Bioautomation, 2008, 10, 59-70 ISSN 1312 – 451X Assessment of the Efficacy of Pulsed Biphasic Defibrillation Shocks for Treatment of Out-of-hospital Cardiac Arrest Irena Jekova 1* , Jean-Philippe Didon 2 , Vessela Krasteva 1 , Guy Fontaine 3 , Manuel Contini 4 , Johann-Jakob Schmid 5 1 Centre of Biomedical Engineering – Bulgarian Academy of Sciences, 105 Acad. G. Bonchev Str., 1113 Sofia, Bulgaria E-mail: irena@clbme.bas.bg , vessika@clbme.bas.bg 2 Schiller Médical SAS, 4 rue L. Pasteur, F-67160 Wissembourg, France E-mail: jean-philippe.didon@schiller.fr 3 La Pitié-Salpétrière University Hospital, 75013 Paris, France E-mail: guy.fontaine@bct.ap-hop-paris.fr 4 SAMU 54, Hôpital central de Nancy, 29 Avenue du Maréchal. de Lattre de Tassigny, 54000 Nancy, France E-mail: mcontini369@aol.com 5 Schiller AG Altgasse 68, P.O. Box 1052, CH-6341 Baar, Switzerland E-mail: jj.schmid@schiller.ch * Corresponding author Received: September 9, 2008 Accepted: October 7, 2008 Published: October 21, 2008 Abstract: This study evaluates the efficacy of a Pulsed Biphasic Waveform (PBW) for treatment of out-of-hospital cardiac arrest (OHCA) patients in ventricular fibrillation (VF). Large database (2001-2006), collected with automated external defibrillators (AED), (FRED®, Schiller Medical SAS, France), is processed. In Study1 we compared the defibrillation efficacy of two energy stacks (90—130—180 J) vs. (130—130—180 J) in 248 OHCA VF patients. The analysis of the first shock PBW efficacy proves that energies as low as 90 J are able to terminate VF in a large proportion of OHCA patients (77% at 5 s and 69% at 30 s). Although the results show a trend towards the benefit of higher energy PBW with 130 J (86% at 5 s, 73% at 30 s), the difference in shock efficacy does not reach statistical significance. Both PBW energy stacks (90—130—180 J) and (130—130—180 J) achieve equal success rates of defibrillation. Analysis of the post-shock rhythm after the first shock is also provided. For Study2 of 21 patients with PBW shocks (130—130—180 J), we assessed some attending OHCA circumstances: call-to-shock delay (median 16min, range 11-41 min), phone advices of CPR (67%). About 50% of the patients were admitted alive to hospital, and 19% were discharged from hospital. After the first shock, patients admitted to hospital are more often presenting organized rhythm (OR) (27% to 55%) than patients not admitted (0% to 10%), with significant difference at 15 s and 30 s. Post-shock VFs appear significantly rare until 15s for patients admitted to hospital (0% to 9%) than for patients not admitted to hospital (40% to 50%). Return of OR (ROOR) and efficacy to defibrillate VF at 5 s and 15 s with first shock are important markers to predict patient admission to hospital. Keywords: Automated external defibrillator, Pulsed biphasic waveform, Low energy defibrillation, Outcome from defibrillation. 59