Sedative Effect Of Dexmedetomidine During Combined-spinal Epidural Anesthesia

As medical technology continues to improve, not only requires theanesthesiologist to provide a comfortable, safe anesthesia, but also required tominimize the pain, and constantly improve the level of anesthesia updateanesthesia concept.Combined spinal-epidural anesthesia is the most commonlyused of the abdomen, perineum, lower limb surgery because of its irreplaceableadvantages, but it can not eliminate the patient’s anxiety, tension, bad memoryand know and other shortcomings in the operation. Awake, fear and stressresponse caused invisible pressure and directly affect the therapeutic effect.Itsnecessary to give appropriate sedation to make the surgery more humanity andmake patients more comfortable. It has very important significance to choice adrug to made the patient calm and comfortable, reduce the stress response andmade respiratory and circulatory system maintain stable. Dexmedetomidinehydrochloride is a new type of high selective α2adrenergic receptoragonists,has analgesic, sedative and anxiolytic effects and can reduce theamount of anesthetic，has fewer adverse reactions. Patients during surgery caneasily be awakened and can communication with doctors. It is really an idealsedation drugs.Objective To observe and study the sedative effect of different doses ofdexmede-tomidine given in patients with combined spinal-epidural anesthesia（CSEA）. Explore dexmedetomidine given for CSEA sedation when appropriatedrug concentration and clinical safety, provide a reference for the clinicalapplication.Methods Fifty patients, ASA Ⅰ^Ⅱ, aged20to60year s, scheduled forwith spinal-epidural anesthesia, were equally randomized into five groups:（n=10in each group）: dexmedetomidine group（D₁D₂D₃）, midazolam group （M） and blank control group （C）. Ramsay score, mean arterial pressure （MAP）,heart rate （HR）, respiratory rate （RR）, pulse oximetry （SpO₂） and the depth ofCerebral State Index （CSI） were recorded before anesthesia, after CSEA, and10,20,40and60min after sedative administration. All patients were followedup24hour postoperatively t o observe the amnestic effect during operation.Results The heart rate, mean arterial blood pressure, respiratory rate ofgroup D₁patients did not change significantly; The heart rate, mean arterialpressure, respiratory rate of group D₂tended to reach the level of sedation;patients in group D₃with heart rate slow down significantly; respiratory rate ofpatients in group M is gradually reduced, including two cases of respiratorydepression; the heart rate, mean arterial pressure, respiratory rate group C didnot change significantly. Comparison between groups,Ramsay sedation scoreswere higher in D₁,D₂, D₃, M groups than C group at T₃～T₅（P<0.05）. T_heheart rate, mean arterial blood pressure is slight decline in D₁,D₂, D₃, M groupsat T₃～T₅;CSI in D₁, D₂, D₃, M groups was significantly lower than in groupC. Heart rate decreased in D₃group than other groups at T₃～T₅（P<0.05）.Ramsay sedation scores in D₁,D₂, D₃, M groups at T₃～T₅were higherthan T₀（P<0.05）.Amnestic effects in dexmedetomidine groups were highercomparing to C group （P<0.05）, while the difference was not statisticallysignificant comparing to M group.Conclusion D_exmedetomidine0.5μg/kg followed by0.3～0.5μg/kg/hintravenous infusion caused effective sedation and amnestic effect duringoperation for patients with CSEA with no respiratory depression and cycleinhibition.