Resuscitation 81 (2010) 1209 1211
Contents lists available at ScienceDirect
Resuscitation
journal homepage: www.elsevier.com/locate/resuscitation
Short communication
In-hospital cardiac arrest: Is it time for an in-hospital  chain of prevention ?
Gary B. Smith"
Department of Critical Care, Queen Alexandra Hospital, Cosham, Portsmouth PO6 3LY, United Kingdom
a r t i c l e i n f o a b s t r a c t
Article history:
The  chain of survival has been a useful tool for improving the understanding of, and the quality of the
Received 21 February 2010
response to, cardiac arrest for many years. In the 2005 European Resuscitation Council Guidelines the
Received in revised form 11 April 2010
importance of recognising critical illness and preventing cardiac arrest was highlighted by their inclusion
Accepted 15 April 2010
as the first link in a new four-ring  chain of survival . However, recognising critical illness and preventing
cardiac arrest are complex tasks, each requiring the presence of several essential steps to ensure clinical
Keywords:
success. This article proposes the adoption of an additional chain for in-hospital settings  a  chain of
Education
prevention  to assist hospitals in structuring their care processes to prevent and detect patient deterio-
Monitoring
ration and cardiac arrest. The five rings of the chain represent  staff education ,  monitoring ,  recognition ,
Vital signs
the  call for help and the  response . It is believed that a  chain of prevention has the potential to be under-
Cardiac arrest
stood well by hospital clinical staff of all grades, disciplines and specialties, patients, and their families
Rapid response system
Medical emergency team and friends. The chain provides a structure for research to identify the importance of each of the various
Early warning score
components of rapid response systems.
Patient safety
© 2010 Elsevier Ireland Ltd. All rights reserved.
Prevention
European Resuscitation Council
Guidelines
1. Introduction 2. The  chain of prevention
The  chain of survival has proven to be useful in improving the The proposed  chain of prevention (Fig. 1) consists of five rings
understanding of, and the quality of the response to, cardiac arrest, linked in series. As no chain is stronger than its weakest link, weak-
both outside and in hospital.1 In the 2005 European Resuscitation ness of one or more of the components (rings) of the chain will
Council Guidelines the importance of recognising critical illness and inevitably result in failure of the whole system. This would be man-
preventing cardiac arrest was highlighted by their inclusion as the ifest by patient deterioration and cardiac arrest. If the components
first link in a new four-ring  chain of survival .2 In the in-hospital of the chain are present and strong, the chain will work perfectly,
setting, patient deterioration is often insidious and potentially pre- and this should be measurable as a reduction in the number of pre-
ventable, with failure of recognition being a frequent problem.3,4 ventable cardiac arrests. The chain and the rationale behind it are
However, recognising critical illness and preventing cardiac arrest described below.
are complex tasks, each requiring the presence of several essential
steps to ensure clinical success. Failures have been reported in each
of these steps, many resulting in adverse outcomes for patients.3,4 2.1. First ring of the chain: Education
This article proposes the use of an additional chain for in-hospital
In general, such education needs to include: how to observe
settings  a  chain of prevention  to assist hospitals in structuring
patients, including vital signs measurement and recording;
their care processes to prevent and detect patient deterioration and
interpretation of observed signs; recognition of the signs of
cardiac arrest.
deterioration; the use of an early warning score (EWS) or med-
ical emergency team (MET) calling criteria; appreciating clinical
urgency; when and how to utilise simple interventions (airway
opening, oxygen therapy, intravenous fluid administration, etc.);
knowing how to seek help from other staff; successful teamwork
and organization; knowing how to use a systematic approach to

A Spanish translated version of the summary of this article appears as Appendix
information delivery, and end-of-life care.
in the final online version at doi:10.1016/j.resuscitation.2010.04.017.
" Evidence supporting the role of education in preventing deterio-
Tel.: [phone]; fax: [phone].
