Adult Basic Life Support (BLS) Using DRSABCD


Published: 25 January 2021

Basic life support (BLS) is a crucial and potentially life-saving skillset for providing emergency treatment to a person experiencing a life-threatening illness until more advanced interventions can be performed.

It’s essential that all healthcare workers know how to correctly perform BLS.

In all Australian healthcare service settings, basic life support is an aspect of patient care directly tied to Standard 8 of the National Safety and Quality Health Service: Recognising and Responding to Acute Deterioration (ACSQHC 2019).

Note: The information is this article applies to adult patients/residents only.

What is Basic Life Support (BLS)?

Basic life support (BLS) is a procedure used to achieve preliminary preservation or restoration of life until advanced life support (ALS) can be performed. It involves establishing and maintaining airway, breathing, circulation and related emergency care using CPR, in addition to using an automated external defibrillator (AED) (Carey 2014a; VIC DoH 2014).

BLS can only generate about 20 to 30% of normal cardiac output, so it should only be used as a temporary substitute for normal ventilation and circulation. However, early, correctly-performed BLS is associated with better oxygenation, an increased likelihood of successful defibrillation, an increased likelihood that the patient will respond to advanced techniques and consequently, a higher chance of survival (HCA 2016; VIC DoH 2014).

What is Advanced Life Support (ALS)?

Advanced life support (ALS) describes interventions that are performed additionally alongside BLS to achieve airway management, ventilation and circulation. Interventions may include advanced airway management, vascular access/therapy and other actions (Carey 2014b).

Who Can Perform BLS?

BLS can be performed by first responders, healthcare professionals and bystanders. The Australian Resuscitation Council holds the belief that ‘any attempt at resuscitation is better than no attempt’ (American Red Cross 2019; ARC 2019).

The Chain of Survival

basic life support chain of survival diagram

The chain of survival summarises the series of crucial actions that should be taken to resuscitate someone who is experiencing cardiac arrest. These actions are vital for successful resuscitation and when performed quickly enough, can significantly increase the likelihood of survival (St John VIC 2016; ERC 2015).

The steps are:

1. Early Access to Get Help

It is crucial to recognise that an emergency is occurring. An ambulance should be called immediately to ensure the patient/resident receives defibrillation and life support as soon as possible (St John VIC 2016).

2. Early CPR to Buy Time

In order to maintain oxygenation of the brain and other crucial organs, cardiopulmonary resuscitation (CPR) should be commenced within four minutes of cardiac arrest (St John VIC 2016).

3. Early Defibrillation to Restart Heart

Survival rate can be significantly improved by applying an AED as soon as possible, ideally within two minutes (ANZCOR 2016b; Ambulance Victoria 2019).

Performing early defibrillation can increase the likelihood of survival by about 70%, but every minute without defibrillation decreases the chance of survival by 10% (St John VIC 2021).

4. Early Advanced Life Support

The likelihood of survival can be further improved by interventions such as medication and stabilisation of the airway (St John VIC 2016).

DRSABCD Action Plan

DRSABCD is an acronym used to outline the steps of BLS. They are:

  • D - Dangers?
  • R - Responsive?
  • S - Send for Help
  • A - Open Airway
  • B - Normal Breathing?
  • C - Start CPR
  • D - Attach Defibrillator

(ANZCOR 2016a)

D - Dangers?

When performing BLS, your first priority is to check the scene for danger and identify any potential hazards or risks that may jeopardise the safety of you, the patient/resident or bystanders (HCA 2016).

Where there is more than one patient/resident in need of assistance, whoever is unconscious takes priority (ANZCOR 2016b).

Dangers generally fall into one of the following categories:

  • Manual handling
  • Infection
  • Environment (e.g. fire, electricity, traffic).

