In recent years, a large number of airway devices have been introduced into clinical practice as adjuncts to management of the difficult airway. Furthermore, education and research in anaesthesia have increasingly focused on management of the difficult airway, which is evidenced by publication in this area, the establishment of airway management societies and registries, such as the Society for Airway Management (USA), the Difficult Airway Society (DAS, UK) and the online Austrian Difficult Airway/Intubation Registry (ADAIR), and the proliferation of conferences on difficult airway management. While the use of various airway devices in specific clinical situations has been extensively published in the anaesthesia literature, the expertise of anaesthetists with the use of these devices is largely unknown. The purpose of this study was to evaluate the practices of Israeli anaesthetists in specific clinical situations and their familiarity with the use of a variety of airway devices and techniques.
In 1998, a survey developed in our institution was sent to 300 attending anaesthetists, representing all board-certified anaesthetists practising in Israel. Each survey sheet was numbered from 1 to 300. This allowed us to follow-up and obviated the problem of duplicates sent by the same anaesthetist. This also allowed us to resend the questionnaires to those who failed to answer in the first round. The survey was sent out to each department of anaesthesia and was distributed to, collected and recollected (after the second round, when applicable) from the surveyed by the head of the department. The completed surveys were returned to us without specifying the identity of the sender. The survey consisted of four sections.
The first section was designed to assess personal characteristics variables of the responders including age, gender, length of practice, call duty and use of the American Society of Anesthesiologists (ASA) Algorithm for Management of the Difficult Airway . The application of the ASA difficult airway algorithms and guidelines for management of specific difficult airway situations (i.e. predicted difficult intubation, failed intubation, failed mask ventilation, etc.) for the responder's decision-making were also assessed. The participation in specific difficult educational courses of airway management was evaluated, including seminars, workshops or simulator training attended within the last 2 yr.
In the second section, the respondents were requested to evaluate their skill with 22 different airway devices and techniques. As defined in the survey, skill with respect to a specific airway device and technique required that the respondent has employed the device or performed such a manoeuvre successfully in his practice.
The third section requested that respondents rank their first airway management choice in three different difficult airway situations presented in the ASA Algorithm for Management of the Difficult Airway: (a) anticipated difficult airway, (b) unanticipated failed intubation with adequate mask ventilation and (c) unanticipated failed intubation with difficult/impossible mask ventilation. The respondents were instructed to answer these three different situations in a manner that best reflects their actual practice.
The fourth section presented the respondents with eight clinical scenarios and eight airway management techniques. For each scenario, the patient's respiratory status was considered stable (awake, not hypoxaemic, with no respiratory distress). Respondents were requested to indicate their preferred management technique with each scenario and to answer in a manner that best reflects their actual practice.
Personal characteristics data were analysed using a t-test and non-parametric data (frequency) were evaluated by using χ2-test analysis. Differences were considered significant if P < 0.05. Individual respondent's skill with 22 different airway devices/techniques was expressed as percentages. Individual respondents' first choice of difficult airway management to three different difficult airway situations presented in the ASA Algorithm for Management of the Difficult Airway were also expressed as percentages. Finally, for each listed clinical scenario, the percentage of respondents choosing each induction condition and intubation technique was calculated.
Initially, 111 questionnaires were completed and returned. Three months later the same questionnaires were resent to those who did not answer the first survey. The final response rate was 59% (177 returned questionnaires). Twenty-four questionnaires were excluded because instructions were not adequately followed. The remaining 153 (51%) questionnaires were analysed.
Personal characteristics and educational data are presented in Table 1. Of the respondents, 77% were males, with a mean age of 46 yr. The mean length of practice was 17 yr. Seventy-five percent practised in academic institutions. Seventy-nine percent of those surveyed performed night duty. Ninety-four percent followed the ASA Algorithm for Management of the Difficult Airway. Finally, 43% had obtained difficult airway education/training in the last 2 yr.
