Defibrillation uses electrical shocks to restore a normal heart rhythm. It is used for ventricular fibrillation and asystole. Biphasic defibrillators are preferred over monophasic as they cause less damage and have higher success rates. Defibrillators include automated external defibrillators for public use, semi-automated defibrillators for paramedics, and implantable defibrillators. Adhesive patches are now commonly used instead of paddles. Defibrillation procedures involve assessing rhythm, applying pads or paddles, delivering shock, and resuming CPR if needed. Causes of failure include patient condition, prolonged arrest, inadequate CPR, and technical issues.

2. DEFINITION
Defibrillation involves delivering a
high intensity electrical charge inorder
to depolarize the entire myocardium at
one time so that the fastest normal
pacemaker can regain control of the
pacing function of the heart.

3. INDICATION
•Ventricular fibrillation
•Asystole

4. DIFFERENCES BETWEEN MONOPHASIC AND BIPHASIC
SYSTEMS
•In monophasic systems, the current travels only in one direction -
from one paddle to the other.
•In biphasic systems, the current travels towards the positive
paddle and then reverse and go back; this occurs several times.
•Biphasic shocks deliver one cycle every 10 milliseconds.
•They are associated with fewer burns and less myocardial
damage.
•With monophasic shocks, the rate of first shock success in
cardiac arrests due to a shockable rhythm is only 60%, whereas
with biphasic shocks, this increases to 90%.
However, this efficacy of biphasic defibrillators over monophasic
defibrillators has not been consistently reported.

5. TYPES OF
DEFIBRILLATORS

6. Automated external defibrillators (AEDs):
•These are useful, as their use does not require
special medical training.
•They are found in public places - e.g., offices,
airports, train stations, shopping centers.
•They analyze the heart rhythm and then charge
and deliver a shock if appropriate.
•However, they cannot be overridden manually
and can take 10-20 seconds to determine
arrhythmias.

7. Semi-automated AEDs:
•These are similar to AEDs but can be overridden
and usually have an ECG display.
•They tend to be used by paramedics.
•They also have the ability to pace.

8. Standard defibrillators with monitor- may be
monophasic or biphasic.

9. Transvenousor implanted.
•An implantable cardioverter-defibrillator (ICD) is a device
combining a cardioverter and a defibrillator into one
implantable unit.
•It is thus a small battery-powered electrical impulse
generator that is implanted in patients who are at risk of
sudden cardiac death due to ventricular fibrillation and
ventricular tachycardia.
•The device is programmed to detect cardiac arrhythmia and
correct it by delivering a brief electrical impulse to the heart.
•In current variants, the ability to revert ventricular fibrillation
has been extended to include both atrial and ventricular
arrhythmias.
•There also exists the ability to perform biventricular pacing
in patients with congestive heart failure or bradycardia.
•The process of implantation of an ICD is similar to
implantation of a pacemaker.

10. PADDLES VERSUS ADHESIVE PATCHES
•Paddles were originally used but their use is being
superseded by adhesive patches.
•Adhesive patches are placed most commonly anterio-
apically - the anterior patch goes under the right clavicle
and the apical patch is placed at the apex.
•Adhesive electrodes are better, as they stick to the
chest wall, so there is no mess with gels.
•Paddles require at least 25 lbs of pressure, which is not
needed with adhesive electrodes.
•Adhesive electrodes also allow good ECG trace without
interference.
•They are also safer, as no operator required - although,
before discharging a shock, it is important to ensure
everyone is clear of the patient.

11. ENERGY LEVELS FOR DEFIBRILLATION
Monophasic - the cardiopulmonary resuscitation (CPR)
algorithm recommends single shocks started at and
repeated at 360 J.
Biphasic - the CPR algorithm recommends shocks
initially of 150-200 J and subsequent shocks of 150-360
J.
The Biphasic Trial in 2007 compared lower fixed (150,
150, 150 J) and gradually increasing energy (200, 300,
360 J) shocks for out-of-hospital cardiac arrests.
Escalating energy shocks were associated with more
frequent conversion and termination of VF as opposed
to low-level fixed shocks. This applied to patients who
remained in VF after the first shock.