(HCA 2016)

You should generally avoid moving the patient/resident, as this may cause their condition to deteriorate further. However, there are some situations where this cannot be avoided (HCA 2016). These include moving the patient/resident to:

  • Ensure the safety of both you and the patient/resident
  • Protect the patient/resident from extreme weather conditions
  • Move the patient/resident from difficult terrain
  • Enable airway and breathing management (e.g. by turning the patient/resident)
  • Help manage severe bleeding.

(ANZCOR 2016b)

Always follow best-practice manual handling principles if attempting to move a patient/resident (HCA 2016).

R - Responsive?

Assess whether the patient/resident will respond to verbal and tactile stimuli (this is known as ‘talk and touch'). Give them a simple command such as ‘open your eyes’ or ‘squeeze my hand’, then firmly grasp and squeeze their shoulders (ANZCOR 2016b).

A person that gives no response or only a minimal response (e.g. groaning without opening their eyes) should be treated as unconscious (ANZCOR 2016b).

Assess for signs of life. Lack of movement, unconsciousness, lack of breathing or abnormal breathing may indicate no signs of life (Ionmhain 2020).

Unconsciousness may be caused by:

  • Low brain oxygen levels
  • Heart and circulation issues (e.g. fainting, arrhythmia)
  • Metabolic issues (e.g. overdose, intoxication, hypoglycaemia)
  • Brain issues (e.g. head injury, stroke, tumour, epilepsy).

(ANZCOR 2016b)

S - Send for Help

basic life support drsabcd send for help
Remember that the Australian Ambulance Service emergency phone number is 000.

Delegate someone to call emergency services and retrieve an AED if possible (Ionmhain 2020). If you are alone with the patient/resident, you may wait until after the first two minutes of CPR to send for help (HCA 2016).

As a healthcare professional, it is your responsibility to know:

  • Relevant emergency phone numbers
  • The method for calling emergency codes in your clinical setting
  • The location of emergency buzzers and alarms
  • The location of the resuscitation trolley and emergency equipment
  • Your facility’s policies and procedures.

(HCA 2016)

Remember that the Australian Ambulance Service emergency phone number is 000.

A - Open Airway

Managing the patient/resident’s airway must take priority over any other injury they have, including a spinal injury (ANZCOR 2016b).

If an unconscious patient/resident is lying on their back, their tongue may fall against the back wall of their throat and obstruct airflow (as unconsciousness causes the muscles to relax). This blockage may be further exacerbated by soft tissues in the airway. Furthermore, an unconscious person will be unable to swallow or cough out foreign bodies (ANZCOR 2016b).

basic life support drsabcd tongue obstructing airflow
If an unconscious patient/resident is lying on their back, their tongue may fall against the back wall of their throat and obstruct airflow.

Other potential causes of airway obstruction include:

  • Semi-solid material (e.g. vomit, seaweed)
  • Solid material in the airway entrance or within the upper airway
  • Laryngeal spasm (a reflexive closure of the trachea entrance in response to foreign matter irritating the vocal cords)
  • Swelling from asthma, allergies etc.
  • Injuries involving the airway (e.g. from smoke, toxic fumes).

(HCA 2016; ANZCOR 2016b)

In order to manage the patient/resident’s airway:

  • Keep the patient/resident in the position they were found in unless there are signs of airway obstruction. Always use gentle handling if moving the patient/resident.
  • Clear the patient/resident’s airway by opening their mouth and turning their head slightly downwards. This will allow foreign material such as food, vomit, blood and secretions to drain. You may use a finger sweep to manually remove foreign bodies.
  • If the patient/resident’s airway becomes compromised during resuscitation, roll them onto their side to clear their airway. Once their airway is clear, reassess for responsiveness and normal breathing.
  • If the patient/resident is unresponsive, use the head tilt/chin lift to open their airway. Place one hand on their forehead or the back of their head and use your other hand to hold their chin up. Tilt their head backwards, holding their jaw slightly open and pulled away from their chest. This should pull their tongue and soft tissues away from the back of their throat, opening up their airway. Note that the head tilt/chin lift maneuver must not be used for infants (children under the age of one).

