CPR: How to Perform Cardiopulmonary Resuscitation

What Is CPR and Why Is It Important?

CPR (Cardiopulmonary Resuscitation) is an emergency life-saving technique that combines chest compressions and rescue breathing to maintain blood circulation when the heart stops. CPR keeps oxygenated blood flowing to the brain and vital organs until advanced medical care arrives, and can double or triple survival rates from cardiac arrest.

Cardiopulmonary resuscitation, commonly known as CPR, is one of the most important first aid skills anyone can learn. When a person experiences cardiac arrest, their heart suddenly stops pumping blood effectively. Without immediate intervention, oxygen-rich blood stops reaching the brain and other vital organs, leading to irreversible damage within minutes. CPR serves as a bridge between the moment of cardiac arrest and the arrival of emergency medical services.

The technique works by manually pumping blood through the body using chest compressions while rescue breaths deliver oxygen to the lungs. This combination maintains a minimal but crucial level of blood flow that can preserve brain function and keep other organs viable. Research consistently shows that high-quality CPR, performed immediately after cardiac arrest, significantly improves the chances of survival and reduces the risk of long-term neurological damage.

According to the American Heart Association, approximately 350,000 out-of-hospital cardiac arrests occur each year in the United States alone, with similar proportions in other countries. Tragically, less than half of cardiac arrest victims receive bystander CPR before emergency services arrive. This gap represents thousands of potentially preventable deaths annually. When bystanders perform CPR immediately, survival rates can increase from single digits to 20-30% or higher, particularly when combined with early defibrillation.

The Science Behind CPR

Understanding why CPR works helps explain the importance of proper technique. During normal heart function, the heart beats approximately 60-100 times per minute, pumping oxygenated blood throughout the body. The brain receives about 20% of this blood flow and is extremely sensitive to oxygen deprivation. Brain cells begin to die within 4-6 minutes without oxygen, which is why immediate action is critical.

Chest compressions create artificial circulation by physically squeezing the heart between the breastbone (sternum) and the spine. Each compression forces blood out of the heart and into the circulatory system. The release phase allows the heart to refill with blood. When performed at the correct rate and depth, compressions can generate approximately 25-30% of normal blood flow - enough to sustain vital organs temporarily.

Rescue breaths deliver oxygen to the lungs, where it enters the bloodstream. While chest compressions alone can circulate blood, that blood gradually becomes depleted of oxygen. For prolonged resuscitation efforts, especially those lasting more than a few minutes, rescue breaths become increasingly important to maintain adequate oxygen levels in the blood.

When Should You Perform CPR?

Perform CPR when someone is unresponsive and not breathing normally. Check by tapping their shoulders and shouting; if no response, look for normal breathing for no more than 10 seconds. Gasping or irregular breathing is NOT normal. If the person is unresponsive and not breathing normally, assume cardiac arrest and begin CPR immediately.

Recognizing when someone needs CPR is just as important as knowing how to perform it. Cardiac arrest can happen suddenly and without warning, even in seemingly healthy individuals. The most common signs that someone needs CPR include sudden collapse, unresponsiveness to stimulation, and absence of normal breathing. Understanding these signs and acting quickly can make the difference between life and death.

The first step in any emergency situation is ensuring your own safety and the safety of the scene. Look for hazards such as traffic, fire, electrical dangers, or unstable structures before approaching the victim. You cannot help someone if you become a victim yourself. Once you've confirmed the scene is safe, approach the person and begin your assessment.

To check responsiveness, tap the person firmly on both shoulders while loudly asking "Are you okay?" Look for any signs of consciousness - eye opening, movement, or verbal response. If there is no response, the person is unconscious and requires immediate help. At this point, you or someone nearby should call emergency services while you continue your assessment.

Checking for Normal Breathing

After confirming unresponsiveness, you must quickly assess whether the person is breathing normally. Open the airway by placing one hand on the forehead and gently tilting the head back while using your other hand to lift the chin. This maneuver moves the tongue away from the back of the throat and opens the airway.

