Difficult intubation due to position of laryngoscope blade light


  • No external funding and no competing interests declared. Published with the written consent of the child's mother.

We would like to alert our colleagues to a design issue in a laryngoscope blade, which has the potential to impact on patient care and safety.

We anaesthetised a 2-month-old, 4.6-kg infant with Stickler Syndrome (a multi-system collagen synthesis disorder) for a tracheostomy to relieve respiratory distress with sub-costal recession and tracheal tug leading to multiple dips in oxygen saturation. The infant had a cleft palate and micrognathia as part of the syndrome. A nasopharyngeal airway was in situ and supplemental oxygen was required to maintain adequate oxygen saturation.

In the anaesthetic room, appropriate monitoring was attached and anaesthesia was induced using 8% sevoflurane in 100% oxygen with the patient breathing spontaneously. Despite careful positioning, laryngoscopic view of the vocal cords was physically obscured by the blade light of the disposable Miller size-0 blade (Flexicare Medical Limited, Mountain Ash, UK) we were using. A second attempt at laryngoscopy using a non-disposable Miller size-0 blade (Penlon Limited, Abingdon, UK) enabled a view of the vocal cords and successful intubation without further incident.

On examination of the two blades we noted that the light position in the blade differs markedly between the Miller 0 disposable and non-disposable (Fig. 4), and believe that this was the reason we were unable to intubate on our first attempt.

Figure 4.

Blade light position in disposable (left) and non-disposable (right) Miller size-0 laryngoscopes.

We have never experienced such problems with the bigger disposable Miller size-1 blade, and believe that this is because generally the child's airway is larger, thus affording a better view. On discussing this with our colleagues, several have also stated their difficulty with the disposable Miller 0 blade and have stopped using it in this age group. A review of the literature has shown there to be a problem with light position in the non-disposable Miller 1.5 blade [1], but we believe there have not been any previous reports regarding the disposable Miller size-0. Our future practice will be to use the non-disposable size-0 blade in infants of a similar weight and size.