Cardiac Arrest

Question 1

Define Cardiac Arrest

Answer 1

Acute cessation of Cardiac Function

Question 2

Explain the Aetiology of Cardiac Arrest

Answer 2

Reversible causes (4Hs + 4Ts)

• Hypothermia
• Hypoxia
• Hypovolaemia
• Hypokalaemia/Hyperkalaemia
• Toxins (other metabolic causes e.g. drugs, therapeutic agents, sepsis)
• Thromboembolic
• Tamponade
• Tension Pneumothorax

Question 3

What are the shockable and non-shockable rhythms?

Answer 3

Shockable:
- Ventricular Fibrillation
- Pulseless Ventricular tachycardi
Non-shockable
- Pulseless electrical activity (PEA)
- Asystole

Question 4

What are the risk factors of Cardiac Arrest?

Answer 4

• Ishaemic Heart disease
• Cardiomyopathy
• Dysrhythmias

Question 5

What are the symptoms of Cardiac Arrest?

Answer 5

• History
• Usually sudden
• May have preceding symptoms e.g. fatigue, fainting, blackouts, dizziness

Question 6

What are the signs of Cardiac Arrest?

Answer 6

• Unconscious
• Not breathing
• Absent carotid pulse

Question 7

Identify the appropriate signs of cardiac arrest

Answer 7

• Cardiac Monitor: allows classification of the rhythm

- Bloods: ABG, U&Es, FBC, cross-match (transfusion), clotting, toxicology screen, blood glucose

Question 8

What are the steps of Managing a Cardiac Arrest?

Answer 8

• Safety
• Basic Life Support
• Advanced Life Support
• Treatment of Reversible causes

Question 9

What are the steps to Basic Life Support?

Answer 9

(DRS ABC)

• If the arrest in witnessed and monitored, consider giving a precordial thump
• Clear and maintain airway with head tilt, jaw thrust and chin lift
• Assess breathing (look, listen feel), if not breathing 2x rescue breaths
• Assess circulation at carotid pulse for 10 seconds. If absent - 30x chest compressions at 100/min
• Continue cycle (30/2)

Proceed to Advanced life support asap

Question 10

What are the steps to Advanced Life Support?

Answer 10

• Attach cardiac monitor and defibrillator
• Assess rhythm

If Shockable (Pulseless VT or VF)

• Defibrillate once (150-360J biphasic, 360J monophasic)
• Resume CPR immediately for 2mins, assess rhythm, and shock again if pulseless
• Administer adrenaline (1mg IV) after second defibrillation and again every 3-5 mins
• If shockable rhythm persists after 3rd shock, administer amiodarone 300mg IV bolus (or lidocaine)

If non-shockable (PEA or asystole)

• CPR for 2 mins, reassess rhythm
• Administer amiodarone (1mg IV) every 2-5mins
• Atropine (3mg IV, once) if asystole or PEA with rate <60bpm

During CPR:

• check electrodes, paddle positions and contacts
• secure airway then give continuous compressions and breaths
• consider magnesium, bicarbonate and external pacing
• stop CPR and check pulse only if change in rhythm or signs of life

Question 11

What is the management plan for the reversible causes?

Answer 11

• Hypothermia: warm slowly
• Hypokalaemia and hyperkalaemia: correct electrolytes
• Hypovolaemia: IV colloids, crystalloids and blood products
• Tamponade: pericardiocentesis
• Tension pneumothorax: aspiration or chest drain
• Thromboembolism: treat as PE or MI
• Toxins: use antidote for given toxin

Question 12

Identify the possible complications of Cardiac Arrest?

Answer 12

• Irreversible hypoxic brain damage

- Death

Question 13

Summarise the prognosis for patients with Cardiac Arrest

Answer 13

• Resuscitation is less successful if the cardiac arrest happens outside of hospital
• Increased duration of inadequate cardiac output = poor prognosis