The system of modern cardiopulmonary resuscitation (CPR) is a
relatively new phenomenon, starting only about 60 years ago. The
road leading to its development, however, stretches back many
centuries and has been a process of gradual evolution1.
Inaccurate and inadequate techniques have been attempted and
rejected along the way as we have learnt more about the science
of resuscitation. Examining the history of resuscitation is a
useful first step to understanding the evolution to modern
practice. The evidence for current practice will be presented,
detailing the rationale behind the most recently published
guidelines. Possibilities for future research and improvement in
the field of resuscitation science will also be discussed.
Airway and Breathing
The earliest recorded attempt at resuscitation is from the Old Testament of the
Bible, in the book of 2 Kings, by the prophet Elisha.
when Elisha was come into the house, behold, the child was dead,
and laid upon his bed. He went in therefore, and shut the door
upon them twain, and prayed unto the LORD. And he went up, and
lay upon the child, and put his mouth upon his mouth, and his
eyes upon his eyes, and his hands upon his hands: and stretched
himself upon the child; and the flesh of the child waxed warm.
Then he returned, and walked in the house to and fro; and went
up, and stretched himself upon him: and the child sneezed seven
times, and the child opened his eyes." (2 Kings 4: 32-35)
Little mention of this method, however, is made in the following
2 millennia until the Renaissance when scientists attempted to
understand the basic workings of the human body. In 1542,
Andreas Vesalius, the famed Flemish anatomist, observed that
when he opened the chest of an experimental animal, the
heartbeat and pulsation of the great vessels stopped but
returned again after he introduced a reed into the airway and
inflated the lungs with bellows2.
This knowledge unfortunately, lay dormant until the 18th
century because the lack of appreciation of its applicability to
humans. In the 1500s, Paracelsus had already documented the use
of fireside bellows to nose resuscitation in humans but it was
not till the 1700s that reports of early mouth-to-mouth
techniques were reported.
In 1767, the Society for the Recovery of Drowned Persons was
founded in Amsterdam. Physicians and laypeople collaborated to
aid victims of drowning in the numerous canals in the city.
Methods of resuscitation were set up and disseminated and
monetary rewards distributed for success. The use of
mouth-to-mouth respiration, however, fell out of favour compared
to the use of bellows, as the expired air was perceived to have
been "devitalized" by passing through the rescuer's lungs.
It was only in the mid 1950s, though, that methodical
investigation in the techniques of resuscitation was carried out
by Peter Safar and James Elam in Baltimore City Hospital. In a
series of daring experiments, Safar paralysed volunteers with
curare or succinylcholine and demonstrated that optimal patency
was attained with the neck extended and the mandible supported.
He also elegantly demonstrated that expired air contained enough
oxygen to maintain normal saturations 3-4.
compressions in resuscitation were largely thought to aid only in ventilation
till the end of the 19th century. In 1874, Moritz Schiff performed
the first cardiac compressions when he noted carotid pulsation after manually
squeezing a canine heart through an open chest5. Boehm and Mickwitz
demonstrated closed chest compression soon after by squeezing the ribs and
sternums of cats6. The first successful case of closed chest cardiac
massage was actually reported by Friedrich Maass in 1892. Unfortunately, the
medical community overlooked this important contribution for almost 70 years.
With the advent of anaesthesia in the form of chloroform in the
latter half of the 19th century, anaesthetic related
cardiac arrests occurred and these were deemed fatal until the
first successful open cardiac massage performed by Kristian
Ingelsrud in 1901. For the next 60 years, sudden cardiac death
was only survivable in a hospital setting where open cardiac
massage could be performed1.
It was only the late 1950s, when Guy Knickerbocker, James Jude
and William Kouwenhoven were researching defibrillation in dogs,
that the technique of external cardiac compression was
rediscovered. They noticed that when the defibrillator paddles
were applied firmly on the sternum, there was a simultaneous
rise in femoral arterial pressure. The technique of external
chest compression was reintroduced to the patient care setting
in 1958 and quickly eclipsed open cardiac massage as a
The connection of mouth-to-mouth ventilation and chest
compression to create CPR as it is practiced today occurred when
Safar, Jude and Kouwenhoven presented their findings at the
annual Maryland Medical Society Meeting on September 16th
1960. The moderator at the meeting stated that the two
techniques “cannot be considered any longer as separate units
but parts of a whole and complete approach to resuscitation. In
1966, the first CPR guidelines were published by the National
Academy of Sciences in the Journal of the American Medical
recorded instance of closed chest defibrillation took place in 1775 when
Abilgaard, a Danish veterinarian, "shocked a single chicken into lifelessness
and on repeating the shock, the bird took off and eluded further
The first successful (open) cardiac defibrillation was performed
by Dr. Claude Beck in 1947 in a 14-year-old boy who underwent an
operation to correct a sternal deformity. When his chest was
closed, he arrested and when the sternotomy was reopened, he was
noted to be ventricular fibrillation. After 70min of open
cardiac massage and 2 direct shocks, a regular pulse was
restored and there was no adverse neurological sequelae10.
