SUDDEN COLLAPSE AND CARDIAC ARREST

Common causes of the sudden collapse:
-Cardiac: due to ventricular fibrillation or ventricular tachycardia in most cases, other causes can be severe bradycardia, asystole or pulmonary embolism.

-Respiratory: tension pneumothorax, aspiration/upper airway obstruction or massive haemoptysis.
-Gastrointestinal: catastrophic bleed (usually from oesophageal varices) or a ruptured abdominal aortic aneurysm.
-Anaphylaxis: a characteristic setting with a recognised trigger, wheeze, oropharyngeal swelling and severe hypotension.

Diagnosing cardiac arrest
There are four common scenarios:
1. pulseless and collapsed with ventricular fibrillation or ventricular tachycardia - cardiac arrest.
2. pulseless and collapsed with a flat trace - cardiac arrest.
3. pulseless and collapsed but with an electrical rythm (pulseless electrical activity or PEA) - cardiac arrest.
4. flat trace but patient looks well - has an electrode come off?.

THE CHAIN OF SURVIVAL

Basic life support (BLS)

Basic life support describes the process of:

-the initial assessment of the collapsed patient

-the techniques to keep the airway open

-the use of expired air ventilation and chest compression - CPR.

The primary helpers continue active resuscitation. Secondary helpers may need to fetch the crash trolley, make the medical and nursing notes available, ensure laboratory results are fed back to the arrest team, put any recent X-rays up on the viewing box, see to other patients in the ward and move any patient if appropiate and handle the relatives: phone calls and direct contact.

Sequence of actions:

1. Ensure safety of rescuer and patient

2. Shout for help. Check the patient and see if he responds.

3. If the patient responds: recovery position, check his condition (ABCDE), give oxygen, secure Iv access and attach monitors. Reassess regularly and handover to the Emergency Medical Team using a standarised communication framework (RSVP: Reason, Story, Vital signs and Plan of management).

If the patient does not respond: turn him on his back and open his airway by tilting his head and lifting his chin, remove any visible obstruction.

Keeping the airway open, look, listen and feel for normal breathing:

-if patient is breathing normally: turn him into recovery position and check for continued breathing.

-if patient is not breathing normally: check for signs of circulation and signs of life.

If there are signs of circulation, start rescue breathing, check for circulation every 10 breaths. If patient starts to breathe on his own but remains unconscious, turn him into the recovery position.

If there are no signs of circulation or signs of life start chest compression, continuing compressions and breaths in a ratio of 30:2, at a rate of about 100-120 times a minute.

Continue resuscitation until the cardiac arrest team arrives to assist. Do not stop CPR to check the patient unless he starts to regain consciousness and shows clear signs of breathing normally again.

Advanced life support (ALS)

Once the arrest team arrives the situation can be reviewed, with the first priority being to analyse the heart rythm from the ECG monitor or via the self adhesive defibrillation pads.

In a cardiac arrest, the heart rhythm falls into one of two categories:

-Shockable rhythms: ventricular fibrillation and pulseless ventriculat tachycardia.

-Non-shockable rhythms: asystole and electrical complexes, but with no palpable pulse (PEA: pulseless electrical activity). This group needs emergency drugs (adrenaline) and continuing CPR.