12. PARTS OF DEFIBRILLATOR
•Machine
•Paddles- adult &pediatric
•ECG printout
•Alarm knobe for selecting energy
•Synchronizer

13. PROCEDURE
•It is an emergency procedure. The main principle is to
ACT QUICKLY. The steps of procedure involves
•Bring defibrillator to bedside
•Confirm diagnosis by palpating carotid pulse, or
analyzing the ECG
•Turn on the defibrillator
•Squeeze generous amount of jelly on to defibrillator
paddles, coat entire surface of the paddles with jelly by
rubbing paddles together, remove the excess jelly if it
spreads to the sides.

14. PROCEDURE
•Select the correct electrical charge on the defibrillator.
The average charge for an adult is 200 to 300 joules or
watt per second.
•Press the charge button to charge the capacitor. When
the intensity meter displays the required energy level.
Place the paddles on the patient’s chest. Put one paddle
to the right of the sternum between the second and third
intercostal space and the other at the fifth intercostal
space on the left side of the chest near the apex of the
heart.
•Make sure the paddles touch flat against the patient’s
body. If not it may cause burns in the patient
•Before delivering shock, tell everyone to stand clear off
the patient and his bed. If the patient is getting oxygen, it
should be turned off.

15. PROCEDURE
•Operator should not stand on wet floornor leaning
against the bed of the patient.
•Discharge the energy by pressing the discharge buttons
on the paddles simultaneously.
•Examine the ECG strip to see whether defibrillation has
altered arrhythmia and restored normal rhythm.
•Ask co-worker to start CPR. If desired rhythm not
restored, defibrillation is repeated with a higher energy
level.
•If the defibrillation is unnecessary, discharge the
machine by turning it off.Once the machine is
discharged, clean the paddles with soap and water,
making sure to remove all conductive jelly. Any jelly that
remains on the paddles will corrode the metal paddles.

16. CAUSES OF FAILURE OF DEFIBRILLATION
•Poor patient condition
Valvular diseases
Massive myocardial infarction
Cardiomegaly
Myocardial rupture and cardiac tamponade
Pulmonary embolism or infarction
Respiratory disease or trauma
•Prolonged cardiac arrest

17. •Inadequate cardio-respiratory resuscitative measures
Hypoxia in the patient
Acidosis
Alkalosis
Electrolyte imbalance
•Drug toxicity
•Inadequate sympathetic tone
•Inadequate electrical current delivered to the heart
Defective equipment
Poor paddle position
Excessive conductive jelly between paddles
Barrel shaped chest of the victim
•Inexperienced operator

18. COMPLICATIONS
•Damage to myocardium due to repeated
high energy electrical shocks
•Chest burns due to repeated high-energy
discharges and poor contract between the
paddles and the skin
•Electrocution of the by-standers
•Formation of short circuits between
paddles due to excessive amount of
conduction jelly applied on the paddles. This
causes loss of electrical energy.

19. NURSING IMPLICATIONS
•As defibrillation is an emergency procedure, the
equipment should be ready at all times.
•It should be kept functioning all the time, and
should be checked before each shift.
•Each staff should be aware of its functioning
•The defibrillator should be tested daily for its
proper functioning. To test the defibrillator, follow
the steps as described below
•Set the defibrillator at 300 joules
•Depress the charge button on the defibrillator
until the display number matches the joules
setting

20. •Leave the paddles in their resting place on the
defibrillator and simultaneously press the
discharge buttons on both paddles
•When someone is getting ready for defibrillation,
the co-worker should begin with basic life
support.
•Patient should be continuously monitored after
defibrillation. He should never be left alone for the
first 24hr. vital signs are to be recorded very
frequently until they are stabilized. Oxygen should
be continuously given to the patient. Drugs
should be administered as ordered. Intake and
output chart to be maintained.

21. THANK YOU