This technical instructions paper provides new employees with a comprehensive guide to operating the ZOLL AED Plus (Automated External Defibrillator). It explains the medical rationale for defibrillation, including the two lethal heart rhythms — ventricular fibrillation and ventricular tachycardia — that the device is designed to treat. The paper walks through step-by-step operation procedures, pad placement, voice prompts, and LCD display indicators. It also covers routine maintenance, key precautions (including contraindications for pacemaker patients and children under eight), and answers frequently asked questions about safety, battery care, and what to expect during a shock.
The Automated External Defibrillator (AED) is a device designed to deliver an electrical shock to the heart in order to stop two dangerous, potentially fatal heart rhythms: ventricular fibrillation and ventricular tachycardia. These are the two most common arrhythmias — that is, irregular heartbeat patterns — associated with sudden cardiac arrest.
The heart is composed of specialized muscle cells that differ from ordinary muscle cells in one important way: they are capable of generating their own electrical impulses. These impulses are conducted throughout the heart muscle and are responsible for maintaining a regular heartbeat. Because each cell can independently generate and conduct an electrical impulse, there is a risk that one type of cell may take over and produce too many impulses — a condition known as ventricular fibrillation.
In ventricular tachycardia, the heart beats too fast. A cell or group of cells in the ventricles begins firing at a rate too rapid to effectively circulate blood. In ventricular fibrillation, a large number of pacemaker cells fire randomly and simultaneously, causing the heart to quiver rather than beat in a coordinated rhythm. Without intervention, this can result in cardiac death.
A well-timed jolt of electricity delivered through the heart muscle — powerful enough to override all of the individual or grouped cells firing irregularly — can cause the heart to pause momentarily. The heart may then resume a normal, coordinated rhythm. The AED combines a defibrillator with a built-in computer that evaluates the heart's rhythm, much like the EKG machines used by paramedics. Most modern research confirms that ventricular fibrillation and ventricular tachycardia are the leading causes of cardiac arrest, and that defibrillation administered within minutes can restore normal rhythm before hypoxia or other serious complications develop (ZOLL, 2000).
Use of the AED is indicated when a person exhibits all of the following symptoms:
If a person falls unconscious, check their pulse first by pressing two fingers along the side of their neck over the carotid artery. If no pulse is found, place your face near the person's nose and mouth to determine whether they are breathing. You may also observe the chest for any rise and fall. If the person is not breathing and has no pulse, they meet the criteria for AED use.
To check for responsiveness, place a hand on the person's shoulder, call them by name, and give a gentle shake. Ask if they are okay. If there is no response, call emergency services immediately. The AED is designed to deliver a shock only when it detects one of the two lethal rhythms described above. If you cannot feel a pulse in the carotid arteries of the neck, and there is no rise and fall of the chest, it is appropriate to proceed with the device.
Remember: The AED will only shock a patient whose electrode readings indicate one of the irregular rhythms the machine is designed to treat. If a shock is not indicated, the machine will guide you through performing CPR. It will not cause harm to a person who is not in one of the two rhythms described above.
The ZOLL AED Plus is designed to guide a lay user through the entire resuscitation process using voice commands and on-screen text prompts. Follow the steps below carefully.
1. Open the machine and turn it on. The ON/OFF button is located on the top of the unit. A light will illuminate to confirm the machine is powered on.
2. Move the patient to a safe area. Ensure the patient is away from any surfaces or devices that may conduct electricity, including metal surfaces. Do not use the machine near water. Accidental spillage could cause injury or death.
3. Clear the area of hazards. Ensure there are no flammable materials nearby, such as oxygen tanks, gasoline, or an artificially oxygenated atmosphere (ZOLL, 2000).
4. Turn off nearby electronic devices. Turn off any cell phones or high-powered radio equipment near the AED, as these may interfere with the machine's ability to accurately analyze the patient's heart rhythm (ZOLL, 2000).
5. Prepare the patient.
6. Apply the electrode pads. A fresh pack of electrode pads is supplied in the AED kit. Ensure the pads are not expired before applying them to the patient — failure to do so may result in burns (ZOLL, 2000). Pad placement is as follows:
The machine includes a pictograph illustrating the correct pad positions.
7. Follow the machine's prompts. Once the pads are applied, the AED will automatically begin analyzing the patient's heart rhythm. The device will issue a warning before delivering a shock: "Don't Touch Patient — Press Treatment Button" (ZOLL, 2000). Press the Treatment Button when instructed to do so. The Treatment Button is located on the top of the machine and will illuminate when the AED is charged and ready to deliver a shock.
If no shock is required, the machine will display and announce: "No Shock Advised — Open Airway / Check Breathing / Check Circulation. If there is no circulation, start CPR." (ZOLL, 2000). Follow these instructions until emergency services arrive.
If the Treatment Button is pressed while it is not illuminated, the machine is not yet charged. In this case, the device will issue a voice prompt indicating how many shocks have already been delivered to the patient, if applicable (ZOLL, 2000).
The AED is designed to be a self-managing piece of emergency equipment that is straightforward enough for a layperson to operate in a crisis. When the unit is opened and powered on, it will verbally guide the user through each step while simultaneously displaying written instructions on the screen.
"Complete list of AED audio prompts"
"Self-test, LCD display, and readiness checks"
"Safety warnings, limits, and common questions"
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