EFFECTS OF SEVERE HEMORRHAGE ON IN VIVO BRAIN AND SMALL INTESTINE MITOCHONDRIAL NADH AND MICROCIRCULATORY BLOOD FLOW

Severe body stress induced by hypoxemia and hypotension may lead to total body energy state deterioration.The perfusion of the most vital organs is maintained at the expense of“less vital”organs.In the present study,we used a multi-site multiparametric(MSMP)monitoring system for real-time evaluation of tissue blood flow(TBF)and mitochondrial NADH fluorescence of the brain and the small intestine following hemorrhage.In Group 1,uncontrolled hemorrhage,mean arterial pressure(MAP)was decreased to 40mmHg within 2 minutes and shed blood was re-infused after 30minutes.In Group 2,controlled hemorrhage,during the 30minutes of hemorrhage,MAP was kept at 40mmHg.During hemorrhage,in both groups,the intestinal TBF and NADH deteriorated,while the brain remained relatively well protected.In Group 1,all parameters partly recovered within the hemorrhage phase,while in Group 2,complete recovery occurred only after resuscitation.At the end of the experiment,both models showed a decrease in intestinal viability(TBF decreased,NADH increased),while the brain metabolic state in Group 2 declined slightly.Our unique multi-parametric monitoring device demonstrated that,under hemorrhage,the small intestine responded entirely differently from the brain.This may suggest the potential usefulness of the monitoring of less vital organs,as proxy organs,in critical conditions such as massive hemorrhage.The present study also highlights the importance of mitochondrial function monitoring in similar conditions in the clinical environment.