Double Down for Refractory VT/VFfrom clic-em
No doubt you have encountered a patient in persistent ventricular fibrillation (VF) cardiac arrest and have run out of options. Beyond high quality uninterrupted CPR, biphasic defibrillation, pressors, and antiarrhythmics, therapy remains limited.
Enter double sequential defibrillation for the refractory VF cardiac arrest patient. First described by Dr. David Hoch in 1994, this concept utilizes two defibrillators set up to provide sequential shocks seconds apart for patients with refractory VF during routine electrophysiology (EP) testing.Hoch et al. found that 5 out of 2990 consecutive patients undergoing 5450 routine EP studies in a 3-year period experienced refractory VF (estimated incidence of 0.1%). These 5 patients received multiple single transthoracic defibrillatory shocks (initial shock at 200J, subsequent shocks at 360J monophasic) without success. This was followed by double sequential shocks, delivered externally at 0.5-4.5 seconds apart by means of two defibrillators (each set at 360J monophasic) with separate pairs of electrodes. All 5 patients were successfully cardioverted with their first double sequential shock.To perform double sequential defibrillation in your ED, attach a second set of pads placed just left of the patient’s existing pads, creating a new vector. At the time of defibrillation, both shock buttons are depressed as near-simultaneously as possible – delivering as much as 720J monophasic – resulting in a delay between the shocks from each defibrillator. This is consistent with the sequential description by Hoch.I have had personal success with double sequential defibrillation for persistent refractory ventricular fibrillation, with one ROSC using 720J and one nonresponder using 400J.EMS Systems in Fort Worth, TX, Wake County, NC and New Orleans, LA have presented good data on this method. At the 2011 EMS State of Sciences Conference in Dallas, TX, Dr. Juliette Saussy, former EMS Medical Director of New Orleans, shared that 4 of 16 deployments of double sequential defibrillation for refractory VF in New Orleans resulted in ROSC. One of the four was a 64 year-old female who went home neurologically intact. Reports from Wake County have been similar with good rhythm conversion by double sequential defibrillation and mixed success in achieving ROSC and neurologic preservation at discharge.Lessons learned from the street are invaluable for practice in the ED. Next time you have a patient in refractory ventricular fibrillation and have exhausted the algorithm, consider using a second defibrillator.– Eric Beck, DO, EMT-P
References:Hoch DM, WP Batsford, SM Greenberg, CM McPherson, LE Rosenfeld, M Marieb, and JH Levine. “Double sequential external shocks for refractory ventricular fibrillation.” Journal of the American College of Cardiology. April 1994. 23(5): 1141-5. SOURCE: http://crashingpatient.com/resuscitation/bcls-acls-cardiac-arrest-care.htm/