Drugs during the treatment of cardiac arrest

Question 1

When is adrenaline used in VF/pVT?

Answer 1

After third shock once compressions have been resumed
Repeat every 3-5 minutes

Question 2

What is the dose of adrenaline in VF/pVT?

Answer 2

1mg (10ml 1:10000 or 1ml 1:1000) IV

Question 2

When is adrenaline given in PEA/asystole?

Answer 2

As soon as circulatory access is obtained
Repeated every 3-5 minutes

Question 3

Why is adrenaline used in cardiac arrest?

Answer 3

Alpha-adrenergic effects cause systemic vasoconstriction, which increases coronary and cerebral perfusion pressure

Question 4

What are the negative effects of adrenaline?

Answer 4

Beta-adrenergic effects (inotropic and chronotropic) may increase coronary and cerebral blood flow but;

• concomitant increases in myocardial oxygen consumption and ectopic ventricular arrhythmias
• transient hypoxaemia because of pulmonary AV shunting
• impaired microcirculation
• increased post-cardiac arrest myocardial dysfunction

Question 5

What does adrenaline do in cardiac arrest?

Answer 5

Increases ROSC and the number of survivors with either a favourable/non-favourable outcome

The benefit may be greater when adrenline is given for a non-shockable rhythm

Question 6

When is amiodarone used in cardiac arrest?

Answer 6

Only in pVT/VF

Given after three defibrillation attempts
Further dose can be given if VF/pVT persists after five defibrillation attempts

Question 7

What does amiodarone do?

Answer 7

Membrane stabilising anti-arrhythmic that increases the duration of the action potential and refractory period in the atrial and ventricular myocardium

AV conduction is slowed, similar effect in accessory pathways

Mild negative inotropic action and causes peripheral vasodilatation through non-competitive alpha-blocking effects

Question 8

How should amiodarone be administered?

Answer 8

300mg bolus IV diluted in 5% dextrose to a volume of 20mL

Further dose of 150mg if persists

Question 9

What is the indication for calcium?

Answer 9

PEA caused by hyperkalaemia, hypocalcaemia or overdose of calcium channel blockers

Question 10

How should calcium be administered?

Answer 10

10mL 10% calcium chloride (contains 6.8 mmol Ca)
or
30mL 10% calcium gluconate IV

Question 11

What are the negative effects of calcium?

Answer 11

High plasma concentrations after injection may be harmful to ischaemic myocardium and may impair cerebral recovery

Question 12

What can calcium not be given at the same time as?

Answer 12

Sodium bicarbonate solutions via the same route

Question 13

What is the dose of sodium bicarbonate?

Answer 13

50 mmol (50mL of an 8.4% solution) IV

Question 14

What is the indication for sodium bicarbonate?

Answer 14

Shockable and non shockable rhythms for
- cardiac arrest associated with hyperkalaemia
- TCA overdose

Question 15

How should sodium bicarbonate use be monitored?

Answer 15

By acid-base analysis

Question 16

What is the best treatment for acidaemia in cardiac arrest?

Answer 16

Chest compression

Question 17

What does cardiac arrest due to the acid-base balance?

Answer 17

combined respiratory and metabolic acidosis as pulmonary gas exchange ceases and cellular metabolism becomes anaerobic

Question 18

What does sodium bicarbonate do in cardiac arrest?

Answer 18

Causes generation of CO2, which diffuses rapidly into cells;
- exacerbates intracellular acidosis
- produces negative inotropic effect on ischaemic myocardium
- presents a large, osmotically active sodium load to an already compromised circulation and brain
- produces a shift to the left in the oxygen dissociation curve, further inhibiting release of 02 in the system

Question 19

When should fluids be used in cardiac arrest?

Answer 19

If hypovolaemia is suspected

Question 20

What fluid should be used in cardiac arrest?

Answer 20

Use 0.9% NaCl or Hartmann’s solution, or blood for major haemorrhage

Question 21

Why is dextrose avoided in cardiac arrest?

Answer 21

Redistributed away from the intravascular space rapidly and causes hyperglycaemia which may worsen neurological outcome and survival

Question 22

What are the options for fibrinolytics in cardiac arrest?

Answer 22

Tenecteplase 500-600mcg kg-1 IV
Alteplase 50mg iv bolus if cardiac arrest with known or suspected PE
Consider giving a further 50mg if prolonged CPR attempt (30 minutes after first dose)