In 1955, Paul Zoll recorded the first successful closed chest
defibrillation in a man with recurrent syncope and ventricular
Current Practice Today
The International Liaison Committee on Resuscitation (ILCOR) was
formed in 1993 and consists of representatives from
resuscitation councils all over the world. Its mission is to
identify and review international science and research relevant
to CPR and emergency cardiovascular care and to generate
consensus on treatment recommendations. Guidelines are revised
every five years by ILCOR-the current set was published in 200512.
The basic building blocks of paediatric life support remain the
same through the many revisions-(1) prevention, (2) basic CPR
(3) early access to emergency services and (4) prompt paediatric
advanced life support (PALS). These 4 links form the American
Heart Association paediatric chain of survival13.
The 2005 algorithm is shown below. The step-wise sequence of
airway, breathing and circulation remain comfortingly
familiar-in reality however, with either multiple bystanders or
when the arrest occurs in-hospital, the ABCs occur in parallel
rather than sequentially.
Airway and Breathing
For both inside and outside the hospital, the measures taken to open
the airway and assess for breathing remain the same. In-hospital,
however, bag mask ventilation is likely to be used to deliver
breaths instead of mouth to mouth or mouth to nose ventilation.
Bag mask ventilation can be as effective as ventilation through an
endotracheal tube and may be safer over short transport distances.
However, it requires training and periodic retraining in the
necessary skills such as selecting the right size, forming an
effective seal, delivering effective ventilation and assessing
effectiveness of ventilation.
Airway adjuncts such as oropharyngeal or nasopharyngeal airways may
be used in the pre-hospital setting but once in hospital, an
advanced airway should be placed. Successful placement of
endotracheal tubes with a low incidence of complications are related
to the length of training, supervised training in the operating room
and in the field, adequate ongoing experience and the use of rapid
sequence intubation. ILCOR strongly recommends that the placement of
the tube is checked clinically, with the use of end tidal CO2
detection and with a chest radiograph in the hospital setting. There
is not enough evidence for or against the use of the laryngeal mask
(LMA) in cardiac arrest. When endotracheal intubation is not
possible, the LMA can be used by experienced providers but it is
associated with a higher rate of complications in young children14.
Care needs to be taken to prevent hyperventilation. In the
adrenaline soaked atmosphere of a resuscitation, healthcare
providers often deliver excessive ventilation particularly when an
advanced airway is in place. Hyperventilation can lead to impaired
venous return, cause air trapping and barotrauma and may increase
gastric distension and risk of regurgitation and aspiration. The aim
should be 8-10 breaths per minute during CPR and 12-20 breaths per
minute in rescue breathing13.
Studies have shown that healthcare providers as well as lay people
are unable to reliably detect a pulse and may falsely detect a pulse
when there is none13. Therefore, if a pulse cannot be
felt or cannot be reliably detected within 10 seconds, chest
compressions are to be commenced.
The ratio for compressions to breaths has been changed to 30:2 for
basic life support with single rescuers. The emphasis is on good
quality chest compressions at 100/min (“Push hard, push fast”),
allowing for chest recoil and minimizing interruptions.
The optimum compression to ventilation ratio is unknown. In the 2000
ILCOR guidelines, a ratio of 5:1 was recommended but subsequent
studies but subsequent studies showed that at that rate, fewer than
60 compressions a minute was achieved on a paediatric manikin, even
under ideal circumstances15. It was also shown that it
takes a number of compressions to raise coronary perfusion pressure
which drops every time CPR is interrupted16. Long and
frequent interruptions in CPR in both in-hospital and out-hospital
settings have been documented by lay-rescuers as well as healthcare
providers17. Interruptions in chest compressions have
been associated with a decrease in the rate of return of spontaneous
The depth of compression is also important-the aim should be to
compress the antero-posterior diameter of the chest by one third to
one half. Dana Edelson and her colleagues showed in 2006 that
successful defibrillation was associated with shorter pre-shock
pauses (adjusted odds ratio (OR) 1.86 for every 5s, 95% CI
1.10-3.85) and with higher mean compression depth in the 30s prior
to defibrillation (adjusted OR 1.99 for every 5mm increased, 95% CI
1.08-3.66)19. One of the major limiting factors in
achieving quality CPR is rescuer fatigue. In the 2005 ILCOR
guidelines, rescuers doing chest compressions should alternate every
2 minutes so as to minimize fatigue and optimize quality CPR
There has been some recent controversy in the literature surrounding
adult CPR comparing conventional CPR and compression-only CPR. In
the adult population where most arrests are primary cardiac arrests,
compression-only CPR while awaiting the arrival of the defibrillator
may be as effective as conventional CPR. However, in the paediatric
population where most arrests are due to hypoxia-asphyxia, the ILCOR
recommendation remains to deliver prompt ventilation and chest
compressions to achieve the optimal results 12.
