Electrical Therapies

Question 1

What % of OOHCA happen at home?

Answer 1

60-80%

Question 2

Should AEDs be considered in hospital?

Answer 2

Yes - esp if it increases chance of early (<3 min) defib

Question 3

Advantages/disadvantages of semi-automatic mode?

Answer 3

Higher VF conversion rates, fewer inappropriate shocks.
Less time on compressions (longer pre-shock pause)

(No survival effect etc)

Question 4

Pads vs paddles?

Answer 4

Pads

Question 5

Why are biphasic waveforms more superior?

Answer 5

• More effective at terminating ventricular arrhythmias at lower energy levels
• Greater first shock efficacy
  NB no evidence re neuro intact survival to discharge
• For AF cardioversion (success, less burns etc)

Question 6

Initial biphasic shock?

Answer 6

Ideally 150J
No lower than 120 J for RLB waveforms
No lower than 150 for BTE waveforms

Question 7

Electrical cardioversion for A/V tachyarrhythmias - when to shock?

Answer 7

With the R wave.

NB can induce VF if shock during the refractory period.

Question 8

Does commencing with high or low energy waveforms make a difference when cardioverting?

Answer 8

No

Question 9

Initial shock when cardioverting?

Answer 9

120-150J

Question 10

Atrial flutter or paroxysmal SVT - initial shock?

Answer 10

100J monophasic

70-120 biphasic

Question 11

When to consider pacing?

Answer 11

Symptomatic bradycardia die to anti-cholinergic drugs.

Immediate if block is at or below Purkinje fibres

Question 12

Who much does an ICD discharge?

Answer 12

40J
Through internal wires in the RV.
Should max at 8.