Brief overview
- What is a defibrillator? A device that emits electric shocks via electrodes to restore a disturbed heart rhythm (e.g. ventricular fibrillation) to its natural rhythm.
- How to use the defibrillator: Attach the electrodes according to the instructions, then follow the (voice) instructions on the device.
- In which cases? The AED should always be connected if a person suddenly becomes unresponsive and is no longer breathing normally. The device then decides whether a shock is required.
- Risks: Danger to first aiders and victims due to current flow in combination with (a lot of) water. Singeing of the chest hair if it is very thick.
Caution!
- During defibrillation, follow the voice instructions or written/graphic instructions of the device (AED) exactly. Then you can do nothing wrong, even as a layperson.
- If there is a second first aider next to you, one will fetch the defibrillator and the other will begin manual resuscitation. If you are alone, you must start chest compressions immediately. If someone else joins you, ask them to look for a defibrillator.
- Do not use the defibrillator in water or standing in a puddle.
- Do not touch the patient while the device is analyzing the patient’s heart rhythm or delivering electrical shocks. The device will prompt you accordingly.
Legally, nothing can happen to a layperson who uses a publicly accessible defibrillator for first aid. According to §34 of the German Criminal Code, this action falls within the scope of “justifiable emergency” and is carried out with the presumed consent of the person concerned.
How does a defibrillator work?
You can see them in companies, public buildings and subway stations: small defibrillator cases on the wall. They are identified by a green sign with a heart on which a green lightning bolt is flashing.
These automated external defibrillators (AED) are somewhat reminiscent of a first aid kit with two cables, each with an electrode pad the size of a postcard at the end. These electrodes are attached to the chest if the heart starts to beat dangerously out of rhythm. The device then emits small electric shocks via the electrodes to bring the heart back into its natural beating rhythm.
Fully and semi-automatic defibrillators
There are fully and semi-automatic defibrillators. The former deliver the shock automatically. Semi-automatic devices, on the other hand, require the first aider to trigger the pulse manually by pressing a button.
An AED (“layman’s defibrillator”) is designed so that it can also be used safely and purposefully by laypersons: Illustrations on the electrode pads show how and where to apply the pads. The device uses a voice function to announce the next steps and their sequence. Depending on the model, there is also illustration-based guidance via a screen or drawings.
Specifically, you proceed as follows during defibrillation:
- Expose the patient’s upper body: a defibrillator can only be used on bare skin. The skin should be dry and free of hair. This is necessary so that the defibrillator can work efficiently and the patient is not burned by any sparks. Therefore, dry the skin on the upper body if necessary and shave if there is a lot of hair on the chest. A razor is usually included in the emergency kit for this purpose. Shave as quickly as possible! Also remove plasters and jewelry from the adhesive area.
- Attach the electrode pads: Follow the instructions – one electrode is placed on the left side a hand’s width below the left armpit, the other on the right side below the collarbone and above the nipple. If a second person has performed chest compressions, interrupt them now.
- Then follow the instructions that the device gives you: If it is a semi-automatic AED, it will ask you to press the so-called shock button in the event of ventricular fibrillation/ventricular flutter. This triggers an electric shock. You can recognize the button by the flash symbol. Caution: During the shock, neither you nor anyone else may touch the patient!
- Continue to follow the defibrillator’s instructions: for example, it may now ask you to resume the chest compressions that were performed before the defibrillation.
- After about two minutes, the AED will respond again to carry out a further analysis. Follow the device’s instructions even then.
Carry out the resuscitation until the emergency services arrive and take over the treatment or until the victim wakes up and is breathing normally. Leave the electrodes attached to the chest.
Many AEDs come with the necessary accessories such as a razor, disposable gloves, clothes scissors and possibly a ventilation foil for mouth-to-mouth resuscitation and cleaning cloths, a small towel, a washcloth or handkerchiefs.
Defibrillator: Special features for use on children
Other defibrillators recognize themselves whether it is a child, for example when the enclosed smaller pads are applied. They then automatically regulate the defibrillation energy downwards.
Circulatory arrest in children is very rare. In an emergency, it is better to use the adult defibrillator than to miss the chance to save the child’s life.
When do I use a defibrillator?
An automated external defibrillator (AED) is used when an unconscious person needs to be resuscitated. The defibrillator automatically analyzes whether an electric shock is appropriate at all. There are two types of heart rhythms:
- Defibrillable rhythm: Here the heart muscle still has its own cardiac activity, i.e. it has its own electrical activity. However, this is out of rhythm as much as possible. These include the cardiac arrhythmias ventricular fibrillation, ventricular flutter and pulseless ventricular tachycardia/pVT. They can be corrected by defibrillation. The device would trigger an electric shock (fully automatic defibrillator) or prompt the first aider to press the corresponding button (semi-automatic defibrillator).
Defibrillation as part of resuscitation
The use of a defibrillator is one of the basic measures of resuscitation (basic life support, bls).
A mnemonic for the sequence of resuscitation is: check – call – press. Check consciousness and breathing, then call the emergency doctor and start chest compressions.
You can tell whether you need to initiate resuscitation measures on a person found unconscious by the following steps:
- Test the person’s reaction: speak to them loudly and gently shake their shoulders. If you are alone, it is best to call for help now, especially if the person does not respond.
- Check the person’s breathing: To do this, tilt the patient’s head back slightly and lift their chin. See if there are any foreign objects in the mouth and throat that you can remove. Then the credo “Hear, see, feel!” applies: Hold your ear close to the unconscious person’s mouth and nose – looking towards the chest. Check whether you can hear breathing noises, feel a breath of air and whether the patient’s chest rises and falls. If the victim is breathing on their own, place them in the recovery position.
- Call the emergency services or ask another person present to do so.
- Start chest compressions immediately, preferably in combination with mouth-to-mouth resuscitation (if you or a bystander feel confident to do so). The 30:2 rule applies, i.e. 30 chest compressions and 2 rescue breaths in alternation. You start with chest compressions as there is usually still enough oxygen in the patient.
- If another first aider is present, they should fetch a defibrillator in the meantime (if one is available). Use the device as described above.
- All these measures should ensure that blood continues to flow to the patient’s brain and heart until the emergency services arrive.
Start resuscitation as soon as possible – even a few minutes without oxygen can result in irreparable brain damage or death of the patient!
Defibrillator for home use – useful or unnecessary?
According to the German Heart Foundation, there is no reliable evidence that a defibrillator at home is useful or not. However, if a home defibrillator is available, for example, someone may delay making an emergency call or neglect or delay starting manual resuscitation (chest compressions and rescue breathing).
Risks when using a defibrillator
If you stick the electrode pads directly over a pacemaker or other implanted device (often recognizable by a scar or similar in the chest area), this can impair the current pulses.
If you use the defibrillator on an unconscious person lying in water, there is a risk of electric shock! The same applies if you are standing in a puddle when using the device. On the other hand, it is not a problem to use a defibrillator in the rain or at the edge of a swimming pool.
You can also get an electric shock if you touch the patient while the device is emitting a current pulse. There is a particular risk with fully automatic defibrillators, which trigger energy pulses independently. Therefore, follow the device’s instructions exactly!
The electrodes must lie flat on the unconscious person’s bare chest. If the pads crease, the current cannot flow. The function of the defibrillator is then restricted.
Shave patients with heavy chest hair as quickly as possible. If too much time passes before the defibrillator is used, it may be too late for the patient!
