The New Youth Anesthesia Forum has more than 78,000 registered anesthesiologists. New Youth Anesthesia WeChat public number can calculate the number of people who read the survey invitation and record their locations. Therefore, we can calculate the response rate. Jane Candlish suggested that the minimum number of survey answers required for a survey to be effective should be equal to the number of questions times 10 . In this study, we received the 1935 reply. The location of the respondents indicated that the participants came from every province in China.
This survey provides the differences of LA and MA’s evaluation, chosed the tools, training, management of difficult airway in the China. Airway management has always been a cornerstone of anaesthetic practice . This study confirms the central role of anesthetists in DAM in/out OR.Given that airway management in the anesthetists is so vital to patient survival, LA and MA must have sufficient opportunities to train their airway knowledge and skills. The guidance of anesthetists in airway management comes not only from teaching exposures, but also from empirical approaches, including patient care in/out the OR.Although large training centers may have many resources available, many anesthetists practice in settings where these resources are limited or non-existent. But the approach and practice of doctors of DAM are more important. In many settings the anesthetists is the sole member of the airway team throughout the hospital in China. So, We conducted the present survey to address anesthesiologists who of different working years in this knowledge gaps in China.
Our study demonstrates that most LA and MA chosed mouth opening as the first index in the evaluation of difficult airway, therefore second choice among MA was experiential methodologies, and LA may choiced less, they tend to Mallampati classification which was classical method in book (Table 1). Although the assessment of DAM are different, they are basically consistent in the treatment of anticipated difficult airways (Table 2). 426 (60%) LA and 888(73%) MA put TA + sedation + VFIS as the first choice to manage anticipated DAM. Cricothyrotomy can provide airway anaesthesia for an awake VFIS, it can also provides a valuable experience in the life threatening CICO scenario. The American Society of Anaesthesiologists (ASA) guidelines  recommend the first choice of awake fibreoptic intubation in difficult airway management.
Hyuk Kim and colleagues  suggested that there was no failed attempt when the resident had performed more than 30 times training endoscopies. Rana K  recommends 10 fibreoptic intubations on asleep patients and 15–20 on awake patients for acceptable expertise. So adequate training in difficult airway management can enhance our confidence.
As mentioned above, the anesthetists is the sole member of the airway team throughout the hospital in China. Out of OR, What respondents are most worried about is the patients with full stomach (68% LA and 71% MA) (Table 4). Maybe they are also worried about some other situations, such as bleeding, drinking and so on. They care about environmental impact less. After intubation, more than 80% respondents selected auscultation which is considered to be Third-class evidence to verify the placement of ETT(Table 4) outside of the OR. Less than 15% of the respondents routinely used capnography (Second-class evidence) and chest rise (Third-class evidence) for ETT placement verification. They rarely trust the intubation graphics(First-class evidence) of the video laryngoscope including VFIS(gold evidence) alone. The results showed that the increased use of experience to verify ETT placement, maybe because of lacked theoretical knowledge. We can provide more training on this in the future. If there is no video tools for ETT placement, revious studies  showed that the increased use of CO2 monitors was the single change which has the greatest potential to prevent death from airway complications outside the OR.
When we encounter difficult airways, we should choose the tools we are most familiar with. Approximately half of the LA and MA put videolaryngoscope as the first chioce and VFIS intubations as the second choice(Fig. 1). There are numerous benefits of videolaryngoscopy, and these include improved laryngeal view, high rates of successful rescue after failure of direct laryngoscopy, improved training of novices, T. M. Cook  suggested that Videolaryngoscopy was used in 91% of operating theatres, 50% of intensive care units (ICUs) and obstetric theatres. Not all difficult airways can be evaluated in advance. When we are in the life threatening difficult intubation or even CICO scenario, what should we do first. 63% LA and 65% MA would ask for help after trying 1–2 times. 23% LA may choice try 2–3 times before seeking help, while 23% MA selected change intubation tools after trying 2–3 times (Fig. 2). But what I want to remind is to put ‘ask for help’ in the first place and try to maintain oxygenation, so as to reduce the risk of patients.
The incidence of CVCI is rare,but when we threatend by it, 506(71.0%) LA and 931(76.2%) MA selected cannula cricothyrotomy(Table 3), 90(12.6%) LA 107(8.7%) chosed tracheotomy. Only very small numbers of anesthetists chosed surgical cricothyrotomy. In a study conducted the next year  only 10% had previous experience of surgical cricothyrotomy in patients, while,Hung  reported that 86% of Canadian training teach surgical cricothyrotomy. Years ago, guidelines  highlight the role of surgical cricothyrotomy in an emergency, is a difficult airway skill where a training-gap may exist. While cannula cricothyrotomy kits can be quickly mastered.
Though it is important to master the intubation skills, it rather have correct treatment approach. There are difficult airway treatment guidelines at home and abroad. The author of Professor Ma also has his own set of ABS algorithm. Such as guideline in USA, less than 30% respondents read one time, most of them even do not know about it. Approximately more than one third respondents read Chinese DAM guidelines, nearly 67% read 2–3 times even more than 3 times in MA and 54% in LA (Fig. 6). Among respondents more than 60% LA and MA read the ABS algorithm, that may because of its simplicity,safety and easy to remember (Fig. 7). Everyone of us may be familiar with these algorithm,as the algorithm is like a light that allows us to make the right selection in the emergency of airway treatment.
As surveyed in our paper, very few people can use the FONA emergency technique, however, cricothyroid puncture used most (Fig. 3). Among MA, they received more airway training than LA, especially DAM (57%), cricothyroid puncture and tracheal jet ventilation(34%). Wong and colleagues  suggested five cannula cricothyrotomy on models as the minimum training requirement, but how this infer to clinical practice is unclear. Surgical cricothyrotomy was trained least. Skills can be taught on commercial mannequins or self-contained models, although they do not really represent clinical practice. LA should participate in more airway related training especially airway workshops.
Finally,this study surveyed difficult extubation. Every difficult airway patient is a difficult extubation object. 72% LA and 85% MA experienced difficult extubation, and 13% LA and 20% MA even experienced re-intubation or failed re-intubtion. So we may master extubation skills to deal with it. Bougie is a good tool for handling difficult extubation. A survey of British anaesthetic departments published in 2009 showed that the bougie was available on more than 90% of difficult airway trolleys . While in our survey less than 20% respondents used it(Fig. 4). That maybe the directon of trainning.