Evaluation of a new recommendation for improved cuffed tracheal tube size selection in infants and small children.

BACKGROUND: The purpose of this study was to evaluate a new recommendation for tracheal tube size selection using second-generation Microcuff paediatric endotracheal tubes (PETs) with optimized outer diameter (OD) of the distal tube.

METHODS: With Ethics Committee approval, patients aged from birth to 5 years, requiring general anaesthesia with orotracheal intubation, were included. Tracheal tube sizes were selected as follows: internal diameter (ID) 3.0 mm, birth (if > or =3 kg) to <6 months; ID 3.5 mm, 6 to <18 months; ID 4.0 mm, 18 months to <3 years; ID 4.5 mm, 3 to <5 years. Tracheal tubes with the cuff not inflated were classified as too large if no air leak was obtained at an airway pressure of < or =20 cmH2O. Post-intubation stridor requiring therapy was noted.

RESULTS: Three hundred and fifty children were studied. Nine tracheal tubes (2.6%) were too large and had to be exchanged: in patients requiring tracheal tubes of ID 3.0 mm and 3.5 mm, three and four tracheal tubes, respectively, and, in patients requiring tracheal tubes of ID 4.0 mm and 4.5 mm, one tracheal tube in each group. In three patients (0.9%), post-intubation stridor occurred which required therapy.

CONCLUSION: The new recommendation presented for the use of second-generation Microcuff PETs with improved OD to ID ratio allows the selection of cuffed tracheal tubes with larger IDs than previously recommended for small children without increased need for tracheal tube exchange or increased incidence of post-intubation stridor in these age groups.