Author/Editor		Tang, WC; Weil, Max Harry; Sun, Shijie; Noč, Marko; Yang, Liying; Gazmuri, Raul J
Title		Epinephrine increases the severity of postresuscitation myocardial dysfunction
Type		članek
Source		Circulation
Vol. and No.		Letnik 92, št. 10
Publication year		1995
Volume		str. 3089-93
Language		eng
Abstract		BACKGROUND: Epinephrine has been the mainstay for cardiac resuscitation for more than 30 years. Its vasopressor effect by which it increases coronary perfusion pressure is likely to favor initial resuscitation. Its beta-adrenergic action, however, may have detrimental effects on postresuscitation myocardial function when administered before resuscitation because it increases myocardial oxygen consumption. In the present study, our focus was on postresuscitation effects of epinephrine when this adrenergic agent was administered during cardiopulmonary resuscitation. Postresuscitation myocardial functions were compared with those of a selective alpha-adrenergic agent, phenylephrine, when epinephrine was combined with a beta 1-adrenergic blocking agent, esmolol, and saline placebo. METHODS AND RESULTS: Ventricular fibrillation was induced in 40 Sprague-Dawley rats. Mechanical ventilation and precordial compression was initiated either 4 or 8 minutes after the start of ventricular fibrillation. The adrenergic drug or saline placebo was administered as a bolus after 4 minutes of precordial compression. Defibrillation was attempted 4 minutes later. Left ventricular pressure, dP/dt40, and negative dP/dt were continuously measured for an interval of 240 minutes after successful cardiac resuscitation. Except for saline placebo, comparable increases in coronary perfusion pressure were observed after each drug intervention. The number of countershocks required for restoration of spontaneous circulation was significantly greater for epinephrine-treated animals (10 +/- 8) when compared with phenylephrine-treated animals (1.8 +/- 0.4, P less th. .01) and with animals treated with epinephrine combined with esmolol (1.6 +/- 0.9, P less th. .01). After resuscitation, dP/dt40 and negative dP/dt were significantly decreased and left ventricular end-diastolic pressure was significantly increased in each animal when compared with prearrest levels.(trunc.)
Descriptors		ADRENERGIC AGONISTS CARDIOPULMONARY RESUSCITATION EPINEPHRINE MYOCARDIAL REPERFUSION INJURY ADRENERGIC ALPHA-AGONISTS ADRENERGIC BETA-ANTAGONISTS DRUG THERAPY, COMBINATION ELECTRIC COUNTERSHOCK MYOCARDIAL CONTRACTION PHENYLEPHRINE PROPANOLAMINES RATS TIME FACTORS VENTRICULAR FIBRILLATION