30:2 CPR—cardiopulmonary resuscitation (CPR) with a ratio of 30 chest compressions to two rescue breaths—is an emergency lifesaving procedure that a bystander can perform if they see someone go into cardiac arrest. But are the rescue breaths really necessary, or can you simply give chest compressions until the emergency medical services arrive?
If you might ever be called upon to save a life, you need to know the latest guidelines with regard to CPR training and bystander CPR.
How Does Cardiopulmonary Resuscitation Work?
When a person’s heart stops beating (referred to as sudden cardiac arrest), the blood stops circulating and their vital organs begin to die. This is a huge problem, especially for an out-of-hospital cardiac arrest, because by the time the ambulance arrives, it may be too late for resuscitation or the person may be left with permanent brain damage[mfn]med.nyu.edu[/mfn].
Immediate CPR keeps the patient’s blood pumping throughout their body until more advanced airway support becomes available in the ambulance or hospital. Ventilation breaths—when provided by a trained rescuer—aim to oxygenate the blood that is being circulated by the compressions.
Early CPR and the Chain of Survival
Early CPR and early defibrillation with an AED are two critical elements in the chain of survival when someone goes into cardiac arrest. In order, the five elements of the cardiac chain of survival as defined by the American Heart Association are:
- Recognition of cardiac arrest and activation of the emergency response system
- Early cardiopulmonary resuscitation (CPR) with an emphasis on chest compressions
- Rapid defibrillation
- Advanced resuscitation by Emergency Medical Services and other healthcare providers
- Post-cardiac arrest care/recovery (including additional treatment, observation, rehabilitation, and psychological support)
The first two steps are the easiest. With proper CPR training that’s simple and straightforward, rescuers can confidently step in and prevent an emergency from becoming a tragedy.
Step three in the chain is best served when every institution carries an AED. The HeartSine Samaritan PAD 350 and Philips HeartStart FRx are two excellent, intuitive defibrillators to have on hand in case of cardiac arrest.
How to Perform CPR
The first step in the chain of survival is the “immediate recognition of cardiac arrest.” If you see the following signs, start working on the victim immediately:
- Unconscious or unresponsive
- Not breathing or only gasps
If you see the victim collapse, you should send someone to call an ambulance and bring the nearest AED, check that it’s safe, and start performing CPR. If you did not see the victim collapse and the victim is a child, perform chest compressions for two minutes before activating the emergency response system and going for an AED.
30:2 CPR
The American Heart Association recommends 30:2 CPR for medical professionals and trained rescuers who have been taught to deliver effective rescue breaths. 30:2 refers to the CPR strategy involving 30 chest compressions followed by two ventilation breaths. This is the recommended compression-ventilation ratio for adult CPR according to AHA guidelines.
While trained rescuers should use a 30:2 ratio on adult victims, two-rescuer resuscitation on infants and children should follow a ratio of 15:2 or 15 chest compressions followed by two rescue breaths.
Chest Compression Technique
Put the heel of your hand on the victim’s sternum (the center of the lower breastplate bone) and place the other hand on top, interlocking your fingers. Press down with a compression rate of 100-120 beats per minute, or to the beat of the popular song Stayin’ Alive.
Chest Compression Depth
Each chest compression should reach a depth of at least 2 inches (5cm) or one-third of the chest depth for an average adult, 2 inches (5cm) for a child, and 1.5 inches (4cm) or one-third of the chest depth for an infant. The chest should be allowed to rise completely between each compression. If applying CPR on a small child who suffered a cardiac arrest, use one hand instead of two. For an infant, use two fingers instead of a hand.
Ventilation Breaths
If you are trained to perform 30:2 CPR, tilt the victim’s head back slightly, pinch their nose closed, and seal their mouth with yours. Blow firmly into their mouth, looking to see that their chest rises each time, then resume CPR. For an infant, it’s not necessary to tilt their head back and you only need to give little breaths.
Chest Compressions Only
Conventional CPR is only recommended for trained rescuers because poorly delivered ventilation breaths will only waste valuable time when you could be delivering high-quality compressions. If an untrained bystander witnesses a cardiac arrest, they should activate the Emergency Medical Services, send someone to fetch an AED, and immediately perform hands-only CPR.
For hands-only CPR or compression-only CPR, follow the description provided above, performing continuous compressions at a rate of 100-120 beats per minute without stopping to provide any breaths. Continue until an AED or the EMS arrives. While it may seem counterintuitive to skip the rescue breaths, trials show that continuous chest compressions without rescue breaths improve resuscitation outcomes at hospital discharge compared to 30:2 CPR performed by an untrained bystander.
In addition, for witnessed victim collapse not involving respiratory compromise (such as choking), compression-only CPR can be beneficial for the first 5 minutes prior to ambulance arrival, regardless of your training level and comfort with giving proper ventilations. This is because during the first 5 minutes after sudden cardiac arrest the blood is often still oxygenated, meaning additional ventilations are of limited value compared to continuous compressions. After 5 minutes, if professional rescuers have not arrived, trained responders should begin incorporating ventilations into their CPR at the recommended 30:2 ratio.
Handing Over to Ambulance Personnel
Once the paramedics arrive, they will take over and provide high-level emergency cardiovascular care. If an AED was used, leave the electrode pads attached to the patient’s chest and the defibrillator turned on. The paramedics will take over the responsibility for monitoring and defibrillation, most likely transferring the patient over to their own equipment.
Learn CPR and Save a Life
In the event of a sudden cardiac arrest, successful resuscitation depends on early chest compressions, early defibrillation, and early activation of the emergency response system.
Because an immediate response is so important, it’s recommended and often mandatory to complete training in cardiopulmonary resuscitation. However, for people who aren’t trained in 30:2 CPR, hands-only CPR can be simpler, safer, and just as effective as providing ventilation breaths. And that could make all the difference in saving a life.
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