Esmolol administered at the start of CPR after 8 minutes of ventricular fibrillation improved return of spontaneous circulation and 4-hour survival compared to saline (87.5% vs 37.5%; P<0.05).
Does esmolol administered at reperfusion improve survival after prolonged ventricular fibrillation in a porcine model?
Esmolol administered at the start of CPR after prolonged ventricular fibrillation improves short-term survival in a porcine model.
Absolute Event Rate: 87.5% vs 37.5%
p-value: p=<0.05
BACKGROUND: High catecholamine concentrations are cytotoxic to cardiac myocytes. We hypothesized that myocardial interstitial catecholamine levels are greatly elevated immediately after long-duration ventricular fibrillation (VF), defibrillation, and reperfusion and that the short-acting beta-antagonist esmolol administered at reperfusion would protect against this catecholamine surge and improve survival. METHODS AND RESULTS: In part 1 of this study, catecholamines from myocardial interstitial fluid (ISF) and aortic and coronary sinus plasma were quantified by use of 3H-labeled radioenzymatic assay in 8 open-chest, anesthetized pigs. Eight minutes of electrically induced VF was followed by internal defibrillation and reperfusion. By 4 minutes of VF, ISF norepinephrine increased significantly, from 1.3+/-0.3 to 7.4+/-2.4 ng/mL. Epinephrine increased significantly, from 0.4+/-0.2 to 1.5+/-0.7 ng/mL. ISF norepinephrine and epinephrine peaked at 219.2+/-92.1 and 63.7+/-25.1 ng/mL after defibrillation and reperfusion and decreased significantly to 12.2+/-3.5 and 6.7+/-3.1 ng/mL 23 minutes after defibrillation. Transcardiac catecholamine changes were similar. In part 2, 8 minutes of VF was followed by external defibrillation in anesthetized, closed-chest pigs. Animals received 1.0 mg/kg esmolol (n=8) or saline (n=8) intravenously at the start of cardiopulmonary resuscitation (CPR). Advanced cardiac life support, including CPR and epinephrine, was delivered to both groups. Esmolol before reperfusion improved return of spontaneous circulation and 4-hour survival (7/8 versus 3/8 survivors, chi2 P<0.05). CONCLUSIONS: Transcardiac and ISF norepinephrine and epinephrine levels are briefly massively elevated after 8 minutes of VF, defibrillation, and reperfusion. A short-acting beta-antagonist administered immediately after defibrillation improves return of spontaneous circulation and 4-hour survival after this prolonged VF.
Killingsworth et al. (Tue,) conducted a other in Prolonged ventricular fibrillation (n=24). Esmolol vs. Saline was evaluated on Return of spontaneous circulation and 4-hour survival (p=<0.05). Esmolol administered at the start of CPR after 8 minutes of ventricular fibrillation improved return of spontaneous circulation and 4-hour survival compared to saline (87.5% vs 37.5%; P<0.05).
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