Introduction: Severe hemorrhagic shock frequently leads to death. Previous studies have found that remote ischemic postconditioning (RIPostC) improved the outcomes of circulatory shock significantly.
Objective: In this study, we investigate the effects of RIPostC on myocardial function in a rat model of hemorrhagic shock.
Methods: Twenty-four male rats weighing between 450-550g were randomized into three groups: Sham, Control, and RIPostC. Hemorrhagic shock was induced by removing 45% of the estimated total blood volume in 60 min and maintained for 40 min. Resuscitation was then attempted by infusion of shed blood for 40min. In RIPostC group, RIPostC was induced by four cycles of 5 min of limb ischemia followed by reperfusion for 5 min during resuscitation. Myocardial function was measured by echocardiography.
Results: All animals were resuscitated successfully. An increased cardiac output (CO) level was observed in the RIPostC group compared to that of control animals (p <0.05). Ejection fraction (EF) was decreased after resuscitation both in the RIPostC and control groups. After resuscitation, EF was increased significantly in the RIPostC group (p<0.05). Myocardial performance indexes (MPI) were increased in both RIPostC and control groups during resuscitation with shed blood. There was a progressive recovery in MPI in RIPostC treated animals during post-resuscitation phase (p<0.05) (Figure 1).
Conclusion: RIPostC attenuates myocardial dysfunction in this rat model of hemorrhagic shock.
Figure 1. Myocardial function *p<0.05