Incorrect compression depth is one of the most common mistakes people make when performing CPR. Cardiopulmonary resuscitation (CPR) is a vital first aid skill that can mean the difference between life and death during a cardiac emergency. Yet, even trained rescuers can make small errors that reduce the effectiveness of chest compressions and rescue breaths.
At First Aid Pro, we’ve trained thousands of Australians to perform CPR the right way. Over the years, we’ve identified the most frequent CPR mistakes to avoid — from poor compression depth to delayed response times. Understanding these errors can help you perform CPR effectively and confidently when it matters most.
Be ready to save a life — enrol in a nationally recognised CPR course with First Aid Pro and learn the correct CPR technique today.
Key Takeaways
Mistake | Why It Matters | Correct Practice |
Incorrect Compression Depth | Reduces blood flow to brain and heart | 5–6 cm for adults |
Wrong Compression Rate | Affects oxygen delivery | 100–120 per minute |
No Full Chest Recoil | Prevents heart from refilling | Lift hands between compressions |
Poor Hand Placement | Causes ineffective compressions | Centre of the chest |
No Rescue Breaths | Low oxygen levels | Two 1-second breaths |
No Call to 000 | Delays professional help | Always call first |
Delayed CPR | Increases risk of brain damage | Start CPR immediately |
No AED Use | Missed chance to restart heart | Apply pads and follow prompts |
Soft Surface | Limits compression depth | Move to firm ground |
No Refresher | Skills fade over time | Train annually |
1. Incorrect Compression Depth – A Common Mistake
One of the biggest mistakes to avoid in CPR is not pressing deep enough (incorrect compression depth) when performing chest compressions. To be effective, CPR must push blood through the heart to vital organs. The Australian Resuscitation Council (ARC) recommends compressing the chest 5–6 centimetres deep for adults, and about one-third of the chest depth for infants and children.
A compression that’s too shallow fails to circulate blood, while one that’s too deep can cause injury. The goal is firm, controlled pressure using the heel of your hand on the centre of the chest, allowing full recoil between compressions.
Correct Depth Guide Table:
Age Group | Correct Compression Depth | Notes |
Adult | 5–6 cm | Push hard and fast |
Child | 4–5 cm | Use one or two hands |
Infant | 1/3 of chest depth (~4 cm) | Use two fingers |
2. Inconsistent Compression Rate – Keeping the Right Rhythm
A common CPR mistake is performing compressions at the wrong speed. The correct rate is 100 to 120 compressions per minute, roughly to the beat of “Stayin’ Alive” by the Bee Gees. Too slow, and blood flow drops; too fast, and the chest can’t refill properly between compressions.
Consistency is essential — keep your arms straight, push from your shoulders, and allow the chest to fully rise each time.
3. Failing to Allow Full Chest Recoil
After each compression, it’s vital to allow full chest recoil. This means taking your weight off the chest completely so the heart can refill with blood before the next compression. One of the most common mistakes to avoid is leaning on the chest, which reduces blood flow and oxygen delivery.
The best way to ensure recoil is to lift your hands slightly between compressions while keeping them in position. This small adjustment improves circulation and overall CPR effectiveness.
4. Incorrect Hand Placement – Finding the Centre of the Chest
Incorrect hand placement is another frequent CPR mistake that can reduce compression effectiveness or cause injury. Your hands should be positioned on the centre of the chest, over the lower half of the sternum, with the heel of one hand on top of the other.
Avoid placing your hands too high (ineffective) or too low (risk of abdominal injury). Keeping your shoulders directly above your hands and your elbows locked helps deliver consistent, powerful compressions.
Proper Hand Placement
CPR Hand Placement Steps
- 1️⃣ Place the heel of one hand on the centre of the chest.
- 2️⃣ Put the other hand on top and interlock fingers.
- 3️⃣ Keep arms straight and push down 5–6 cm.
- 4️⃣ Allow full chest rise before the next compression.
5. Inadequate Rescue Breaths – The Airway Connection
Rescue breaths are essential in standard CPR because they deliver oxygen to the lungs. A common mistake is failing to tilt the head back or give effective breaths. The correct technique is to tilt the head back, lift the chin, pinch the nose, and give two breaths that make the chest visibly rise.
Each breath should last about one second. Avoid blowing too forcefully — excessive air can enter the stomach and cause vomiting. If you’re not sure or unable to give rescue breaths, continue with hands-only CPR until help arrives.
6. Not Calling Triple Zero (000) – A Delayed Response
In an emergency, it’s easy to focus on CPR and forget the most important first step: call for help. Always dial Triple Zero (000) before starting CPR, or have someone else make the call while you begin compressions.
Calling 000 connects you to emergency operators who can guide you through CPR steps until paramedics arrive. If you’re alone, use speakerphone mode so you can continue CPR while speaking with the operator.
