Chapter 9 Flashcards
(13 cards)
How is time to defibrillation and mortality related?
Without bystander CPR - every minute that passes between collapse and attempted defibrillation increased mortality by 7-10%
With bystander CPR - every minute that passes between collapse and attempted defibrillation increases mortality by 3-4%
Alternative defib pad positions
Antero-posterior - one anteriorly over left precordium, other on the back behind the heart just inferior to the left scapula
Postero-lateral - one in mid-axillary line, level with V6 electrode and other on the back, inferior to the right scapula
Bi-axillary - each electrode on the lateral chest wall, one on the right and one on the left
How to place the defib pads in patients with implantable medical devices
Away from device (at least 10-15cm) or use alternative electrode position (antero-lateral or antero-posterior)
Considerations for safe defibrillation
Avoid water - dry patients chest
Make sure everyone is clear of the patient/their surroundings - don’t hold IV access or trolley
Take of oxygen mask/nasal cannulae and place them 1m away from the patient’s chest
Leave the ventilation bag connected to the tracheal tube or supraglottic airway - no increase in oxygen concentration occurs with these
Can detach and move 1m away
Are automated external defibrillators accurately able to analyse rhythms?
Yes
What are the advantages of manual defibrillators over AEDs?
Allow operator to diagnose rhythm and deliver a shock rapidly without having to wait for rhythm analysis, which minimises interruptions to chest compressions.
Manual defibrillators also allow for synchronised shocks and external pacing
Appropriate energy level for delivering shocks
Initial shock 120-150J
Same or higher for subsequent shocks
When is synchronised cardioversion appropriate? How is it performed?
For atrial or ventricular tachyarrhythmias (not required for VT/VF), shock must be synchronised with the R wave of the QRS complex.
Conscious patients should be sedated before cardioversion.
Manual defibrillators allow for synchronisation
Need to account for delay between pressing button and delivering shock as next R wave comes
If peri-arrest with VT and synchronised shock fails - give unsynchronised shock
How should defibrillation be approached in patients with implantable electronic devices?
Follow resuscitation guidelines, awareness of the presence of device allows for additional measures to optimise outcome.
Put defib pads away from device - >10cm. Use alternative position (antero-posterior).
If ICD senses shockable rhythm will deliver shocks - can disable this with ring magnet placed over ICD
Can use ICD after resuscitation to analyse rhythm which led to cardiac arrest
How should loop recorders be managed during cardiac arrest?
Not relevant during resuscitation
Small chance of damage to device
Can be interrogated after event to analyse rhythm
How should implantable neurostimulators be managed during resuscitation?
Place defib pads 10-15cm away from device
How much energy is applied during internal defibrillation?
10-20J
How much energy do ICDs deliver?
40J via pacing wire to R ventricle, 80J for subcutaneous devices