Cervical spine motion during tracheal intubation with videolaryngoscopy versus macintosh laryngoscopy in adults undergoing cervical spine surgery: a randomized controlled trial.

BACKGROUND

Excessive cervical spine motion during tracheal intubation may increase neurological risk in individuals with cervical spine pathology. Videolaryngoscopy may reduce cervical motion compared with Macintosh direct laryngoscopy, but any biomechanical reduction should be distinguished from neurological protection.

METHODS

Adults scheduled for elective cervical spine surgery were randomized 1:1 to intubation with a ClearVue videolaryngoscope (group V) or a Macintosh laryngoscope (group M) under manual in-line stabilization. Lateral fluoroscopy was acquired immediately before laryngoscopy (G0, neutral position) and at best glottic view (G1). The prespecified primary endpoint was directly measured cumulative C0‒C5 cervical motion. Cervical spine motion (ΔG) was also calculated at C0‒C1, C1‒C2, C2‒C3, C3‒C4 and C4‒C5. ΔG was expressed in degrees (°).

RESULTS

Fifty-six patients were randomized and analyzed (28 per group). Mean (SD) ΔG at C0‒C5 was 19.71 (4.75) in group V and 26.32 (8.46) in group M (mean difference [M‒V], 6.61; 95% CI 2.91‒10.31; p < 0.001). At C0‒C1, ΔG was 2.68 (2.53) vs. 4.68 (2.42) (difference = 2.00; 95% CI 0.67‒3.33; p = 0.004). First-attempt success was 89.3% (25/28) vs. 78.6% (22/28) (p = 0.47). Among patients intubated successfully on the first attempt, intubation time was shorter in group V (21.75 ± 3.64s) than group M (31.71 ± 21.25s).

CONCLUSION

ClearVue videolaryngoscopy reduced fluoroscopically measured upper cervical and directly measured cumulative C0‒C5 motion compared with Macintosh direct laryngoscopy. These findings should be interpreted as biomechanical surrogate outcomes, not as evidence of neurological protection.