What is the Chain of Survival?

Key Takeaways – Chain of Survival & Cardiac Arrest Response

• Cardiac arrest can strike anywhere – over 75% occur outside hospitals, with survival rates under 5% if untreated.

• Early access saves lives – recognise unconsciousness or lack of breathing and call 000 immediately with clear, accurate details.

• Early CPR is critical – starting CPR within 2–3 minutes can double or triple survival chances and prevent brain damage.

• Early defibrillation is the most vital step – every minute without an AED reduces survival by ~10%.

• AEDs are simple to use – they analyse heart rhythm, give voice prompts, and can be operated by any first aider.

• Use AEDs safely – ensure chest is dry, pads are placed correctly, and no one touches the casualty during a shock.

• Early advanced care from expert greatly improves stabilisation and long-term survival outcomes.

• Post-incident debriefing supports mental health for first aiders, bystanders, and casualties after a critical event.

• Learn CPR and AED use – training ensures you can respond effectively in emergencies.

• Know your nearest AED location – quick access can be the difference between life and death.

• Cardiac arrest can happen anytime, anywhere. More than 75% of cardiac arrests occur outside a hospital, and of that – only 5% survive if left untreated.
• Survival from cardiac arrest depends on a series of critical interventions.
• Survival is unlikely if one of these critical actions is neglected or delayed.
• The American Heart Association has used the term Chain of Survival to describe this sequence.

First Link – Early Access

Early access is recognizing that a person is unconscious or not breathing and that they need more than basic first aid and then calling for an ambulance or medical assistance as soon as possible.

When calling 000 for assistance, you must be clear on your information. Please provide specific details about your location and the nature of the emergency, and follow all their instructions.

Second Link – Early CPR

The two most vital anatomical systems in our body are the Cardiovascular and Respiratory Systems. If these systems fail for only a short time, the body cannot function normally, and this will eventually cause death.

Statistics show that our brain cells begin to die in as little as 3-4 minutes without oxygen. Brain cells do not regenerate; therefore, if CPR is delayed, the more chance the casualty may suffer permanent brain damage and the less chance of survival.

Early CPR within the first 2-3 minutes can significantly improve the chances of survival.

Third Link – Early Defibrillation (D – Defibrillation)

An automated External Defibrillator (AED) is a portable computerised device that provides an electrical charge to return the heart to a normal rhythm.

The portable device has a built-in computer and sensor that checks for the heart rhythm once placed on the casualty’s chest and determines if defibrillation is required. Voice prompts are given to the user to follow and streamline the defibrillation process.

• Access to Early Defibrillation is the most critical step in this cycle.
• Every minute of early defibrillation is delayed, which reduces the person’s chances of survival by 10%. This is why it is so important to call 000 / 112 if a cardiac arrest is suspected. A defibrillator is necessary to reverse this process and ‘reboot’ the heart back into its normal cycle.
• An AED can be used effectively with minimal training, as all current models are designed to function only if the unit detects an abnormal “shockable” heart rhythm.
• AED use is not restricted to trained personnel – any first aider can use an AED
• AED units can accurately identify the casualty’s cardiac rhythm as ‘shockable’ or ‘non-shockable.’
• An AED is only to be applied to a non-breathing casualty!

AED for Adults

Once it is determined that the casualty is unconscious and not breathing after having a suspected cardiac arrest and after calling 000, the following steps should be taken to use an AED as soon as one is available correctly:

