Post anoxic coma is not increased in out of hospital cardiac arrest patients treated with aed shock only

Abstract

Background: This is a retrospective observational study of all episodes of ventricular fibrillation (VF), recorded in out-of-hospital cardiac arrest cases in the two tiered system of early defibrillation called Progetto Vita. The Emergency dispatcher activate the "blue code" when a cardiac arrest is suspected by the phone interview. When Blue Code is activated simultaneously police or lay volunteers, BLS Ambulance and ACLS-ambulance intervene. Aim: Was to evaluate if only delivery of AED shock could affect survival rate in pts with VF and influence the coma caused by brain anoxia. Method: From 1999 to 2011 all cases of out-of-hospital VF in Piacenza and county were analyzed. Follow-up after discharge from emergency department was performed to evaluate all cases of coma caused by brain anoxia. All patients (pts) with VF were divided in two groups: group A, when the Blue Code was activated and group B, when the Blue Code was not activated. Results: 398 cases of VF were recorded. Group A consisted of 115/398 pts (28,89%) and group B 283/398 (71,11%). Survival rate was higher in Group A: 39/115 pts (33,91%) compared to group B: 58/283 pts (20,49%) (39/115 pts vs 58/283 pts; p<0,05). Coma caused by brain anoxia was not significantly different in the two groups: group A 6/115 (5,22%) compared to group B 20/283 (7,07%) (6/115 vs 20/283 p=ns). Time from call to shock was 5,96 + 5,86 min in group A compared to 7,13 + 5,82 min in group B (p<0,05), and was not significantly different in alive pts of the two groups (Alive pts: group A = 4.9 + 5.8 min vs group B = 5.2 + 5.8 min, p=ns). Survival rate in Group A and Group B Conclusions: Only 28,89% of cases where correctly dispatched as Blue Code thus underlying the importance of dispatcher in managing sudden cardiac arrest by phone interview. Survival rate was higher in pts treated firstly by lay responders mainly due to shorter defibrillation time. The number of cases of coma caused by brain anoxia was not influenced by adding CPR to AED shock.