Risk Factors And Clinical Interventions In Emergency Airway Management

PartⅠ:Accuracy of CHANNEL in predicting difficult airway of patients in Emergency DepartmentObjective To evaluate the accuracy of CHANNEL in predicting difficult airway of patients in Emergency Department.Methods The improved Mallampati score(MMT)and CHANNEL score were measured before intubation in 122 patients who underwent emergency endotracheal intubation.The Cormack Lehane grade was recorded,difficult airway was defined as Cormack-Lehane grade Ⅲ or Ⅳ.The receiver-operating characteristics curve was used to compare the accuracy of MMT and CHANNEL in predicting difficult airway.Results The sensitivity of CHANNEL in predicting difficult airway was 88.2%,the specificity was 92.3%,the area under the curve(95%confidence interval)was 0.945(0.905-0.985),and the odds ratio 30.3.Compared with MMT,the area under the curve of CHANNEL in predicting difficult airway was significantly increased(P<0.05).Conclusion CHANNEL can accurately predict difficult airway of patients in the Emergency Department.Part Ⅱ:Risk factors for severe cardiovascular collapse after endotracheal intubation in the Emergency DepartmentObjective:This study evaluated the incidence of severe cardiovascular collapse(CVC)after endotracheal intubation(ETI)in the Emergency Department and analyzed the predictors of severe CVC.Methods:122 patients who were hemodynamically stable before intubation in the Emergency Department between March 2015 and May 2017.The factors predictive of severe CVC were determined by multivariate analysis based on patient and procedural characteristics.The primary endpoint was the incidence of severe CVC after ETI and secondary endpoints were risk factors associated with severe CVC in these critically ill patientsResults:Of all,75(64.7%)of 116 patients developed severe CVC after intubation Univariate analysis showed that the risk factors of CVC included ages(OR 4.24,95%C11.79～1 0.51.p=0.001 compared with age less than 60),male gender(OR.0.41,95%CI 0.18～0.88,p=0.024),diabetes mellitus(OR 2.14.95%CI 0.99～4.70,p 0.053),midazolam sedation(OR.9.67,95%CI 3.67～30.68,p=0.001).FiO2>50%post-intubation(OR 57.47,95%CI 15.62～374.67,p<0.001),continuous intravenously pumped sedative agents post-intubation(OR 8.64,95%CI 3.71～21.40,p=0.001),positive end-expiratory pressure(PEEP)>5cmH2O(OR 60.41,95%CI 18.48～278.30,p<0.001).And multivariate analysis showed that independent risk factors for circulatory collapse after tracheal intubation included male gender(OR 0.06,95%CI 0.02～0.34,p=0.01),and sedative agents use immediately post-intubation(OR 44.87,95%CI 7.12～920.71,p=0.001),PEEP>5cmH2O(OR 29.84,95%CI 1.48～88.30,p=0.032).The 7-day survival rate of those patients with severe CVC was significantly lower than that without circulatory collapse(P<0.001).Conclusions:Severe CVC is a common complication after intubation.Specific bundles to prevent CVC that may reduce morbidity and mortality related to intubation of these high-risk patientsPart Ⅲ:The predictive value of MAP and ETCO2 changes after emergeney endotracheal intubation for severe cardiovascular collapseObjective:To analyze the changes of mean arterial pressure(MAP)and end tidal CO2(ETCO2)in patients after emergency endotracheal intubation(ETI).To explore the values of MAP and ETCO2 monitoring in the early prediction of severe circulatory collapse(CVC).Methods:The clinical data of patients who underwent ETI from March 2015 to May 2017 were collected consecutively in Peking Union Medical College Hospital.All patients enrolled in the study were required to have hemodynamic stability before emergency ETI.The values of both MAP and ETCO2 were observed and recorded at 5 minutes,10 minutes,30 minutes,60 minutes and 120 minutes post intubation According to whether severe CVC occurred after ETI,the patients were divided into severe CVC group and non-severe CVC group.The values of MAP and ETCO2 were compared at the same time points between groups and the adjacent time points within groups.The correlation between MAP and ETCO2 after ETI was also analyzed.ROC curve was used to analyze the ability of MAP and ETCO2 at 5 minutes and 10 minutes after ETI to predict severe CVCResults:116 patients were enrolled in this study,among them 75(64.7%)cases had severe CVC after ETI.The majority were male and elderly patients in severe CVC group.The values of MAP and ETCO2 in 5 minutes,10 minutes,30 minutes,60 minutes and 120 minutes after ETI in severe CVC group were significantly lower than those in the non-severe CVC group.Both MAP and ETCO2 in the two groups showed simultaneous decrease from 5 minutes to 30 minutes after ETI,reached the lowest value at 30 minutes after ETI,and from then to 120 minutes after ETI appeared the synchronous recover.After ETI,the changes of MAP was correlated with that of ETCO2(rs=0.653,P<0.001).At 5 minutes after ETI,MAP could predict severe CVC(AUC 0.86,P<0.001),MAP≤72mmHg was the best cutoff value(sensitivity 78.7%,specificity 87.8%),ETCO2 could also predict