Table of Contents
- What Is CAB in CPR?
- Who Created the ABC of CPR?
- Why the Update From ABC of CPR to CAB of CPR?
- Is CAB That Much Better Than the ABC of CPR Model?
- How to Practically Apply CAB in CPR
- When Not to Perform CAB CPR
- Stay on Top of CPR Best Practices With ProTrainings
- CAB in CPR Frequently Asked Questions
It’s the middle of a busy afternoon in a coffee shop when suddenly, a person near the counter collapses. A silence falls over the room as bystanders look around, unsure what to do.
Then one person steps forward — an off-duty paramedic who’s CPR-certified and ready to act. They immediately assess the situation, and within seconds, the rhythm of chest compressions begins. But how do they know where to start? How do they know that chest compressions are the first thing they should do?
The answer lies in CPR’s core principles: CAB (circulation, airway, breathing).
When CPR was invented, the focus was on the ABC method: airway, breathing, and circulation. The idea was first to check the victim’s airway and their breathing before moving on to chest compressions. However, as research evolved, so did best practices.
Now, experts agree that starting with chest compressions is more effective in keeping blood circulating, especially in those critical first moments.
What changed, and why is the CAB method so important for survival? This blog will explain the details of ABC and CAB, the reasoning behind the shift, and why understanding the updates makes all the difference in saving a life.
What Is CAB in CPR?
CAB is the standard approach used in CPR to help someone experiencing cardiac arrest. It outlines the steps rescuers should take to keep oxygen-rich blood circulating and provide lifesaving care until emergency responders arrive.
This method focuses on maintaining blood flow to organs before addressing other medical concerns, making it the most effective way to assist someone whose heart has stopped beating.
CAB puts the most urgent action first — compressions — which have been shown to improve survival rates in out-of-hospital cardiac arrest.
It provides a clear structure for responders to follow: Begin chest compressions immediately while also addressing breathing and airway concerns when necessary.
While the steps remain the same for all ages, slight modifications may be needed depending on whether the victim is an adult, child, or infant. Some situations, such as drowning or respiratory-related emergencies, may also require adjustments to the process.
What Does CAB Stand for in CPR?
The CAB sequence in CPR stands for compressions, airway, and breathing. It represents the three essential steps of CPR, each serving a distinct purpose in helping someone experiencing cardiac arrest.
This sequence focuses on maintaining circulation, checking that the airway is open, and delivering oxygen to the lungs when needed. Understanding what each step involves helps rescuers provide effective care in a structured and lifesaving manner.
C: Compressions
Chest compressions are the most important step in CPR because they manually pump oxygen-rich blood through the body when the heart has stopped. Without immediate compressions, oxygen can’t reach the brain, heart, and other organs, leading to irreversible damage within minutes.
To perform effective chest compressions:
- For adults and children, place the heel of both hands (or one hand for less force) on the center of the chest, just below the nipple line. For infants, use two fingers in the center of the chest.
- Press down at least 2 inches for adults and children and about 1.5 inches for infants.
- Maintain a speed of 100–120 beats per minute, which is about the same as the beat of “Stayin’ Alive” by the Bee Gees. You can learn more about other CPR songs to keep the proper rhythm here.
- After each compression, be sure to take all the pressure off the chest, usually referred to as full chest recoil. This allows the heart to refill with blood before the next compression.
- Pausing compressions for too long can lower survival chances. Only stop briefly to provide rescue breaths or when medical professionals arrive and take over.
If a rescuer is untrained or uncomfortable with performing breaths, hands-only CPR can still be effective.
A: Airway
Once compressions have been started, the next step is making sure the person’s airway is open. If the airway is blocked, oxygen won’t be able to reach the lungs, even if breaths are given. A clear airway allows for proper airflow and makes rescue breathing more effective.
To open the airway:
- Use the Head Tilt–Chin Lift maneuver. Place one hand on the person’s forehead and two fingers on the bony part of their chin. Gently tilt the head back to open the airway.
- Check for obstructions. Look inside the person’s mouth for visible blockages, such as food, vomit, or another object. If something is blocking airflow and can be easily removed, do so carefully.
