Difficulty Inserting Cuffed Endotracheal Tubes in a Child: A Case Report.

We experienced difficulty inserting cuffed inner diameter (ID) 4.5- and 5.0-mm endotracheal tubes (ETTs) in a 5-year-old boy. Postoperative ultrasound investigations showed that the internal transverse width of the cricoid cartilage was 8.0 mm. The maximum outer diameter (OD) of the deflated cuff portion of the cuffed ID 4.5- and 5.0-mm ETTs was 8.5 and 9.6 mm, respectively. The OD of an uncuffed ID 5.5-mm ETT was 7.6 mm; this tube passed the cricoid cartilage. Hence, the transverse width of the cricoid cartilage and ETT diameter including cuff folds should be considered when selecting cuffed ETTs.