(ANZCOR 2016b; Ionmhain 2020)

basic life support drsabcd head tilt chin lift
If the patient/resident is unresponsive, use the head tilt/chin lift to open their airway.

B - Normal Breathing?

If the patient/resident is unresponsive and gasping or breathing abnormally, they require resuscitation. Abnormal breathing may be caused by:

  • Depression of or damage to the respiratory centre in the brain
  • Upper airway obstruction
  • Paralysis or impairment of the nerves and/or muscles required for breathing
  • Lung problems
  • Drowning
  • Suffocation.

(ANZCOR 2016b)

When assessing the patient/resident’s breathing:

  • Look for upper abdomen or chest movement
  • Listen for air escaping from the nose and mouth
  • Feel for air movement at the nose and mouth.

(ANZCOR 2016b)

C - Start CPR

If the patient/resident is unresponsive and breathing abnormally once the airway has been opened and cleared, you must commence chest compressions and rescue breathing (ANZCOR 2016b).

To perform CPR:

  • Chest compressions should be performed at a rate of 100 to 120 bpm (beats per minute) (about 2 per second) regardless of age.
  • To perform a compression, place the heel of one hand in the centre of the patient/resident’s lower sternum and the other hand on top of the first hand. Push down firmly, depressing the sternum about one-third of the depth of the chest for each compression (this is approximately 5cm in adults). Avoid compressing below the lower limit of the sternum, as this may lead to organ damage or regurgitation. Compressing too high may achieve inadequate depth.
  • Ensure the compression rhythm is regular.
  • Ensure the patient/resident’s chest completely recoils between each compression.
  • If possible, rotate rescuers every two minutes to prevent fatigue, and consequently poor compression quality.
  • Minimise interruptions to compressions. Do not pause compressions to check for breathing or responsiveness. CPR should only be interrupted for AED defibrillation.
  • Rescuers who are appropriately trained and willing to give rescue breaths should do so. Two rescue breaths should be performed after every 30 compressions.

(ANZCOR 2016b; HCA 2016)

To perform a mouth-to-mouth rescue breath:

  1. Kneel next to the patient/resident’s head and keep their airway open.
  2. Take a breath and open your mouth as widely as possible.
  3. Place your mouth over the patient/resident’s slightly open mouth.
  4. Ensure you are keeping the patient/resident’s airway open.
  5. Pinch the patient/resident’s nostrils or seal them with your cheek.
  6. Blow to inflate the patient/resident’s lungs. The breath should be about one second in duration.
  7. The volume of the breath should achieve chest rise, but avoid over-inflating.
  8. If the chest does not rise this may indicate obstruction or improper technique (not enough air being blown into the lungs or inadequate air seal around the patient/resident’s mouth and nose).
  9. After blowing air into the patient/resident’s lungs, lift your mouth away, turn your head to the patient/resident’s chest and listen for air being exhaled.
  10. Alternatives to mouth-to-mouth include mouth-to-nose, mouth-to-mask and mouth-to-neck stoma.

(ANZCOR 2016b; HCA 2016)

Consider using a barrier device if one is available. However, risk of disease transmission through rescue breaths is low so do not be deterred if a barrier device is unavailable (ANZCOR 2016b).

A bag-mask device or advanced airway is advised for airway management, however, anyone using such equipment should be adequately trained and competent (ANZCOR 2016b).

D - Attach Defibrillator

basic life support drsabcd automated external defibrillator
AEDs can be found in many public places, including supermarkets, workplaces and sporting facilities.

Automated external defibrillators (AEDs) are devices used to deliver controlled electrical shocks to people experiencing particular cardiac arrhythmias. AEDs are small and portable. They can be found in many public places, including supermarkets, workplaces and sporting facilities. It is your responsibility to know the location of AEDs in your workplace. AEDs must only be used alongside CPR (NSW DoH 2020a; St John VIC 2020).

The Ambulance Victoria AED Registry can be used to locate publicly accessible AEDs in Victoria.

