Discussion

 

 

For successful airway management (AM), preparatory provisions and formulated strategies for difficult airway (DA) management are needed. Based on the results of a comprehensive survey quesionnaire, we also evaluated to which extend these needs are fulfilled at anesthesia departments in Austria. 

 

Study Limitations

 

The study has some limitations. The questionnaire forms were mailed to the clinical directors; their answers may not necessarily be in accordance with those of the staff anesthetists of the departments. The major limitation of this survey questionnaire may be the relatively low response rate of 66 percent restricting the accuracy of the responses. 

 

Preparatory Provisions

 

Preparatory provisions may enhance the success of AM and minimize the risks and compliations associated with DA management (2) and were provided in 90 percent. In 10 percent, the consequence of DA information for patients requiring general anesthesia was routine management; in these situations, reliance on conventional AM techniques without caring for special provisions is a risk-enhancing behavior and requires no further comments.

 

Knowledge of Guidelines and Recommendations

 

Knowledge of guidelines and recommendations for DA management is essential to formulate departmental strategies. Since the landmark publication of the American Society of Anesthesiologists guidelines in 1993 (1), further guidelines and recommendation for the management of the DA have been published. Knowledge of at least one of these guidelines and recommendations published in English or German was confirmed in 72 percent; the guidelines of the American Society of Anesthesiologists task force (1, 2) were best known with 68 percent.

 

Formulated Departmental Strategies

 

DA management strategies should be formulated at departmental levels and adapted to the patients, preferences, and equipment availability (5). Formulated departmental strategies for the management of the DA in general were provided in only 52 percent. This percentage is comparable with results obtained in a survey performed in Denmark (12), but significantly higher than that obtained in a survey at Germany university and university-affiliated teaching hospitals with a percentage of merely 22 percent (8).

 

Strategies for the management of the anticipated DA airway were formulated in 46 percent. The American Society of Anesthesiologists task force highly recommends flexible-bronchoscopy assisted tracheal intubation under topical anesthesia and conscious sedation as primary option in the management of the anticipated DA (2). Awake tracheal intubation was considered in 62 percent, but consideration does not mean real performance. We suppose that awake tracheal intubation, particularly using a flexible bronchoscope, is a largely underused technique.

 

Strategies for the management of the unanticipated failed conventional tracheal intubation and adequate face-mask ventilation (MV) situation and the unanticipaed failed conventional tracheal intubation and impossible MV situation were formulated in only 44 and 40 percent, respectively. These numbers demonstrate a modest awareness to the problem of the DA.     

 

Multiple and prolonged conventional tracheal intubation attempts frequently lead to the development of progressive difficulties with MV and may increase the risk for a cannot-ventilate and cannot-intubate situation (13). Therefore, the number of conventional tracheal intubation attempts and the time required should be limited. Optimum preparation for conventional laryngoscopy and tracheal intubation should be already provided for the first attempt. Poor laryngeal views at this early state, indicating a difficult conventional tracheal intubation situation even for an experienced operator, should give rise to initiate rational decisions and strategies (2, 3), but only 30 percent of the departments had formulated limitations of conventional tracheal intubation attempts to a maximum of four or less and only 5 departments limited them up to two attempts. These numbers are an indicator for the weak adhence to published guidelines and recommendations.  

 

The provision of tracheal extubation strategies for patients with a DA, experienced or developing during the surgical procedure performed, is a recommended safety measure (2, 5), but strategies for difficult tracheal extubation were formulated in only 22 percent. For example, the short-term use of a ventilating airway exchange catheter as continuous airway access may allow rescue ventilation and reversible tracheal extubation when necessary and should be considered particularly in high-risk tracheal extubations (14).

 

Provision of Experienced Assistance

 

The establishment of a formal on-call group of staff anesthesists experienced in emergency AM may minimize airway related major complications (14). A team for cardiopulmonary resuscitation is usually implemented even in small institutions, but this survey showed that an experienced AM team or at least one experienced airway manager on call was available in only 28 percent. Early call for help is generally recommended particularly in unanticipated DA situations (2, 3, 11); consequently, the immediate availability of an additional experienced operator should be provided independent of the size of the institution.  

 

Follow-up Patient Care

 

Injuries associated with airway interventions are a significant source of morbidity and mortality (9). Domino and co-workers (6) found that  early signs of perforations, pneumothorax and subcutaneous emphysema, occuring in the immediate perioperative period were present in about 50 percent, whereas late sequelae, retropharyngeal abscess, mediastinitis, or mediastinal abscess) occured in 65 percent. Follow-up care of patients with an experienced DA is highly recommended by the American Society of Anesthesiologists task force (2). Unfortunately, patients at risk were routinely observed for complaints and potential complications in only 34 percent.

 

With physical airway examination, some causes of the unanticipated DA, for example the presence of lingual tonsil hyperplasia or obstructive sleep apnea, will remain undetected without further consultations and examinations. Follow-up care to identify the cause(s) of the nonapparent DA was provided in only 16 percent. 

 

Conclusions

 

We demonstrated that there is much room for improvements in AM behavior at anesthesia departments in Austria. Benchmarking with the results of this survey and refining departmental directives may contribute to improved patient care.

 

 

References