RESUMO
Objective To investigate the dynamic changes and coordination of macrocirculation and microcirculation in rats with severe hemorrhagic shock and septic shock. Methods A total of 20 male Sprague-Dawley rats (450～550 g) were randomly divided into two groups (n = 10) : hemorrhagic shock group (H-Shock) and septic shock group (S-Shock). 40％ of the systemic blood volume was withdrawn in 1 hour in H-Shock group.While in the S-Shock group, cereal ligation and puncture (CLP) was performed and then the abdomen was closed.Mean arterial pressure (MAP) and the end-tidal carbon dioxide (ETCO2) were recorded continuously. Cardiac ultrasonography and sublingual microcirculation were performed per hour till 12 hours or the rat die (End). A total of 12 hours were observed or the rat die. Arterial blood gas was measured at baseline (BL) , MAP ≤ 65 mmHg (Shock) and at the termination of observation respectively. Results The values reflect macrocirculation or microcirculation in the H-Shock group were all decreased than BL respectively at each time. In the S-Shock group, the values that reflect macrocirculation such as MAP, ETC02 and cardiac output (CO) showed no significant changes within 3 hours (P> 0.05) , while the values of microcirculation were decreased compared with BL respectively at each time (P < 0.05). With the progress of shock, the pH was decreased compared with BL in both groups, while the level of Lac were increased (P < 0.05). Conclusions The changes of macrocirculation and microcirculation in severe hemorrhagic shock are basically the same; while they are inconsistent in septic shock, the changes of microcirculation occurred earlier than that of macrocirculation.
RESUMO
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.