Once the airway is open, look, listen, and feel for breathing for no more than 10 seconds. Look for chest rise and fall, listen for breath sounds, and feel for air movement on your cheek. Normal breathing should be regular and effortless. During cardiac arrest, people often exhibit abnormal breathing patterns that can be mistaken for adequate breathing.

Agonal breathing, also called gasping, is a common occurrence in the early stages of cardiac arrest. These are irregular, infrequent gasps that occur as the brain stem responds to oxygen deprivation. Agonal breathing is NOT normal breathing and indicates that the person needs CPR. Do not delay CPR if you observe gasping, snoring, or gurgling sounds instead of regular breathing.

Common Causes of Cardiac Arrest

Understanding what causes cardiac arrest can help you recognize high-risk situations. The most common cause of sudden cardiac arrest in adults is coronary artery disease, where blocked arteries lead to heart attack and potentially fatal heart rhythm disturbances. Other cardiac conditions, including heart failure, cardiomyopathy, and inherited heart rhythm disorders, also increase risk.

Non-cardiac causes of cardiac arrest include drowning, choking, severe trauma, drug overdose, electrocution, and severe allergic reactions (anaphylaxis). Respiratory arrest - where breathing stops - will lead to cardiac arrest within minutes if not addressed. In children, respiratory causes are more common than primary heart problems.

Risk factors for cardiac arrest include previous heart attack, family history of heart disease, smoking, high blood pressure, high cholesterol, obesity, diabetes, and sedentary lifestyle. However, cardiac arrest can occur in anyone, including young, apparently healthy individuals. This unpredictability is why CPR training is valuable for everyone, not just healthcare professionals.

How Do You Perform CPR on an Adult?

To perform CPR: 1) Call emergency services, 2) Place the heel of your hand on the center of the chest, 3) Push hard and fast at 100-120 compressions per minute, at least 5cm deep, 4) Give 2 rescue breaths after every 30 compressions if trained. Continue until help arrives or the person recovers.

Performing effective CPR requires proper technique to maximize blood flow to vital organs. While the basic concept is straightforward - push hard and fast on the chest - there are specific guidelines that optimize outcomes. The following step-by-step guide is based on current international resuscitation guidelines from the American Heart Association and European Resuscitation Council.

Before beginning CPR, ensure you have called emergency services or directed someone else to do so. Modern smartphones allow you to use speaker function, enabling you to receive real-time guidance from the emergency dispatcher while performing CPR. Many dispatchers are trained to provide telephone CPR instructions and can coach you through the process.

Compression Technique Details

Proper compression technique is critical for effective CPR. Position yourself so that your shoulders are directly over your hands, allowing you to compress straight down using your body weight rather than just arm strength. Keep your arms locked straight at the elbows throughout the compressions. This positioning maximizes the force of each compression while reducing fatigue.

The compression rate of 100-120 per minute corresponds to the tempo of songs like "Stayin' Alive" by the Bee Gees or "Crazy in Love" by Beyonce. Many people find it helpful to mentally sing one of these songs to maintain the correct rhythm. Compressing too slowly reduces blood flow, while compressing too fast doesn't allow adequate filling of the heart between compressions.

Full chest recoil between compressions is often overlooked but essential for effective CPR. During the release phase, the chest must return completely to its normal position. This allows the heart to refill with blood before the next compression. Leaning on the chest between compressions, even slightly, reduces this refill and decreases the effectiveness of CPR.

Rescue Breath Technique

Rescue breaths deliver oxygen to the lungs and should be given after every 30 chest compressions. To give effective breaths, ensure the airway is open by tilting the head back and lifting the chin. Pinch the nose closed with your thumb and forefinger to prevent air from escaping. Take a normal breath (not a deep breath), create a seal over the person's mouth, and blow steadily for about 1 second while watching for chest rise.

Each rescue breath should make the chest visibly rise. If the chest doesn't rise, the airway may be blocked. Reposition the head by tilting further back and ensure a good seal before trying again. Do not give more than 2 attempts at breaths before returning to compressions - maintaining blood flow through compressions is the priority.

How Do You Use an AED (Automated External Defibrillator)?

