The Influences Of Deep Or Awake Removal Of Laryngeal Mask Airway On Respiratory Complications In Children Undergoing General Anesthesia: A Meta-analysis

Objective:To compare the effects of deep or awake removal of LMA(laryngeal mask airway,LMA)on the respiratory complications of general anesthesia in children.Methods:PubMed,Embase,the Cochrane Library,VIP,CNKI and Wanfang databases were searched for all of the RCTs(Randomsized Controlled Trials,RCTs)on respiratory complications of deep or awake removal of LMA under pediatric general anesthesia from the establishment of the databases to January,2019.Two researchers independently conducted screening of the titles and abstracts according to the inclusion and exclusion criteria.The titles and abstracts were all retrieved full text were reviewed by two authors.The following data were extracted:(1)general information:author,publish year and data sources;(2)basic characteristics of the included studies:ample size,mean age,gender,weight,ASA grade,types of surgeries;(3)outcomes:Primary outcomes:airway obstruction,cough,laryngospasm,bronchospasm,hypoxemia,apnea.Secondary outcomes:excessive salivation,stridor,bitting,clenching of teeth.The quality of the articles was evaluated by using the Cochrane risk-of-bias tool.The meta-analysis was performed by using Stata 12.0software.If the extracted data were non-continuous data,RR(Relative ratios,RR)was used to combine the effect quantities.The heterogeneity of the included trials was evaluated by Q test and?~2 test.A fixed-effect models was used for statistical analysis if statistical study heterogeneity was not significant(P?0.1).On the contrary,a random-effect models was used when the heterogeneity was significant(P<0.1).Sensitivity analysis was used to evaluate the stability of the results,which was sequentially eliminated the consistency of the combined results of the remaining studies and the combined results of all studies.The publication bias was evaluated by using the funnel plot and Begg's test.Results:A total of 15 randomized controlled trials,including 2,650 children,were included.The meta-analysis showed that the removal of the LMA under anesthesia increased the risk of airway obstruction in children[RR=2.14,95%CI(1.11,4.12),P=0.02],but excessive salivation[RR=0.21,95%CI(0.07,0.59),P<0.01]and bitting[RR=0.10,95%CI(0.03,0.34),P<0.01]were prone to happened when the LMA was removed awake.There were no significant difference in the rates of laryngospam[RR=0.99,95%CI(0.67,1.45),P=0.94],bronchospasm[RR=0.50,95%CI(0.10,2.68),P=0.42],cough[RR=0.56,95%CI(0.26,1.20),P=0.14],apnea[RR=0.58,95%CI(0.27,1.21),P=0.14],hypoxemia[RR=0.68,95%CI(0.35,1.34),P=0.26],stridor[RR=1.75,95%CI(0.62,4.99),P=0.29]and clenching of teeth[RR=0.21,95%CI(0.01,4.29),P=0.31].Conclusion:Compared with awake removel,airway obstruction is frequent in patients after the removal of the LMA under anesthesia.However,removal of the LMA during awake is more likely to increase the risks of excessive salivation and bitting,which may lead to cough and hypoxemia.Therefore,the timing to remove the LMA should be based on the child's own risk of airway complications.