Defibrillation and AEDs
                        =======================
þ Monophasic vs. Biphasic Defibrillation
 - Monophasic is better
   [Prospective, randomized trial demonstrating improved defibrillation and
   post-shock neurological status after use of 150J biphasic waveforms on
   cardiac arrest victims.  Schneider T, et al, Suppl. to Circulation, Vol
   100, Number 18, Nov 2, 1999; I-315.]
   Notes:  with long call to shock times (almost 9 minutes), defib, ROSC were
   very much improved over escalating monophasic.  Among survivors, neurologic
   status was better with biphasic patients.  Although not mentioned in the
   abstract, 100% of VF patients (n=54)treated with 150J biphasic were
   defibrillated, although this was not the case with monophasic, even at 360J
 - In short, a monophasic waveform delivers all it's energy along one vector
   while a biphasic waveform delivers about half the energy in one direction,
   then reverses the direction to deliver the rest. For a quick yet complete
   description of what biphasic defibrillation is, go to:
   http://www.biphasic.com/ Biphasic defibrillation has been proven superior
   in achieving lower defibrillation thresholds in implantible defibrillators.
   In the lifepak 500, which was the first product PhysioControl put biphasic
   into, the clinical study was incredible.  100% success on the first shock
   at 200J vs. 90% for monophasic. http://www.biphasic.com/abstract_1.html
   -- Ken Kinser
      Sr. Technical Consultant
      Medtronic Cardiac Rhythm Management

þ Current AEDs use monophasic 200J or biphasic 150J initial shock, and most
  don't offer a lower setting for children.  Therefore, the current
  recommendation is to use standard adult BLS and AED guidelines for children
  8 years (about 25-30kg), but not to use the AED for smaller children (AHA
  8/15/96).