To use an AED: Turn it on and follow voice prompts, attach electrode pads to bare chest (one below right collarbone, one on left side below armpit), ensure no one is touching the person during analysis, and press the shock button if advised. Resume CPR immediately after the shock. AEDs are designed for untrained users and will only deliver a shock if needed.

An Automated External Defibrillator (AED) is a portable device that can analyze heart rhythms and deliver an electrical shock to restore normal heart function during certain types of cardiac arrest. AEDs are increasingly available in public places such as airports, shopping centers, sports facilities, schools, and offices. Learning to use an AED significantly increases the chances of saving someone's life during cardiac arrest.

The presence of an AED should not delay the start of CPR. If you are alone, call emergency services and begin CPR immediately. If others are available, send someone to locate and retrieve an AED while CPR continues. The combination of early CPR and early defibrillation provides the best chance of survival - each minute without defibrillation in a shockable rhythm decreases survival by approximately 10%.

Modern AEDs are designed to be used by anyone, regardless of training. They provide clear voice and visual instructions that guide users through each step. Importantly, AEDs are safe - they analyze the heart rhythm automatically and will only allow a shock to be delivered if a shockable rhythm is detected. You cannot accidentally shock someone who doesn't need it.

Step-by-Step AED Use

When an AED arrives, turn it on immediately - most devices activate with a button press or by opening the lid. The AED will begin providing voice instructions. While following these instructions, continue CPR until the AED prompts you to stop for rhythm analysis.

Expose the person's chest completely. The AED pads must be placed directly on bare skin for proper function. If the chest is wet, dry it quickly with a towel. If the person has excessive chest hair that might prevent pad adhesion, use the razor often included in AED kits to shave the areas where pads will be placed.

Remove the electrode pads from their packaging and attach them to the chest as shown in the diagrams on the pads. One pad goes below the right collarbone, and the other goes on the left side of the chest, below the armpit. Press the pads firmly to ensure good contact. Some AEDs have the pads pre-connected; others require you to plug in the pad connector.

Once pads are attached, the AED will analyze the heart rhythm. Ensure no one is touching the person during this analysis - movement can interfere with accurate rhythm detection. The AED will announce whether a shock is advised. If a shock is advised, ensure everyone is clear of the person (loudly state "Clear!" and visually confirm), then press the shock button when prompted.

Immediately after delivering the shock (or if no shock is advised), resume CPR starting with chest compressions. The AED will prompt you to continue CPR for two minutes before reanalyzing the rhythm. Continue following the AED's instructions until emergency services arrive and take over.

What Are Important Things to Remember During CPR?

Key CPR reminders: Minimize interruptions to chest compressions, push hard enough (at least 5 cm), maintain the correct rate (100-120/min), allow full chest recoil, switch rescuers every 2 minutes if possible to prevent fatigue, and don't stop until professional help arrives or the person recovers.

Performing CPR in a real emergency is physically and emotionally demanding. Understanding common challenges and how to address them helps ensure the best possible outcome for the victim. Several factors significantly impact CPR quality and should be kept in mind throughout the resuscitation effort.

Minimizing interruptions to chest compressions is one of the most important aspects of high-quality CPR. Every pause in compressions allows blood flow to stop, and it takes several compressions to rebuild adequate pressure. Aim to keep hands-off time to less than 10 seconds when switching tasks. When transitioning between compressions and rescue breaths, move quickly and smoothly.

Compression depth often decreases as rescuers become fatigued, even when they don't feel tired. Studies show that compression quality begins to deteriorate after just 1-2 minutes of continuous CPR. If multiple rescuers are available, switching every 2 minutes (during the rhythm check if an AED is being used) helps maintain effective compressions. Make switches quickly to minimize interruption.

Managing Multiple Rescuers

When multiple bystanders are present, coordinating the response improves effectiveness. Assign specific roles: one person performs CPR, another calls emergency services, and a third retrieves an AED if available. The person calling emergency services should stay on the line to relay instructions and provide updates to the caller.

