Abstract 118: Ischemic Postconditioning with Controlled Pause at the Beginning of CPR Improves the Hemodynamic Effects of Epinephrine After 15 Minutes of Untreated Ventricular Fibrillation
Background: Ischemic postconditioning (IPC), by intermittent initiation of flow during the first minutes of re-establishment of blood flow, protects the heart from injury and improves outcomes in animals and humans. We hypothesized that IPC at the initiation of CPR would improve cardiac and vascular viability and thus enhance the hemodynamic response to epinephrine administered during CPR.
Methods: Following 15 minutes of untreated VF, 16 pigs were randomized to receive standard CPR (SCPR, n=9) or SCPR+IPC (n=7). IPC was delivered during the first 3 minutes of CPR with 4 cycles of 20 seconds of chest compressions followed by 20-second pauses. Epinephrine was administered as a 0.5 mg IV bolus at minute 3 and repeated every 3 minutes until return of spontaneous circulation (ROSC). Systolic (SBP), diastolic (DBP), mean arterial (MAP) blood pressure and right atrial pressure (RAP) were measured continuously. Carotid flow was measured by placing a Doppler flow probe at the common carotid artery. Coronary perfusion pressure (CPP) was calculated as the difference between DAP and diastolic RAP. T test was used for statistical comparisons between groups.
Results: Prior to epinephrine, carotid flow was higher with SCPR+IPC vs. SCPR. There were no other differences between the groups at minute 3. Following epinephrine, SCPR+IPC resulted in significantly greater SBP, DBP, MAP, CPP, and carotid flow compared to SCPR alone. Results are shown in table, † denotes significant difference between groups with p value < 0.02. All animals had ROSC.
Conclusions: IPC with controlled pauses at the initiation of SCPR drastically improves the hemodynamic effects of epinephrine.
- © 2012 by American Heart Association, Inc.