The Effects Of Airway Topical Anesthesia By Cricothyroid Membrane Injection At Different Sevoflurane Concentrations

Objective:In this study,we use inhalation of sevoflurane combined with cricothyroid membrane injection local anesthesia in the induction phase of general anesthesia,in order to observe the effects of cricothyroid membrane injection at different sevoflurane concentrations and the inhibition of intubation response.Then assessing the safety and feasibility of sevoflurane with cricothyroid membrane injection in the induction to providing experience for future research and clinical work.Methods:The study subjects were 120 patients operated under general anesthesia with tracheal intubation in the Affiliated Hospital of Yan'an University from October 2017 to October 2018.We randomly divided these patients into four groups of 30 people each.Group?(C_ETSev%=2%±0.1%);Group?(C_ETSev%=3%±0.1%);Group?(C_ETSev%=4%±0.1%);Group?(C_ETSev%=5%±0.1%).The Oxygen flow rate was set to 6L/min.Patients were asked to inhale pure oxygen for 5 minute,then the concentration of sevoflurane volatilization tank was opened to 8%.Observe the C_ETSev%on the monitor.After reaching the predetermined concentration of each group and stabilizing for 30seconds,we injected 2%lidocaine 5 ml into the airway by puncturing the cricothyroid membrane with an improved method.When the topical anesthesia was completed,the C_ETSev%of each group remained stable at the predetermined value.Slowly injected sufentanil 0.2ug/kg and tracheal intubation was performed 3 minutes later.The success of intubation was judged by Pet-CO₂.MAP?HR and SpO₂ were recorded before anesthesia induction;before cricothyroid membrane puncture;after cricothyroid membrane puncture;before tracheal intubation;immediately after tracheal intubation,1 minute after tracheal intubation and 3 minutes after tracheal intubation in each group.Then,we should evaluate the adverse reactions during cricothyroid membrane puncture and tracheal intubation.Results:1.There was no significant difference in sex,age,weight and BMI between the four groups?P>0.05?.2.Compared with that before induction,the MAP of the four groups decreased before cricothyroid membrane puncture?P<0.05?,and there were significant differences among the four groups?P<0.05?.The degree of decline was?>?>?>?in turn.HR decreased in all four groups?P<0.05?,but there was no significant difference between the four groups?P>0.05?.3.Compared with the pre-cricothyroid membrane puncture,after cricothyroid membrane puncture the MAP of the I and II groups increased?P<0.05?,and the degree of increase was statistically significant?P<0.05?.Group III increased and Group IV decreased,but the difference was not significant?P>0.05?,and the change of MAP was in the order of?>?>?=?.The HR of all the four groups increased?P<0.05?,and there was significant difference among the four groups?P<0.05?.The order was?>?>?>?.4.Compared with that before tracheal intubation,MAP increased in all four groups increased after tracheal intubation?P<0.05?,but the degree of increase between group?and?was not statistically significant?P>0.05?,the degree of MAP rise is?>?>?=?.HR increased in all four groups?P<0.05?,but there was no significant difference between group III and group IV?P>0.05?,followed by I>II>III=IV.5.There was no significant difference in SpO₂ between the four groups at each time?P>0.05?.6.There were statistically significant difference in adverse reactions during cricothyroid membrane puncture in four groups.I=II>III=IV.7.There were statistically significant differences in adverse reactions during tracheal intubation between the four groups.I>II>III=IV.Conclusions:1.Perform cricothyroid membrane puncture at four different concentrations of sevoflurane.The inhibitory effect of sevoflurane on this stress response was 5%=4%>3%>2%.However,when the C_ETSev%reached 5%,the patient's MAP decreased more significantly than before induction.2.After the topical anesthesia by cricothyroid membrane puncture,the tracheal intubation was performed under four different concentrations of sevoflurane.The inhibitory effect of sevoflurane on the stress response induced by tracheal intubation was5%>4%>3%>2%.For patients requiring general anesthesia and tracheal intubation,it is a safe and feasible method to induce by combined use of cricothyroid membrane puncture and sevoflurane.And the overall cost of this scheme is low,which has great economic advantages for primary hospitals.Patients requiring tracheal intubation,with sevoflurane induction,when the C_ETSev%reached 4%,the clinical effect of cricothyroid membrane puncture was the best,the patient's Circulation fluctuations were relatively stable and reactions occur less.At the same time,it has a better inhibitory effect on cardiovascular response induced by tracheal intubation stimulation.