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It is five years now since the last European
resuscitation guidelines were published
in 2000(1).The science of resuscitation
has been enriched with a significant
scientific evidence, this in turn has
lead to the birth of the new evidence
based guidelines for resuscitation.
These guidelines were released in
November 2005, and published in the
international Journal of resuscitation,
November 2005(2).
There are new major changes in the current
guidelines, In fact clinical guidelines
must be updated regularly to advise the
health care providers on best practice.
Nevertheless, guidelines in general
don't define the only way that
resuscitation should be achieved, they
merely represent a widely accepted view
of how resuscitation can be undertaken
both safely and effectively (3).
The new guidelines aimed at not only applying the
best evidence available in the science
of resuscitation but also focused on
easier approach for lay people and
health care professionals.
The new guidelines paid much attention to the
early recognition of very ill patients
and early prevention and treatment of
cardiac arrest.The importance of
recognizing critical illness and
preventing cardiac arrest (in-or
out-of-hospital) and post-resuscitation
care has been highlighted by the
inclusion of these elements in a new
four-ring chain of survival(1) .
According to the new guidelines, rescuers begin
cardiopulmonary resuscitation (CPR) if
the victim is unconscious or
unresponsive and not breathing normally.
Checking for carotid pulse has been
omitted as it is an inaccurate method
for confirming the presence or absence
of circulation(5,6) .
During the first few minutes after non-asphyxial
cardiac arrest the blood oxygen content
remains high and myocardial and cerebral
oxygen delivery is limited more by
diminished cardiac output than by a lack
of oxygen in the lungs, therefore
initial rescue breaths are less
important than chest compression. This
has lead to the removal of the initial
two rescue breaths from the Basic life
support (BLS) new guidelines (6,7).
During CPR, the new recommendation is to
give each rescue breath over about 1
second, with enough volume to make the
victim's chest rise, but to avoid rapid
and forceful breaths. This
recommendation applies to all forms of
ventilation during CPR, including mouth
to mouth and Bag-Valve-Mask (BMV) (6).
This is based on the following evidence:
1. During CPR, blood flow to the lungs
is substantially reduced, so an adequate
ventilation-
perfusion ratio can be
maintained with lower tidal volumes and
respiratory rates than normal (8)...
2. Not only is hyperventilation (too
many breaths or too large volumes)
unnecessary, but it is
harmful because
it increases intra thoracic pressure,
thus decreasing venous return to the
heart
and diminishing cardiac output,
survival is consequently reduced (9).
3. When the airway is unprotected, a
tidal volume of 1 L produces
significantly more gastric
distention
than a tidal volume of 500 ml (10).
4. Low minute ventilation (lower than
normal tidal volume and respiratory
rate) can maintain
effective oxygenation
and ventilation during CPR
(11,12,13,14). During CPR a tidal volume
of
approximately 500 - 600 ml should be
adequate.
5. Interruptions in chest compressions
(for example to give rescue breaths)
have a detrimental
effect on survival
(15). Giving rescue breaths over a
shorter time will help to reduce the
duration
of essential interruptions.
A major change in the new guidelines, is
the emphasis on minimizing the
interruptions of chest compressions. The
new recommendation is to give 30
compression and 2 rescue breaths rather
than 15 and 2 in the guidelines of
2000(1). The reason behind this
recommendation as published in the
recent guidelines is that coronary blood
flow decreases substantially on stopping
chest compressions, in addition several
compressions are necessary before the
coronary flow recovers to its previous
levels (3,4) .
There is insufficient evidence to
support a specific hand position for
chest compression during CPR in adults.
The new guidelines recommend to place
the heel of the hand in the center of
the chest with the other hand on the top
(6) .
Previous guidelines of finding the
middle of the lower half of the sternum
by placing one finger on the lower end
of the sternum and sliding the other
hand down to it has been omitted in the
new guidelines.
Another major change from the previous
guidelines is related to defibrillation.
The new guidelines emphasize the
importance of early defibrillation as
the ability to deliver early
defibrillation is one of the most
important factors in determining
survival from cardiac arrest. However
these guidelines recommend for
out-of-hospital but not in-hospital
Ventricular fibrillation (VF) or
Ventricular tachycardia (VT) to give a
period of CPR for 2 minutes before
defibrillation despite that the evidence
supporting this is weak and shown only
in animal studies(16,17,18). The recent
guidelines recommend to give only one
shock wave of 150-360 J of biphasic or
360 J of mono phasic defibrillators,
followed immediately by CPR for two
minutes without the need to check for
the rhythm or pulse after delivering the
shock wave. The reasons behind this is
to prevent interruptions of CPR during
defibrillation as this is associated
with post-resuscitation myocardial
dysfunction and reduced survival as well
as it reduces the chances of converting
VF to another rhythm. Furthermore, first
shock efficacy of biphasic wave forms
exceeds 90% and failure to convert VF
successfully more likely to suggest the
need for a period of CPR rather than a
further shock. In addition, even if the
defibrillation attempt is successful in
restoring a perfusing rhythm, it is very
rare for the pulse to be palpable
immediately after defibrillation. More
over, even if a perfusing rhythm has
been restored, giving chest compressions
doesn't increase the chances of VF
recurring(15,16,19,20,21 ).
