Dose-response of vasopressin in a rat model of asphyxial cardiac arrest.
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.
Chen
Meng-Hua
MH
Institute of Cardiovascular Diseases, the First Affiliated Hospital of Guangxi Medical University, Nanning, PR China. cmhnn@sina.com
Song
Feng-Qing
FQ
Xie
Lu
L
Wang
Li-Ping
LP
Lu
Jun-Yu
JY
Zhang
Xian-Wei
XW
Tian
Xiao-Fen
XF
D000818:Animals; D001237:Asphyxia / Q000150:complications*; D016887:Cardiopulmonary Resuscitation; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D006323:Heart Arrest / Q000188:drug therapy* / Q000209:etiology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D014662:Vasoconstrictor Agents / Q000008:administration & dosage / Q000494:pharmacology*; D014667:Vasopressins / Q000008:administration & dosage / Q000494:pharmacology*
D014662:Vasoconstrictor Agents; D014667:Vasopressins