severe CVC(AUC=0.85,P<0.001).ETCO2≤35mmHg was the best cutoff value for predicting severe CVC(sensitivity 77.3%,specificity 85.4%).At 10 minutes after ETI,MAP could predict severe CVC(AUC=0.90,P<0.001),MAP≤67mmHg was the best cutoff value(sensitivity 89.3%,specificity 85.4%),ETCO2 could also predict severe CVC(AUC=0.87,P<0.001).ETCO2≤33mmHg was the best cutoff value for predicting severe CVC(sensitivity 81.3%,specificity 78%).There was no significant difference in the ability of prediction between any two indexes of the MAP and ETCO2 at 5 minutes and 10 minutes after ETI(P>0.05).Conclusion:Both MAP and ETCO2 of the patients with severe CVC were significantly lower than those without severe CVC from 5 minutes to 120 minutes after ETI,and reached the lowest value at 30 minutes after ETI.MAP and ETCO2 change synchronously with the time after intubation.There is a positive correlation between MAP and ETCO2 after ETI.MAP and ETCO2 in the early stage after ETI have high accuracy in predicting severe CVC.MAP≤72mmHg,ETCO2≤35mmHg at 5 minutes after intubation,MAP≤6 7mmHg and ETCO2≤33mmHg at 10 minutes after intubation all suggest that patients are more likely to have severe CVC.Part Ⅳ:The Effect of Videolaryngoscope Assisted Endotracheal Intubation Simulation Training and Key Points AnalysisObjective:To investigate the application of emergency videolaryngoscope assisted endotracheal intubation(ETI),to observe the effect of videolaryngoscope assisted endotracheal intubation simulation training for emergency doctors,analyze and summarize the training key points.Methods:According to the different teaching methods,120 emergency physicians were randomly divided into simulation training group and non-simulation training group,60 doctors in each group.Questionnaire surveies were performed before and after training.After training,each emergency doctor independently completed a simulated videolaryngoscope assisted ETI and the whole process was recorded.The intubating success rate on the first attempt,glottis exposure,total intubation time,glottis exposure time and catheter insertion time were analyzed and compared.Results:There was no difference in gender,age,title and directed laryngoscope assited ETI experience between the simulation training group and the non-simulation training group.Most of the doctors in the emergency departments were equipped with videolaryngoscope,and there was no significant difference between the simulation training group and the non-simulation training group(91.7%vs 83.3%,P>0.05).But the willingness of emergency physicians using videolaryngoscope to assist ETI in clinical practice was not strong in both simulation training group and the non-simulation training group,and no significant difference existed between the two groups(43.3%vs 50%,P>0.05).The emergency physicians in both simulation training group and the non-simulation training group were reluctant to use the videolaryngoscope attributed mainly to difficulty in intubating,and no significant difference existed between the two groups(70.6%vs 70%,P>0.05).Other reasons included personal experience habits and unsatisfactory exposure using videolaryngoscope,and no significant difference existed between the two groups(17.6%vs 16.7%;11.8%vs 13.3%,both P>0.05).After training,the intention of using videolaryngoscope to assist ETI in both the simulation training group and non-simulation training group increased obviously,and the increase was more significant in the simulation training group than the non-simulation training group(95%vs 83.3%,P<0.05).In the performance of simulated videolaryngoscope assisted ETI,all doctors in the two groups successfully exposed glottis,but the intubating success rate on the first attempt in the simulation training group was higher than that in the non-simulation training group(93.3%vs 58.3%,P<0.05).The total ETI time and catheter insertion time in the simulation training group were shorter than those in the non-simulation training group[s:22(19,24)vs.34.5(24.41.75),14.5(13,17)vs.29(18,35),both P<0.05],and no significant difference existed in the exposure time of glottis between the two groups[s:7(6,7.75)vs.7(6,8),P>0.05].Conclusion:Although videolaryngoscope are generally available in emergency departments,but it has not been widely used.About half of the emergency doctors most of them with the title of attending physician or above are unwilling to use it.The main reason for this phenomenon is that it is not easy to insert a catheter although the glottis is clearly exposed under the videolaryngoscope.Therefore,no matter whether emergency doctors have rich experience in direct laryngoscopy operation,training is very important for emergency doctors to master the skills of using videolaryngoscope and enhance operation confidence.The training should focus on how to insert the catheter under the videolaryngoscope,the effect of simulation training which apply step by step demonstration and explanation is better,and the operation performance of the trainees is more excellent.