Videolaryngoscopy: a small step for men, a giant leap for mankind, a monumental leap foward in intubation technology

Abstract

Airway management is one of the mayor tasks of the anaesthetist, either in or outside the operating theatre. A secured airway can be achieved by placing a tracheal tube (TT) between the vocal cords of the patient. The most common way to do this is to perform direct laryngoscopy (DL), achieving a direct view of the vocal cords and thus placing the TT under direct sight. In this thesis, we describe the development of airway management from early history until today. Centuries ago, one only had the deposition of bulky instruments to get an indirect view of the glottis. Instruments lacked a direct light source, so illumination of the oral cavity and glottis was the biggest obstacle. Only when a direct light source was developed, many different endoscopes were designed. Laryngoscopy improved with the development of flexible fibreoptic cables enabling a much better visualization and illumination of the larynx for both direct and indirect laryngoscopy. In the early 21st century, there has been a return to indirect laryngoscopy via videolaryngoscopy using different videolaryngoscopes (VLS). VLS can differ greatly; they can roughly be divided into two groups: channelled and non-channelled. The non-channelled devices can then further be divided in angulated and non-angulated. To find an answer concerning the added value of videolaryngoscopy for anaesthetists confronted with patients with a known difficult airway, a systematic review and meta-analysis is presented. This meta-analysis shows that videolaryngoscopy has an added value for experienced anaesthetists. Also, a very wide range of devices was tested across different key groups. Not one single device was best for all caregivers and this points out that a balance between the advantages of VLS and the disadvantage of new skill requirements can be found in VLS with a classic-shaped Macintosh blade. These results underline the importance of variability in device performance across individuals and staff groups. The intensity of illumination from the light source of different VLS was also compared. Illumination was poor with all VLS tested, except for one when used in the operating theatre. It is important that clinicians are aware of these possible shortcomings and differences between devices. Further exploring the advantages of videolaryngoscopy, we confirmed that the forces applied to teeth are reduced when using VLS. Based on this result, it is strongly recommended to use videolaryngoscopy in patients with poor dentition, dental crowns and/or fixed partial denture, needing intubation. Finally, a new successful intubation technique is presented, combining a Macintosh blade videolaryngoscope with a Bonfils® intubation endoscope (BIE). The combined intubation technique provides the anaesthetist with an alternative option when confronted with difficult intubation conditions.