First-choice videolaryngoscopy for paediatric tracheal intubation

In a study of 904 tracheal intubations in 809 children, Sasu et al. showed that using a C-MAC® videolaryngoscope (Karl Storz, Tuttlingen, Germany) reduced the incidence of poor glottic views from 13% to 4% [1]. They also found the modified six-grade Cormack and Lehane system ineffective for predicting the ease of videolaryngoscopic tracheal intubation. The primary outcome of this study was defined as vocal cords only just or not visible. Restricted glottic views in the modified Cormack and Lehane classifications 2b, 2c and 3 during videolaryngoscopy in adult and paediatric patients are typically due to an enlarged epiglottis and impaired epiglottic movement. Such issues can be resolved by correct head positioning, increased lifting force, directly lifting the epiglottis or external laryngeal manipulation [2-4]. However, the results do not specify whether these techniques were applied to enhance the view of the glottis, leaving us unsure if the observed glottic view grades represent the best possible outcome using both modes of laryngoscopy, particularly direct laryngoscopy that requires aligning the three airway axes for proper visualisation.

Difficult videolaryngoscopic tracheal intubation was documented as a difficult airway alert based on the videolaryngoscopic intubation and difficult airway classification (VIDIAC) score in adult patients with anticipated difficult airways. Kohse et al. classified difficulty into four levels using VIDIAC scores [2], but it is unclear whether a score of 1, which indicates a 50% probability of a difficult airway, was counted as difficult in this study. Although the VIDIAC score was a secondary outcome, its results were not reported, nor was its effectiveness in differentiating easy from difficult videolaryngoscopic tracheal intubations in paediatric patients analysed, despite most having normal airways. Clarifying these aspects could strengthen the conclusions.

The overall first attempt tracheal intubation success rate is significantly lower at 67% compared with a rate of 86.8% in a previous study, which focused on children undergoing elective airway management using videolaryngoscopes with standard blades [5]. Similarly, the success rate for first attempt tracheal intubation in children aged ≤ 1 y (48%) is much lower than the rate in a recent trial studying urgent tracheal intubations in newborns using C-MAC videolaryngoscopy (74%) [6]. Based on our own experience and existing studies [7], a stylet aids in directing the tracheal tube tip to the glottis and enhances tracheal intubation performance with the C-MAC videolaryngoscopy, even when there is a clear view of a child's vocal cords. Hence, we would like to know if a stylet was used in all cases.