Cardiac arrest

Question 1

Define cardiac arrest

Answer 1

Acute cessation of cardiac function

Question 2

Explain the aetiology and risk factors of cardiac arrest

Answer 2

The REVERSIBLE causes of cardiac arrest can be summarised as the 4 Hs and 4 Ts

FOUR Hs
Hypothermia
Hypoxia
Hypovolaemia
Hypokalaemia/Hyperkalaemia

FOUR Ts
Toxins (and other metabolic disorders (drugs, therapeutic agents, sepsis))
Thromboembolic
Tamponade
Tension pneumothorax

Question 3

Summarise the epidemiology of cardiac arrest

Answer 3

None available

Question 4

Recognise the presenting symptoms of cardiac arrest

Answer 4

Management precedes or is concurrent to history

Cardiac arrest is usually sudden but some symptoms that may preceded by fatigue, fainting, blackouts,
dizziness

Question 5

Recognise the signs of cardiac arrest on physical examination

Answer 5

Unconscious
Not breathing
Absent carotid pulse

Question 6

Identify appropriate investigations for cardiac arrest

Answer 6

Cardiac Monitor
Allows classification of the rhythm

Bloods
ABG
U&E
FBC
X-match
Clotting
Toxicology screen
Blood glucose

Question 7

Generate a management plan for cardiac arrest

Answer 7

DR ABC 
Advanced Life Support
Attach cardiac monitor and defibrillator
Assess rhythm
If pulseless ventricular tachycardia or ventricular fibrillation (shockable rhythms) Defibrillate once (150 -360 J biphasic, 360 J monophasic)

Make sure no one is touching the patient or the bed
Resume CPR immediately for 2 minutes and then reassess rhythm, and shock again if still in pulseless VT or VF

Administer adrenaline (1 mg IV) after second defibrillation and again every 3-5 mins

If shockable rhythm persists after 3rd shock administer
amiodarone 300 mg IV bolus (or lidocaine)

If pulseless electrical activity (PEA) or asystole (non-shockable rhythms) - CPR for 2, and then reassess rhythm
Administer adrenaline (1 mg IV) every 3-5 mins
Atropine (3 mg IV, once only) if asystole or PEA with rate < 60 bpm

Question 8

Treatment of REVERSIBLE cardiac arrest causes

Answer 8

Hypothermia - warm slowly
Hypokalaemia and Hyperkalaemia - correction of electrolyte levels
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 9

Identify the possible complications of cardiac arrest

Answer 9

Irreversible hypoxic brain damage

Death

Question 10

Summarise the prognosis for patients with cardiac arrest

Answer 10

Resuscitation is less successful if cardiac arrest happens outside the hospital

Increased duration of inadequate effective cardiac output –> poor prognosis