Once pulseless ventricular tachycardia (VT) or ventricular
fibrillation (VF) is detected, immediate defibrillation is required.
VF occurs in 5-15% of paediatric out-of-hospital cardiac arrests and
is reported in 20% of in-hospital arrests at some point during the
The 1st shock is at 2J/kg; subsequent shocks should be at
4J/kg. Effective, good quality CPR should be delivered until the
shock is delivered and CPR resumed immediately following the shock.
If 1 shock fails to eliminate VF, the incremental benefit of a
second shock delivered is likely to be low and resumption of CPR is
likely to be of greater value.
Automated external defibrillators (AEDs) are now widely used in the
public and many have high specificity in detecting paediatric
shockable rhythms. Some are also equipped to lower the energy
delivered, making them suitable for use in children 1-8 years of
age. The ILCOR 2005 guidelines do recommend the use of AEDs in
children from 1-8 years, preferably those with a paediatric
attenuator system. If in an emergency, only a standard AED is
available, use the AED as data has shown that many AEDs can detect
VF in children of all ages. The lowest energy dose for successful
defibrillation and the upper safety limit is not known but energy
doses > 4 J/kg (energy up to 9J/kg) has successfully defibrillated
children and paediatric animal models with negligible adverse
The use of high dose adrenaline (1:1000) in resuscitation is no
longer recommended as there was no improvement in survival rates and
may be associated with poorer neurological outcome. A prospective,
randomized controlled trial by Perondi and colleagues in 2004,
comparing standard dose (1: 10000) with high dose adrenaline (1:
1000) for the second and subsequent rescue doses in resuscitation
showed reduced 24 hours survival rates in the high dose group20.
While we appear to have all the tools in place, outcomes from
cardiopulmonary resuscitation remain poor. Survival from
out-of-hospital CPR is usually reported as between 2-14% and most
have severe neurological disability. Bystander CPR is provided to
only approximately 30% of pediatric cardiac arrest victims before
reaching hospital so it is not surprising that the outcomes are poor21.
Outcomes for CPR for out-of-hospital arrest due to trauma is also
poor with one study reporting survival to discharge at 8.75%22.
In-hospital CPR outcomes are unsurprisingly much better due to the
availability of experienced staff and paediatric advanced life
support. Age, the presence of a shockable rhythm as the first
documented rhythm and the 24 hour presence of paediatric residents
and fellows are all associated with better survival rates and
However, can we do better? Can we improve the dismal outcomes from
out-of-hospital arrests and ensure even higher survival rates and
better neurological outcomes from those that occur in-hospital?
There are 4 phases of cardiac arrest, common to all ages: (1)
pre-arrest; (2) no flow (untreated cardiac arrest); (3) low flow
(CPR) and (4) post resuscitation. Interventions can be targeted at
each phase to improve outcomes and selected to focus on the timing,
intensity and duration of resuscitation to the physiology and
metabolic state of the cardiac arrest patient.
Interventions at this phase are mainly targeted at community level
preventative strategies for arrests outside of the hospital as well
as monitoring high-risk patients in hospital. Campaigns such as for
child road and water safety and awareness of sudden infant death
syndrome (e.g. the “Back to Sleep” Campaign) help to raise public
knowledge and prevent harm to children.
for in-hospital strategies, recent literature has shown that among
the adult population, the formation of in-house Medical Emergency
Teams (MET) that respond when certain critical clinical parameters
are breached result in better outcomes following CPR. In his 2006
paper, Prof Tibballs of the Royal Children's Hospital in Melbourne
described a similar set up for a paediatric Medical Emergency Team.
The MET team was activated when early signs of respiratory failure
and/or shock occurred and aimed to treat these children early.
Though there was no statistical significance in the reduction of
cardiac arrests, one of the key changes that arose as a result of
the study was the empowerment of all nursing and medical staff to
call for help once they felt a patient was deteriorating rapidly23-24.
