Dose-response of vasopressin in a rat model of asphyxial cardiac arrest

• Published in: The American journal of emergency medicine 2009-10, Vol.27 (8), p.935-941
• Main Authors: Chen, Meng-Hua, MD, Song, Feng-Qing, MD, Xie, Lu, DPharm, Wang, Li-Ping, MD, Lu, Jun-Yu, MM, Zhang, Xian-Wei, MM, Tian, Xiao-Fen, MM
• Format: Article
• Language: English
• Subjects: Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Animals; Asphyxia - complications; Biological and medical sciences; Blood pressure; Cardiac arrest; Cardiac arrhythmia; Cardiopulmonary Resuscitation; Disease Models, Animal; Dose-Response Relationship, Drug; Emergency; Emergency and intensive cardiocirculatory care. Cardiogenic shock. Coronary intensive care; Emergency medical care; Heart Arrest - drug therapy; Heart Arrest - etiology; Heart rate; Intensive care medicine; Male; Medical sciences; Ostomy; Rats; Rats, Sprague-Dawley; Respiratory function; Rodents; Sodium chloride; Studies; Vasoconstrictor Agents - administration & dosage; Vasoconstrictor Agents - pharmacology; Vasopressins - administration & dosage; Vasopressins - pharmacology
• ISSN: 0735-6757; 1532-8171
• DOI: 10.1016/j.ajem.2008.07.031

Abstract The advantage of vasopressin over epinephrine in the treatment of cardiac arrest (CA) is still being debated, and it is not clear whether a high dose of vasopressin is beneficial or detrimental during or after cardiopulmonary resuscitation (CPR) in a rat model of CA. In this study, asphyxial CA was induced in 40 male Sprague-Dawley rats. After 10 minutes of asphyxia, CPR was initiated; and the effects of different doses of vasopressin (low dose, 0.4 U/kg; medium dose, 0.8 U/kg; and high dose, 2.4 U/kg; intravenous; n = 10 in each group) and a saline control (isotonic sodium chloride solution, 1 mL, intravenous) were compared. Outcome measures included the rate of restoration of spontaneous circulation (ROSC) and changes of hemodynamic and respiratory variables after ROSC. The rates of ROSC were 1 of 10 in the saline group and 8 of 10 in each of the 3 vasopressin groups. There were no differences in mean aortic pressure or changes of respiratory function after CPR among the vasopressin groups. However, the heart rate was lower in the high-dose vasopressin group than in the low- and medium-dose groups. These findings indicate that different doses of vasopressin result in a similar outcome of CPR, with no additional benefits afforded by a high dose of vasopressin during or after CPR, in a rat model of asphyxial CA. The mechanism and physiologic significance of the relative bradycardia that occurred in the high-dose vasopressin group are currently unknown and require further investigation.