7. Delaying the Start of CPR – Time Is Critical
Every second counts in a cardiac arrest. Delaying CPR even for a minute can significantly reduce survival chances. When someone collapses and is unresponsive, start CPR immediately.
Many rescuers hesitate due to uncertainty or fear of doing it wrong, but doing something is better than doing nothing. As the ARC advises: “Any CPR is better than no CPR.” Quick action ensures oxygen continues to reach the brain and heart, buying precious time until medical help arrives.
Be prepared to act — enrol in a First Aid Pro CPR course and learn how to respond quickly and confidently.
8. Neglecting to Use an AED – Missing a Vital Step
An Automated External Defibrillator (AED) is designed to help restart a heart that has stopped beating. One of the most common mistakes during resuscitation is failing to use an AED when available.
AEDs are found in shopping centres, gyms, offices, and schools across Australia. Once turned on, they provide clear voice prompts guiding you through pad placement and shock delivery.
Continue chest compressions while the AED analyses or recharges. Using an AED alongside CPR greatly improves survival rates.
Simple AED Use Steps:
Step | Action | Purpose |
1 | Turn on AED | Activate voice instructions |
2 | Attach pads | Follow diagrams on AED |
3 | Stand clear during analysis | Safety step |
4 | Deliver shock if advised | Restart heart rhythm |
5 | Continue CPR | Maintain circulation |
9. Performing CPR on a Soft or Uneven Surface
Performing CPR on a bed, couch, or soft ground makes compressions less effective because the body sinks with each push. Always move the person to a firm, flat surface before beginning chest compressions.
This ensures full compression depth and proper recoil. In public areas, roll the person onto the floor or use a rigid board if available.
10. Not Refreshing CPR Skills Regularly
Even well-trained rescuers forget CPR techniques over time. One of the most common mistakes to avoid is neglecting refresher courses. The Australian Resuscitation Council recommends updating your CPR certification every 12 months to maintain accuracy and confidence.
New techniques and updated guidelines are regularly introduced, and ongoing practice ensures your CPR remains effective and compliant with national standards.
Stay current — enrol in a nationally recognised First Aid and CPR course with First Aid Pro and keep your lifesaving skills sharp.
Knowledge Quiz: Common CPR Mistakes
Test your CPR knowledge below!
Avoid Common CPR Mistakes to Save a Life
Knowing how to perform CPR correctly is one of the most powerful skills a person can have during a cardiac emergency. Yet, common CPR mistakes such as incorrect compression depth, inconsistent compression rate, and poor hand placement can seriously reduce the effectiveness of resuscitation efforts. Every second counts, and doing CPR the right way — at the correct depth and rate, allowing full chest recoil, and calling Triple Zero (000) immediately — can be the difference between life and death.
Continuous training is the key to mastering and maintaining your CPR skills. Whether you’re a first aider, a parent, or simply someone who wants to be prepared, taking the time to learn and refresh your skills ensures you can act quickly and confidently when emergencies strike.
CPR can truly save a life — but only when performed correctly. Avoid these common CPR mistakes, practise regularly, and stay confident in emergencies.
Enrol in a nationally recognised first aid with CPR course with First Aid Pro and learn the right way to perform CPR today.
References
- Australian Resuscitation Council (ARC) Guidelines.
- Healthdirect: How To Perform CPR
- Better Health Channel: Cardiopulmonary Resuscitation
- Safe Work Australia – First Aid in the Workplace Code of Practice.
- NSW Health – CPR and AED Usage
Frequently Asked Questions
What’s the correct chest compression depth for adult CPR?
The chest should be compressed 5–6 cm for adults, allowing full chest recoil between compressions.
How many compressions per minute should I perform?
Aim for 100–120 compressions per minute to maintain effective blood flow.
Do I need to give rescue breaths when performing CPR?
Yes. The standard ratio is 30 compressions to 2 breaths. If unable or untrained, continue with hands-only CPR.
When should I call emergency services?
Immediately. Dial Triple Zero (000) before starting CPR or have someone else call while you begin compressions.
How often should I refresh my CPR and first aid skills?
Every 12 months for CPR and every three years for first aid courses.
regular refresher training will ensure that you avoid costly mistakes such as incorrect compression depth.
How can I avoid incorrect compression depth when I perform CPR?
To avoid incorrect compression depth when you perform CPR, focus on pressing the chest down firmly and consistently. For adults, compress the chest about 5–6 centimetres deep at a steady rhythm of 100–120 compressions per minute. Ensure you’re on a firm surface, keep your shoulders directly above your hands, and allow full chest recoil between compressions. Regular CPR practice on a manikin during accredited training helps you develop the correct feel for proper depth and pressure, ensuring your compressions are effective and safe.