4. Defibrillation
1. Defibrillation is an asynchronous countershock used
to terminate pulseless ventricular tachycardia (VT) or
VF.
2. Three rapid consecutive shocks are delivered, with the
first at an energy of 200 J.
3. If unsuccessful, the shock is repeated at 200 to 300 J.
4. The third and subsequent shocks will be 360 J. Before
defibrillating a client be sure that the
oxygen is shut off to avoid the hazard of fire and be sure
that no one is touching the bed or the client.
5. Use of paddle electrodes
1. Apply conductive pads.
2. One paddle is placed at the third intercostals space to
the right of the sternum; the other is placed at the fifth
intercostal space on the left midaxillary line.
3. Apply firm pressure of at least 25 lb to each of the
paddles.
4. Be sure that no one is touching the bed or the client
when delivering the countershock.
6.
7. Cardioversion
Description
a. Cardioversion is synchronized countershock to convert
an undesirable rhythm to a stable rhythm.
b. Cardioversion can be an elective procedure performed by
the physician for stable tachydysrhythmias resistant to
medical therapies or an emergent procedure for
hemodynamically unstable ventricular or supraventricular
tachydysrhythmias.
c. A lower amount of energy is used than with defibrillation.
d. The defibrillator is synchronized to the client’s R wave to
avoid discharging the shock during the vulnerable period
(T wave).
e. If the defibrillator were not synchronized, it could
discharge on the T wave and cause VF.
8. 2. Preprocedure interventions
a. Obtain an informed consent if an elective procedure.
b. Administer sedation as prescribed.
c. If an elective procedure, hold digoxin (Lanoxin) 48
hours preprocedure as prescribed to prevent
postcardioversion ventricular irritability.
d. If an elective procedure for atrial fibrillation or atrial
flutter, the client should receive anticoagulant therapy
for 4 to 6 weeks preprocedure.
9. 3. During the procedure
a. Ensure that the skin is clean and dry in the area where
the electrode paddles will be placed.
b. Stop the oxygen during the procedure to avoid the
hazard of fire.
c. Be sure that no one is touching the bed or the client
when delivering the countershock.
10. 4. Postprocedure interventions
a. Priority assessment includes ability of the client to
maintain the airway and breathing.
b. Resume oxygen administration as prescribed.
c. Assess vital signs.
d. Assess level of consciousness.
e. Monitor cardiac rhythm.
f. Monitor for indications of successful response, such
as conversion to sinus rhythm, strong peripheral
pulses, an adequate BP, and adequate urine output.
g. Assess the skin on the chest for evidence of burns
from the edges of the paddles.
11. Automatic external defibrillator
• An automatic external defibrillator is used by
laypersons and emergency medical technicians
• for prehospital cardiac arrest.
• Place the client on a firm dry surface.
• Ensure that no one is touching the client to avoid
motion artifact during rhythm analysis.
• Place the electrode patches in the correct position on
the client’s chest.
• Press the analyzer button to identify the
rhythm,which may take 30 seconds; the machine will
13. • advise whether a shock is necessary.
• Shocks are recommended for pulseless VT or VF
only.
• If shock is recommended, the shock initially is
delivered at an energy of 200 J.
• If unsuccessful, the shock is repeated at 200 to 300 J.
• The third and subsequent shock will be 360 J.
• If unsuccessful, CPR is continued for 1 minute and
then another series of three shocks is delivered, each
at 360 J.
14. Implantable cardioverter-defibrillator (ICD)
1. Description
a. An ICD monitors cardiac rhythm and detects and terminates
episodes of VT and VF.
b. The ICD senses VT or VF and delivers 25 to 30 J up to four
times, if necessary.
c. An ICD is used in clients with episodes of spontaneous
sustained VT or VF unrelated
to an MI or in clients whose medication therapy has been
unsuccessful in controlling life threatening dysrhythmias.
d. Transvenous electrode leads are placed in the right atrium and
ventricle in contact with the endocardium; leads are used for
sensing, pacing, and delivery of cardioversion or defibrillation.
e. The generator is most commonly implanted in the left pectoral
region.
16. 2. Client education
a. Instruct the client in the basic functions of the ICD.
b. Knowthe rate cutoff of the ICD and the number of consecutive
shocks that it will deliver.
c. Wear loose-fitting clothing over the ICD generator site.
d. Avoid contact sports to prevent trauma to the ICD generator and lead
wires.
e. Report any fever, redness, swelling, or drainage from the insertion
site.
f. Report symptoms of fainting, nausea, weakness, blackouts, and rapid
pulse rates to the physician.
g. During shock discharge, the client may feel faint or short of breath.
h. Instruct the client to sit or lie down if he or she feels a shock and to
notify the physician.
i. Advise the client to maintain a log of the date, time, and activity
preceding the shock, the symptoms preceding the shock, and
postshock sensations.
17. j. Instruct the client and family in how to access emergency
medical system.
k. Encourage the family to learn CPR.
l. Instruct the client to avoid electromagnetic fields directly
over the ICD because they can inactivate the device.
m. Instruct the client to move away from the magnetic field
immediately if beeping tones are heard, and to notify the
physician.
n. Keep an ICD identification card in the wallet and obtain and
wear a Medic-Alert bracelet.
o. Inform all health care providers that an ICD has been
inserted; certain diagnostic tests, such as an MRI, and
procedures using diathermy or electrocautery interfere with
ICD function.
p. Advise the client of restrictions on activities such as driving
and operating dangerous equipment.
