CPR keeps blood moving when someone’s heart has stopped. Worrying about when to use CPR is fair; no one wants to push on the chest of a person who did not need it, and no one wants to stand still while someone is having an emergency. Settle which situations call for compressions and which do not and you can become the person who acts at the right moment rather than waiting to be sure.
The Signs That Tell You When to Use CPR
Two signs tell you when to use CPR. These are when the person does not respond, and when they are not breathing normally. Check for a response first. Talk to them, touch them, and squeeze their shoulders. If they do not move, speak, or open their eyes, they are unresponsive.
Next, check their breathing. Open their airway by resting one hand on their forehead and lifting their chin with the other. This tilts the head back and lifts the tongue clear of the airway. Look for the chest to rise and fall, listen for air, and feel for breath on your cheek for up to ten seconds. Slow, gasping breaths are not normal breathing, so treat them as a reason to act.
When someone is both unresponsive and not breathing normally, their heart has most likely stopped, and you start CPR straight away. You do not need to check for a pulse, and you do not wait to be certain of the cause.
Heart Attacks Versus Cardiac Arrest
These two words get mixed up, and the difference can decide when to use CPR. Cardiac arrest is when the heart’s electrical rhythm fails and it stops pumping, causing the person to drop unconscious and stops breathing. When someone’s heart stops is the time to use CPR.
A heart attack is a blood flow problem. When an artery that feeds the heart muscle gets blocked, usually by a build-up of fat and cholesterol, that part of the heart is starved of oxygen. The person may hold their chest, feel pain spreading to their arm, jaw, or back, sweat, or feel sick, but their heart keeps beating. They do not necessarily need chest compressions, but they do need an ambulance fast. An untreated heart attack can tip into cardiac arrest.
How to Start CPR: Giving Chest Compressions and Rescue Breaths
Once you know when to use CPR, you also need to know how. CPR consists of 30 chest compressions, then 2 rescue breaths.
Lay the person flat on their back on a firm surface, and kneel beside their chest. Place the heel of one of your hands on the centre of their chest, cover it with your other hand, and link your fingers. Push down hard and fast, to about a third of the depth of their chest. Let their chest rise all the way back between compressions. Aim for 100 to 120 compressions per minute, or 1 every 1 to 2 seconds.
After the 30th compression, open their airway with a head tilt and chin lift, pinch their nose shut, and seal your mouth over theirs. Give them one breath over about a second, just enough to see their chest rise, then a second breath the same way. Go back to compressions straight away and keep the cycle going, 30 and 2, pausing only as long as the breaths take.
When to Use an Automated External Defibrillator (AED)
The same two signs that tell you when to use CPR also call for an AED. An automated external defibrillator reads the heart’s rhythm and delivers a shock if that rhythm can be corrected. Send someone to fetch the AED the moment you start CPR
When you get the AED, turn it on, then follow the spoken prompts. Peel the pads and place them on the person’s bare chest where the diagram shows, one below the right collarbone and one on the left side below the armpit. The machine then checks the person’s heart rhythm, so make sure no one touches the person while it reads them as this can cause a false positive. If it advises that a shock is needed, stand clear of the person and press the button before resuming CPR.
How the Decision to Perform CPR Changes for Children and Infants
The signs that tell you when to use CPR do not change with age. A child or infant who is unresponsive and not breathing normally needs CPR, the same as an adult. What changes is how you give it, and why the breaths count for more.
The way you deliver the 30 compressions changes with the size of the victim’s body. For a child, press down with one or two hands, one-third of the way into the chest. For an infant under one year, use two fingers or two thumbs, pressing about four centimetres deep. The rescue breaths also change for infants under one year old; they do not need a head tilt due to their developing airways, and you should only blow gentle puffs of air instead of full breaths.
AEDs should never be used on a child under the age of one by anyone other than a trained medical professional who can make the necessary adjustments to the pads.
When to Stop Cardiopulmonary Resuscitation
Just as two signs tell you when to use CPR, a few clear conditions tell you when to stop. Keep going without stopping until one of the following things happens:
when the person responds or starts breathing normally on their own.
when paramedics or another trained responder arrives and take over.
If another trained person is there, swap roles every 2 minutes.
if you become too exhausted to continue.
if a health professional tells you to.
Once the person’s breathing returns to normal, roll them onto their side. Keep an eye on them and be ready to start CPR again if the breathing stops.
When is Mouth-to-Mouth Resuscitation Enough?
Mouth-to-mouth resuscitation puts oxygen into the lungs, but it does nothing to move blood around the body. That decides when breaths alone will do and when to use CPR fully. A person who has been pulled from the water early, or one whose blocked airway has just been cleared, may have a pulse but no breath, and rescue breaths can keep them going until they breathe on their own.
Learn CPR and First Aid to Save a Life
Two signs settle when to use CPR. Whether someone survives can depend on the short window before professional help arrives. Taking our first aid and CPR course means you can be the one who keeps a person alive when no one else around them knows what to do.
FAQs
Can You Be Sued for Performing CPR in Australia?
No. Every Australian state and territory has Good Samaritan laws that protect a person who gives emergency help in good faith. As long as you are not impaired by drugs or alcohol, you are covered when you step in.
How Often Should You Renew Your CPR Training?
Every twelve months. CPR skills fade in the months after a course, so a yearly refresher keeps your technique sharp. A broader first aid certificate is renewed every three years, but the CPR component is updated each year.
Can You Injure Someone by Performing CPR?
Yes. When done correctly, chest compressions have enough force that they can crack ribs. However, you should keep going even if you hear a crack. These injuries can heal, while a lack of CPR can be fatal.