Effect of 90° counterclockwise rotation of the endotracheal tube on its advancement through the larynx during nasal fiberoptic intubation in children: A randomized and blinded study

Background: Resistance to the passage of the endotracheal tube (ETT) is frequently encountered in children as it is advanced over the fiberoptic scope for placement into the trachea because it gets hung up at the laryngeal inlet. Literature in adults indicates that a 90° counterclockwise rotation (CCR) of the ETT before advancing results in smooth passage. We found no literature in children. Objectives: Our aim was to study if a 90° counterclockwise rotation (CCR) of the ETT before advancement leads to smooth passage of the ETT into the larynx in children. Methods: Following IRB approval, we performed this study in two parts: Part 1: An unblinded, observational, pilot study on 20 children scheduled for oral rehabilitation where we concurrently used a fiberoptic scope nasally and GlideScope orally. We visualized the ETT path and observed that 90° CCR allowed smooth passage without hang up. Part 2: A blinded and randomized study on 40 children to confirm if 90° CCR from the outset would improve passage of the ETT during nasal intubation with a fiberoptic scope in children. All children were divided into two groups: group S, ETT bevel facing left; group R, ETT bevel facing down. Results: In Part 1, we observed that the ETT got hung up in 57% of children with standard bevel direction (facing left) and in 0% of children when prerotated. In Part 2, efficacy of prerotation was confirmed; the ETT got hung up in 50% of children in group S but in only 10.5% of children in group R. Conclusion: A change in ETT tip orientation from bevel facing left to facing down by 90° CCR, leads to a significantly higher first-attempt success rate by nasal approach in children. We believe the ETT should be rotated before insertion into the nostril to ensure that full 90° CCR of the tip has been accomplished.