E-mail address: [e-mail]. ration and cardiac arrest already exists. For example, virtually all of
0300-9572/$  see front matter © 2010 Elsevier Ireland Ltd. All rights reserved.
doi:10.1016/j.resuscitation.2010.04.017
1210 G.B. Smith / Resuscitation 81 (2010) 1209 1211
staff on general wards may help them to identify better those
patients in need of additional monitoring or intervention. The
design of vital signs charts has an important role in the detection of
deterioration,16 but, at present, the optimal layout is unknown. The
use of colour-coded or colour-banded vital signs charts are believed
to assist in the recognition of patient deterioration, but again tech-
nology may have a future role to play. Within a given institution a
starting point for improvement could be the use of a single chart
format.
Many hospitals now also use a set of predetermined  calling cri-
teria to  flag the need to escalate monitoring or to call for more
expert help. These calling criteria, or  track and trigger systems, can
Fig. 1. The chain of prevention. © Gary Smith.
be categorized as single-parameter systems, multiple-parameter
the observed decrease in the hospital cardiac arrest rate in an Aus-
systems, aggregate weighted scoring systems or combination sys-
tralian, prospective before-and-after trial of a MET occurred before
tems. The aggregate weighted track and trigger systems offer a
the introduction of the MET during the period when ward staff were
graded escalation of care, whereas single-parameter track and trig-
being educated about, and prepared for, its implementation.5,6
ger systems provide an all-or-nothing response. The performance
Additionally in hospitals with established rapid response teams
of these systems is variable.17,18
(RRTs), the introduction of specific, objective criteria for ward staff
A simple criterion that would identify whether this ring of the
to activate the RRT has been associated with improved use of the
chain was in place might be whether the hospital used either stan-
RRTs and significant reductions in cardiac arrest rates.7,8 Recently,
dardized calling criteria18 or a standardized, uniform early warning
a Portuguese group concluded that the effectiveness of a rapid
score17 to assist ward staff in the early recognition of patient dete-
response system (RRS) programme  ...is dependent not only on
rioration for all adult patients.
the existence of an MET but mainly on the periodic and continued
education and training of the entire hospital staff ... .9
2.4. Fourth ring of the chain: Call for help
Suitable audit criteria that would identify whether this ring of
the chain was in place might include: the presence of a specific
All hospitals should have a universally known and understood,
education programme for the recognition and management of the
mandated, unambiguous, activation protocol for summoning a
acutely ill patient in the hospital10; the percentage of hospital staff
response to a deteriorating patient. The culture of the organisation
successfully completing such a course per annum; and the number
should be such that staff are never criticised for calling. However,
of staff possessing agreed levels of competencies relating to the
data from Australia has demonstrated that, even when patients
deteriorating patient.11
had documented physiological MET calling criteria present, the
team is not always called.19 In such circumstances, failures to call
2.2. Second ring of the chain: Monitoring
may result from a lack of recognition of patient deterioration, lack
This includes patient assessment and the measurement and
of knowledge of the escalation protocol, incorrect clinical judge-
recording of patient vital signs, which may include the use of elec-
ment, a lack of confidence in escalating or worry on the part of the
tronic monitoring devices. However, evidence suggests that vital
caller that they might receive criticism. Using quantifiable evidence
signs monitoring occurs infrequently and that observation sets are
appears to be the most effective means for nurses to refer patients
often incomplete. The UK report  An Acute Problem found that
to doctors, but the use of a standardized method of communica-
the notes of medical patients seldom contained written requests
tion, such as the RSVP (Reason-Story-Vital Signs-Plan) system20
regarding the type and frequency of physiological observations to
may also improve communication about patient deterioration. In
be measured.4 Pulse rate, blood pressure and temperature were
some hospitals, the RRT can be called directly by the patient s family
the most frequently recorded variables and breathing rate the
or visitors; their intimate knowledge of the patient often provides
least.4 Improved vital signs monitoring might be achievable using
an additional method for recognizing the subtle changes of early
technology, but the consequence of failing to staff clinical areas
deterioration.21
appropriately should not be minimised. Studies of nurse staffing
One criterion that would identify whether this ring of the chain
levels suggest that the incidence of deterioration, cardiac arrest and
was in place might be whether the hospital uses an unambiguous,
failure-to-rescue is likely to be less in areas with increased levels
activation protocol for summoning a response to a deteriorating
of trained staff, probably due to enhanced patient surveillance.12 patient, such as RSVP.20 Spot audits of clinical notes might be used
Improvements in monitoring can be achieved by documenting a
to determine the number of times that calls for help were made
vital signs monitoring plan for each patient that identifies the vari-
after a patient s physiology met criteria that should trigger a call
ables to be measured and the frequency of measurement.13 Using
for help.
