Chapter 9 Defibrillation

Question 1

Following cardiac arrest, how long till a patient suffers a hypoxic brain injury?

Answer 1

3 minutes

Question 2

In the classic positioning of defibrillation pads (right chest below clavicle + left lower chest/axilla), how much current actually reached the heart?

Answer 2

As little as 4% (consider changing to AP position in refractory VT/VF)

Question 3

The patient is very hairy and in VF and there are no clippers immediately available, what are your options?

Answer 3

1) Apply over hair and hope it works
2) Use a bi-axillary placement

Find clippers ASAP

Question 4

Where do you place defibrillator pads for anteior-posterior placement?

Answer 4

Anterior over left precordium
Posterior just inferior to scapula

Preferred position for transcutaneous pacing

Question 5

After termination of VF by defibrillation, how often does it return within a two minute period?

Answer 5

50%

Be ready

Question 6

What can happy if you place a defibrillator pad over a pacemaker of ICD and deliver a shock?

Answer 6

You can damage the leads

Do not place pads over them and ideally should be 10cm away

Question 7

What is the total time that should not be exceeded during a pause for defibrillation/rhythm check?

Answer 7

5 seconds

Question 8

When you give 3 stacked shocks?

Answer 8

If 1st shock can be given within 20 seconds
Patient was monitored and pre-oxygened and well perfused beforehand
Rhythm is VT/VF

Question 9

How do you give 3 stacked shocks?

Answer 9

Give 1st shock
Check rhythm and pulse or other signs of ROSC after shock
All 3 shocks count as 1st shock on algorithm

Question 10

Does hold an infusion or the patient’s bed count as touching the patient during defibrillation?

Answer 10

yes

Question 11

The patient is wet/very sweat and needs defibrillation, what should you do first?

Answer 11

Dry the patient. Shocking a wet patient is dangerous.

Question 12

How far away should free flowing oxygen (mask, nasal prongs) be from the patient during defibrillation?

Answer 12

1 meter

Question 13

A patient has an ETT/LMA connected to a bag-valve ventilator with 15L flowing. You need to defibrillate. Is this oxygen ok?

Answer 13

Yes.
Can leave bag attached with oxygen.
No oxygen will be in the zone of defibrillation.
Though if concerned about movement of the airway by unsupported bag-valve ventilator you can disconnect bag if you want.

Question 14

A patient is on a ventilator already (ICU/surgical patient). Do you leave them on the ventilator or disconnect and use ventilation bag?

Answer 14

Ideally leave them on the ventilator (keeps their PEEP) but ensure they are still receiving adequate tidal volumes. If not, disconnect and use manual ventilation bag

Question 15

The defibrillator is set to shock at 200J biphasic. How may joules can you go up to ?

Answer 15

360 J

Question 16

What is the COACHED acronym stand for?

Answer 16

Compressions continue
Oxygen away
All others away
Charge the defib
Hands off
Evaluate rhythm
Defib or disarm

Question 17

What phrase does the defibrillating person say to the person giving chest compressions if they are not sure if they are cleared of the patient before a shock is to be given?

Answer 17

“Are you safe?”

Question 18

Do you ever feel for a pulse after defibrillation?

Answer 18

No (only if obvious signs of life)

Pause should be less than 5 seconds for defibrillation

Question 19

It is the first rhythm check OR you have been on the shockable side of the algorithm and you see organised electrical activity during a rhythm. What do you do?

Answer 19

Look for signs of ROSC:
Central pulse
Rise end tidal CO2

If no signs of life, switch to non-shockable side of algorithm. Do not keep checking pulse during rhythm checks, once is enough.

Question 20

When do you give amiodarone and how much?

Answer 20

300mg

After 3 shocks (any three, do not need to be sequetial)

Question 21

When do you give adrenaline and how much ?

Answer 21

1mg immediately if non-shockable rhythm
After 2nd shock if shockable rhythm

Then every alternate loop

Question 22

When do you use a paediatric defibrillator?

Answer 22

Age 1 - 8

Question 23

What do you do if there is no paediatric defibrillator present for your paediatric patient and all you have in an AED set to 200J?

Answer 23

Use adult one but ensure pads are not overlapping. May need to use anterior-posterior in infants/very small children

Question 24

During a sychronised shock for an atrial or ventricular tacharrythmia, where do you want the shock to land on the QRS complex?

Answer 24

R wave. On the R wave.

Question 25

Do you use a synchronised shock for VT?

Answer 25

Only if they have a pulse.

If pulseless VT, non-synchronised

Question 26

You want to do synchronised cardioversion. You have defibrillation pads on. What else can you apply to ensure a good cardiac tract is acheived?

Answer 26

ECG monitoring.
White = RIGHT (beneight right clavicle)
Smoke (black under left clavicle) over fire (red lead over left lower chest/abdomen)

Question 27

The patient has an ICD that is firing. How do you stop it?

Answer 27

Place a magnet over the ICD and secure it in place with a strong adhesive.
the ICD may beep or vibrate to confirm it is disabled its ICD component.
A magent will NOT disable any pacing abilties.

Question 28

What happens when you place a magnet over a permanent pacemaker?

Answer 28

Resets most pacemakers to asynchronous pacing however depends on each pacemaker.
Some are programmed not to be disabled by a magnet.

Question 29

How many joules are needed for internal defibrillation (thoracotomy/cardiac surgery patient)

Answer 29

10-20 J for biphasic

Do not exceed 50J