Effects Of Dexmedetomidine On Serum S-100? Protein,NSE And Cerebral Oxygen Metabolism In Patients Undergoing Total Arch Replacement

Research backgroundAortic dissection?Aortic dissection AD?with an acute onset and a high mortality is one of the most dangerous disease of cardiovascular surgery,the incidence rate of AD is increasing in our country.AD refers to the aortic intimal rupture,under a powerful blood shock,blood flow into the aortic wall and cause the separation of the normal aortic wall,the formation of true and false two cavity in the wall.Patients with suspected aortic dissection should be diagnosed as soon as possible,and surgery as soon as possible,Aortic dissection is a complex and time-consuming operation,patients need to be establishing extracorporeal circulation during the operation?CPB?,and be in deep hypothermic circulatory arrest?DHCA?under the assistance of the implementation,these operations will inevitably lead to the body's important organs of ischemia and hypoxia.The injury of the central nervous system caused by DHCA has become one of the most important factors that affect the survival and prognosis of the patients.CPB is a non physiological means of life support,The patient's brain injury is still the main complication after cardiopulmonary bypass.How to prevent and reduce the brain damage after the operation of large blood vessels has become a key issue in the protection of complex cardiovascular surgery.S-100? protein is mainly distributed in the glial cells of the central nervous system,When the brain is injured by ischemia and hypoxia,the release of S-100? protein into the brain can be detected.Neuron-specific enolase?NSE?is mainly distributed in neurons and neuroendocrine cells,When the brain is injured,the neurons die and NSE can be released from the cells into the cerebrospinal fluid and blood,S-100?protein and NSE can be used as biochemical markers of brain injury.The jugular bulb oxygen saturation?SjvO₂?can reflect the matching degree of cerebral oxygen supply and oxygen consumption.Da-jvO₂ reflects the brain's ability to absorb oxygen,and the significance of Da-jvO₂ are similar to that of CERO₂,So it is more suitable for evaluating the changes of cerebral oxygen metabolism,with the characteristic of no-affecting by Hb.Dexmedetomidine?dexmedetomidine,DEX?as a highly selective adrenergic receptor agonist is a new safe and effective anesthetic adjuvant,it can produce anti-sympathetic,anti-anxiety,sedative,analgesic,anti-inflammatory and so on,So it has a positive significance for patients with brain protection.There is not so mach brain protection of dexmedetomidine in total arch replacement in the role of research,This study aims to investigate the effect of protective effects in dexmedetomidine on cardiopulmonary bypass?CPB?in total arch replacement in patients with cerebral ischemic injury,as well as provide the clinical basis for the choice of anesthesia auxiliary drugs in cardiovascular surgery.ObjectiveTo investigate the effects of dexmedetomidine on serum S-100? protein,NSE and cerebral oxygen metabolism in patients undergoing total arch replacement MethodsDuring October 2014 to December 2016,there were 38 acute aortic dissection patients who received total arch replacement surgery under extracorporeal circulation at our hospital.The patients were from all genders,age from 33 to 68,weight from 44 to 87 kg,ASA Grade? or Grade ?.Based on applied medicines during operations,all patients were divided as two groups at randomly: the compared group?Group C,totally 19 patients?and Dexmedetomidine group?Group Dex,totally 19 patients?.These patients were routinely given tracheal intubation after induction of anesthesia.Before the induction of anesthesia,Dex patients ware treat with 10 min intravenous infusion of dexmedetomidine 1?g/kg,then followed by a rate of 0.5?g/?kg·h?infusion which last 12 hours after the operation;C group were treated with equal volume of normal saline instead.Both Group C and Group Dex were measured the level of serum tumor necrosis factors such as S-100? protein and neuron specific enolase?NSE?by the time of the before anesthesia induction?T0?,the CPB operation last for 30 minutes?T1?,1 hours after the CPB operation?T2?,6 hours after the CPB operation?T3?,12 hours after the CPB operation?T4?,24 hours after the CPB operation?T5?.And do a collection of patients with radial artery and internal jugular vein blood samples for blood gas analysis,the jugular venous oxygen saturation?SjvO₂?,arterial oxygen content difference?Da-jvO₂?and cerebral oxygen uptake?CERO₂?were recorded and calculated.All the data were analyzed by SPSS 20 statistical software,and the measurement data is expressed in???|-?±S?,T-test was used to compare the two groups,the differences of serum levels of NSE,S-100? protein and blood gas analysis at different time points were analyzed by variance analysis,enumeration data were compared by chi-square test,?=0.05.Results1.there was no significant difference in gender,age,weight,LVEF and the operation time,CPB time,aortic occlusion time between the two groups?P > 0.05?.2.The serum S-100? protein and NSE level at T1-T5 time points in zhe two groups were both higher than that at T0 time point,the difference was statistically significant?P<0.05?.The serum S-100? protein and NSE level in Dex group was lower than that in C group at the time points of T1-T5,the difference was statistically significant?P<0.05?.3.At T1-T3 time point,the levels of SjvO₂ in the two groups were higher than that at T0 time point,the levels of Da-jvO₂ and CERO₂ in the two groups were lower than that at T0 time points,the difference was statistically significant?P<0.05?.The levels of Sjv O₂ in Dex group were higher than that in C group at T1-T3 time points,The levels of Da-jvO₂ and CERO₂ in Dex group were lower than that in C group at T1-T3 time points,the difference was statistically significant?P<0.05?.Conclusion1.Compared to the total arch replacement surgery of dexmedetomidine group and control group,the S-100? protein,NSE levels decreased.2.In total arch replacement perioperative the use of dexmedetomidine can reduce cerebral oxygen uptake rate,stable cerebral oxygen balance,this have a certain protective effect on the brain.