Accuracy, intra- and inter-rater reliability of three scoring systems for the glottic view at videolaryngoscopy.

An accurate and reproducible recording of laryngoscopic view at tracheal intubation is an important aspect of anaesthetic practice. Unlike direct laryngoscopy, in which the view achieved by the line of sight directly relates to the ease of intubating the trachea, videolaryngoscopy can create a situation in which the view is good, but intubation difficult or impossible. Communicating this to a subsequent anaesthetist is important. We compared three scoring systems: Cormack and Lehane; POGO (percentage of glottic opening); and the Fremantle score, as used by 74 critical care doctors rating 30 anonymised videos of videolaryngoscopic intubations. Accuracy (degree of agreement of score with an expert panel assessment) was higher for POGO (75.5%) and the Fremantle score (73.9%) than for Cormack and Lehane (65.4%; p < 0.001). Intra-rater reliability (mean free marginal Kappa for ordinal scores and mean Cronbach's Alpha for continuous score) was higher for Fremantle score (0.796) and Cormack and Lehane (0.773) than POGO (0.693). Inter-rater reliability for Fremantle score (0.618) and POGO (0.614) were similar and higher than the inter-rater reliability of Cormack and Lehane 0.464 (p < 0.001). The higher accuracy and inter-rater reliability of POGO and the Fremantle score suggest they are preferable to Cormack and Lehane for use when documenting videolaryngoscopy. The additional information about ease of intubation conveyed by the Fremantle score may support its routine use in recording videolaryngoscopic intubation.

The development and preliminary evaluation of a proposed new scoring system for videolaryngoscopy.

Clear documentation of anaesthetic technique, difficulties and complications is an essential part of good anaesthetic practice, particularly in the area of airway management. The current convention of describing intubation using a videolaryngoscope only in terms of a Cormack and Lehane score is at best unhelpful and at worst dangerous. In an attempt to address the inadequacy of a Cormack and Lehane score to describe videoscopic intubation, we propose a three part scoring system: view, ease and device - the 'Fremantle Score'. Preliminary evaluation of this system in a diverse group of anaesthetists utilising four available videolaryngoscopes in a simulated normal and difficult airway manikin has demonstrated that the system is easy to use, easy to understand and relevant. In three of the eight device and manikin combinations studied, the videolaryngoscopic view correlated with the ease of intubation. This highlights the need for an alternative tool to describe intubation with a videolaryngoscope. We consider this development of a specific videoscopic scoring system a first step in better describing intubation by a videolaryngoscope and improving patient care.