The Effect Of Different Doses Of Dexmedetomidine Pretreatment On Postoperative Agitation In Pediatric General Anesthesia

Objective:Through observing the effect of different doses of dexmedetomidine on postoperative agitation in pediatric general anesthesia,we aimed to investigate the preventive effect and the optimal dose of dexmedetomidine pretreatment on postoperative agitation in pediatric general anesthesia.Methods:200 cases of children,aged 1～8 yrs,American Society of Anesthesiologists（ASA）gradeⅠorⅡ,undergoing elective surgery from April2018 to September 2019 in tenth affiliated hospital of Guangxi Medical University were selected and randomly divided into four groups（n=50）.After induction intubation of anesthesia,children in group D_1.0were given dexmedetomidine 1μg/kg on average into both nostrils,children in group D_1.5were given dexmedetomidine 1.5μg/kg on average into both nostrils,children in group D_2.0were given dexmedetomidine 2.0μg/kg on average into both nostrils,and children in group C were given normal saline 0.3ml on average into both nostrils as the contral group.Before induction（T₀）,ten minutes after nasal drip（T₁）,at the beginning of the operation（T₂）,into the postanesthesia caer unit（PACU）（T₃）,tracheal extubation（T₄）,out of PACU（T₅）,one hour after returning to the ward（T₆）,heart rate（HR）and pulse oximetry（Sp O₂）were recorded.Recovery time of spontaneous breathing after surgery,extubation time and stay time in PACU were recorded.Observed and recorded the adverse events of children during anesthesia and surgery,in the recovery of anesthesia and returning to ward within one hour.Evaluated and recorded ramsay sedation score when leaving the PACU.Compared HR and Sp O₂at different time points,sedation degree when leaving the PACU and the occurrence of adverse events in the whole process.Results:Compared with T₀,HR increased obviously at T₄in group C（P<0.05）,and there was no significant difference at T₄in group D₁,group D_1.5and group D₂（P>0.05）.All Sp O₂of the four groups decreased at T₃-T₆compared with T₀（P<0.05）,but there was no significant difference in Sp O₂at T₀-T₆among the four groups（P>0.05）.There was no significant difference in the recovery time of spontaneous breathing after surgery,extubation time and stay time in PACU among the four groups（P>0.05）.There were statistically significant differences in the incidence of agitation,good sedation and excessive sedation among the four groups（P<0.05）.Compared with group C,the incidence of agitation in group D₁,group D_1.5and group D₂was significantly reduced（P<0.05）,the incidence of good sedation was significantly increased in group D_1.5（P<0.05）,and the incidence of excessive sedation was significantly increased in group D₂（P<0.05）.The incidence of agitation in group D₁was significantly higher than that in group D_1.5and group D₂（P<0.05）,the incidence of good sedation in group D_1.5was significantly higher than that in group D₁and group D₂（P<0.05）,and the incidence of excessive sedation in group D₂was significantly higher than that in group D₁and group D_1.5（P<0.05）.The incidence of bradycardia was highest in group D₂（46%）,followed by group D_1.5（22%）,group C（20%）and group D₁（18%）.There was a significant difference in the occurrence of bradycardia among the four groups（P<0.05）.Compared with group C,there was no significant difference in group D₁and group D_1.5（P>0.05）,the difference in group D₂was statistically significant（P<0.05）.No other adverse events（such as laryngospasm,bronchospasm,ponv,hypoxemia,etc）occurred in the four groups during the period.Conclusion:Dexmedetomidine pretreatment can safely and effectively reduce the occurrence of postoperative agitation in pediatric general anesthesia.The optimal dose is 1.5μg/kg.When increased to 2.0μg/kg,the incidence of bradycardia and postoperative excessive sedation increases,but it increases the risk and reduces the safely of anesthesia.