an EWS and/or a MET can also increase the frequency of vital signs
measurements.14,15
2.5. Final ring of the chain: Response
Criteria that would identify whether this ring of the chain was in
place might include the percentage of patients who have a written
So far this is the area of practice that has seen the greatest invest-
vital signs plan that identifies the variables to be measured and
ment in terms of time, money and education. In many countries of
dictates the frequency of measurement number of patients,13 the
the world, hospitals have attempted to solve the problem of patient
number of patients whose vital signs measurements occur with
deterioration by introducing RRTs. Although several, single-centre
the agreed frequency and the number of vital signs datasets that
studies using historical control groups have suggested a positive
include an agreed core dataset of vital signs parameters.
impact of RRTs, others have been unable to prove a benefit.19,22
However, having recognized that a patient is deteriorating or has
2.3. Third ring of the chain: Recognition
deteriorated, it makes perfect sense to escalate the patients moni-
Recognizing patient illness can be difficult, and is a common toring status and care. In certain institutions, doing so may include
feature of adverse incidents.3 Improving the tools available to calling an RRT.
G.B. Smith / Resuscitation 81 (2010) 1209 1211 1211
Criteria that would identify whether this ring of the chain was ing Clinic Ltd., which markets an electronic vital signs capturing
in place might include whether a specific response team for med- and charting system (VitalPAC). VitalPAC is a collaborative devel-
ical crises exists in the hospital, whether a team response occurs opment of The Learning Clinic Ltd. and Portsmouth Hospitals NHS
following a call for help and the time taken from  call for help to Trust.
team response.
References
3. A better alternative?
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4. Summary
14. McBride J, Knight D, Piper J, Smith G. Long-term effect of introducing an early
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This short paper proposes the introduction of a five-ringed
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 chain of prevention to assist hospitals in structuring their care pro-
medical emergency team system on the documentations of vital signs. Resusci-
cesses to best prevent and detect patient deterioration and cardiac
tation 2009;80:35 43.
arrest. The rings represent  staff education ,  monitoring ,  recogni- 16. Chatterjee MT, Moon JC, Murphy R, McCrea D. The  OBS chart: an evidence
based approach to re-design of the patient observation chart in a district general
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of prevention has the potential to be understood well by hospital
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Conflicts of interest statememt 20. Featherstone P, Chalmers T, Smith GB. RSVP: a system for communication of
deterioration in hospital patients. Br J Nurs 2008;17:860 4.
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Professor Smith is a member of the Executive Committee of
activation of a pediatric rapid response team. Jt Comm J Qual Patient Saf
the Resuscitation Council (UK) and contributed to the 2005 Euro- 2009;35:575 80.
22. Esmonde L, McDonnell A, Ball C, et al. Investigating the effectiveness of
pean Resuscitation Council Guidelines for Resuscitation. He is
critical care outreach services: a systematic review. Intensive Care Med
the Director of the Acute Life-threatening Events: Recognition
2006;32:1713 21.
and Treatment (ALERT) course, which is run by his employers,
23. DeVita MA, Bellomo R, Hillman K, et al. Findings of the first consensus conference
Portsmouth Hospitals NHS Trust. His wife hold shares in The Learn- on medical emergency teams. Crit Care Med 2006;34:2463 78.