Though the formation of a specialized team would be redundant in our
context, the awareness of all staff to escalate rapidly and get help
when certain parameters are breached is important.
Arrest (No Flow Phase)
Interventions during these phase focus on early recognition of
cardiac arrest, effective monitoring and prompt initiation of basic
and advanced life support. Public awareness and lay rescuer
education in CPR is vital in improving outcomes outside of the
hospital. The use of educational tools such as the Voice Advisory
Manikin (Laerdal) which provides immediate audio feedback during
training may improve the incidence and quality of bystander CPR25.
An effective nationwide emergency response system is also important.
hospital, an effective Code Blue/Crash team Response system should
be in place and the interval between basic and advanced life support
should be minimal.
Low Flow Phase (CPR)
Once CPR has commenced, the focus should be on delivering
high-quality, effective CPR to optimize coronary perfusion pressure
and cardiac output to critical organs to support organ viability
during the low flow phase.
Feedback systems in conjunction with AEDs (e.g. Phillips HeartStart)
are already available and have been shown to optimize the quality of
CPR. Perhaps in the future, these feedback systems can become
pocket-sized and have prompts for rate and quality of CPR. Popular
songs may even be incorporated to ensure the right rate of CPR! In
order to alleviate rescuer fatigue, adjuncts such as mechanical
compression devices (e.g. the Autopulse), may be used in the
community to deliver quality CPR.
hospital, though feedback systems will also be useful, the key will
be to ensure training and education so that quality BLS as well as
ALS will be delivered promptly.
Junior medical staff are usually the first to respond to an arrest
situation and it is well recognized that there is a lack of
confidence and fear in dealing with these situations without
adequate training. A recent study by Turner et al in 2007 showed
that residents perceived a significantly increased self-efficacy
following attendance in the Advanced Paediatric Life Support course
and this effect lasted 6 months26.
ILCOR and all professional bodies such as the Royal Colleges of
Paediatrics and Child Health recommend that clinicians maintain
their advanced resuscitation knowledge and skills and that failure
to do so contravenes the principles of clinical governance and has
implications for clinical negligence. This is particularly important
for middle and senior grade staff, the majority of whom have
completed an advanced resuscitation course at some point in their
career but have not retrained and let their provider status lapse27.
Recent changes in working practice with reduced hours and shorter
training may also result in trainees attending fewer arrests and
thus reduce their experience, skills, knowledge and confidence to
perform effective resuscitation. Studies from mock codes and
simulation training have showed that there are often alarming delays
and deviations from paediatric basic life support protocols and
delays in administering treatment28-29.
However simulation training also provides a safe platform for
controlled clinical practice without putting patients or others at
risk. The training can be targeted to the need of the learner,
allowing multiple practice attempts in order to achieve competence.
Learners are also allowed to “fail” and learn from these
experiences. Simulators also allow objective feedback on
performance, allowing learners to evaluate their performance in
detail. This powerful tool allows medical and nursing staff to
retrain, gain confidence and aid teamwork in dealing with
Post Resuscitation Phase
The immediate post resuscitation phase is a high-risk period for
arrhythmias and reperfusion injuries. Interventions at this phase
target goal directed therapies to match oxygen and substrate
delivery to meet metabolic demands and therefore minimize
reperfusion injury and support cellular recovery21.
Careful attention therefore to maintaining homeostasis is required.
Management of temperature, glucose, blood pressure, coagulation and
ventilation may be particularly important in this phase. The 2005
ILCOR guidelines suggested consideration of induced hypothermia in
children 12-24 hours post arrest may have potential benefits in
improving outcome. At a minimum, avoiding mild hyperthermia in
children post CPR is advisable as fever following cardiac arrest is
associated with poor outcome.
These measures though, remain crude and future strategies are likely
to be targeted at the cellular level as we learn more about the
physiology of cardiac arrest and recovery. The roles of
anti-oxidants, anti-inflammatory agents, thrombolytics, mediator
cascades, modulation of excitatory neurotransmitters are likely to
become increasingly important in the future of post-resuscitation
Cardiopulmonary resuscitation has evolved remarkably over its
history but the goal of saving lives through early and effective
techniques has remained the same. Achieving high quality CPR and
acquiring and retaining confidence and skill in advanced paediatric
life support are key areas for all clinicians. As we learn more
about the physiology of cardiac arrest and recovery, survival and
neurological outcomes from cardiac arrest are likely to improve.
- Cooper et al, Cardiopulmonary Resuscitation: History, Current Practice and
Future Direction. Circulation 2006; 114: 2839-2849.
