Abstract 10851: Can a Waveform-guided Approach to Direct the Duration of Post-shock Chest Compressions Shorten the Time to Achieve Rosc and Improve Neurological Outcome in an Acute Mi and Normal Swine Model of Vf Cardiac Arrest?
Background: In swine investigations of cardiac arrest due to ventricular fibrillation (VF), retrospective analysis of the waveform characteristic, amplitude spectral area (AMSA), is predictive of achieving a return of spontaneous circulation (ROSC). We hypothesized that a waveform-guided approach to resuscitation using AMSA in realtime to direct the duration of post-shock chest compressions (CC) would shorten the time to achieve ROSC and improve neurological outcome.
Methods: Acute myocardial infarction (AMI) was induced by occlusion of the left anterior descending artery. VF was untreated for 10 minutes, then followed by one minute of CC and resumption of mechanical ventilation. Animals were then randomized to either traditional resuscitation with 2 minutes of CC after each shock or to a waveform-guided algorithm where post-shock CC were shortened to 1 minute if the pre-shock AMSA >20mV-Hz.
Results: A total of 48 animals were studied, with 12 in each group (AMI vs normal, and traditional vs waveform guided). For AMI swine, there was a non-significant trend for a shorter time to ROSC (17.2 ± 3.4 vs 18.5 ± 4.7 min, P=NS). In normal swine, the waveform guided animals also showed a non-significant trend for a shorter time to ROSC: (13.5± 1.1 vs 14.4 ± 1.2, P=NS). Neurological outcome was similar between traditional and waveform-guided treated animals. AMSA was a predictor of achieving ROSC (P<0.001) following a shock, and a receiver-operator-characteristic analysis showed that the threshold of 20mV-Hz corresponded to a sensitivity of 89% with specificity of 29%.
Conclusion: While AMSA is predictive of achieving ROSC following a shock in a swine model of VF arrest in both acute MI and normal animals, a waveform guided approach that uses AMSA to direct the duration of post-shock chest compressions does not significantly shorten the time to ROSC or alter neurological outcome.
- © 2013 by American Heart Association, Inc.