- Listen and look for breathing. Place your ear near the person’s mouth to listen and feel for normal breathing. At the same time, look toward the person’s feet and watch for their chest to rise and fall. If the person is gasping or not breathing at all, move to the next step: breathing.
If the person has a suspected neck or spinal injury, avoid excessive head tilting and try using the jaw thrust maneuver instead, provided that you’re trained in the technique.
B: Breathing
Rescue breaths provide the body with oxygen, which is especially important in cases where breathing issues cause cardiac arrest, such as drowning or choking. While hands-only CPR is recommended for untrained bystanders, trained individuals should provide rescue breaths in combination with compressions.
To give rescue breaths:
- Make sure the airway is open using the head tilt–chin lift maneuver.
- Pinch the nose shut and create a seal by covering the person’s mouth with yours. For infants, cover both the nose and mouth with your mouth.
- Give the first breath by breathing in steadily for about one second while watching for the chest to rise. If the chest doesn’t rise, reposition the head and try again.
- Give the second breath, then immediately return to chest compressions.
The standard ratio for CPR is 30 compressions followed by 2 breaths for adults, children, and infants. This cycle should be repeated until the person starts breathing on their own or emergency responders arrive to take over.
If the person starts breathing but remains unconscious, place them in the recovery position by turning them onto their side with their head slightly tilted back. This helps keep the airway open and prevents choking if they vomit.
This sequence is designed to be straightforward and effective, making it easier for both trained responders and bystanders to act in an emergency.
Who Created the ABC of CPR?
The ABC of CPR has been the go-to initialism for remembering to check the victim’s airway, perform rescue breaths, and give chest compressions to help provide lifesaving circulation of oxygenated blood.
One possible outlet that may have contributed to the inception of ABC is the International Liaison Committee on Resuscitation (ILCOR), an international group that continually analyzes submitted research to review and update CPR best practices based on the most recent data.
The guidelines are compiled through different organizations, such as the American Heart Association’s (AHA) Emergency Cardiovascular Care (ECC), then shared with the public in the United States, as was the case when the ABC of CPR was amended to today’s CAB CPR model.
Why the Update From ABC of CPR to CAB of CPR?
In 2010, ILCOR reviewed several studies that found that compression-only (also known as hands-only) CPR was more effective than conventional CPR when provided by untrained bystanders. In other words, it was shown to increase survivability for cardiac arrest victims.
This finding was quite a shake-up in the CPR-training world, as it invalidated so many posters and infographics that had long taught the ABC of CPR approach. After publishing their findings in 2010, the AHA and ILCOR shifted from the ABC model to the new CAB model that prioritizes reestablishing circulation to save lives with emergency CPR.
Common Misconceptions About CAB in CPR
Despite the widespread adoption of the CAB sequence in CPR, misconceptions about how it works and why it’s structured this way still persist. These misunderstandings can cause hesitation in an emergency or lead to ineffective CPR.
“Rescue breaths are no longer part of CPR.”
A common misunderstanding is that rescue breaths are unnecessary. While hands-only CPR is recommended for untrained bystanders or situations where giving breaths isn’t possible, rescue breaths are still an essential part of the CAB sequence for trained individuals.
The CAB sequence doesn’t remove compressions; it simply prioritizes compressions first to keep blood flowing before focusing on the airway and breathing.
“Airway and breathing should come before compressions.”
Some people assume that opening the airway and delivering breaths should be the first step in CPR, but the CAB sequence was designed to address the most immediate need — circulation. Chest compressions come first because keeping blood moving is the top priority.
Airway and breathing follow only after compressions have started so that the person receives both circulation and oxygen in the most effective order.
“Compressions alone are enough, so airway and breathing aren’t important.”
Yes, compressions are the most critical component of CPR, but the airway and breathing steps still play an essential role. The CAB method simply organizes the steps in a way that maximizes survival. In cases where oxygen deprivation causes cardiac arrest, opening the airway and delivering breaths is just as important as compressions.
The key is knowing when to incorporate each step rather than skipping any of them entirely.
“You should always stop compressions to check the airway first.”
