Question: How Does CPR Work?

Cardiopulmonary Resuscitation (CPR) is a critical emergency procedure designed to save lives when someone's heart has stopped beating (cardiac arrest) or when they have stopped breathing. CPR works by providing artificial circulation and oxygenation to the body's vital organs until professional medical help arrives. In this blog post, we will explain how CPR works and the key steps involved in performing it effectively.

The Objectives of CPR

The primary objectives of CPR are to:

  1. Maintain Blood Circulation: CPR aims to simulate the heart's pumping action by manually compressing the chest. This helps circulate oxygenated blood throughout the body, particularly to the brain and other vital organs.
  2. Provide Oxygen: CPR includes rescue breaths (in traditional CPR) or ventilation (in hands-only CPR) to supply oxygen to the lungs. The oxygen-rich air is then transported to the bloodstream and distributed to vital organs.
  3. Delay Brain and Tissue Damage: CPR buys time by preventing brain and tissue damage that occurs rapidly when the heart stops beating and breathing ceases. Effective CPR can sustain life until professional medical care, including advanced life support, is available.

Key Steps in Performing CPR

Effective CPR involves a sequence of actions that should be performed in a specific order. Here are the key steps in performing CPR:

Check Responsiveness:

  • First, approach the victim and check for responsiveness. Gently tap or shake the person and shout, "Are you okay?" to determine if they respond.

Call for Help:

  • If the victim is unresponsive or not breathing normally, immediately call emergency services (911 or your local emergency number) for professional medical assistance.

Open the Airway:

  • Ensure the victim is lying on their back on a firm, flat surface. Tilt their head backward slightly to open the airway by lifting the chin. This helps create a clear passage for air.

Check for Breathing:

  • Lean close to the victim's mouth and nose, look for chest rise and fall, and listen for normal breathing. If the victim is not breathing or is only gasping, it is a sign of cardiac arrest.

Start Chest Compressions:

  • If the victim is unresponsive and not breathing or only gasping, begin chest compressions. Place the heel of one hand on the center of the victim's chest, just below the nipple line.
  • For adults, compress the chest at least 2 inches (5 centimeters) deep, allowing for complete chest recoil between compressions. Maintain a compression rate of 100-120 compressions per minute.
  • For children and infants, use appropriate hand placement, depth, and compression rates according to their age group.

Provide Rescue Breaths (if Trained):

  • If you are trained in CPR with rescue breaths and willing to provide ventilations, give two rescue breaths after every 30 compressions. Ensure that the victim's airway remains open during rescue breaths.

Continue CPR Cycles:

  • Continue the cycle of chest compressions and rescue breaths (if trained) until one of the following occurs:
    • Professional medical help arrives and takes over.
    • The victim shows signs of life, such as normal breathing and responsiveness.
    • You are too fatigued to continue, in which case another trained rescuer should take over if available.

The Role of Automated External Defibrillators (AEDs)

In addition to CPR, the use of Automated External Defibrillators (AEDs) can significantly increase the chances of survival during cardiac arrest. AEDs are portable devices that can analyze the heart's rhythm and deliver an electrical shock (defibrillation) if necessary to restore a normal heartbeat. If an AED is available, use it following the device's instructions.


CPR is a vital emergency procedure that can save lives by maintaining blood circulation and oxygenation when the heart stops beating or breathing ceases. Knowing how to perform CPR correctly and promptly can make a significant difference in the outcome of cardiac emergencies. Remember to call for professional medical assistance immediately and continue CPR until help arrives or the victim shows signs of life. Regular training and practice in CPR techniques are essential to be prepared for critical situations where CPR may be needed.

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