In patients/residents who are unresponsive and breathing abnormally, prompt defibrillation is crucial. An AED should be retrieved as quickly as possible, as every minute in delay reduces the patient/resident’s chance of survival. Note that anyone, regardless of whether they are trained or not, can operate an AED if required (ANZCOR 2016b).

CPR should be performed until an AED is retrieved, turned on and attached. Once the AED is ready, follow the prompts (ANZCOR 2016b).

Proper pad placement is crucial to ensure the shock is delivered on an axis through the heart. Place one pad just below the collarbone on the patient/resident’s right chest and the second below the patient/resident’s left armpit. If the patient/resident is big-breasted, you can place the second pad lateral to the left breast instead. The chest must be exposed, and you may need to remove moisture or chest hair to ensure pad-to-skin contact. However, keep in mind that delays in defibrillation must be minimised (ANZCOR 2016b).

Other acceptable pad placements include anterior-posterior (where the anterior pad is placed over the praecordium or apex, and the posterior pad is placed on the back in the left or right infrascapular region) and apex-posterior (ANZCOR 2016b).

Anterior-posterior electrode placement may be considered if defibrillation electrodes are at risk of overlapping (paediatric patients) (CC: Queensland Ambulance Service, Clinical Practice Procedures: Resuscitation/Defibrillation 2019).

basic life support drsabcd defibrillator placement sterno-apical
Place one pad just below the collarbone on the patient/resident’s right chest and the second below the patient/resident’s left armpit.

AED Pad Placement Considerations

  • The patient/resident may have drain tubes that occupy the intended anterolateral pad placement.
  • Avoid chronic or surgical wounds.
  • You may be unable to access the side of the resident/patient depending on the position you found them in. Consider alternative manual handling options in this situation.
  • Implantable medical devices may hinder pad placement. Pad must be placed 8cms away from these devices.
  • Medication patches must be removed and skin cleaned prior to pad placement.

(ANZCOR 2016b)

Always check safety before delivering a shock:

  • Ensure nobody (you, the patient/resident or others) is in contact with metal objects;
  • Move oxygen away from the patient/resident;
  • Ensure nobody is touching the patient/resident;
  • Perform a 360-degree visual safety check before pushing the ‘shock’ button; and
  • Give a clear, loud order to ‘stand clear’ before pushing the ‘shock’ button.

(HCA 2016)

Remember that AED must only be used for unresponsive patients/residents who are breathing abnormally (ANZCOR 2016b).

If the defibrillation is successful, the patient/resident will have a return of spontaneous circulation (ROSC), become responsive and start to breathe independently. You should:

  • Stop CPR
  • Leave the AED pads attached (in case the patient/resident goes back into arrest)
  • Closely monitor the patient/resident
  • Place the patient/resident in the left lateral (recovery) position
  • Wait for help to arrive.

(HCA 2016)

basic life support drsabcd recovery position
If the defibrillation is successful, you should place the patient/resident in the left lateral (recovery) position.

Note: There is a possibility that the patient/resident could deteriorate once again, which may require recommencement of CPR and further defibrillation as per AED if the patient/resident becomes unresponsive.

If the defibrillation is unsuccessful, continue CPR. Only stop if:

  • You are alone in an isolated place and cannot continue due to exhaustion
  • The operator stops and declares the patient/resident deceased after a long attempt at resuscitation (where the patient/resident is unresponsive and you have no other help)
  • CPR is ordered to be stopped at the discretion of a healthcare professional and the patient/resident is declared deceased.

(HCA 2016)

BLS For Suspected or Confirmed COVID-19

The New South Wales Department of Health has developed a refined version of the DRS ABCD guidelines to use for patients/residents who are confirmed or suspected to have COVID-19. This can be viewed here.


It is crucial that you continue to practise BLS so that when the time comes, you feel confident in your practice and clinical judgement.

Note that this is a written refresher on basic life support and not designed to be a substitute for comprehensive education and hands-on training. Always follow your organisation's policies and procedures.

Additional Resources