should be performed
every 2 minutes.
2005
(New):
When
attempting defibrillation, all rescuers
should deliver 1 shock followed
by
immediate CPR, beginning with chest
compressions. All rescuers should check the
victims rhythm after giving about 5 cycles
(about 2 minutes) of CPR. Once AEDs are
reprogrammed by
the manufacturers, they should prompt
rescuers to allow a rhythm
check every 2 minutes.
The rhythm analysis by
current AEDs after each shock typically
results in delays
of 37
seconds or even longer before the delivery
of the first post-shock
compression. Such long
interruptions in compressions can be harmful
(see
information above and Figure 1).
With most
defibrillators now available, the first
shock eliminates VF more than 85%
of the
time. In cases where the first shock fails,
resumption of CPR is likely to
confer a greater
value than another shock.
Even when a shock
eliminates VF, it takes several minutes for
a normal heart
rhythm to
return and more time for the heart to create
blood flow. A brief period of
chest compressions
can deliver oxygen and sources of energy to
the heart,
increasing the likelihood that the
heart will be able to effectively pump blood
after
the shock. There is no evidence that chest
compressions immediately after
defibrillation will provoke recurrent VF.
5. Endorsement of the 2003 ILCOR
recommendation for use of AEDs in
children 1 to 8
years old (and older); use a child
dose-reduction system if
available. This section
presents an overview of these major changes.
The
changes are also discussed in the
sections for lay rescuers and healthcare
providers.
2005
(New):
AEDs
are recommended for use in children 1 year
of age and older. The
evidence is insufficient to recommend for or
against the use of AEDs in infants under 1
year
of age (Class Indeterminate).
For sudden witnessed
collapse in a child, use the AED as soon as
it is available.
For un-witnessed
cardiac arrest in the out-of-hospital
setting, use the AED after
about 5 cycles (about 2 minutes) of
CPR. Ideally the AED should be proven (via
published studies) to accurately
and reliably recognize pediatric shockable
rhythms and be capable of
delivering a child energy dose.
Many AEDs are now
equipped to deliver smaller doses through
the use of smaller
child pads or a key or other means
to reduce the energy dose. If you are giving
CPR to a child (older than 1 year)
and the available AED does not have child
pads
or a way to deliver a smaller dose,
use a regular AED with adult pads.
DO NOT use child pads
or a child dose for adult victims of cardiac
arrest.
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