During rescuer switches, the incoming rescuer should position themselves on the opposite side of the victim and be ready to begin compressions immediately when the current rescuer moves away. The transition should take no more than 5 seconds. After switching, the previous rescuer can prepare for rescue breaths or monitor the situation.

When to Stop CPR

Knowing when to continue and when to stop CPR is important. In general, continue CPR until one of the following occurs: emergency medical services arrive and take over care, the person shows obvious signs of life (moves, opens eyes, breathes normally), an AED indicates the heart has returned to a normal rhythm, or you become too exhausted to continue effectively and no other rescuer is available.

Do not stop CPR based on how long you've been performing it. Remarkable recoveries have occurred after prolonged resuscitation efforts, particularly in cases of hypothermia (low body temperature) or drowning in cold water, where the body's reduced metabolic needs can preserve organ function for extended periods.

When Should You NOT Perform CPR?

Do not perform CPR if the person is responsive and breathing normally. If someone is unconscious but breathing normally, place them in the recovery position (on their side) to keep the airway open while waiting for help. Continue to monitor breathing and be ready to start CPR if it stops.

CPR is specifically indicated for cardiac arrest - when the heart has stopped effectively pumping blood. Not every medical emergency requires CPR, and knowing when CPR is not appropriate is just as important as knowing when to perform it. Performing chest compressions on someone whose heart is beating could potentially cause harm and would distract from other necessary care.

If a person is unresponsive but breathing normally, they should be placed in the recovery position (also called the lateral recumbent position) rather than receiving CPR. This position keeps the airway open and allows fluids to drain from the mouth, reducing the risk of choking. Stay with the person, monitor their breathing continuously, and be prepared to begin CPR if breathing stops or becomes abnormal.

The Recovery Position

To place someone in the recovery position, kneel beside them while they lie on their back. Take the arm nearest to you and place it at a right angle to the body, elbow bent with the palm facing up. Bring their far arm across the chest and hold the back of their hand against the cheek nearest to you.

With your other hand, grasp the far leg just above the knee and pull it up, keeping the foot on the ground. While holding their hand against their cheek, pull on the far leg to roll them toward you onto their side. Adjust the upper leg so both the hip and knee are bent at right angles. Tilt their head back slightly to ensure the airway remains open.

The recovery position is appropriate for unconscious persons who are breathing normally. It is NOT appropriate for suspected spinal injuries (unless necessary to protect the airway) or for trauma victims who should remain still until professional help arrives. Always continue to monitor breathing and be ready to roll them onto their back and begin CPR if necessary.

Why Should You Get CPR Training?

Formal CPR training provides hands-on practice that builds confidence and skill. Training courses typically last 2-4 hours and cover adult CPR, AED use, and often choking response. Many organizations offer courses, including the American Heart Association, Red Cross, and local health services. Certification is usually valid for 2 years.

While reading about CPR is valuable, hands-on training provides the confidence and muscle memory needed to perform effectively in a real emergency. Training courses allow you to practice on manikins, receive feedback on your technique, and ask questions in a supportive environment. The physical experience of performing compressions at the correct depth and rate is difficult to replicate from reading alone.

CPR training courses are widely available and typically take only a few hours to complete. Basic Life Support (BLS) courses cover adult CPR, rescue breathing, choking response, and AED use. Many courses also include information on recognizing heart attack and stroke symptoms. Healthcare providers usually receive more extensive training that includes team dynamics and advanced techniques.

Several organizations offer CPR training worldwide, including the American Heart Association, American Red Cross, European Resuscitation Council member organizations, St. John Ambulance, and many hospitals and community health centers. Workplace CPR training is also common, with many employers providing courses to employees. Some countries require CPR training for certain occupations or driver's license renewal.

CPR for Children

While this guide focuses on adult CPR, the technique differs somewhat for infants and children. The basic principles remain the same, but compression depth, hand placement, and the emphasis on rescue breaths vary by age. If you care for children regularly, consider taking a course that specifically covers pediatric CPR techniques.

In an emergency involving a child, adult CPR techniques can be modified with less compression depth and force. Some CPR is always better than no CPR. If you find yourself needing to perform CPR on a child without specific training, use the technique you know while emergency services are on the way.