CPR, or cardiopulmonary resuscitation, is an emergency skill used when a person is unresponsive and not breathing normally. It helps move oxygen-rich blood to the brain and other organs until trained medical help arrives. Learning the basics matters because quick action from a bystander can greatly improve a person’s chance of survival.
Students should always follow school safety rules, get an adult, and call emergency services right away.
Understanding Safety & Emergency Preparedness: CPR Basics
Cardiac arrest is different from a heart attack. A heart attack is a blocked blood supply to part of the heart muscle. The person may be awake and able to speak.
Cardiac arrest means the heart has stopped pumping blood effectively. It can follow a heart attack, but it can happen for other reasons, including an electric shock, severe injury, drowning, poisoning, or a heart rhythm problem.
In an arrest, every minute without effective care raises the risk of serious brain injury. This is why people nearby matter before paramedics arrive.
Chest compressions work by pressing the breastbone downward to squeeze the heart between the breastbone and spine. That pressure pushes a small amount of blood through the body. When the chest rises fully again, the heart can refill before the next press.
Good compressions need a steady rhythm, straight arms, and enough force. They are tiring, even for adults.
If another trained helper is present, switching when fatigue starts can keep the compressions effective. Practice on a training manikin helps students learn the correct body position and feel how much force is needed without hurting anyone.
Not all breathing means a person is breathing normally. A person in cardiac arrest may make occasional gasps, snorts, or irregular sounds. These are called agonal breaths.
They do not provide enough oxygen and should be treated as an emergency sign. Students should first make sure the area is safe. Traffic, fire, water, damaged electrical wires, or violence can put a helper in danger.
Getting an adult, calling local emergency services, and clearly giving the location are important jobs. In a school, one person can call for help while another finds the nearest AED and tells staff what happened.
An AED checks the heart rhythm and can advise a shock only when a shock may help. It does not shock by itself without its safety checks. The pads carry pictures that show where they go.
Everyone must stay clear while the machine analyzes the rhythm or gives a shock. Afterward, chest compressions should restart promptly if the AED instructs it. For adults and teens who suddenly collapse, hands-only CPR is often the first action taught to untrained bystanders.
Rescue breaths are especially important in some situations, such as drowning or for infants and children, but they require proper training. A certified course teaches age-specific methods, safe use of barriers, and how to stay focused in a frightening event.
Key Facts
- Check, call, compress: check for responsiveness and breathing, call emergency services, then start chest compressions if needed.
- Compression rate for adults and teens: 100 to 120 compressions per minute.
- Compression depth for adults and teens: about 5 to 6 cm, or about 2 inches.
- Hand placement: place the heel of one hand in the center of the chest, with the other hand on top.
- Allow full chest recoil after each compression so the heart can refill with blood.
- Use an AED as soon as it is available and follow its voice or screen instructions.
Vocabulary
- CPR
- CPR is an emergency procedure that uses chest compressions, and sometimes rescue breaths, to help circulate blood when the heart is not pumping effectively.
- AED
- An AED is an automated external defibrillator that can check heart rhythm and give an electric shock if needed.
- Chest compression
- A chest compression is a firm push on the center of the chest that helps move blood through the body.
- Cardiac arrest
- Cardiac arrest is a life-threatening emergency in which the heart suddenly stops pumping blood effectively.
- Bystander
- A bystander is a person nearby who may be able to help during an emergency before professionals arrive.
Common Mistakes to Avoid
- Waiting too long to call emergency services: CPR is not a replacement for professional medical care, so help should be called immediately.
- Pressing too slowly or too fast: compressions outside the 100 to 120 per minute range may move blood less effectively.
- Leaning on the chest between compressions: this prevents full recoil and can reduce blood flow back into the heart.
- Stopping compressions for long pauses: frequent or long interruptions reduce circulation to the brain and organs.
Practice Questions
- 1 A student performs CPR at 110 compressions per minute for 2 minutes. How many compressions are completed?
- 2 During practice on a mannequin, a class completes 330 compressions in 3 minutes. What is the compression rate in compressions per minute, and is it in the recommended 100 to 120 range?
- 3 A helper finds an unresponsive person who is not breathing normally, and an AED is visible on the wall nearby. Explain the safest sequence of actions the helper should take.