Here is a summary of the latest Euoropean Resuscitation Council (ERC)
Guidelines for Adult resuscitation (2005-12-03) released by ERC
A) Main changes in Adult Basic Life Support (Figure 1)
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Fig. 1. Adult Basic
Life Support
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* The decision to start CPR is made if
the victim is unresponsive and not
breathing normally.
* Rescuers should be taught to place the
hands on the center of the chest, rather
than to spend
more time using the "rib margin" method.
* Each rescue breath is given over 1
second rather than 2 seconds.
* The ratio of compression to
ventilations is 30:2 for adult victims
of cardiac arrest.
* For an adult victim, the 2 initial
rescue breaths are omitted , with 30
compressions being given
immediately after cardiac arrest is established.
B) Main changes in automated external defibrillation
* Public Access Defibrillation (PAD)
programs are recommended for locations
where the expected
use of an Automated external defibrillator (AED) for witnessed cardiac
arrest exceeds once in two
years.
* A single defibrillatory shock ( at
least 150 J biphasic or 360 J monophasic
) is delivered ,
immediately followed by 2 minutes of uninterrupted CPR, without a
check for termination of VF
or check for signs of life or a pulse.
C) Main changes in adult advanced life support (Figure 2)
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Fig. 2. Adult life support
cardiac arrest algorithm(21)
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CPR before defibrillation
* In out-of-hospital cardiac arrest
attended, but unwitnessed, by health
care professionals equipped
with manual defibrillators, give CPR for 2 minutes (i.e. about 5
cycles at 30:2) before
defibrillation.
* Do not delay defibrillation if an
out-of-hospital arrest is witnessed by
health care professional.
* Do not delay defibrillation for
in-hospital cardiac arrest.
Defibrillation strategy
* Treat VF/pulseless VT with a single
shock , followed by immediate resumption
of CPR (30
compressions to 2 ventilations). Do not reassess the rhythm or feel for a
pulse. After 2 minutes
of CPR, check the rhythm and give another shock (if indicated).
* The recommended initial energy for
biphasic defibrillators is 150-200 J.
Give second and
subsequent shocks at 150-360 J.
* The recommended energy when using a
monophasic defibrillator is 360 J for
both the initial and
subsequent shocks.
Fine VF
* If there is doubt about whether the
rhythm is asystole or fine VF, do not
attempt defibrillation,
instead continue chest compressions and ventilation.
Adrenaline
* VF/VT: Give adrenaline 1 mg IV if
VF/VT persists after a second shock.
Repeat the Adrenaline
every 3-5 min thereafter if VF/VT persists.
* Pulseless Electrical Activity (PEA)/Asystole:
Give Adrenaline 1mg IV as soon as
intravenous
access is obtained, and repeat every 3-5 min thereafter until Return of
Spontaneous Circulation
(ROSC) is achieved.
Anti-arrhythmic drugs
* If VF/VT persists after three shocks,
give amiodarone 300 mg by bolus
injection. A further dose
of 150 mg may be given for recurrent or refractory VF/VT, followed by an
infusion of 900 mg over
24 h.
* If amiodarone is is not available,
lidocaine 1mg/kg may be used as an
alternative, but don't give
lidocaine if amiodarone has already been given. Don't exceed a
total of 3 mg/kg during the first
hour.
Thrombolytic therapy for cardiac arrest
* Consider thrombolytic therapy when
cardiac arrest is thought to be due to
proven or suspected
pulmonary embolus. Thrombolysis may be considered in adult cardiac arrest
on a case by case
basis following initial failure of standard resuscitation in patients in
whom an acute thrombotic
etiology for the arrest is suspected. Ongoing CPR is not a
contraindication to thrombolysis.
* Consider performing CPR for up to
60-90 min when thrombolytic agents have
been given during
CPR.
Post resuscitation care - therapeutic hypothermia
* Unconscious adult patients, with
spontaneous circulation, after
out-of-hospital VF cardiac arrest
should be cooled to 32-34oC for 12-24 h.
* Mild hypothermia may also benefit
adult patients, with spontaneous
circulation, after out-of-
hospital arrest from a non-shockable rhythm or after a cardiac
arrest in hospital.
References
Other
Topics:
Review Article # 1
- Poisoning with Organophosphorus Compounds (OPC): Mythology vs. Reality
Review Article # 2
- Minimally Invasive Treatment of Benign Prostatic Hyper Plasia: What
Vanished and what Survied ?
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