A Defibrillator: Who Can it Help?
A defibrillator can be used on the following victims: individuals experiencing sudden cardiac arrest due to specific heart rhythm abnormalities, primarily ventricular fibrillation and ventricular tachycardia with no pulse. This life-saving device delivers an electrical shock to restore a normal heart rhythm.
Understanding Defibrillation and Sudden Cardiac Arrest
Sudden cardiac arrest (SCA) is a leading cause of death worldwide. It occurs when the heart’s electrical system malfunctions, causing it to beat chaotically or stop beating altogether. Understanding when a defibrillator can be used on the following victims is crucial for saving lives.
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Ventricular Fibrillation (VF): This is a chaotic, disorganized electrical activity in the ventricles (lower chambers of the heart), preventing them from pumping blood effectively.
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Ventricular Tachycardia (VT): This is a rapid heartbeat originating in the ventricles. In some cases, VT is stable with a pulse; however, unstable VT (without a pulse) requires defibrillation.
It’s important to note that a defibrillator can be used on the following victims only if they are experiencing pulseless VF or VT. A person who is simply having a heart attack, but is conscious and has a pulse, does not need defibrillation.
How a Defibrillator Works
A defibrillator delivers a controlled electrical shock to the heart. This shock momentarily stops all electrical activity, giving the heart a chance to resume a normal rhythm.
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The Shock: The electrical shock depolarizes the heart muscle cells.
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Resumption of Rhythm: Ideally, the heart’s natural pacemaker (the sinoatrial node) will then resume its normal pacing activity, restoring a regular heartbeat.
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Automated External Defibrillators (AEDs): These devices are designed for use by laypersons. They analyze the victim’s heart rhythm and provide voice prompts to guide the user through the process.
The Importance of Early Defibrillation
The chances of survival from sudden cardiac arrest decrease by approximately 10% for every minute that passes without defibrillation. This is why rapid access to a defibrillator can be used on the following victims is vital.
- The Chain of Survival: This refers to the sequence of actions that maximize the chances of survival from SCA:
- Early Recognition of SCA
- Early CPR
- Early Defibrillation
- Early Advanced Medical Care
Who Should Not Be Defibrillated?
Understanding when a defibrillator can be used on the following victims also means knowing when not to use it.
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Individuals with a Pulse: Defibrillation should never be used on someone who has a detectable pulse.
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Individuals with Asystole (Flatline): While commonly depicted in movies, defibrillation is not effective for asystole. CPR and other advanced life support measures are needed in this situation. The AED will typically state “No shock advised” during rhythm analysis.
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Individuals with Pulseless Electrical Activity (PEA): PEA is a condition where there is electrical activity in the heart, but it’s not producing a pulse. Defibrillation is not the primary treatment for PEA.
Common Mistakes to Avoid
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Delaying Defibrillation: Hesitation can be fatal. Once an AED is available, use it as quickly as possible.
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Failing to Perform CPR: CPR should be performed before and after defibrillation. It helps circulate blood and oxygen to the vital organs.
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Ignoring Voice Prompts: AEDs provide clear and concise instructions. Follow them carefully.
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Touching the Victim During Shock Delivery: Ensure that no one, including yourself, is touching the victim when the AED delivers a shock.
| Condition | Can a Defibrillator Be Used? | Reason |
|---|---|---|
| Ventricular Fibrillation (VF) | Yes | Defibrillation is the primary treatment for VF. |
| Ventricular Tachycardia (VT) (Pulseless) | Yes | Defibrillation is the primary treatment for unstable VT (without a pulse). |
| Asystole (Flatline) | No | Defibrillation is not effective for asystole. |
| Pulseless Electrical Activity (PEA) | No | Defibrillation is not the primary treatment for PEA. |
| Normal Heart Rhythm | No | Defibrillation is harmful to a heart beating with a normal rhythm. |
Frequently Asked Questions (FAQs)
Can I use a defibrillator on a child?
Yes, automated external defibrillators (AEDs) can be used on children. Many AEDs have pediatric pads or a child mode that delivers a lower dose of electricity. If pediatric pads are not available, adult pads can be used, but they should be placed on the front and back of the child’s chest.
What if the person is wet?
It is critical to dry the person’s chest before applying the AED pads. Water can conduct electricity and create a safety hazard for both the victim and the rescuer.
What if the person has a pacemaker?
Do not place the AED pads directly over the pacemaker. Position the pads to the side of the pacemaker, ensuring that the shock will still pass through the heart.
What if the person has body hair on their chest?
Excessive body hair can interfere with the AED pads’ ability to adhere properly to the skin. If possible, quickly shave the area where the pads will be placed. Some AED kits include a razor for this purpose. If a razor is not available, press the pads firmly onto the chest.
What if the person is wearing a metal necklace or has body piercings?
Remove any metal jewelry or piercings from the chest area if possible, as they can interfere with the delivery of the electrical shock. If removal isn’t possible, reposition the pads to avoid direct contact with the metal.
How do I know if the defibrillator worked?
The AED will typically reassess the heart rhythm after delivering a shock. If the AED advises another shock, follow its instructions. If the AED advises no shock and instructs you to continue CPR, do so until emergency medical services arrive. You may observe signs of improved circulation, such as breathing or movement.
Can I use a defibrillator if I’m not a medical professional?
Absolutely. AEDs are designed for use by laypersons. The voice prompts will guide you through the entire process. Early defibrillation by a bystander significantly increases the chances of survival.
Is it dangerous to use a defibrillator?
When used correctly, AEDs are very safe. The device will not deliver a shock unless it detects a shockable rhythm. It’s important to follow the voice prompts and ensure that no one is touching the victim during shock delivery.
What happens if I accidentally shock someone who doesn’t need it?
AEDs are designed to prevent accidental shocks. They will only deliver a shock if they detect a shockable rhythm. However, it’s still crucial to confirm that the person is pulseless before using the AED.
What is the difference between a defibrillator and a pacemaker?
A defibrillator is used to correct life-threatening arrhythmias by delivering an electrical shock. A pacemaker is a small device implanted in the chest to help regulate the heart’s rhythm, usually by delivering small, regular electrical impulses.
Where can I find a defibrillator?
AEDs are becoming increasingly common in public places, such as schools, airports, shopping malls, and businesses. Look for signage indicating the location of the AED. Familiarize yourself with the location of AEDs in your community.
What training is required to use a defibrillator?
While formal training is recommended, AEDs are designed to be user-friendly and provide clear instructions. Taking a CPR and AED certification course is highly beneficial and provides hands-on practice. Several organizations, such as the American Heart Association and the American Red Cross, offer these courses.