The self-assessment of skills in airway management devices and techniques is presented in Table 2. Ninety-six percent were skilled with laryngeal mask airways and 73% with fibreoptics.
The choices for airway management in the three proposed difficult airway situations are presented in Table 3. Seventy percent would employ regional anaesthesia if suitable, and 23% would perform awake, fibreoptic intubation for anticipated difficult airway. For unanticipated failed intubation with adequate mask ventilation, 29% would continue the case using a laryngeal mask airway, 27% would wake-up the patient and perform a fibreoptic intubation and 24% would wake-up and perform regional anaesthesia if appropriate. For failed intubation with difficult/impossible mask ventilation, the laryngeal mask was the first option for the majority of participants (83%). The selection of airway management of each scenario choices is listed in Table 4.
The preferred management techniques of the difficult airway scenarios assumed are presented in Table 5. Awake fibreoptic intubation, awake, direct laryngoscopy, intubation under inhalation anaesthesia with spontaneous ventilation and tracheostomy were equally shared (each for two of the scenarios) as preferred methods of airway management.
To date, no information has been published about airway practice patterns among anaesthesiologists in Israel. Studies dedicated to the investigation of theoretical background and technical skills with airway management among anaesthetists are limited. Recently, Rosenblatt and colleagues  conducted a survey (1998) by mail of a random sample of active members of the ASA living in the USA. They compared the results with another survey of the attendants of the 1981 annual meeting of the International Anesthesia Research Society. It was found that 78% of the participants in the latter survey were familiar with fibreoptic intubation, as compared with only 25% in 1981. A comparison between Rosenblatt and colleagues' study with another survey by Dykes  (1984-1989) reveals significant differences among the participants in the two study groups about theoretical knowledge and technical skills in airway management. This may reflect the increased level of education and introduction of special airway devices in the practice of modern anaesthesia. The differences may also reflect some problems in using small heterogeneous study populations. We chose a more homogeneous population by limiting our group to attending anaesthesiologists practising in Israel. Compared with Rosenblatt and colleagues' study , 75% of our respondents versus 17% belonged to academic institutions. Although our respondents belonged mostly to academic institutions (75%), the results of the survey may be representative to almost all the Israeli anaesthetists, because >90% of the Israeli hospitals are academic institutions. In our study, there was a discrepancy between the declared percentage of those who adhered to the ASA difficult airway management algorithm and having had experience with some of the airway devices and modalities they used that at different difficult airway scenarios. For example, only 73% of our respondents were skilled with fibreoptics, whereas as much as 94% adhered to the ASA algorithm. Rosenblatt and colleagues  and Rose and Cohen  have reported a similar discrepancy. However, the ASA algorithm does not provide management solutions for every possible difficult airway scenario. We believe, therefore, that this discrepancy is essentially irrelevant. The great adherence to the ASA algorithm in our study may be explained by the high percentage of Israeli anaesthetists working in academic institutions, and the more uniform sample population. Rosenblatt and colleagues also found that in spite of the availability of a large variety of airway devices, most anaesthetists continue to perform direct laryngoscopy with paralysis or awake-fibreoptic intubation for most scenarios of difficult intubation. The success rate of direct laryngoscopy under difficult airway conditions is limited. Awake, fibreoptic intubation enables the anaesthetist to gain access to the very difficult airway with little risk to the patient and without urgency. Teaching this method of intubation must be continued to the point where the user can rely upon it. The participants in our study first used the laryngeal mask as a ventilation device and, second, the fibreoptic bronchoscope as an intubation device in most of the difficult airway scenarios listed in Table 3. However, awake fibreoptic intubation, awake direct laryngoscopy and intubation under inhalation anaesthesia with spontaneous ventilation and tracheostomy were the preferred methods of intubation in the difficult airway scenarios shown in Table 5. Owing to the limited skills in fibreoptics (73%), only that percentage of respondents selected awake fibreoptic intubation in predicted difficulty before Caesarean section. The rest performed awake, direct laryngoscopy. This is an important consideration in light of the findings of a recent German survey of 993 departments of anaesthesia . Of the obstetric operating rooms surveyed in this study, only 36% were equipped with laryngeal masks, 24% with fibrescopes and 22% with equipment for tracheal puncture. A national departmental survey of obstetric anaesthesia units would be required for the assessment of the airway management in these critical cases.
