Chest
Compressions Alone Best for Resuscitation in Cardiac Arrest Patients
News Author:
Sue Hughes
CME Author: Désirée Lie, MD, MSEd
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from Heartwire
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The study,
published in the March 17 issue of The Lancet, found no evidence for any
benefit from the addition of mouth-to-mouth ventilation to chest compressions
and that certain groups of patients had better outcomes with chest compressions
alone.
An accompanying editorial states, "This critically
important finding ... should lead to changes in guidelines. Advocating,
encouraging, and teaching chest-compression only for witnessed unexpected
sudden collapse will dramatically increase bystander initiated resuscitation
efforts and thereby give these patients a better chance of survival when
emergency personnel arrive."
The study
authors, led by Ken Nagao, MD, from the Surugadai Nihon University Hospital in
Tokyo, Japan, note that although bystander CPR improves the likelihood of
survival for people with cardiac arrest, it is attempted in less than one third
of patients who collapse. They say that one of the major barriers to bystanders
performing CPR is their reluctance to undertake mouth-to-mouth ventilation,
partly because of fear of transmission of infectious diseases, and the
complexity of the CPR technique as presently taught.
They point out
that cardiac-only resuscitation is recommended if a rescuer is unwilling or
unable to do mouth-to-mouth ventilation, but that this technique is not
generally taught to the public, and few clinical studies have evaluated this
approach.
They therefore
conducted a prospective, multicenter, observational study of patients who had
witnessed out-of-hospital cardiac arrest in which, on arrival at the scene,
paramedics assessed the technique of bystander resuscitation. Of 4068 adult
cardiac arrest patients included, 11% received cardiac-only resuscitation from
bystanders, 18% received conventional CPR with both cardiac compression and
mouth-to-mouth ventilation, and 72% received no bystander CPR.
Results showed
that any resuscitation attempt was associated with a higher likelihood of
having favorable neurologic outcomes at 30 days than no resuscitation.
Neurologic Outcome |
Any Resuscitation
Technique |
No Bystander
Resuscitation |
P |
Favorable outcome |
5.0% |
2.2% |
< .0001 |
Source. Lancet.
2007;369:882-884, 920-926.
Although
favorable neurologic outcomes did not differ between the cardiac-only
resuscitation group and the conventional CPR group for the whole cohort (P
= .1459), cardiac-only resuscitation resulted in a higher proportion of
patients with favorable neurologic outcomes than conventional CPR in the
subgroups of patients with apnea (about 90% of patients in this study),
ventricular fibrillation, or tachycardia as initial cardiac rhythm, and in
those in whom resuscitation was started within 4 minutes of collapse. Furthermore,
there was no evidence for any benefit from the addition of mouth-to-mouth
ventilation in any subgroup of patients.
Patients |
Cardiac-Only
Resuscitation |
Conventional CPR |
P |
Patients with apnea |
6.2% |
3.1% |
.0195 |
Patients with a shockable rhythm |
19.4% |
11.2% |
.041 |
Patients in whom resuscitation started within 4 minutes |
10.1% |
5.1% |
.0221 |
Source: Lancet.
2007;369:882-884, 920-926.
The authors
suggest several reasons for their results. They cite previous studies that have
suggested that ventilation is not essential during the initial 12 minutes of
resuscitation, and note that time spent on mouth-to-mouth ventilation takes
precious time away from chest compressions that support cerebral and coronary
perfusion.
In the
editorial, Gordon Ewy, MD, from the University of Arizona
College of Medicine in
Dr. Ewy says a
major flaw with the current, and all previous, guidelines for cardiac arrest is
that they recommend the same approach of CPR for 2 entirely different clinical
conditions: primary cardiac arrest where the arterial blood is well oxygenated
at the time of the cardiac arrest and respiratory arrest when the arterial blood
is so severely desaturated that it contributes to hypotension and secondary
cardiac arrest.
"We should
continue, for now, to follow the newer guidelines of assisted ventilations and
chest compressions for respiratory arrest (such as in drowning or drug
overdose), but the guidelines should promptly be changed to chest-compression
alone for witnessed unexpected sudden collapse (a condition that is, in all
probability, cardiac arrest)," he concludes.
Lancet. 2007;369:882-884, 920-926.
The complete
contents of Heartwire, a professional news
service of WebMD, can be found at www.theheart.org, a Web
site for cardiovascular healthcare professionals.
Clinical
Context
CPR consisting
of chest compression plus mouth-to-mouth ventilation is a major element in the
chain of survival for people with cardiac arrest. However, although bystander
CPR improves the likelihood of survival, it is attempted in less than one third
of patients who collapse, partly due to the reluctance of bystanders to
undertake mouth-to-mouth ventilation. In CPR guidelines, according to the
current authors, cardiac-only resuscitation by bystanders is recommended in
dispatch-assisted resuscitation or if a rescuer is unwilling or unable to do
mouth-to-mouth ventilation, but this technique is not generally known or taught
to the public. One study has shown that cardiac-only resuscitation results in
better survival without neurologic impairment.
This is a
prospective, multicenter, observational study of bystander cardiac-only
compared with conventional CPR and no resuscitation in patients who experienced
out-of-hospital cardiac arrest.
Study
Highlights
Pearls for
Practice