Clinical Research On New Techniques For Difficult Tracheal Intubation And Simulation Teaching Training For Emergency Airway Management

Background:"Can’t Intubate, Can’t Oxygenate (CICO)" emergency airway is the crisis situation which no anesthesiologist would like to face it in the clinical work. The false judgment, the delayed decision, and the lack of rescue skills directly contribute to the disastrous consequences. The anesthesiologists need to master a variety of difficult airway management techniques in order to deal with difficult airways, even though one sort of technology failed, another feasible technology can be selected quickly. So, it can effectively prevent/avoid the occurrence of the CICO emergency airway which will seriously threaten the patients’ safety. Cookgas intubating laryngeal airway (CILA) has lots of improvements in the structure and accessories, that can make it play an important role in ventilation maintenance of difficult airway, difficult intubation management, especially in the management of severe difficult endotracheal intubation. CILA may provide the referential effective method for the anesthesiologists to manage the severe difficult endotracheal intubation, eventually prevent the happening of CICO emergency airway. In addition, cricothyrotomy acts as the final effective choice for rescuing the CICO emergency airway and saving patients’lives. It is necessary to let all of the anesthesiologists skillfully master the cricothyrotomy, so that they are able to implement quickly and effectively in crisis times of CICO. However, so far, there are not only the lack of appropriate training materials, but also the emergency airway management simulation training that are carried out regularly and termly in China. Therefore, in the area of difficult airway management, how to effectively carry out emergency airway management simulation training is still need further study.Objective:1. To evaluate the feasibility and safety of Cookgas intubating laryngeal airway (CILA) and the Fastrach intubating laryngeal mask airway (FT-LMA) in serious anticipated difficult airways. To verify the intubation successs rate of CILA is higher than Fastrach’s in guiding serious predicted difficult oraltrachel intubation.2. To investigate the knowledge, skill and confidence of Chinese anesthesiologists on performing cricothyrotomy; To collect and collate the the teaching materials for training the lifesaving procedure, cricothyrotomy; To design a simple inexpensive model for the skill training of cricothyrotomy; Furthermore, to establish the appropriate teaching method and evaluation system of cricothyrotomy training.Methods and Results:Part One:The clinical study of the new technique deals with difficult oraltrachel intubationMethods:Sixty healthy patients with all of three difficult intubation criterion (thyromental distance<60 mm, opening mouth distance< 35mm and Mallampati class III or IV) who were undergoing elective plastic surgery under general anesthesia were randomly allocated into CILA group (n=30) and FT-LMA group (n-30). After anesthesia being induced and CILA or FT-LMA being inserted, the patients were treated with FOB-guided intubation through CILA or FT-LMA. The success of the intubating laryngeal airway (ILA) insertion and FOB-guided intubation, the number of attempts and duration of the successful attempt were recorded. The patients with serirous predicted difficult airways did not meet the inclusion/exclusion criteria, but needed to be intubated with ILA. The types of the ILA were chosen by the anesthesiologists according to the airway evaluation results of patients and their favorite tools. These cases belonged to registry study and all of intubation information was collected during the study period.Results:In randomized controlled trial (RCT), the ILA was inserted successfully in 30 patients of CILA group and 27 ones of FT-LMA group.3 failed cases in FT-LMA group were inserted successfully with CILA. In CILA group, the first FOB-guided intubation attempt succeeded in 26 patients,4 cases were intubated at the second attempt. In 27 patients of FT-LMA group,20 cases were intubated successfully at the first attempt,4 at the second attempt, and 3 cases failed, two of them were intubated smoothly with FOB through CILA at the first attempt, and one was intubated by FOB via CILA at the second attempt. Compared to CILA group, the time of FT-LMA insertion was significantly longer.In registry study,7 cases were intubated using CILA with FOB,8 patients using FT-LMA with FOB and 6 cases using CTrach ILA. In CILA group,5 patients with limited mouth opening< 15mm,11cm was the least one among of these cases. The least mouth opening was 15mm in Fastrach and CTrach group. The success rate was no significant difference during the three groups, but compared with CILA group, the time of FT-LMA and CTrach insertion were significantly longer.Part Two:Simulation training of emergency airway managementMethods:A questionnaire is produced by making use of the mobile phone WeChat platform in order to investigate the knowledge, skill and confidence of Chinese anesthesiologists on performing cricothyrotomy. "cricothyrotomy training" vedio is made through searching a large number of literature and relevant materials, with the great help of the anatomists, three-dimensional animation and teaching video production specialists. Taking advantange of the unexpensive materials to design and make the economic and practical training model for training cricothyrotomy procedure. During emergency cricothyrotyomy simulation training, the information about the knowledge, skill and confidence of the trainees before training, after didactic instruction, and after simulation training will be gathered by finishing a questionnaire respectively. Two judges score the task-specific checklist and the global rating scale according to the operation videos of the trainees recorded after the didactic instruction and after simulation training.Results:445 effective questionnaires showed that, nearly 60%of the anesthesiologists don’t clearly know the local anatomy of the criothyroid membrane; only less than 10% of the anesthesiologists master the skills of cricothyrotomy procedure; and more than 65% of the anesthesiologists have never received the skill training of cricothyrotomy. A 30-minute intstructional vedio on the performance of cricothyrotomy is elaborated which covers Difficult Airway Society 2015 guidelines for management of unanticipated difficult intubation in adults; the three-dimensional animation display of the cricothyroid membrane local anatomy, and the detailed explanation of the cricothyrotomy procedural skills as well as the method to make the simple model for cricothyrotomy training and the related knowledge that must be known to operate the emergency cricothyrotomy. The cricothytomy training model which is designed and produced has obtained a national practical new type patent. It has established and improved the appropriate teaching method and evaluation system of cricothyrotomy training through carrying out the simulation training. The results of this study demonstrated that the simulation training can significantly improve trianees’knowledge and confidence on performing cricothyrotomy compared with the results before training and after didactic instruction. Also, the task-specific checklist score and the global rating scale have significantly improved.Conclusions:1. It is safe and effective of FOB-guided intubation through CILA and FT-LMA in serious anticipated difficult tracheal intubation. However, in patients with serious scar contracture of face and neck and/or patients with huge expender in neck, the success rate of the CILA insertion and FOB-guided intubation via CILA is higher than that of FT-LMA.2. All three types of ILA are safe and effective tools for predicted severe difficult airways, but CILA has obvious advantages for patients with at least one of the presences:mouth opening< 15mm; severe cervical scar contracture malformations; large skin soft -tissue expanders implanted in cervical area.3. It is extremely necessary to carry out the procedural skill training of emergency cricothyrotomy for the anesthesiologists. Meanwhile, the vast majority of the anesthesiologists are eager to accept emergency airway management training.4. The elaborated intstructional vedio and training model can meet the demand of the cricothyrotomy skill training.5. The simulation training significantly improves knowledge, skill and self-confidence of trianees on performing cricothyrotomy.