Cardiopulmonary resuscitation (CPR) is a life-saving emergency procedure that restores blood circulation and breathing in people whose hearts or lungs have stopped working. CPR works by manually providing oxygen to the body’s vital organs until medical professionals can take over.
The CAB acronym refers to circulation, airway, and breathing, and it is a well-known method of performing cardiopulmonary resuscitation (CPR). The CAB method reflects a change from the previously recommended method of airway, breathing, and compression, which was focused on checking for an open airway before starting compressions.
The CAB method relies on a knowledge of the physiological variables involved in cardiac arrest.
In this article, we will focus on the physiological mechanisms that support CAB CPR.
What is CAB and its Importance When Performing CPR?
CAB CPR is a type of CPR that prioritizes chest compressions over airway and breathing and the acronym CAB stands for compressions, airway, and breathing. The American Heart Association approved this approach in their 2010 CPR recommendations, and it is now commonly taught in CPR training classes.
What does CAB stand for in CPR and why is it important? It is because chest compressions should be initiated as soon as possible before any further delays while checking the victim’s breathing and airway. By starting chest compressions first, blood flow and oxygenation to vital organs can be restored more quickly, potentially increasing the victim’s chance of survival.
CAB CPR is used to treat people who have suffered a cardiac arrest, an electric shock, smoke inhalation, near-drowning, or other medical emergencies. It is advised that everyone, not only people with medical expertise practice CPR in order to be prepared to respond in an emergency.
According to the American Heart Association, performing CPR on the victim immediately after cardiac arrest can double a person’s chances of survival and heart recovery. The CAB technique is priceless when it comes to assisting people in need, and below we will better understand how CAB CPR works and how it is performed.
The Role of Compressions in CAB CPR
When a person goes into cardiac arrest, the heart stops pumping blood, and the absence of oxygenated blood supply to the brain and other organs can cause permanent damage or even death, which will explain why compressions are crucial when it comes to this.
Chest compressions include physically pumping the heart and maintaining blood flow throughout the body by applying pressure to the chest. This can assist in protecting the brain and keep important organs functioning until a team of medical experts comes.
The Role of Airway in CAB CPR
Maintaining an open airway is crucial in performing effective CAB CPR. When the airway is blocked or obstructed, the person cannot breathe, and the oxygen supply to the brain and other organs is cut off, leading to serious consequences.
When performing CAB CPR, rescuers should tilt the head back and elevate the chin to ensure that the person’s airway is free and open. This allows air to flow easily into the lungs during rescue breaths, assisting in the supply of oxygen to the body.
The Role of Breathing in CAB CPR
Rescue breath or breathing brings oxygen-rich air into the lungs and eliminates carbon dioxide from the body during the procedure. This procedure is especially crucial when a person is not breathing. Being unable to breathe means the body’s oxygen can rapidly decrease, causing irreversible organ and brain damage.
In a cardiac arrest emergency, giving rescue breaths in combination with chest compressions is critical for maintaining the body’s oxygen supply and ensuring the best possible result.
CAB CPR in Case of Cardiac Arrest
When performing CPR using the C-A-B sequence, specific physiological mechanisms occur. According to research published in Anesthesia & Analgesia, chest compressions raise the pressure in the lungs and compress the heart between the sternum and the spine.
As a result, both the aortic and right atrial pressures rise, with the right atrial pressure matching or occasionally exceeding the left-sided pressures. This action pumps oxygenated blood to the body and reduces the delay to the first compression.
The following is a list of steps to perform CPR using the CAB sequence:
- Check the surroundings for any potential risks to you and the patient.
- If you’re dealing with an unresponsive person, immediately call for emergency medical services.
- Check the person’s breathing and pulse. If there is none, start chest compressions immediately.
- Using a firm surface, position the patient by laying them on their back.
- Place your knees next to the patient’s neck and shoulders.
- Put the lower palm of one hand over the middle of the patient’s chest.
- Covering the first hand with the other, interlock your fingers.
- The elbows should be straight, positioning the shoulders over the hands.
