Optimal Dosage And Timing Of Intranasal Dexmedetomidine For Reducing Emergence Agitation In Pediatrics Undergoing Laparoscopy

Background and objective:Emergence agitation in children is a common adverse event in recovery period,which is related to age,pain,anesthetics and other factors.Dexmedetomidine,a highly selectiveα₂ adrenergic receptor agonist,act onα₂ receptors of locus coeruleus nucleus of brainstem,which is excellent for sedation,hypnosis,analgesia and antianxiety and can reduce the incidence of emergence agitation.Because of these characteristics,Dexmedetomidine plays a sedative role in pediatric anesthesia.This randomized,double-blind study was designed to evaluate the use of intranasally administered dexmedetomidine at the end of surgery in pediatric undergoing minor surgery.The main purpose is to explore the effect of intranasal dexmedetomidine on agitation during recovery period.The secondary purpose is observation of hemodynamics changes and adverse events,such as prolonged recovery time,nausea and vomiting,respiratory depression,hypotension and bradycardia.Methods:120 children aged 6 months to 6 years,who underwent minor surgery,of American Society of Anesthesiologists（ASA）Ⅰwere enrolled in this study.The 120children were randomly divided into three groups.Group D1:Administered with intranasal dexmedetomidine of 1.0μg/kg;Group D2:Administered with intranasal dexmedetomidine of 1.5μg/kg;Group NS:administered with the same volume of normal saline.Prepared study drugs in a 1-ml syringe was individually dropped into each nostril in an equal volume when the surgery came to the end.Patients’MAP,HR,and SPO₂ were observed and recorded by a nurse who was blinded to the study group assignment at the time of administration（t）,leaving operating room（T0）,extubation（T1）,5 minutes later extubation（T2）,10 minutes later extubation（T3）and leaving PACU（T4）.Then the agitation and sedation scores at T1,T2,T3 and T4time points were assessed and the probable adverse events were recorded.And the time of extubation and postoperative revival were recorded.Results:（1）The incidence of emergence agitation was 47.50%in group NS,22.50%in group D1 and 12.50%in groups D2.Compared with group NS,the incidence of agitation in group D1 and group D2 decreased significantly（P<0.05）.Although the incidence of agitation of group D2 was lower than group D1,it is no statistical significance（P>0.05）.（2）The incidence of excessive sedation was 2.50%in group NS,12.50%in group D1,and 17.50%in group D2.There are significant differences between D2and NS groups（P<0.05）,whereas there are no significant differences between D1and NS groups（P>0.05）and D1 versus D2 groups（P>0.05）.（3）Compared with group NS,intranasal administration of 1.0μg/kg of dexmedetomidine does not cause significant changes in hemodynamics,and only causes a slight decrease in HR at T4 time point（P<0.05）.Whereas,1.5μg/kg of dexmedetomidine can reduce the children’s heart rate significantly during awakening period compared with the other two groups（P<0.05）.（4）The three groups had no significant effect on pulse oxygen saturation.And no postoperative adverse reactions were observed,such as nausea and vomiting,respiratory depression,hypotension and bradycardia.And the extubation time and recovery time among the three groups did not extend significantly.Conclusion:For minor surgery in children,1.0μg/kg and 1.5μg/kg of intranasal dexmedetomidine at the end of surgery can effectively reduce the incidence of postoperative agitation without prolonging the recovery time,and the latter is more effective.