Response to repeated equal doses of epinephrine during cardiopulmonary resuscitation in dogs

• Published in: Annals of emergency medicine 2000, Vol.35 (1), p.3-10
• Main Authors: Bar-Joseph, Gad, Weinberger, Tuvia, Ben-Haim, Shlomo
• Format: Article
• Language: English
• Subjects: Adrenergic alpha-Agonists - administration & dosage; Adrenergic alpha-Agonists - pharmacology; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Animals; Biological and medical sciences; Blood Pressure - drug effects; Buffers; Carbonates - administration & dosage; Carbonates - pharmacology; Cardiopulmonary Resuscitation - methods; Disease Models, Animal; Dogs; Drug Administration Schedule; Drug Combinations; Drug Evaluation, Preclinical; Drug Therapy, Combination; Emergency and intensive cardiocirculatory care. Cardiogenic shock. Coronary intensive care; Epinephrine - administration & dosage; Epinephrine - pharmacology; Intensive care medicine; Medical sciences; Practice Guidelines as Topic; Random Allocation; Sodium Bicarbonate - administration & dosage; Sodium Bicarbonate - pharmacology; Sodium Chloride - administration & dosage; Sodium Chloride - pharmacology; Time Factors; Tromethamine - administration & dosage; Tromethamine - pharmacology; Tropical medicine; Vasoconstrictor Agents - administration & dosage; Vasoconstrictor Agents - pharmacology; Ventricular Fibrillation - drug therapy; Ventricular Fibrillation - physiopathology
• ISSN: 0196-0644; 1097-6760
• DOI: 10.1016/S0196-0644(00)70098-9

Study Objective: Advanced cardiac life support (ACLS) guidelines recommend a 3- to 5-minute interval between repeated doses of epinephrine. This recommendation does not take into account the dose of epinephrine used, and only very limited data exist regarding the hemodynamic responses to repeated “high” doses of epinephrine. The objective of this study was to analyze the hemodynamic responses to repeated, equal, high doses of epinephrine administered during cardiopulmonary resuscitation (CPR) in a canine model of ventricular fibrillation (VF). Methods: This study used a secondary analysis of data collected in a prospective, randomized study, primarily designed to assess the effects of acid buffers in a canine model of cardiac arrest. VF was electrically induced. After 10 minutes, CPR was initiated, including ventilation with F IO 2=1.0, external chest compressions, administration of epinephrine (0.1 mg/kg repeated every 5 minutes) and defibrillation. Animals were randomized to receive either NaHCO 3, Carbicarb, tromethamine (THAM), or NaCl. The hemodynamic variables were sampled from each experiment’s paper chart at 1-minute intervals, and the responses to the first 4 doses of epinephrine were compared. Results: Thirty-six animals (9 in each buffer group) were included in this analysis. Systolic, diastolic, and coronary perfusion pressures increased steeply (by 100%, 130%, and 190%, respectively) only after the first epinephrine dose. These pressures peaked at 2 to 3 minutes and decreased only slightly and insignificantly during the rest of the 5-minute interval, until the next epinephrine dose. No further significant increases in arterial pressures were observed in response to the next 3 doses of epinephrine, administered 5 minutes apart. Conclusion: The hemodynamic effects of high-dose epinephrine (0.1 mg/kg) during CPR appear to last longer than 5 minutes. Therefore, longer intervals between doses may be justified with high doses of epinephrine. [Bar-Joseph G, Weinberger T, Ben-Haim S. Response to repeated equal doses of epinephrine during cardiopulmonary resuscitation in dogs. Ann Emerg Med. January 2000;35:3-10.]