First, increasing the size of the target area the TT must negotiate (i.e. dilating the laryngeal introitus and supra-glottis). This can be done by asking the patient to take a deep breath when the tube is advanced or similarly, advancing the tube on inspiration. Patient compliance is assured by using minimal sedation and topical anaesthesia. Equally, in spontaneously breathing anaesthetized patients, tube advancement should be synchronized to the inspiratory phase.
Second, personal experience is that it is more straightforward to advance a TT when an awake patient is sitting upright than when recumbent. This may relate to optimal positioning of the head and neck and is the position mandated by many patients who have jeopardized airways.
Lastly, although Asai and Shingu refer to flexing the patient's neck, full optimization of the airway may be facilitated by asking a sitting patient to look upwards; they automatically adopt a posture to sniff the morning air, which, again, seems to minimize hold-up of the TT.
So, as Asai and Shingu eloquently point out, there are many evidenced-based manoeuvres and pieces of equipment that are used to advance TTs over fibrescopes, but we must never forget that the patient can be of vital help too.
Warrington, UK
References
1 Asai T, Shingu K. Difficulty in advancing a tracheal tube over a fibreoptic bronchoscope: incidence, causes and solutions. Br J Anaesth 2004; 92: 87081