This document discusses defibrillation, which is a treatment used to restore normal heart rhythm in patients experiencing ventricular fibrillation or pulseless ventricular tachycardia. It defines defibrillation and describes the different types of defibrillators, including manual external defibrillators, automated external defibrillators, implantable cardioverter defibrillators, and wearable cardiac defibrillators. It also covers how defibrillation works, the precautions that must be taken with the procedure, and the risks involved.
4. To eradicate life-threatening ventricular
fibrillation or pulseless ventricular
tachycardia.
To restore cardiac output lost due to
dysrhythmias and reestablish tissue
perfusion and oxygenation.
5. The exact mechanism of defibrillation is not well
understood.
One theory is that successful defibrillation affects a
critical mass of the heart, resulting in insufficient
remaining heart muscle to continue the
arrhythmia.
Recent mathematical models of defibrillation are
providing new insight into how cardiac tissue
responds to a strong electrical shock.
Fibrillations cause the heart to stop pumping blood,
leading to brain damage.
Defibrillators deliver a brief electric shock to the
heart, which enables the heart's natural
pacemaker to regain control and establish a
normal heart rhythm.
9. 1. Manual external defibrillator:-
These defibrillators require more experience
and training to effectively handle them. Hence,
they are only common in hospitals and a few
ambulances where capable hands are present.
In conjunction with an ECG, the trained provider
determines the cardiac rhythm and then
manually determines the voltage and timing of
the shock—through external paddles—to the
patient’s chest.
10. 2. Manual internal defibrillator:-The manual
internal defibrillators use internal paddles to
send the electric shock directly to the heart. They
are used on open chests, so they are only
common in the operating room. It was invented
after 1959.
3. Automated external defibrillator:-These are
defibrillators that use computer technology,
thereby making it easy to analyze the heart’s
rhythm and effectively determine if the rhythm is
shockable. They can be found in medical
facilities, government offices, airports, hotels,
sports stadiums, and schools.
11. 4. Implantable cardioverter defibrillator:-Another
name for this is automatic internal cardiac
defibrillator (AICD). They constantly monitor the
patient’s heart, similar to a pacemaker, and can
detect ventricular fibrillation, ventricular tachycardia,
supraventricular tachycardia, and atrial fibrillation.
When an abnormal rhythm is detected, the device
automatically determines the voltage of the shock to
restore cardiac function.
5. Wearable cardiac defibrillator:-is a portable
external defibrillator generally indicated for
patients who are not in an immediate need for an
AICD. This device is capable of monitoring the patient
24-hours-a-day. It is only functional when it is worn
and sends a shock to the heart whenever it is
needed.
12. Resuscitation electrodes are placed according to
one of two schemes. The anterior-posterior scheme
is the preferred scheme for long-term electrode
placement. One electrode is placed over the left
precordium (the lower part of the chest, in front of
the heart). The other electrode is placed on the
back, behind the heart in the region between the
scapula. This placement is preferred because it is
best for non-invasive pacing.
The anterior-apex scheme can be used when the
anterior-posterior scheme is inconvenient or
unnecessary. In this scheme, the anterior electrode
is placed on the right, below the clavicle. The apex
electrode is applied to the left side of the patient,
just below and to the left of the pectoral muscle.
This scheme works well for defibrillation and
cardio version, as well as for monitoring an ECG.
13.
14. Precautions:-
1. should not be performed on a patient who has a pulse or is alert, as this could
cause a lethal heart rhythm disturbance or cardiac arrest.
2. paddles used in the procedure should not be placed on a woman's breasts or
over an internal pacemaker.
3. During external defibrillation, the paddles are placed on the patient's chest with a
conducting gel ensuring good contact with the skin.
4. Direct contact with the patient is discontinued by all caregivers.
5. The patient's pulse and/or electrocardiogram are continually monitored when
defibrillation is not in progress.
6. Defibrillation continues until the patient's condition stabilizes or the procedure is
ordered to be discontinued.
7. Medications to treat possible causes of the abnormal heart rhythm may be
administered.
15. patient is found in cardiac distress, without a pulse
and non-responsive, and help is summoned,
cardiopulmonary resuscitation is begun and
continued until the caregivers arrive and are able
to provide defibrillation. Electrocardiogram leads
are attached to the patient chest. Gel or paste is
applied to the defibrillator paddles, or two gel
pads are placed on the patient's chest. The
caregivers verify lack of a pulse while visualizing
the electrocardiogram, assure contact with the
patient is discontinued, and deliver the electrical
charge.
16. 1. Vital signs are monitored with a cardiac monitor
2. 12 lead electrocardiogram,
3. A chest x-ray
4. Cardiac catheterization
Risks:-
1. Skin burns from the defibrillator paddles.
2. injury to the heart muscle
3. abnormal heart rhythms
4. blood clots.