Discussion

 

 

For safe patient care, effective measures for the identification of the difficult airway (DA) and the documentation, dissemination, and communication of DA information 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. 

 

Preoperative Airway Evaluation

 

Focused interview of the patient and review of available medical records may substantially contribute to the detection of the presence of a DA and should be performed on a regular basis in all patients prior to the initiation of anesthetic care (1, 2, 13). Some features of the medical history and medical records may be related to the likelyhood of encountering a DA; this presumption is based on recognized associations between a DA and a variety of congenital and acquired diseases  (1, 2). During the preoperative evaluation, focused patient interviews and reviews of available medical records were routinely performed in 78 percent and the presence of congenital abnormalities and acquired diseases was routinely noted in 80 percent.

 

Currently available screening tests for difficult conventional laryngoscopy and tracheal intubation have only poor to moderate discriminative power when used alone (12, 14); the combination of tests add some incremental diagnostic value in comparison to the value of each test alone. Routine physical airway examination was performed in 88 percent; this percentage is comparable with results obtained by surveys performed in Denmark (8, 11), Germany (7), and The Netherlands (4). Mouth opening, Mallampati classification, and cervical range of motion were most frequently examined, comparable with results obtained by a survey performed in Denmark (11), but the measurement of the thyromental distance was performed in only 22 percent. In a recently published meta-analysis (14), the most useful tests for prediction were found to be a combination of the Mallampati classification and the thyromental distance; therefore, the measurement of the thyromental distance should be included in routine airway assessment.

 

Documentation of Preoperative Findings and Test Results

 

The documentation of DA information was nonuniform; the preoperative findings and test results were routinely documented in only 74 percent, although a lower documentation rate of 38 percent was found in a survey performed in Denmark (11). Their reliable documentation should be standardized (13), particularly at institutions where anesthetists often make preoperative evaluations on patients which are later anesthetized by other operators. The preoperative evaluation protocols provided specific entries for DA information in only 56 percent; all preoperative evaluation protocols should provide entries for these informations. 

 

Documentation of Arrangements with the Patient

 

When difficulties with airway management (AM) are obvious, the anesthetist must carefully inform the patient about the risks and advantages of the various procedures proposed and should obtain written informed consent for the planned strategy and in case of failure, for the backup plan (13). The low percentage of 48 percent for routine obtaining informed consent is incomprehensible. The preoperative evaluation protocols provided a specific entry for the documentation of DA arrangements with the patient in only 28 percent; all preoperative evaluation protocols should provide an entry for these arrangements.

 

Dissemination of Preoperative Findings and Test Results

 

Mark and Marsh (10) place particular emphasis on an in-hospital medic alert system. Based on their experiences, dissemination of DA information after hospital admission of the patient is best ensured by the attachment of an alert label on the cover of the medical record and placing the preoperative evaluation protocol, with precise documentation of the findings and test results, instructions for patient care and preparation for the normal ward and the preoperative admission area, and the informed patient consent for the planned strategies of AM, right in front the medical record; unfortunately, at least one of these medic alerts were routinely provided in only 30 percent. In addition, a color-coded alert wrist band should accompany the patient during the preoperative period unless the DA is disproved (10).

 

Documentation of the Experienced Difficult Airway

 

The experienced DA was routinely documented in the anesthesia record in 80 percent, lower than in surveys performed in the United Kingdom with 100 percent (3) and in Denmark with 98 percent (11), probably because specific entries for DA information were provided in only 54 percent of the records. Anesthesia records should provide entries for grading of face-mask ventilation, conventional laryngoscopic view grading, and the techniques used for (un)successful AM.

 

Dissemination of the Experienced Difficult Airway

 

The dissemination of the experienced DA should start immediately after the incidence. The patients should first receive a color-coded alert wrist band that accompanies them throughout the subsequent hospital stay (9). Further in-hospital dissemination of DA information is best ensured by the attachement of a DA alert label on the cover of the medical record and placing the anesthesia record with detailede documentation of the experienced DA right in front of the medical record. In-hospital medic alert systems for the experienced DA were provided in only 30 percent; in a survey performed in the United Kingdom (3), an alert label for the medical record was provided in 77 percent.

 

Communication of the Experienced Difficult Airway

 

The experienced DA is an insufficiently communicated problem (3, 11). Verbal communication of DA information to the patient was performed in 78 percent, less than in a survey performed in the United Kingdom with 98 percent (3), but this method of communication is unreliable. The patient may not understand the significance of this information and may be physically unable to communicate in a medical emergency situation. The distribution of a notification and a written report to the patient and the explanation of the importance of these documents are more effective options.   

 

The information on a previously experienced DA, as the most reliable predictor of a DA during subsequent general anesthesia (6), is considered essential for future patient care (2, 13). Therefore, it is of great importance to obtain information on a previously experienced DA, especially in cases where face-mask ventilation and/or conventional tracheal intubation turn out to be difficult or impossible despite accurate preoperative airway evaluation. Notifications and written reports on the experienced DA were given to the patients in only 68 and 12 percent, respectively, and a written report was achieved in an uniform location of the medical record in only 16 percent, comparable with results obtained by surveys performed in Denmark (11), Germany (7), and in the United Kingdom (3).

 

Difficult Airway Database

 

Patients with an experienced DA should be encouraged to give consent for enrollment in a departmental DA database with agreement to confidential exchange of medical information for use within the institution and for external queries (5). In only 12 percent, a departmental DA database for patients with an experienced DA was established; this low percentage is comparable with results obtained by surveys performed in Denmark (11) and the United Kingdom (3).

 

Conclusions

 

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

 

 

References