Vesalius A. De Humani Corporis Fabrica Libri Septum,
Safar et al, Upper Airway Obstruction in the Unconscious
Patient. J Appl Physiol. 1959; 14: 760-764.
Safar et al, Ventilatory efficacy of mouth to mouth artificial
respiration, JAMA 1958; 167:335-341.
Schiff M. Ueber direkte reitzung der herzoberflaeche. Arch
Ges Physiol. 1882; 28: 200.
Boehm, R. Ueber wiederbelebung nach vergiftungen und asphyxia.
Arch Exp Pathol Pharm
Kouwenhoven WB, Jude JR, Knickerbocker GG, Closed chest cardiac
massage. JAMA, 1960; 173: 1064-1067.
Ad Hoc Committee on Cardiopulmonary Resuscitation of the
Division of Medical Sciences, National Academy of
Sciences-National Research Council, Cardiopulmonary
Resuscitation. JAMA 1966; 198: 138-145.
Abildgaard, CP. Tentamina electrica in animalibus institute.
Societatis Med Havniensis Colect. 1775; 2: 157.
Beck et al. Ventricular fibrillation of long duration abolished
by electric shock. JAMA 1947; 135: 985.
Zoll et al. Termination of ventricular fibrillation in man by
externally applied electric countershock. N Eng J Med.
1956; 254: 727.
The International Liaison Committee on Resuscitation (ILCOR)
Consensus on Science with Treatment Recommendations for
Pediatric and Neonatal Patients: Pediatric Basic and Advanced
Life Support. Pediatrics 2006: 117; e955-977.
2005 American Heart Association (AHA) Guidelines for
Cardiopulmonary Resuscitation and Emergency Cardiovascular Care
of Pediatric and Neonatal Patients: Pediatric Basic Life
Support. Pediatrics 2006: 117; e989-e1004.
2005 American Heart Association (AHA) Guidelines for
Cardiopulmonary Resuscitation and Emergency Cardiovascular Care
of Pediatric and Neonatal Patients: Pediatric Advanced Life
Support. Pediatrics 2006: 117; e1005-e1028.
Srikantan et al, Effect of one-rescuer compression/ventilation
ratios on cardiopulmonary resuscitation in infant, pediatric and
adult manikins. Pediatr Crit Care Med. 2005; 6: 293-297.
Berg et al. Adverse hemodynamic effects of interrupting chest
compressions for rescue breathing during cardiopulmonary
resuscitation for ventricular fibrillation cardiac arrest.
Circulation 2001; 104: 2465-2470.
Yu T, et al. Adverse outcomes of interrupted pre-cordial
compression during automated defibrillation. Circulation
2002; 106: 368-372.
Abella BS et al, Chest compression rates during cardiopulmonary
resuscitation are suboptimal: a prospective study during
in-hospital cardiac arrest. Circulation 2005; 111:
Edelson D et al. Effects of compression depth and pre-shock
pauses predict defibrillation failure during cardiac arrest.
Resuscitation 2006; 71: 137-145.
Perondi M et al. A comparison of high-dose and standard-dose
epinephrine in children with cardiac arrest. N Eng J Med
2004; 350: 1722-1730.
Berg RA, Nadkarni, VM, Goal Directed Post-resuscitation
Therapies, Pediatric Multiprofessional Critical Care Review,
Crewdson K. et al. Outcome from paediatric cardiac arrest
associated with trauma. Resuscitation 2007; 75: 29-34.
Tibballs J, Kinney S, Duke T, et al. Reduction of paediatric
in-patient cardiac arrest and death with a medical emergency
team: preliminary results. Arch Dis Child 2005, 90:
Tasker RC, Paediatric Cardiac Resuscitation: can we do better?
Arch Dis Child 2005, 90: 1102-03.
Sutton et al, The voice advisory manikin (VAM): An innovative
approach to pediatric lay provider basic life support skill
education. Resuscitation 2007 75: 161-168.
Turner et al, The effect of the Advanced Paediatric Life Support
Course on perceived self-efficacy and use of resuscitation
skills. Resuscitation 2007: 430-436.
Broster et al, Review of resuscitation training amongst
consultants and middle grade paediatricians. Resuscitation
2007; 74: 495-499.
Nadel FM et al, Assessing pediatric senior residents' training
in resuscitation: fund of knowledge, technical skill and
perception of confidence. Pediatr Emerg Care 2000; 16
Hunt et al, Simulation of In-Hospital Pediatric Medical
Emergencies and Cardiopulmonary Arrests: Highlighting the
Importance of the First 5 Min. Pediatrics 2008: 121;
Perkins, G. Simulation in resuscitation training.
Resuscitation 2007 73: 202-211.
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