This study demonstrates that in acute stroke patients assessing salient findings of endoscopic swallowing examination following the here described protocol can be done reliably with a minimum of experience. After receiving an introductory lecture the previously untrained participants of our study gave a correct rating of characteristic video sequences in nearly 90% of cases, which corresponded to a κ-coefficient of 0.73.
The assessment of liquid and pureed food swallows proved relatively difficult in comparison to semisolid food. This is probably because the former consistencies typically showed predeglutitive key findings only for fractions of a second. Here, replaying of the respective sequences in slow motion, which is also advocated by Langmore and co-workers [13
], might have been useful. The further improvement seen at the complete examination-rating with 96% correct assessments (corresponding κ-coefficient = 0.91) was probably due to a marked training effect of the previous testing and the subsequent discussion. Since systematic curricula on the present subject are sparse, this point may be of relevance for future teaching of endoscopic evaluation of swallowing.
Looking in detail at the few mistakes made at the second testing, it is striking that in each single case participants erred on "safe side" leading to a worse score than necessary.
Furthermore, the excellent κ-coefficient achieved by the previously untrained participants of our study at the complete examination-rating may suggest that endoscopic swallowing assessment according to the here described protocol is simpler to score and more reliable compared to videofluoroscopic swallowing evaluations of acute stroke patients [5
When we developed our screening protocol for acute stroke patients, we aimed for a simple way of scoring endoscopic key findings making this tool more easy to adopt for inexperienced clinicians [4
]. Thus, in comparison to the well-known 8-point Penetration-Aspiration Scale (PAS) developed by Rosenbek and co-workers [15
], we chose a simplified 5-point scale to score penetration and aspiration events. By using this 5-point scale, the here described endoscopic dysphagia screening protocol showed an excellent interrater reliability when applied to acute stroke patients [4
Apart from being able to correctly identify key findings of endoscopic swallowing examination, our protocol for acute stroke patients also requires demanding technical skills from the clinicians. Murray suggests that, after observing several examinations, the novice should perform at least 20 to 30 examinations under supervision before starting to work on his own [13
]. Therefore, when intending to involve so far inexperienced clinicians in the endoscopic examination of swallowing, one has to provide sufficient practical instructions along with the mentioned theoretical tutorials.
Moreover, we would like to emphasise that the inexperienced clinicians participating in our study did not score and interpret complete FEES examinations, but only a small number of relevant parameters for the purpose of dysphagia screening. In comparison to the examination protocol outlined here, Langmore's original FEES protocol is clearly more differentiated [16
]. Apart from identifying salient findings, it also comprises of additional important aspects like a detailed anatomic-physiologic assessment including a pharyngo-laryngeal sensory testing [8
], evaluation of therapeutic maneuvers and their effect on the swallow, and testing of different methods of food delivery. Furthermore, the interpretation of endoscopic findings is not confined to the assessment of the aspiration risk alone but deduces the underlying pathophysiology of dysphagia for suggesting suitable therapeutic interventions and for giving a prognosis. Of course, analyzing and interpreting abnormal findings according to this differentiated and comprehensive protocol needs a lot more of clinical experience with the FEES procedure that cannot be learned in a 30 minutes-lecture.