Abstract 159: Epinephrine Increases Cerebral Perfusion and Oxygenation in a Pre-Clinical Model of Pediatric In-Hospital Cardiac Arrest

Introduction: Despite controversies, epinephrine remains a mainstay of CPR. Recent animal studies have suggested that epinephrine may decrease cerebral blood flow (CBF) and cerebral oxygenation, possibly potentiating neurological injury during CPR. We investigated the cerebrovascular effects of intravenous epinephrine in a swine model of pediatric in-hospital cardiac arrest. Hypothesis: Epinephrine will increase CBF and cerebral oxygenation during CPR. Methods: One-month old piglets (n=20, 8-10kg) underwent asphyxia for 7 minutes, VF, and CPR according to AHA guidelines for 10-20 minutes. Epinephrine boluses (20 mcg/kg) were administered at minutes 2, 6, 10, and 14 of CPR. Invasive (laser Doppler) and noninvasive (diffuse optical) continuous measurements of CBF and oxygenation were recorded. Wilcoxon Rank-Sum test was used to compare measurements 15 seconds prior to epinephrine doses to sequential measurements at 1-minute intervals following epinephrine; data are described as median [IQR]. Results: Compared to pre-epinephrine values, CBF was most significantly increased one minute after the first dose of epinephrine (noninvasive: +37.7% [6.1, 79]; invasive: +24% [-0.3, 118], p<0.004 for both) and returned to baseline by 3 minutes post-epinephrine. Cerebral tissue oxygenation was also most significantly increased one-minute after the first dose of epinephrine (noninvasive: +25.2% [9.0, 45]; invasive: +160% [30.3, 428], p<0.001 for both) and remained elevated 4 minutes post-epinephrine. Effects were also significant one minute following the second dose on CBF (noninvasive: +11.5% [4.5, 29]; invasive: +9.5% [0.6, 19, p<0.03 for both) and on cerebral tissue oxygenation (noninvasive: +12.3% [1.6, 19]; invasive: +17.8% [-2.3,34, p<0.037 for both). There was no significant effect on any parameter following the third and fourth doses. Conclusions: In a swine model of pediatric in-hospital cardiac arrest, bolus-dosed epinephrine increases CBF and cerebral tissue oxygen saturation. These effects are only significant following the first two doses. Our findings are underscore the importance of further research to elucidate the transient pharmacodynamics of epinephrine to optimize both survival and neurological outcomes.