Clinical comparison of midline versus right-sided video laryngoscope insertion for endotracheal intubation in difficult airways: a randomized controlled trial

Video laryngoscopy (VLS) is a common tool for airway management. During conventional intubation, the blade is inserted from the right side, moving the tongue toward the left side to provide a direct view. Recent clinical evidence suggests that VLS midline insertion may provide a better glottic view in non-difficult airways.

In this randomized controlled trial, we compared midline vs. right-sided VLS insertion (C-MAC® ) for anticipated difficult airways. The study included adult patients undergoing elective surgery who required primary VLS intubation. The primary endpoint was the Cormack-Lehane (C/L) grade derived from the VLS. Secondary endpoints included the duration of airway management, complications, first-pass success, Arné score, and anesthetist experience level.

Patients (n = 162) were randomized into Midline (M; n = 80) and Right-sided (R; n = 82) study groups. The median (1Q, 3Q) C/L was 2.0 (2.0, 2.5) for M and 2.0 (1.0, 2.5) for R; P = 0.089. No difference was observed in Arné scores (P = 0.224), first-pass success (P > 0.999), duration of airway management (P = 0.390), or complications (P = 0.907). No significant difference (P = 0.324) was observed in C/L grade between the specialists (n = 42) and residents with 1 and 2 months of training (n = 53).

No significant difference was found in the glottic view based on the insertion point of the blade (midline or right) or the duration of airway management. This was independent of the experience level of the anesthesiologist performing the procedure.