Your browser is no longer supported

For the best possible experience using our website we recommend you upgrade to a newer version or another browser.

Your browser appears to have cookies disabled. For the best experience of this website, please enable cookies in your browser

We'll assume we have your consent to use cookies, for example so you won't need to log in each time you visit our site.
Learn more

Basic life support and AED

  • Comment

Brendan Docherty, MSc, RN, PGCE.

Clinical Manager - Cardiology and Critical Care

The earlier that effective treatment is provided, the more likely it is that a person suffering from cardiopulmonary arrest will survive (RCUK and ERC, 2000).

The earlier that effective treatment is provided, the more likely it is that a person suffering from cardiopulmonary arrest will survive (RCUK and ERC, 2000).

The interventions that contribute to a successful outcome after cardiopulmonary arrest can be conceptualised as a chain, which has been called the ‘chain of survival’ (Smith, 2000). The chain is only as strong as its weakest link. Each link must therefore be strong and comprise:

- Recognition of cardiorespiratory arrest

- Early activation of emergency services

- Early basic life support (BLS)

- Early defibrillation

- Early advanced life support (ALS).

Failure of the circulation for three to four minutes will lead to irreversible cerebral damage. BLS acts to slow down the deterioration of the brain and the heart until defibrillation and/or ALS can be provided (RCUK and ERC, 2000). Prompt recognition of cardiopulmonary arrest and prompt instigation of BLS can double the patient’s chance of survival (BHF, 2001). Although national guidelines may continue to vary, the underlying scientific principles upon which resuscitation guidelines are based are now international (Winser, 2001).

Health-care professionals in the UK are legally liable for any act or omission on their part that harms such a patient (BMA, 2001; NMC, 2002). The national guidelines indicate health professionals must attend BLS training at least once every 12 months (NHSLA, 2000).

Wherever patients are treated, automated external defibrillation (AED) is a proven effective means for any health-care professional to deliver a defibrillator shock quickly in an emergency (Mancini and Kaye, 1999; Smith, 2000). Use of an AED removes the need for the operator to be able to interpret an electrocardiogram (ECG) trace.

Basic life support procedure

The guidelines (RCUK and ERC, 2000). indicate that a rescuer should:

1. Ensure own safety and that of the patient.

2. Check the patient’s responsiveness by gently shaking them and shouting ‘Can you hear me?’

3. If there is no response the rescuer should shout for help.

4. Check the patient’s mouth and remove any debris and then open the patient’s airway using the head-tilt, chin-lift manoeuvre. If cervical spine injury is suspected the jaw-thrust method should be employed.

5. Look, listen and feel for breathing in the patient for 10 seconds.

6. If patient is not breathing call emergency services or hospital cardiac arrest team.

7. Give the patient two rescue breaths with a pocket mask or bag-valve-mask (Jevon, 2002).

8. Check for signs of circulation for 10 seconds. The carotid pulse is located by placing the second and third finger on the patient’s trachea - locating the Adam’s apple or cricoid cartilage. Move fingers laterally approximately 4-5cm to the sternomastoid muscle mass. Pushing medially you should then be able to locate the carotid artery.

9. If there are no signs of circulation start chest compressions.

10. Continue rescue breathing and chest compressions at a ratio of 2:15 until the emergency services/cardiac team arrive and take over or the patient makes a sign of life.

AED procedure

When an AED is available the RCUK and ERC guidelines (2000) state:

1. Follow BLS steps 1-5

2. If the patient is not breathing call the emergency services or cardiac arrest team and bring the AED to the patient. If the AED is not immediately available start BLS as above.

3. Switch on the AED and attach the electrode pads following spoken or visual directions given by the AED.

4. Ensure that nobody touches the patient while the AED is analysing the rhythm.

5. If a shock is indicated, ensure that everybody is clear of the patient, push the shock button as directed by the AED.

6. Repeat analyse +/- shock, as directed by AED.

7. If there are no signs of circulation after three shocks perform one minute of BLS.

8. Continue to follow AED instructions until advanced life support is available.

If at any time signs of a circulation are present, check for breathing. If breathing is present place the patient in the recovery position and, where possible, give oxygen.

If breathing is absent give rescue breaths at a rate of 10 per minute and then reassess. This action should continue until the emergency services/cardiac arrest team arrive or the patient starts to breathe unaided.


- The heart lies between the sternum and the spine. External compressions force the sternum down onto the left ventricle, squeezing it between the sternum and the spine and resulting in blood ejection from the heart (RCUK and ERC, 2000; Tortora and Grabowski, 2001)

- Carotid pulse checks are difficult to undertake in patients who have had a cardiorespiratory arrest. These checks are also something not normally performed in everyday practice due to the possibility of undiagnosed thickened carotid arteries - usually due to artherosclerosis. In such cases trying to locate a carotid pulse may result in a small clot breaking off the thickened layer of the artery, resulting in a stroke (RCUK and ERC, 2000; Tortora and Grabowski, 2001)

- The cardiovascular and the respiratory nervous centres are positioned in the medulla oblongata, which is a continuation of the upper portion of the spinal cord. This centre provides the neural control for increasing heart rate and breathing rate. You can expect abnormalities in these functions following a successful resuscitation if the medulla has received a reduced oxygen supply during resuscitation attempts (RCUK and ERC, 2000; Tortora and Grabowski, 2001).


- Successful resuscitation is defined as a return of spontaneous circulation that lasts longer than 20 minutes

- For cardiac compressions, being taught to locate your hands in the centre of the chest (simple method) resulted in greater accuracy of hand placement when compared to the standard method of sliding up the rib cage to the xiphisternum. This resulted in less delay between ventilation and resuming chest compressions

- Effectiveness declines in cardiac compressions after one minute. A study has demonstrated that one minute of compressions followed by two minutes rest (a three-person compression team) was significantly better than a two-person team with only one minute’s rest in between each cycle of BLS.

(RCUK, 2000a; RCUK, 2000b; RCUK, 2000c)

  • Comment

Have your say

You must sign in to make a comment

Please remember that the submission of any material is governed by our Terms and Conditions and by submitting material you confirm your agreement to these Terms and Conditions. Links may be included in your comments but HTML is not permitted.