Flexed-Neck Flexible Nasolaryngoscopy for Evaluation of the Subglottis and Trachea in Children

Objective: Determine if a flexed-neck posture during flexible nasolaryngoscopy (FNL) improves visualization of the subglottis.

Study design: Retrospective review of children undergoing FNL in the neutral (FNL) and flexed-neck (FN-FNL) positions.

Setting: Tertiary children's hospital.

Methods: FNL was performed with each child's head in neutral and flexed-neck positions. Videos in each posture were captured and randomized. The most distal view of the subglottis in each position was evaluated with 4 rating scales: (1) subjective view (SV); of the subglottis and trachea, (2) airway grade (AG); most distal anatomical structure visualized, (3) airway area (AA); percentage of the subglottis visualized; and (4) modified Cormack-Lehane grade.

Results: Twenty children had 80 FNL views blindly evaluated by 5 pediatric otolaryngologists. The SV, AG, and AA were all significantly better with the neck flexed compared to a neutral position (7.3 vs 3.0, interquartile range [IQR]: 2.0-6.8, P < .001; 2.3 vs 1.5, IQR: 1.0-2.0, P < .001; 3.4 vs 1.7, IQR: 2.3-3.8, P = .001). There was no difference in the modified Cormack-Lehane grade between positions. Interrater reliability was excellent or strong (0.93-0.94, confidence interval: 0.91-0.93).

Conclusion: FN-FNL is a simple maneuver performed in children undergoing FNL that partially improves the subjective visualization of the subglottis.