1. CPR should not be delayed while waiting for the AED to arrive – Start CPR immediately
2. Defibrillation is to be used in conjunction with CPR on casualties who are unconscious and not breathing. The casualty is to be supine (lying on their back)
3. (If possible, have a second person complete the AED aspects while the first person continues with CPR). Turn on the AED and follow the voice or display commands. 
4. Move any clothing out of the way of the casualty’s chest 
5. If the casualty is wet or sweaty, remove any moisture with something dry before placing the AED pads on the casualty 
6. Tear open the AED pad packets and remove the pads 
7. If the casualty has a lot of body hair and the pads don’t stick to the chest, you must shave the hair. Attach one pad to the casualty’s upper right chest and the other to the casualty’s lower left chest – these positions will be labelled on the pads (see diagram). Pads must adhere firmly to the chest, so it is essential to roll the pads onto the chest so that there are no air pockets underneath the pads. Press the pads on firmly, including the edges of the pad.
8. Avoid placing pads over any implantable devices – pads should be placed at least 8cm from any such devices 
9. Do not place pads over medication patches – remove the patches before continuing, as these can block the current and cause burns to the casualty 
10. If not already attached, plug the cables from the pads into the unit (most units already have this ready for use) 
11. Do not put or place the electrodes or connected pads together or allow them to touch if the AED is ‘on’. This may complete a circuit and cause an electrocution
12. Move any bystanders out of the way – ensure no one else is touching the casualty
13. AED will analyse casualty. If the AED determines that a shock is needed, move everyone away from the casualty
14. Other first-aiders continue CPR until the AED operator is ready to shock
15. Make sure no one is touching the casualty, press the ‘Shock’ button, and then let the AED re-analyse
16. Follow the instructions of the AED – at this point, you may be instructed to commence CPR, DO NOT remove the pads, or the AED unit may otherwise instruct you that another shock is necessary
17. Continue CPR and AED until the ambulance arrives

AED for children

• Standard adult AED pads are suitable for persons 8 years and older.
• For children under 8 years of age, paediatric pads should be used when available.
• When using paediatric pads on a child, they should be positioned the same way as an adult.
• If these are not available, standard adult AED pads can be used. Ensure the pads do not touch each other on the child’s chest. If the pads are too large, pad-to-pad arcing is dangerous. In this case, the pad placement is different for adult AED. One pad must be placed in the centre of the chest, and the other on the back in the centre. This will be labelled on the pads.

NOTE: Always refer to the manufacturer’s directions/guidelines, as they may vary between brands

AED Safety

An AED, just like any electrical appliance, has safety precautions to prevent injury. The AED operator is responsible for keeping all persons from touching the casualty when a shock is delivered. State a ‘clear’ message. For example, say loudly “don’t touch the casualty” or “stand clear”. Ensure that no one touches the casualty before pressing the shock button.

The AED should never be connected to anyone other than a casualty in cardiac arrest, nor should an AED be attached to a person for training or demonstration purposes.

Beware of water

Ensure the casualty’s chest area is dry. Do not use an AED if the casualty is in water. Water is an effective electricity transmitter, and the shock may be transmitted to the AED operator.

Fourth Link – Early Advanced Care

Early advanced care means the sooner a expert can attend to the casualty, the greater the chance a casualty can be stabilised. As such, you must call 000 as quickly as possible. The sooner you contact emergency services, the sooner a expert will be on the scene, dramatically increasing the casualties’ chance of survival.

When they arrive, it is essential to calmly provide accurate and detailed information about the casualty and the incident to expert and emergency workers. The actions taken and treatment you have provided, the time of the incident, any medications involved, and the behaviour of the casualty are all essential things emergency workers will want to know. Provide details in a way that recognises that it is time-critical.

Post-Incident Debriefing

Once you have provided CPR or first aid to a casualty and handed over responsibility to the expert, it is recommended that you undergo a debriefing.

• Discuss your actions with your manager, other first aiders, psychologists, doctors, family or friends.
• Take time to calm down and reflect on your actions. If the incident occurred in a workplace, don’t return to work.

Note that anyone around the incident, such as the casualty, the first aiders, and onlookers, who may include children, can be affected by stress from the trauma that had occurred. Psychological stress can badly affect people of all ages, either during or after the incident. For example, talk with children about their emotions and responses to the incident. Provide support as required.

Post Incident Reactions

The following reactions are normal and help people understand a critical incident.

Physical reactions

Disturbed sleep, nausea, nightmares, restlessness, headaches, excessive alertness, undue crying and being easily startled.

Cognitive reactions

Poor concentration, visual images of the event, intrusive thoughts, disorientation or confusion, poor attention and memory.

