To the Editor:—
I read with interest the study by Watt et al .1of telescoping tracheal tubes into catheters to minimize epistaxis during nasotracheal intubation in children.
The authors selected uncuffed tracheal tubes (nasal RAE; Mallinckrodt, St. Louis, MO) for their 2- to 10-yr-old study patients using the formula (age of the patient in years divided by 4) + 4. Khine et al .2demonstrated that 23% of their patients, full term to 8 yr old, needed reintubation to obtain an appropriate fit using the same modified Cole formula for uncuffed Mallinckrodt tubes. I have had air leaks often with the uncuffed Mallinckrodt tracheal tubes selected by the same formula; sometimes the proper size tube was two sizes larger. The authors chose not to investigate this relevant sequela. As a result, readers are left pondering how the authors managed the rest of the anesthetics. In a previous study about telescoping by Elwood et al .,3the nasal RAE uncuffed tubes, selected using the formula (age/4) + 3.5, were even smaller. In 1 of 103 study patients, the leak around the tube was large, necessitating a change of tube. Could there be a regional difference of larynx size in the United States?
The OD of the funnel end of a 10- or a 12-French Davol® urethral catheter (Davol Inc., Cranston, RI) is approximately 9–10 mm. The end is made to accept a connector from a urine-collecting bag. When an ID 4.0 endotracheal tube is telescoped into the funnel end, the combination is bulky. It is difficult to visualize how this combination, without any modification, can pass the naris or choana easily.
Telescoping a cuffed pediatric endotracheal tube, instead of an uncuffed tube, may be the better approach to minimize epistaxis and avoid nasal reintubation to achieve an appropriate air leak. Although no cuffed RAE-type nasal tubes are currently available in sizes smaller than ID 5.0, cuffed pediatric oral tracheal tubes are available down to ID 3.0. The cuffed oral endotracheal tube can be cut proximally to the proper length, and a standard 90° endotracheal connector can be inserted to lower the profile.
Children’s Hospital of Michigan, Detroit, Michigan. firstname.lastname@example.org