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 
o  Hypothermia 
o  Hypoxia 
o  Hypovolaemia 
o  Hypokalaemia/Hyperkalaemia 

•  FOUR Ts 
o  Toxins (and other metabolic disorders (drugs, therapeutic agents, sepsis))  
o  Thromboembolic 
o  Tamponade 
o  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 pulses

Question 6

Identify appropriate investigations for cardiac arrest

Answer 6

• Cardiac Monitor
o Allows classification of the rhythm

•  Bloods 
o  ABG 
o  U&E 
o  FBC 
o  XMmatch 
o  Clotting  
o  Toxicology screen  
o  Blood glucose

Question 7

Generate a management plan for cardiac arrest

Answer 7

• SAFETY IS IMPORTANT
o Approach any arrest scene with caution
o The cause of the arrest may pose a threat
o Defibrillators and oxygen are hazards

• BASIC LIFE SUPPORT
o If the arrest is witnessed and monitored, consider giving a precordial thump
(thump the sternum of the patient with the ulnar aspect of your fist)
o Clear and maintain the airway with head tilt, jaw thrust and chin lift
o Assess breathing by look, listen and feel
• If they are not breathing, give two rescue breaths
o Assess circulation at carotid pulse for 10 seconds
• If absent - give 30 chest compressions at around 100/min
• Continue cycle of 30 chest compressions for every 2 rescue breaths
o Proceed to advanced life support as soon as possible

ADVANCE LIFE SUPPORT
• Advanced Life Support
o Attach cardiac monitor and defibrillator
o Assess rhythm
• If pulseless ventricular tachycardia or ventricular fibrillation (shockable rhythms)
! Defibrillate once (150M360 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 ever 3M5 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

o During CPR:
• Check electrodes, paddle positions and contacts
• Secure airway
! Once secure, 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 8

Treatment of REVERSIBLE causes

Answer 8

o Hypothermia –> warm slowly
o Hypokalaemia and Hyperkalaemia –> correction of electrolyte levels
o Hypovolaemia –> IV colloids, crystalloids and blood products
o Tamponade –> pericardiocentesis
o Tension Pneumothorax–> aspiration or chest drain
o Thromboembolism –> treat as PE or MI
o 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