Cardiac arrest

Question 1

Define cardiac arrest?

Answer 1

acute cessation of cardiac function

Question 2

what are the 5Hs and 5Ts causes of cardiac arrest

Answer 2

FIVE Hs

• Hypothermia
• Hypoxia
• Hypovolaemia – dec blood volume
• Hypokalaemia/Hyperkalaemia
• hypo/hyperglycaemia

FIVE Ts

• Toxins (and other metabolic disorders (drugs, therapeutic agents, sepsis))
• Thromboembolic (MI and PE)
• Tamponade
• Tension pneumothorax
• Trauma

Question 3

what are the presenting symptoms

Answer 3

Management precedes or is concurrent to history

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

Question 4

what are the signs of carrest arrest on physical examination?

Answer 4

Unconscious

Not breathing

Absent carotid pulses

Question 5

what are the appopriate investigations for cardiac arrest?

Answer 5

ECG- done immediately then subsequently to assess evolving changes

cardiac monitor- allow classification of rhythm

bloods- find cause

CXR – endotracheal tube placement evaluated and may show complications of the cardiac arrest

Echo – assess cardiac activity and LV function (should be assessed 48hrs after)

Question 6

what are the possible complications of a cardiac arrest?

Answer 6

Systemic Hypoperfusion of kidneys

Microvasc changes – endo changes => Hypoperfusion of tissues

Immune dysreg

MSK changes e.g. muscle wasting

GI tract – malabsorpton across mucosa

Irreversible hypoxic brain damage

Death

Question 7

summarise the prognosis for patients with cardiac arrest?

Answer 7

Resuscitation is less successful if cardiac arrest happens outside the hospital

Increased duration of inadequate effective cardiac output –> poor prognosis

Question 8

describe ECG changes in cardiac arrest?

Answer 8

May show QT interval, ST-segment or Twave changes

Condution abnormalities

Ventricular hypertrophy

Question 9

describe what may be seen on the bloods in a cardiac arrest?

Answer 9

ABG – may show acidosis (could be the result or the cause of a cardiac arrest)

U&E – may show electrolyte abnormalities

FBC – haemorrhage may cause hypovol so low haematocrit should be evaluated for

Cardiac markers – MI may be the result or cause of cardiac arrest

Clotting

Toxicology screen

Blood glucose

Question 10

describe basic life support for cardiac arret?

Answer 10

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)

Clear and maintain the airway with head tilt, jaw thrust and chin lift

Assess breathing by look, listen and feel

• If they are not breathing, give two rescue breaths

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

Proceed to advanced life support as soon as possible

Question 11

describe advanced lif support for cardiac arrest?

Answer 11

Question 12

describe the post cardia arrest treatment?

Answer 12

ABCDE approach

Controlled oxygenation and ventilation

12 lead ECG

Treat precipitating cause

Temperature control/therapeutic hypothermia

Question 13

describe the treatment of the reversible causes of cardiac arrest?

Answer 13

• 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 14

describe advanced life support if there is If pulseless electrical activity (PEA) or asystole (non-shockable rhythms)

Answer 14

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 15

describe advanced life support if pulseless ventricular tachycardia or ventricular fibrillation (shockable) rhythms – rhythms caused by aberration in electrical conduction system

Answer 15

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 ever 3-5 mins

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