Abstract 98: The Association Between Manual Mode Defibrillation, Preshock Pause Duration and Appropriate Shock Delivery When Employed by Basic Life Support Paramedics During Out-of-Hospital Cardiac Arrest
BACKGROUND: Pre-shock pause duration of < 20 seconds is associated with improved survival after cardiac arrest. Manual mode defibrillation has been associated with the shortest duration of pre-shock pause but is largely practiced by paramedics (EMT-P) whereas defibrillator only providers (EMT-D) routinely use the defibrillator in automatic mode.
OBJECTIVE: We sought to explore the relationship between manual mode defibrillation, pre-shock pause duration and shock appropriateness when defibrillation is provided by EMT-P vs. EMT-D level of providers.
METHODS: We performed a retrospective review of all treated non-traumatic adult OHCA presenting in a shockable rhythm over a one year period beginning January 1, 2012. Our primary outcome measure was the proportion of manual mode shocks delivered by EMT-D’s with pre- shock pause duration of < 20 secs when compared to EMT-P’s. Our secondary outcome measures were the duration of pre-, post- and peri-shock pause and the proportion of appropriate shocks (defined as correct identification and shock delivery to patients in a shockable rhythm) delivered by either level of provider. This study had a power of 90% to detect an absolute difference of 15% between provider levels in proportion of shocks delivered with pre-shock pause duration <20 secs.
RESULTS: Among 2019 treated OHCA, 335(20%) presented in a shockable rhythm. Manual defibrillation was performed in 155 (46%) of these cases (196 shocks by EMT-P, 143 shocks by EMT-D). There were no differences in the proportion of shocks delivered with pre-shock pause duration <20 secs (EMT-P 82.8% vs EMT-D 84.8%, p =.65) nor pre-shock pause duration (sec) (median, Q1, Q3); EMT-P: 12.0 (7.0,17.0) vs. EMT-D: 11.0 (5.0,17.0), p= .13 while EMT-D had shorter peri- shock pause duration (sec) (median, Q1, Q3); EMT-P: 17.0 (12.0, 23.0) vs. EMT-D: 15.0 (9.0, 22.0), p =.03. There were no differences in the rate of inappropriate shocks (EMT-P 1.0% vs EMT-D 0.7%), p=1.0.
CONCLUSIONS: Manual mode defibrillation by EMT-D’s produced similar measures of pre-shock pause when compared to EMT-P’s without increasing the rate of inappropriate shocks. More widespread use of EMT-D manual mode defibrillation may have the potential to decrease shock pause duration and improve survival.
Author Disclosures: S. Cheskes: Research Grant; Significant; CO PI Toronto Site, Resuscitation Outcomes Consortium. Honoraria; Modest; Zoll Medical for speaking on CPR quality. M. Hillier: None. C. Zhan: None. A. Byers: None. P.R. Verbeek: None. I. Drennan: None. L.J. Morrison: Research Grant; Significant; PI, Toronto site, Resuscitation Outcomes Consortium.
- © 2014 by American Heart Association, Inc.