Because compressions are the top priority, they should not be paused unnecessarily. While checking for airway blockages is an important part of the process, it comes after compressions have started. If a blockage is suspected, a quick check should be performed without prolonged interruptions to compressions.
The goal is to minimize pauses so circulation remains as consistent as possible.
“The CAB sequence is only for use on adults.”
While slight modifications exist for infants and children, the CAB sequence applies to all age groups. The main differences involve hand placement and compression depth, but the order of steps remains the same. The emphasis on starting with compressions before addressing airway and breathing applies to adults, children, and infants alike.
Understanding the reasoning behind this approach and correcting misconceptions helps rescuers do the right thing in an emergency.
Is CAB That Much Better Than the ABC of CPR Model?
In short, yes the CAB approach is much more effective than the ABC approach because it’s been shown to significantly reduce the time it takes to circulate oxygenated blood through a victim’s body. An unconscious person with a reduced amount of oxygen, compared to one with normal respiration, still has enough oxygen in his or her blood to sustain tissue life.
Tissue death occurs at various speeds depending on the type of tissue involved. One study published by the National Institute of Health found that brain tissue damage can occur in under three minutes when cardiac arrest occurs and respiration is stopped. This urgency underlines the immediate need for chest compressions when providing emergency first aid.
Following the updated CAB model, meaning chest compressions first, followed by checking the airway and performing rescue breaths, is a key step in improving the survivability of out-of-hospital cardiac arrest.
How to Practically Apply CAB in CPR
Knowing the CAB sequence is important, but applying it in a real emergency requires quick thinking and decisive action. Understanding how to move through each step efficiently can make the difference between life and death.
Here’s how to put CAB into practice when responding to a cardiac arrest situation.
Step 1: Assess the Scene and the Victim
Before beginning CPR, take a moment to ensure that the environment is safe for both you and the victim. Look for potential hazards such as traffic, chemicals, fire, or electrical dangers that could put you at risk.
Once the area is safe, check the victim for responsiveness by tapping their shoulder and shouting, “Are you okay?” If they don’t respond, assess their breathing by looking for chest movement and listening for normal breaths. Gasping or no breathing at all are signs that CPR is needed immediately.
Step 2: Initiate CAB
If the person is unresponsive and not breathing normally, start CPR using the CAB sequence:
- Compressions: Begin chest compressions immediately. Position your hands in the center of the chest (or use two fingers for infants) and push hard and fast at a rate of 100–120 beats per minute. Maintain a depth of 2-2.4 inches for adults, about 2 inches for children, and about 1.5 inches for infants. Let the chest fully recoil between compressions.
- Airway: After 30 compressions, check the airway by using the head tilt–chin lift maneuver. If you see an obstruction, carefully remove it. If the airway is clear, proceed to breathing.
- Breathing: If trained and comfortable, give two rescue breaths. Pinch the nose shut, cover the victim’s mouth with yours to create a seal, and breathe in steadily for about one second. Watch for the chest to rise. If it does not, reposition the head and try again before resuming compressions.
Step 3: Call for Help and Use an AED
If you’re not alone, instruct someone to call 911 and find an automated external defibrillator (AED) while you begin compressions. When you’re alone, call emergency services yourself before starting CPR.
If an AED is available, use it as soon as possible by following the voice-guided instructions. The AED will analyze the heart rhythm and advise if a shock is needed. Continue CPR between shocks until professional medical help arrives.
Step 4: Transition to Professional Care
Continue performing CPR using the CAB sequence until one of the following occurs:
- The person starts breathing on their own.
- Emergency responders arrive and take over care.
- You’re too physically exhausted to continue.
- The scene becomes unsafe.
If the person regains breathing but remains unconscious, place them in the recovery position, on their side with their head slightly tilted back, to keep their airway open and prevent choking.
Applying CAB in a real emergency requires efficiency. Practicing these steps in a CPR course or refresher training can help you respond faster and more effectively.
When Not to Perform CAB CPR
While CPR can be a lifesaving measure, there are situations where performing CAB CPR is either unnecessary or inappropriate. Understanding when not to initiate or continue CPR is equally as important as knowing how to perform it.
A do-not-resuscitate (DNR) order or a do-not-resuscitate comfort care (DNRCC) order indicates a person’s wish to avoid lifesaving interventions.
