Cardiopulmonary
resuscitation, commonly known as CPR, is an emergency procedure performed
in an effort to manually preserve intact brain function until further measures
are taken to restore spontaneous blood circulation and breathing in a person
who is in cardiac arrest. It is indicated in those who are
unresponsive with no breathing or abnormal breathing, for example, agonal
respirations.
According to
the International Liaison Committee on Resuscitation guidelines, CPR
involves chest compressions at least 5 cm (2 in) deep and at a rate
of at least 100 per minute in an effort to create artificial circulation by
manually pumping blood through the heart and thus the body. The rescuer may
also provide breaths by either exhaling into the subject's mouth or nose or
using a device that pushes air into the subject's lungs. This process of
externally providing ventilation is termed artificial respiration. Current
recommendations place emphasis on high-quality chest compressions over
artificial respiration; a simplified CPR method involving chest compressions
only is recommended for untrained rescuers.
CPR alone is
unlikely to restart the heart. Its main purpose is to restore partial flow of
oxygenated blood to the brain and heart. The objective is to
delay tissue death and to extend the brief window of opportunity for
a successful resuscitation without permanent brain damage. Administration
of an electric shock to the subject's heart, termed defibrillation, is usually
needed in order to restore a viable or "perfusing" heart rhythm.
Defibrillation is effective only for certain heart rhythms, namely ventricular
fibrillation or pulseless ventricular tachycardia, rather than asystole or pulseless
electrical activity. CPR may succeed in inducing a heart rhythm that may be
shockable. In general, CPR is continued until the patient has a return of
spontaneous circulation (ROSC) or is declared dead.
Before you begin
Before starting CPR, check:
v Is the person conscious or
unconscious?
v If the person appears unconscious,
tap or shake his or her shoulder and ask loudly, "Are you OK?"
v If the person doesn't respond and two
people are available, one should call 911 or the local emergency number and one
should begin CPR. If you are alone and have immediate access to a telephone,
call 911 before beginning CPR — unless you think the person has become unresponsive
because of suffocation (such as from drowning). In this special case, begin CPR
for one minute and then call 911 or the local emergency number.
v If an AED is immediately available,
deliver one shock if instructed by the device, then begin CPR.
Remember to spell C-A-B
The American Heart Association uses
the acronym of CAB — compressions, airway, breathing — to help people remember
the order to perform the steps of CPR.
Compressions:
Restore blood circulation
a. Put the person on his or her back on
a firm surface.
b. Kneel next to the person's neck and
shoulders.
c. Place the heel of one hand over the
center of the person's chest, between the nipples. Place your other hand on top
of the first hand. Keep your elbows straight and position your shoulders directly
above your hands.
d. Use your upper body weight (not just
your arms) as you push straight down on (compress) the chest at least 2 inches
(approximately 5 centimeters). Push hard at a rate of about 100 compressions a
minute.
e. If you haven't been trained in CPR,
continue chest compressions until there are signs of movement or until
emergency medical personnel take over. If you have been trained in CPR, go on
to checking the airway and rescue breathing.
Airway:
Clear the airway
I.
If
you're trained in CPR and you've performed 30 chest compressions, open the
person's airway using the head-tilt, chin-lift maneuver. Put your palm on the
person's forehead and gently tilt the head back. Then with the other hand,
gently lift the chin forward to open the airway.
II.
Check
for normal breathing, taking no more than five or 10 seconds. Look for chest
motion, listen for normal breath sounds, and feel for the person's breath on
your cheek and ear. Gasping is not considered to be normal breathing. If the
person isn't breathing normally and you are trained in CPR, begin
mouth-to-mouth breathing. If you believe the person is unconscious from a heart
attack and you haven't been trained in emergency procedures, skip
mouth-to-mouth breathing and continue chest compressions.
Breathing:
Breathe for the person
Rescue
breathing can be mouth-to-mouth breathing or mouth-to-nose breathing if the
mouth is seriously injured or can't be opened.
a) With the airway open (using the
head-tilt, chin-lift maneuver), pinch the nostrils shut for mouth-to-mouth
breathing and cover the person's mouth with yours, making a seal.
b) Prepare to give two rescue breaths.
Give the first rescue breath — lasting one second — and watch to see if the
chest rises. If it does rise, give the second breath. If the chest doesn't
rise, repeat the head-tilt, chin-lift maneuver and then give the second breath.
Thirty chest compressions followed by two rescue breaths is considered one
cycle.
c) Resume chest compressions to restore
circulation.
d) If the person has not begun moving after
five cycles (about two minutes) and an automated external defibrillator (AED)
is available, apply it and follow the prompts. Administer one shock, then
resume CPR — starting with chest compressions — for two more minutes before
administering a second shock. If an AED
isn't available, go to step 5 below.
e) Continue CPR until there are signs of
movement or emergency medical personnel take over.
