Risks to the
rescuer and victim
The
safety of both the rescuer and victim are paramount during a resuscitation
attempt. There have been few incidents of rescuers suffering adverse effects
from undertaking CPR, with only isolated reports of infections such as
tuberculosis (TB) and severe acute respiratory distress syndrome (SARS).
Transmission of HIV during CPR has never been reported.16
There
have been no human studies to address the effectiveness of barrier devices
during CPR; however, laboratory studies have shown that certain filters, or
barrier devices with one-way valves, prevent transmission of oral bacteria from
the victim to the rescuer during mouth-to-mouth ventilation. Rescuers should
take appropriate safety precautions where feasible, especially if the victim is
known to have a serious infection such as TB or SARS. During an outbreak of a
highly infectious condition (such as SARS), full protective precautions for the
rescuer are essential.
Initial rescue
breaths
During
the first few minutes after non-asphyxial cardiac arrest the blood oxygen
content
remains
high. Therefore, ventilation is less important than chest compression at this time.
It is well recognised that skill acquisition and retention are aided by
simplification of the BLS sequence of actions. It is also recognised that
rescuers are frequently unwilling to carry out mouth-to-mouth ventilation for a
variety of reasons, including fear of infection and distaste for the procedure.
For these reasons, and to emphasise the priority of chest compressions, it is
recommended that, in adults, CPR should start with chest compressions rather
than initial ventilations.
Jaw thrust
The
jaw thrust technique is not recommended for lay rescuers because it is
difficult to learn and perform. Therefore, the lay rescuer should open the
airway using a head-tiltchin-lift manoeuvre for both injured and non-injured
victims.
Agonal gasps
Agonal
gasps are present in up to 40% of cardiac arrest victims.10 Therefore laypeople
should be taught to begin CPR if the victim is unconscious (unresponsive) and
not breathing normally. It should be emphasised during training that agonal
gasps occur commonly in the first few minutes after sudden cardiac arrest; they
are an indication for starting CPR immediately and should not be confused with
normal breathing.
Use of oxygen
during basic life support
There
is no evidence that oxygen administration is of benefit during basic life
support in
the
majority of cases of cardiac arrest before healthcare professionals are available
with equipment to secure the airway. Its use may lead to interruption in chest
compressions, and is not recommended, except in cases of drowning (see below).
Mouth-to-nose
ventilation
Mouth-to-nose
ventilation is an effective alternative to mouth-to-mouth ventilation. It may
be considered if the victim’s mouth is seriously injured or cannot be opened,
if the rescuer is assisting a victim in the water, or if a mouth-to-mouth seal
is difficult to achive
Mouth-to-tracheostomy
ventilation
Mouth-to-tracheostomy
ventilation may be used for a victim with a tracheostomy tube or
tracheal
stoma who requires rescue breathing.
Bag-mask
ventilation
Considerable
practice and skill are required to use a bag and mask for ventilation. The lone
rescuer has to be able to open the airway with a jaw thrust whilst
simultaneously holding the mask to the victim’s face. It is a technique that is
appropriate only for lay rescuers who work in highly specialised areas, such as
where there is a risk of cyanide poisoning or exposure to other toxic agents.
There are other specific circumstances in which non-healthcare providers
receive extended training in first aid, which could include training, and
retraining, in the use of bag-mask ventilation. The same strict training that
applies to healthcare professionals should be followed and the two-person technique
is preferable.
Chest
compression
In
most circumstances it will be possible to identify the correct hand position
for chest compression without removing the victim’s clothes. If in any doubt,
remove outer clothing. Each time compressions are resumed on an adult, the
rescuer should place his hands on the lower half of the sternum. It is
recommended that this location be taught in a simple way, such as ‘place the
heel of your hand in the centre of the chest with the other hand on top.’ This
teaching should be accompanied by a demonstration of placing the hands on the
lower half of the sternum.17 Use of the internipple line as a landmark for hand
placement is not reliable. Performing chest compression:
a.
Compress the chest at a rate of 100-120 min-1.
b.
Each time compressions are resumed, place your hands without delay ‘in the centre
of the chest’ (see above).
c.
Pay attention to achieving the full compression depth of 5-6 cm (for an adult).
d.
Allow the chest to recoil completely after each compression.
e.
Take approximately the same amount of time for compression and relaxation.
f.
Minimise interruptions in chest compression.
g.
Do not rely on a palpable carotid or femoral pulse as a gauge of effective arterial
flow.
h. ‘Compression
rate’ refers to the speed at which compressions are given, not the total number
delivered in each minute. The number delivered is not only by the rate, but
also by the number of interruptions to open the airway, deliver rescue breaths,
and allow AED analysis.
Compression-only
CPR
Studies
have shown that compression-only CPR may be as effective as combined ventilation
and compression in the first few minutes after non-asphyxial arrest. However, chest
compression combined with rescue breaths is the method of choice for CPR by
trained lay rescuers and professionals and should be the basis for lay-rescuer education.
Lay rescuers who are unable or unwilling to provide rescue breaths, should be
encouraged to give chest compressions alone. When advising untrained laypeople by
telephone, ambulance dispatchers should give instruction on compression-only CPR.18,
19, 19a.
Regurgitation
during CPR
Regurgitation
of stomach contents is common during CPR, particularly in victims of drowning.
If regurgitation occurs:
Turn
the victim away from you.
Keep
him on his side and prevent him from toppling on to his front.
Ensure
that his head is turned towards the floor and his mouth is open and
at
the lowest point, thus allowing vomit to drain away.
Clear
any residual debris from his mouth with your fingers; and immediately
turn
him on to his back, re-establish an airway, and continue rescue
breathing
and chest compressions at the recommended rate.
Teaching CPR
Compression-only
CPR has potential advantages over chest compression and ventilation,
particularly when the rescuer is an untrained or partially-trained layperson. However,
there are situations where combining chest compressions with ventilation is better,
for example in children, asphyxial arrests, and prolonged arrests.20, 21 Therefore,
CPR should remain standard care for healthcare professionals and the preferred
target for laypeople, the emphasis always being on minimal interruption in compressions.
A
simple, education-based approach is recommended:
Ideally,
full CPR skills should be taught to all citizens.
Initial
or limited-time training should always include chest compression.
Subsequent
training (which may follow immediately or at a later date) should
include
ventilation as well as chest compression.
CPR
training for citizens should be promoted, but untrained lay people should be encouraged
to give chest compressions only, when possible and appropriate with telephone
advice from an ambulance dispatcher. Those laypeople with a duty of care, such
as first aid workers, lifeguards, and child minders, should be taught chest
compression and ventilation.
Over-the-head
CPR
Over-the-head
CPR for a single rescuer and straddle CPR for two rescuers may be
considered
for resuscitation in confined spaces
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