Electrical Therapies in CPR discusses defibrillation and cardioversion as electrical therapies used in emergency situations. Defibrillation involves delivering an electrical shock to the heart to convert ventricular fibrillation or ventricular tachycardia back to normal rhythm, while cardioversion is used to convert abnormal rhythms like atrial fibrillation back to normal sinus rhythm. Biphasic waveforms are now most commonly used because they require less energy than monophasic waveforms. Proper electrode placement on the chest is important for effective defibrillation. Potential complications include skin burns, muscle injuries, or myocardial injuries from high-energy shocks. Immediate CPR and defibrillation within 3 minutes of ventricular fibrillation

1. Electrical Therapies in CPR
By : Mohammed suleiman al-jajeh
Phase V 20133422
NEAR EAST UNIVERSITY
HOSPITAL
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2. Contents :
 Definition
 Indications & contraindications
 Defibrillation Waveforms and Energy Levels
 Electrode Placement
 Procedure of Electrical defibrillation
 Complication of defibrillation
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3. Definition :
 The most common electrical therapy in ER is
Defibrillation.
 Defibrillator is a device used to shock the heart
back into action when it stops contracting due
to a disorder of the rhythm as ventricular
fibrillation (VF). The electrodes used to deliver
the shock could be either defibrillator paddles
or patches, directly applied to the chest below
the left clavicle and at the apex of the heart.
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4. Other type of electrical therapy :
Cardioversion
 is a corrective
procedure where an
electrical shock is
delivered to the
heart to convert or
change abnormal
heart rhythm back to
normal sinus rhythm .
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5. electrical cardioversion Indications :
 Supraventricular tachycardia
 Atrial fibrillation
 Atrial tachycardia
 Monomorphic VT with pulses
 Reentrant tachycardia with narrow or wide QRS
complex (ventricular rate >150 bpm) who is
unstable (eg. ischemic chest pain, acute
pulmonary edema, hypotension, acute altered
mental status, signs of shock )
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6. Defibrillator INDICATIONS :
 ventricular arrhythmia (ventricular tachycardia
or ventricular fibrillation)
 cardiac arrest (unresponsive patient without a
pulse)
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7. Defibrillator Contraindications :
 The main contraindication is in a patient who
has made it clear that he does not wish to be
resuscitated (awake patients) .
 Defibrillation should not be used for
arrhythmias other than ventricular tachycardia
or ventricular fibrillation.
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8. Shock First vs. CPR First ?
 start CPR and use the AED as soon as possible
 So the time from VF to defibrillation should be
under 3 minutes.
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9. Defibrillation Waveforms :
① Monophasic Waveform Defibrillators
② Biphasic Waveform Defibrillators
from one electrode to the other
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10. Energy Levels :
 Biphasic shocks are more effective than
monophasic shocks and need lesser energy.
Typically when 360 Joules are delivered for
monophasic defibrillator, 200 Joules are given in a
biphasic defibrillator. This could reduce the potential
damage to the heart muscle.
 For pediatric patients, it is acceptable to use an
initial dose of 2 to 4 J/kg. not to exceed 10 J/kg or
the adult maximum dose
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11. Biphasic wave forms were initially
developed for use in implantable
cardioverter-defibrillator (ICD) and
later adapted to external
defibrillators.
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12. Electrode Placement :
Antero-apical position:
one paddle is placed to the right
of the sternum just below the
clavicle. Another paddle is
placed to the normal cardiac
apex .
Antero-posterior position:
the anterior paddle placed over
the apex, and the posterior
paddle on the back in the left or
right infrascapular region. Proper position of the paddles
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13. Procedure of Electrical defibrillation :
(1) perform CPR untill the equipment arrive.
(2) Assess the patient’s pulse and ECG.
(3) Seletion of proper energy level
(4) Apply electrode gel between paddles and skin
(5) Proper position of the paddles
(6) Clear the area. no contact with anyone other
than the victim.
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14. Cont.
(7) Recheck the ECG
(8) Activate the firing button.
(9) If no skeletal muscle spasm has
occurred ，you should check the
equipment，contacts，and synchronizer
switch.
(10) The rhythm should be assessed after
each countershock and the patient should
be checked for a pulse at appropriate time.
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15. Recommendation :
 For defibrillation when using
biphasic defibrillators, self-
adhesive defibrillation pads
are safe and effective and
offer advantages (eg.
facilitating pacing, charging
during compressions, safety
[including removing risk of
fires]) over defibrillation
paddles
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16. Complication of defibrillation :
 Skin burns(common)
 Skeletal muscle injury or thoracic vertebral fractures
(uncommon)
 Myocadial injury and post-defibrillation dysrhythmias
(high-energy shocks)
 The rescuer can receive electrical injures (due to
electrical contact with the patients during
defibrillation )
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17. FAILURE OF DEFIBRILLATION :
 If the attempt at defibrillation is unsuccessful:
Start CPR with oxygen.
Check paddle or electrode position.
Check that there is adequate skin contact. (Clipping or
shaving of body hair under the defibrillator paddle/pad
may be required).
Consider changing the defibrillator pads.
 If several shocks fail to stop VF , optimal chest
compression, oxygen , intermittent positive-pressure
ventilation and epinephrine should be given in this
sequence.
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18. Be carful :
AVOID charging the paddles unless they are placed on
the victim’s chest
AVOID placing the defibrillator paddles/pads over ECG
electrodes (risk of burns or sparks) or an implanted device
(e.g. a pacemaker)
AVOID having, or allowing any person to have, any
direct or indirect contact with the victim during defibrillation
AVOID allowing oxygen from a resuscitator to flow onto
the victim’s chest during delivery of the shock when using
paddles (risk of fire).
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19. References :
 Highlights of the 2010 American Heart Association
Guidelines for CPR and EC
 2010 American Heart Association Guidelines for
Cardiopulmonary Resuscitation and Emergency
Cardiovascular Care
 AUSTRALIAN RESUSCITATION COUNCIL
 www.mayoclinic.org
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20. Thank you for listening
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