Effectiveness Of Low-dose Dexmedetomidine For Prevention Of Emergence Agitation After Thoracic Surgery

Objective:To investigate whether prophylactic low-dose dexmedetomidine could effectively decrease the incidence of emergence agitation after thoracic surgery under general anesthesia in PACU.Methods:One hundred ASA I-III patients undergone scheduled thoracic surgery under general anesthesia were enrolled in this study.Aged 18?75 years.The patients were randomly?in a 1:1 ratio?divided into Dex group?group D?and control group?group C?.Patients received venous transfusion,radial artery puncture to monitor invasive arterial blood pressure?ABP?in operation room.All patients were given general anesthesia,with induction of midazolam 0.04mg·kg-1,sufentanil 0.6ug·kg-1,etomidate0.2mg·kg^-11 and cisatracurium 0.2mg·kg^-1,then inserted a double-lumen endotracheal tube after the medicine took effect,the tube suitable position confirmed and fixed.Both group received continuous infusion of propofol 4-6mg·kg^-1·h^-1,remifentanil0.1-0.2ug·kg^-1·h^-1,and cisatracurium 0.03-0.05mg·kg^-11 intermittently to keep muscle relaxed.Mechanical ventilation mode was IPPV,and to maintain Pet CO2 between35-45mmHg.MAP value within±20%was allowed,vasoactive drug was chosen to given when needed.Both groups were received postoperative analgesia,the analgesic formulation was sufentanil 1.5?g·kg^-1+butorphanol tartrate 4mg.All were diluted with normal saline to 100ml.Patients in group D were infused Dex 0.5ug·kg-1 in PACU after operation,patients in group C,were given equal volume of normal saline.Sedation-Agitation Scale?SAS?was assessed as main indicator.Secondary observation index included:VAS score,HR and MAP were collected at the moment of eyes opening?T1??extubation?T2??5min after extubation?T3?,respectively.Record total stay time in PACU?T4?and incidence of postoperative complications.Results:1.General data comparison:According to inclusion and exclusion criteria,90patients were included in the final statistical analysis.There were no significant differences between two groups in gender,age,height,weight,operation time?P>0.05?;2.Main indicator:About the risk of agitation,incidence rate of emergence agitation in group D?2.2%vs17.8%,?²=6.050,P=0.030?and Riker Sedation-Agitation Scale?3.87±0.41vs4.13±0.46,?²=0.332,P=0.004?were lower than group C.There were statistically significant differences.3.Secondary observation index:Compared with group C,VAS score in group D were lower?1.31±0.63vs1.62±0.65,?²=2.300,P=0.024?.At T2 and T3,both HR and MAP were also lower,the differences were statistically significant.In terms of recovery time,there were no statistically significant differences in eye opening time?15.02±5.56vs16.31±4.65,?²=1.193,P=0.236?and extubation time?18.31±6.05vs19.42±5.13,?²=0.94,P=0.35?.But total stay time in PACU in group D was less than group C?32.4±7.78vs37.69±8.79,?²=0.295,P=0.003?,which had statistically significant difference.On the risk of adverse event,there were no statistically significant difference in incidence rate of hypertension,hypotension,tachycardia,bradycardia and shiver?P>0.05?;group D exhibited lower incidence rate of EA after thoracic surgery?P<0.05?;both two groups had not PONV occurred.Conclusion:During the recovery period of anesthesia,low-dose 0.5ug·kg^-1·h^-11 Dex could maintain hemodynamics stable,reduce the risk of EA,and did not prolong the recovery time.