The Observation On The Anaesthetic Effect Of Dexmedetomidine For The PCABG

Background: in recent years, the incidence and mortality of coronaryheart disease increased year by year. In the past30years, CABG has beenconsidered to be the most effective method for treatment of coronary heartdisease. In1964, Kolessov for the first time take the anastomosis of the internalmammary artery and coronary artery in the beating heart successful. Due to thebeating heart for the operation effects, as well as the technology of extractor-poreal circulation improvement, then OPCABG stagnation. At the end of the80’s, more and more doctors are aware of the advantages of OPCABG.Compared with conventional coronary artery bypass grafting compared,OPCABG avoids the non physiological effects of the position loop on the body.Since90time, along with the coronary exposure method and the fixed devicedevelopment, for the operation to provide a clear and relatively static field ofoperation has become possible. With the addition of some drugs and circulatoryassist device applications, OPCABG has been widely carried out. However,off-pump open-heart operation still to the anesthesiologist brought enormouschallenge, how to maintain perioperative hemodynamic stability andmyocardial oxygen supply and demand balance is the key of anesthesia.DxM is the alpha2adrenergic receptor agonist,made by Orion Pharmacompany and Abott company cooperation research and development. Ourcountry also has production, in July2009,approved its application in clinic.DxM with sedation, analgesia and anti sympathetic role, can produce stablestabilization and arousal, and can also promote the catecholamine hemo-dynamic stability, effectively alleviating endotracheal intubation, operationstress and anesthesia and recovery of early hemodynamic response. Study on DxM used in OPCABG assisted anesthesia effect, to evaluate the effectivenessand safety, provide the basis for the clinical medication.Objective: T_o study the effect of the DxM used in OPCABG assistedanesthesiaMethods: the study was divided into two parts:（1） Observation of DxM onOPCABG patients during induction of anesthesia hemodynamics;（2）the effectof BIS and hemodynamics between different doses of DxM on OPCABG inpatients.Experiment1: choose30cases undergoing CABG patients, age40-70years old, male or female, were randomly divided into2groups: DxM （Agroup） and normal saline control group （group B）,15cases in each group.Group A intravenous pump infusion DxM loading dose of1ug/kg,10mininfusion is finished, to DxM0.5ug/kg.h continued until the end of theoperation; group B infusion of an equal volume of saline solution. T_ake recordsof heart rate, systolic pressure, diastolic pressure on before drug administration,after administration of2min,4min,6min,8min,10min, intubation, trachealintubation after1min,5min.Experiment2:30cases of patients undergoing CABG,40-70age, sex is notlimited; were randomly divided into3groups: a small dose of DxM （A group）,a large dose of DxM （B group） and normal saline control group （group C）,10cases in each group. In three cases the routine anesthesia induction wereaccomplished, dosing after the hemodynamic stability. Group A: DxM loadingdose of0.5ug/kg,15min infusion is finished, the maintenance dose of0.5ug/kg. H until the end of operation; group B: DxM loading dose of1.0ug/kg,15min infusion is finished, the maintenance dose of1.0ug/kg. h until theend of operation; group C: an equal volume of normal saline in the samemethod of infusion. Multi function monitor （Philips MP60,Germany）continuous monitoring of patients with SBP, DBP, MAP, HR, CVP. Ultrasound monitoring of RAP, PAP, LVESV, LVEDV, According to the formula CI、SI、PVRI、SVRI. Provisions before induction （T₀）, before drug administration（T₁）, skin anterior （T₂）, following sternotomy （T₃）, vascular anastomosis （T₄）,anastomosis of anterior descending artery （T₅）, anastomosed to the rightcoronary artery or the posterior descending artery （T₆）, with circumflex ordiagonal branch （T₇）, vascular anastomosis, the heart to restore the originalposition （T₈）, closing the sternum and anterior （T₉） and the end of operation（T₁0） for recording point, And in T₀, T₁, T₂, T₃, T₄, T₈and the operationended after2hours （T₁1）,7time points from arterial blood5ml, Using highperformance liquid chromatography electrochemical monitoring method indetermination of plasma concentrations of norepinephrine and epinephrine.Using the bispectral index monitor test BIS value, set before induction （S0）,before drug administration （S1）, after the administration of3min （S2）, after theadministration of6min （S3）, after the administration of9min （S4）, after theadministration of12min （S5）, after the administration of15min （S6） as arecording point.Results:（1） in the group of patients in general had no significantdifference （P>0.05）.（2） during anesthesia induction and intubation period:comparison between two groups, the experimental group at each time pointafter intubation of SBP, DBP and HR were lower than the control group, twogroups have significant difference （P <0.05）.（3） anesthesia maintenance:conventional period after the induction of the BIS values were45.2+11.2,40.1+6,41.2+10.7. After administration of DxM, A group, B group BIS valuesdown further. In group A after administration of9min BIS value is reduced to38.7+9.2（P=0.025）, after the administration of15min, BIS values decreasedto31.2+7.7（P=0.001）; in group B after administration of6min BIS valuesdecreased to38.2+6.1（P=0.037）, the15min BIS value significantly afterAdministration of decreased to30.3+6.2（P=0.002）; C group have no difference before and after drug administration.（5） intraoperative hormonelevel change of operation: in group B patients plasma norepinephrineconcentration was significantly lower than that in C group,（P <0.01）;2hoursafter operation, patients in group C in plasma norepinephrine concentrationswere significantly increased in group B patients, plasma norepinephrineconcentrations increased at relatively low levels of. In two groups of patientswith plasma epinephrine concentrations no statistical difference （P>0.05）.Conclusion: DxM for OPCABG assisted anesthesia, can reduce theinduction and tracheal intubation hemodynamic instability; during anestheticmaintenance period, we can further deepen the depth of sedation, reduction ofother narcotic drugs drug consumption; intraoperative hemodynamics showedno significant differences, but the apparent decrease in plasma norepinephrinelevels.