Another situation when CAB CPR shouldn’t be performed is when there are obvious signs of death. Emergency personnel should confirm the death, and further action isn’t required.
Lastly, in a dangerous environment, such as a fire or electrical hazard, CPR should only begin when the scene is safe.
Recognizing when to refrain from or stop CPR ensures respect for the person’s wishes. When in doubt, always start CPR if safe to do so and continue until rescue personnel take over. They have the knowledge, equipment, and direct communication with emergency physicians to decide treatment options.
Stay on Top of CPR Best Practices With ProTrainings
While knowledge is the cornerstone of emergency preparedness, nothing can replace hands-on training when it comes to providing first aid.
The CAB sequence is a lifesaving approach in CPR for immediate and effective action during cardiac arrest. Prioritizing chest compressions helps maintain blood flow while clearing the airway and providing oxygen the body needs to survive through rescue breaths.
When people ask, “What is the ABC of CPR?” it’s an opportunity to share knowledge about the importance of using the most current techniques to save lives. It also highlights the need for updates on best practices, like the CAB model, which help rescuers act with the highest chance of success.
At ProTrainings, we pride ourselves on offering CPR certification courses that exceed the latest ILCOR CPR guidelines. Our experienced instructors provide both in-classroom and remote-staff training so you receive the most relevant and up-to-date techniques.
Learning the CAB sequence through our courses not only enhances your ability to perform CPR effectively but also gives you the knowledge and confidence to respond properly in emergency situations.
We encourage widespread training to get more people equipped to handle emergencies, ultimately improving survival rates. No matter if you’re looking for individual certification or group training, our training is designed to give you the skills and knowledge to make a lifesaving difference.
Reach out today to learn more about our group and remote-staff CPR certification programs.
CAB in CPR Frequently Asked Questions
Many people have questions about the specifics of each step of CAB, how to apply it in different situations, and what to do in particular circumstances. To clarify these points and empower you when responding to an emergency, we’ve answered some of the most frequently asked questions about CAB in CPR.
- Is rescue breathing necessary for all CPR scenarios?
No, rescue breathing isn’t necessary in all CPR scenarios. In cases of adult sudden cardiac arrest, hands-only CPR is recommended for untrained bystanders. For situations involving infants, children, or drowning victims, rescue breaths should be incorporated along with compressions. - Can CAB be used on infants and children?
Yes, CAB should be used on infants and children, but with a few adjustments. Learn more about compressions here. Rescue breaths are also more important in pediatric CPR because cardiac arrest in young children is often respiratory in nature. - Do I need to check for a pulse before starting CPR?
No, checking for a pulse isn’t necessary for laypeople when deciding to start CPR. If a person is unresponsive and not breathing normally, CPR should begin immediately, starting with chest compressions. Trying to detect a pulse can waste valuable time in a life-threatening situation. - What happens if I don’t allow the chest to fully recoil between compressions?
Allowing the chest to fully recoil between compressions is crucial for effective CPR. When the chest doesn’t fully return to its normal position, blood isn’t able to refill the heart properly, which means less blood gets circulated with each compression. This reduces the effectiveness of CPR and could decrease the chances of survival. - When should I check for the airway in the CAB sequence?
The airway should be checked immediately after starting chest compressions. Once you’ve completed 30 compressions, check the airway by performing the head tilt–chin lift maneuver to ensure it’s open. Clearing any visible obstructions from the airway ensures that the rescue breaths you deliver will be effective. - Can I skip the airway and breathing steps in certain situations?
In cases of hands-only CPR (such as for adult sudden cardiac arrest where the cause is typically heart-related), you’d skip the airway and breathing steps and focus only on chest compressions. However, for children, infants, or cases like drowning, the airway and breathing steps are essential for providing effective CPR. - How do I know when to stop CPR and hand it over to professional care?
CPR should continue until emergency responders arrive and take over, the person starts breathing on their own, the scene becomes unsafe for you, or you’re too exhausted to continue.
Knowing the correct approach for each step in the CAB sequence can make a significant difference in the outcome. With this information, you’ll be prepared to perform effective CPR anytime, anywhere.