- Use the arm strength and upper body to press down on the chest.
- Make 100-120 chest compressions per minute, 2-2.4 inches deep.
- After 30 compressions, give two breaths to the patient.
- If giving CPR to a child, using the technique of tilting head/ lifting chin, slightly open the airway to a past-neutral position.
- If a baby is in question, using the technique of tilting head/ lifting chin to open the airway to a neutral position. Blow for about one second in the patient’s mouth, ensuring the chest rises from each breath. Let the air exit before administering the next breath.
- Use cycles of 30 compressions followed by two breaths until EMS arrives or the patient starts breathing again.
The Role of Compressions With Rescue Breathing
Chest compressions can be physically demanding and require a proper technique to be effective. It is important to avoid leaning or rocking on the chest, which can reduce the effectiveness of compressions.
Rescue breathing, on the other hand, includes expanding the person’s lungs using mouth-to-mouth or mouth-to-nose resuscitation to provide oxygen. Breathing should be performed after every 30 chest compressions in the ratio of 30:2.
It’s worth noting that the American Heart Association changed the suggested sequence from ABC to CAB in 2010, which means chest compressions should come first, followed by airway and breathing.
The Effects of CAB CPR
Chest compressions affect both circulation and oxygenation since they both aim to restore blood flow and oxygen supply to the body. The aim of chest compressions is to maintain circulation until a defibrillator or other medical intervention can restore the heart’s normal rhythm.
Due to its high oxygen demand and limited ability to retain oxygen, the brain is one of the organs most vulnerable to harm during CPR. Efficient chest compressions can aid in the maintenance of cerebral perfusion pressure, which is the difference in pressure between the arterial and venous sides of the brain.
This gradient is necessary to maintain blood flow to the brain and prevent hypoxia, or a lack of oxygen which can lead to further organ damage.
Blood Circulation and CAB
During the performance of CAB CPR, the organs in the body are affected in various ways due to the changes in blood flow and oxygenation. When the heart stops beating, blood flow stops throughout the body, including to the organs.
This lack of blood flow, and therefore lack of oxygen, can quickly cause damage to organs such as the brain, kidneys, and liver. The purpose of CAB CPR is to provide circulation and oxygenation to the organs until normal heart function can be restored.
Kidneys and liver filter and remove waste products from the blood. Their proper functioning is important, but they cannot filter if there is no proper blood circulation.
Blood is manually pumped throughout the body during chest compressions, delivering as much circulation to the organs as possible. With this method, blood and oxygen can be restored in the body, and the organs can properly function again.
When Not to Perform CAB CPR?
There are cases when performing CPR is not advisable. Here are some situations when it should be avoided.
Do Not Resuscitate (DNR)
CAB CPR is not acceptable in certain conditions. This includes the patient having a “do not resuscitate” (DNR) order or advanced directive in effect. In these circumstances, the patient or their family has chosen not to receive life-sustaining therapies, such as CAB CPR.
Another instance when CPR is not suitable is if the patient displays apparent evidence of permanent death, such as rigor mortis or dependent lividity. CPR would be useless in these cases and would cause unnecessary trauma to the patient’s body.
Lack of Skill
Moreover, if the person giving CPR lacks the proper knowledge or skill, they may accidentally cause damage to the patient. In these situations, it is critical to dial Emergency and wait for trained professionals to arrive.
The CAB CPR is a life-saving technique that can save a person’s life or delay possible irreversible damage to organs. CAB works by manually moving blood and supplying oxygen to the body’s important organs after the heart or lungs have stopped working.
The CAB strategy relies on a knowledge of the physiological factors at work in cardiac arrest. The heart stops pumping blood during a cardiac arrest, resulting in a shortage of oxygen flow to the body’s organs and tissues.
Overall, in CPR, the CAB sequence stands for compression, airway, and breathing. It is an important part of CPR that can keep a person alive until expert help comes. Everyone who wishes to learn how to conduct CPR and be prepared to save a life in an emergency circumstance must remember the CAB sequence.