Abstract 129: Assessment of Reperfusion Effects in an Extracorporeal Life Support and Cardiopulmonary Resuscitation Cardiac Arrest Model in Rats by Cerebral Microdialysis
Background: Comparison of ischemia- and reperfusion markers determined by brain microdialysis in a model of two different reperfusion methods after ventricular fibrillation (VF) cardiac arrest in rats. The goal was to establish online measurement of ischemic stress and reperfusion to guide an experimental approach and future therapies.
Methods: Male Sprague-Dawley rats were used in a model of 8 minutes VF cardiac arrest. Microdialysis assessment was performed in the right hippocampal CA1 region with 4 baseline and 6 intervention samples. Probe placement was verified histologically after necropsy. Sampling was performed at 1μl/min with 8 minutes intervals. Lactate and pyruvate were assessed. Lactate/pyruvate ratios, reflecting ischemia, were calculated during extracorporeal life support (ECLS), with cardiopulmonary bypass and were compared to cardiopulmonary resuscitation (CPR). A sham group was used for baseline assessment. In this preliminary analysis one animal was used in each group.
Results: Return of spontaneous circulation (ROSC) was achieved in both intervention animals after 4 minutes of reperfusion. The lactate/ pyruvate ratio increased 6 fold in intervention animals after cardiac arrest, while sham measurements showed a constant baseline (Figure 1). The normalization of lactate/pyruvate ratio after ROSC differed in intervention animals, showing faster normalization in CPR and slower decline in ECLS.
Conclusions: To our knowledge this is the first report of cerebral microdialysis in a cardiac arrest reperfusion model in rats comparing ECLS and CPR. Reperfusion strategies seem to affect the release of hypoxia markers. This model could be used for investigation of different resuscitation regimens and subsequently for guiding clinical strategies. Further data is needed to validate these results.
Figure: Lactate/pyruvate ratios of Sham (red), CPR (blue) and ECLS (black) animal. X-axis: count of measurements. Y-axis: lactate pyruvate ratio.
- Extracorporeal circulation
- Cardiopulmonary resuscitation
- Cardiac arrest
- Ventricular fibrillation
Author Disclosures: A. Schober: None. A.M. Warenits: None. C. Testori: None. W. Weihs: None. A. Hosmann: None. I. Magnet: None. F. Ettl: None. D. Grassmann: None. C. Clodi: None. C. Schriefl: None. S. Högler: None. T. Scherer: None. A. Laggner: None. F. Sterz: None. A. Janata: None. M. Zeitlinger: None.
- © 2014 by American Heart Association, Inc.