Our study also revealed that tracheostomy was the first option for Ludwig's angina (Table 1). This seems apparently surprising, but essentially is in concordance with the ASA guidelines that elective tracheostomy may be the best first intubation choice in upper airway abscesses distorting the route of intubation . Similarly, upper airway trauma requiring maxillary surgery or obstructing the upper airway may also necessitate the performance of elective tracheostomy , a choice also opted by the majority of our respondents. This is in contrast with the results of another recent survey of 218 trauma centres in the USA that revealed that mid-face fractures were most often managed with nasotracheal intubation .
Seventy percent of respondents would employ regional anaesthesia if suitable (Table 3). That practice should be criticized because the use of regional anaesthesia in patients with a recognized difficult airway does not solve the problem of the difficult airway; it still exists. The danger of regional anaesthesia in a patient with a known or suspected difficult airway is that it may turn an elective procedure to an emergency situation with requirement of urgent airway management. Therefore, the ASA guidelines emphasize that regional anaesthesia is an acceptable choice in this patient population, if the surgery can be discontinued at any point and awake intubation can be performed, if it is necessary .
Most (83%) of our respondents seemed to adhere to the ASA difficult airway algorithm by choosing the laryngeal mask as the first management option in case of failure to intubate/failure to ventilate. However, we do not know why the other two devices (Combitube® and transtracheal needle jet ventilation) recommended by the ASA difficult airway algorithm under these circumstances were not included among the respondents' choices.
Although educational programmes and devices for difficult airway management are continuously increasing in number, the instruction of advanced or alternative airway management skills of residents remains sporadic. In 1995, only 27% of the 143 American anaesthesia residency programmes surveyed had formal instruction (specific block rotation) dedicated to management of difficult airways. More commonly, these were considered as 'clinical situations' . A more recently performed survey showed only a slight increase of this kind of education up to 33% in the curriculum . In our present survey, 43% of the attending anaesthetists were exposed to various airway management-oriented courses or other education modalities in the last 2 yr. To date, there is no formal airway rotation during anaesthesia residency in Israel. It has been demonstrated that enhanced education and individualized feedback can change anaesthetists practice patterns . Thus, we strongly suggest that more effort should be made to disseminate information and promote the learning of new techniques and devices for airway management. Postgraduates must obtain specialized training in courses of continuing medical education dedicated to the instruction and learning of difficult airway management. The practice of airway management has seemingly become more complex clinical entity evidenced by the introduction of many new airway devices - several of these have been incorporated into the ASA Difficult Airway Management algorithm . It should also be considered that many airway devices available in the market are not equally applicable and valuable in the clinical practice. A limited but available and efficiently applicable spectrum of devices should be selected by experts responsible for anaesthesia to meet all airway management demands in departments .
We have to point out that the use of regional anaesthesia in the case of expected difficult intubation is limited. It must be stressed that regional anaesthesia can only be used if the surgery can easily be discontinued at any time during the surgical intervention for an awake intubation or any other intervention for maintaining airways. The teaching and training of airway management should have more emphasis in the curriculum as an integral part of the education programme for all residents in anaesthesiology. The result of teaching of specialized knowledge and skills in block rotations has already been proven [7-13]. It is our opinion that inclusion of difficult airway management in formal block rotation during residency training would ensure that each trainee receives an adequate exposure to both the conceptual knowledge and practical experience required for both routine and difficult airway management. Our study was intended to evaluate the current airway management practice patterns in Israel and to share the findings of this study with practitioners from abroad. Finally, further study is also necessary for the assessment of the clinical outcome of the different difficult airway management and the effect of education and training on current practice patterns.
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