in the guidelines of the ERC is written first shock wil be 150 - 200 j bifasic or 360 monofasic. ( page 46 on top) on the new poster for ALS I see 150 - 360 j bifasic. our defib can handdle 360 j bifasic. What do I use in the first shockblock?
Becasue biphasic waveforms are many and varied, the exact joules to use depends on the waveform of your defib.
With monophasic, it was easy. they are all the same so a standardised number of joules was advised.
However, with biphasic, i would recommend that you follow the manufacturers guidance. If you are unsure, contact the sales department of the defib manufacturer.
thank you for your repley Steve, but the problem for me is more in the theory of the ERC: 150-200 j or 360 j. What do i theach my students. personaly, I doe prefere 360 j in the first block.
Steve's right, we pretty much have to follow the guidelines set by the manufacturers. We use LifePaks at 200J for the first shock simply because that's what they've told us we have to do. To be honest, I'm not sure it really matters - the patients who are going to revert first time usually do so whether it's 200J or 360J. I suppose the less energy we use the better, although again with biphasic defibs the peak currents are so much lower than monophasic it's not that important.
The new ERC ALS poster is identical to the algorithm in the ERC guidelines on page S45. The algorithm states 150-360 J because it covers not just the initial shock but also subsequent shocks. Thus the first shock is 150-200 J but subsequent shocks can be anywhere between 150 and 360 J depending on the defibrillator.
Koen Monsieurs Hon. Secretary European Resuscitation Council
-monofasic always maximum 360 joules -bifasic depends on the maximum the defibrillator can give. For example Zoll maximum is 200 joules. You give first 150 next maximum always 200 Medtronic maximum 360 joules. You give first 200 next maximum always 360.
This may be correct with the defibrillators that you are using (sounds suspiciously like pre 2005 guidelines) but different manufacturers have different recomendations.
Until a specific biphasic waveform has been agreed as standard in defibrillators we should follow the manufacturers recomendations. We currently use phillips biphasic machines and our protocol in VT/VF is to deliver 150j shocks throughout the VT/VF
Here are my views on the matter according to the way i see the guidelines
1. monophasic allways give 360J very easy...
2. Biphasic BTE (all defibrillators but Zoll)
for the initial shock use energy level of 150-200 J, for second and subsuqent shocks use the same or higher energy levels.
The ERC guidelines states that if you had deliverd a 200 J for the initial shock without acehiving defibrillation and your device is capable of delivering shocks of higher energy, it is rational to increase the energy level...well something to think about before you buy a defibrillator ...
The A.H.A states that a low energy shock will not supply enough current to achieve defibrillation in a high impedence paitent.
And again Steve is right if you use a certain device follow the manufacture recommendations.
For sure the attitude now is to focos mainly on chest compressions and to waste as little time and attempts to achieve defibrillation as possible.(analyzing the rhythm, cheking for a pulse every 20 sec.., "forgeting" to provide chest compressions when they are due are all acting to decrase the chances of survival)
External electrical cardioversion remains the technique of choice for restoring sinus rhythm in patients with persistent atrial fibrillation. Most currently used external defibrillators deliver monophasic damped sine waveform shocks. However, it has been shown that a comparable or even higher rate of transthoracic cardioversion can be achieved with biphasic shocks. These studies assessed efficacy using step up protocols starting at low energy levels. However, 75% of the patients can be cardioverted successfully by the currently recommended 200 J initial energy level using monophasic shock waveforms
200 j vs 360 j first shock, what's the best.
in the guidelines of the ERC is written first shock wil be 150 - 200 j bifasic or 360 monofasic. ( page 46 on top)
