Left-molar approach for direct laryngoscopy: is it easy?

Abstract

Difficulty in the insertion of the endotracheal tube limits the efficacy of the left-molar approach. It is not possible to predict the failure of intubation with the left-molar approach by considering the preoperative risk factors.

A comparison between left molar direct laryngoscopy and the use of a Bonfils intubation fibrescope for tracheal intubation in a simulated difficult airway

“…11 Cuvas et al showed that the LM approach improved the glottic view, but 81.5% of cases could not be intubated on the first attempt. 24 Bozdogan et al also found that the LM approach improved the view in 90% (18/20) of patients who had a difficult midline laryngoscopy, although tracheal intubation could not be performed in 35% (7/20) of these patients. 13 The narrow space and a bulging tongue over the blade obscured the view of the glottis and made tracheal intubation difficult under vision.…”

The midline approach for endotracheal intubation using GlideScope video laryngoscopy could provide better glottis exposure in adults： A randomized controlled trial

“…Additionally, different from both approaches, the left-molar approach requires that the tongue be displaced to the right. It was reported that the left molar approach can also provide a better laryngeal view in cases of unexpected difficult intubation and mitigate difficult intubation when performed by direct laryngoscopy [16,17] .…”

The use of the left-molar approach for direct laryngoscopy combined with a gum-elastic bougie

“…It was observed that insertion of the tracheal tube using left-molar approach was not easy, causing the failure of intubation [3]. It is not possible to predict the failure of intubation with the left-molar approach by considering the preoperative risk factors [3]. There is no data in literature for the left-molar approach combined with a gum-elastic bougie for difficult intubation.…”

“…In contrast, the left-molar approach may offer advantage in terms of laryngoscopic view, but the difficulty in the insertion of the tracheal tube limits this technique's efficacy [3]. In this technique, the tracheal tube has to be inserted through a triangle framed by the flange, the lingual surface of the blade, and the tongue bulging to the right of the blade.…”

“…In some cases, bulging of the tongue does not disturb the direct visualization, but it limits the triangle, making the intubation difficult. It was observed that insertion of the tracheal tube using left-molar approach was not easy, causing the failure of intubation [3]. It is not possible to predict the failure of intubation with the left-molar approach by considering the preoperative risk factors [3].…”