Emotional reactions

Fear, numbness and detachment, avoidance, depression, guilt, over-sensitivity, anxiety and panic, withdrawal and tearfulness.

Seek Professional Help

Traumatic stress can cause extreme reactions in some people. You should seek professional help if you:

• Are unable to handle the intense feelings or physical sensations
• Don’t have normal feelings but continue to feel numb and empty
• Feel that your emotions are not returning to normal after three or four weeks
• Continue to have physical symptoms
• Continue to have disturbed sleep or nightmares
• Find that relationships with family and friends are suffering
• They are becoming accident-prone and using more alcohol or drugs.

Support can be accessed through counselling, educational material explaining the situation, stress-management techniques, professional help, and wellness programmes.

Positional Asphyxia

Positional Asphyxia is a condition that occurs when a person’s position causes their breathing to be restricted. It can be potentially fatal if they are in such a position for any time. Positional asphyxia occurs commonly in small infants who find themselves in a position where their airways are restricted and are unable to reposition themselves.

This can also occur in adults either by an accident where they become stuck in a difficult position, i.e., a car accident or more commonly during restraint by police officers, security guards or even health care staff if not carefully performed.

People who are at higher risk include those with:

• Heart problems, such as angina
• High blood pressure or diabetes
• Intoxicated or drug-affected people
• The elderly

Warning Signs:

If the person complains of or demonstrates any of the following:

• Difficulty breathing
• Feeling sick/nauseous
• Obvious distension of the veins in their neck
• A change in behaviour – either becomes more or less resistant
• Becomes limp or unresponsive
• Loss of consciousness

What to do if they lose consciousness:

Follow DRS ABCD

• If the person is breathing, lay them in the recovery position and monitor closely.
• If the person is not breathing, then you should start CPR immediately and call 000

Fainting

Fainting is a temporary loss of consciousness, otherwise called syncope. It is generally caused by a temporary reduction in the blood supply to the brain. Before fainting, the casualty may feel light-headed, nauseous or dizzy and appear pale and clammy.

Fainting can be caused by a variety of factors, such as:

• A sudden drop in blood pressure
• A sudden change in position, i.e. from lying to standing
• Dehydration
• Stress or fear
• Poison or Alcohol
• Heat
• Pain

Management of Fainting

Before Fainting:

• If a casualty is light-headed and appears near to fainting, the best thing to do is to lie down on their back and raise their legs, increasing the blood supply to the brain
• If the casualty refuses to lie down, keep close to the casualty in case they collapse. Remember also to protect your back – if the casualty is falling, do not attempt to keep them upright, but rather guide them gently down onto the ground
• Once on the ground, they can be placed in the recovery position

If Unconscious:

• If they lose consciousness, follow DRS ABCD. Fainting usually lasts only a few seconds to a minute or two, and the casualty may even have a slight seizure.
• Proper placement into the recovery position will assist recovery. Once conscious, encourage the casualty to lie down until they feel better, then very gradually move back into an upright position to reduce the risk of fainting again

Determining Appropriate Treatment of a Casualty

Respectful Behaviour Towards a Casualty

The first aider should always display a respectful attitude towards the casualty (conscious or not) by respecting privacy, cultural beliefs, religious beliefs, ethnicity, languages, genders, disabilities and age when communicating and interacting with the casualty. While giving aid to a casualty, be mindful of the following:

• Help comfort the casualty to feel safe, secure and supported
• Be gentle and help maintain their dignity
• Avoid any unnecessary personal contact with the casualty
• Use appropriate and respectful communication. Speak in a clear, calm and slow manner
• Help the casualty to remain calm and reassure them that help is on the way
• Stay with the casualty until help arrives

Determining appropriate treatment of a casualty relies heavily on assessing the situation and the casualty themselves. A visual survey is the first key to determining the necessary response when arriving at a scene with one or multiple casualties.

What to look for:

• Does the casualty appear conscious or unconscious?
• If conscious, does the casualty appear in pain, or are they demonstrating signs of an altered mental status?
• Is there blood present or any signs of violence?
• Is medication in the casualty’s hand or lying nearby?
• Is the casualty wearing a medical bracelet or necklace?
• Based on the location and circumstances, is there a high risk of alcohol and illicit drugs being involved?

