The effect of mild hypothermia on the myocardial and microcirculatory dysfunction induced by epinephrine during early post-resuscitation / 中华急诊医学杂志

ABSTRACT

Objective To investigate the effect of mild hypothermia on the myocardial and microcirculation dysfunction induced by epinephrine during early post-resuscitation in a rat model of cardiac arrest and cardiopulmonary resuscitation (CPR).Methods Transesophageal cardiac pacing was performed in order to elicit cardiac arrest for 5 min in SD male rats.Totally 40 rats were randomly (random number) divided into 4 groups (n=10)normothermic control group (N),normothermic epinephrine group (N+E),hypothermic control group (H),and hypothermic epinephrine group (H+E).Chest compression was then initiated.Epinephrine (0.02 mg/kg) or saline was administrated at 1 min during CPR.Restoration of spontaneous circulation (ROSC) was recorded,and the rates of ROSC were observed.Myocardial and microcirculatory function were observed at 1,2,3,and 4 h during early post-resuscitation.Serum lactate level was assessed at baseline and ROSC 4 h.Results The ROSC rates were 10/10 in the H+E group,9/10 in the N+E group,4/10 in the H group,and 1/10 in the N group,respectively.Ejection fraction (EF)and cardiac output (CO) in the H+E group were significantly higher than that of other groups (P＜0.05).Total vessel density,perfused vessel density,proportion of perfused vessels,and microvascular flow index in the H+E group were also significantly higher than those of other groups during early post-resuscitation.The serum lactate level in the H+E group was significantly lower than that in the N+E and H groups..Conclusions Both epinephrine and mild hypothermia can improve the success rate of resuscitation.However,mild hypothermia can improve the epinephrine induced myocardial and microcirculatory dysfunction during postresuscitation in the rat cardiac arrest.