If the casualty is unconscious, always follow DRS ABCD. This highly recommended method covers the most essential aspects of assessing a casualty’s well-being in a logical and easy-to-remember order.

If the casualty is conscious, follow a logical progression of questioning and assessment to determine what has occurred.

Ask the conscious casualty:

• TIME: Does the casualty know what the time is? What is the date? The year?
• PERSON: Does the casualty remember their name?
• PLACE: Does the casualty understand where they are?
• EVENT: Does the casualty know how they got here? What are they doing here?

If the casualty can answer all of these and is cooperative, they can generally indicate what has occurred and how they are injured.

Generally speaking, an excellent visual assessment and verbal questioning can almost always give you a good idea of what is occurring. From there, it is simply a matter of using your first aid skills to determine the best action and prioritise treatments.

• If they are bleeding, apply direct pressure, then immobilise and restrict movement of the injured part if possible.
• If they are suffering from an impaired level of consciousness, call an ambulance and monitor them closely until expert arrive.

Drowning

Drowning is the process of experiencing respiratory impairment from immersion in liquid.

Drowning is a common cause of accidental death. The most important consideration the first aid provider can make is to ensure safety, so do not attempt a rescue beyond your capabilities.

Remove all drowning casualties from water by the fastest and safest means available.

Signs & Symptoms

• Pale, cool skin
• Absent, rapid or difficult breathing
• Absent or decreased level of consciousness
• Coughing, wheezing, spluttering
• Cyanosis (bluish colour around lips)

Treatment of a casualty who has been rescued from drowning and is unconscious involves following DRS ABCD.

The first step is to place the casualty on their side during the checking/assessment stages of DRS ABCD, including checking for breathing (if possible). This allows any liquid to drain from the lungs with the assistance of gravity. If the casualty is unconscious and not breathing, lay the casualty on their back and commence CPR.

Note: Compression-only CPR is not the recommended resuscitation method for a drowning victim as it fails to address the casualty’s need for immediate ventilation

Specific problems related to the treatment of a drowning casualty:

Vomiting/regurgitation

• This is a possibility whenever CPR is performed; however, due to inhalation of water during drowning, it is much more likely to occur in this situation.
• Laying the casualty on their side during the initial assessment will assist in reducing this risk during CPR.
• If the casualty does vomit/regurgitate during CPR, immediately roll them onto their side, clear the airways, reassess DRS ABCD and continue CPR if necessary.

Respiratory Distress

Breathing difficulties can range from:

• Being short of breath
• Being unable to take a deep breath and gasping for air
• Feeling like you are not getting enough air

Some causes of acute ineffective breathing:

• Upper airway obstruction
• Problems affecting the lungs
• Drowning or near-drowning
• Asthma
• Suffocation
• Damage to the breathing control centre of the brain
• Multiple other conditions will result in respiratory distress as symptoms progress

In any situation where a casualty is unconscious and not breathing effectively, follow DRS ABCD and perform CPR.

Treatment for conditions causing respiratory distress:

There are specific treatments for different conditions causing respiratory distress.

Some respiratory distress conditions include:

• Asthma (will also often be accompanied by wheezing)
• Airway obstruction (casualty may be distressed and clutching at the throat)
• Heart Attack (accompanied by symptoms such as chest pain)
• Anaphylaxis (after exposure to an allergen, may be accompanied by hives and extreme anxiety)

Please refer to the appropriate sections in this text for first aid directions for these causes of respiratory distress.

CONCLUSION

Each of these links in the ‘Chain of Survival’ is important; if one fails, it can lead to tragedy. That’s why it’s essential for everyone – not just first responders – to learn CPR and how to use a defibrillator. You never know when you might be called on to save someone’s life. Have you been trained in CPR? Do you know where your nearest AED is located? If not, now is the time to take action, take a CPR course or first aid course, and get prepared for an emergency. Post-incident debriefings can help identify issues that led to the cardiac arrest and prevent them from happening again.