OBJECTIVE: To compare actual tracheostomy tube sizes with estimated endotracheal tube sizes using age-related formula and tracheal diameter from preoperative radiographs among pediatric Filipino patients aged 0-18 years old undergoing tracheostomy.

METHODS:

          DESIGN: Review of records

          SETTING:           Tertiary Private University Hospital in Dasmarinas, Cavite, Philippines

          PATIENTS:         Pediatric patients regardless of gender, aged 0 to 18 years old, with a preoperative radiograph of the trachea, and who subsequently underwent tracheostomy anytime from January 1, 2007 to                December 31, 2016 were considered for inclusion. Radiographs were measured, endotracheal tube sizes were computed using age-related formula, and recorded tracheotomy tube sizes were retrieved.

RESULTS: Twenty-two patients (12 males, 10 females) aged 10 months to 18-years-old (median age: 11 years) were included in the study. Mean tube sizes were 6.46mm (+/- 1.492 SD) for age-related formula, 5.67mm (+/- 1.1849 SD) for radiograph-based estimation, and 5.0 for actual tracheostomy tube inserted in each patient. The Bland-Altman plot showed the bias estimate at 0.7913 and the lower and upper limits of agreement at -1.3598 and 2.9423 (confidence level 95% or 2 standard deviations away from the mean).

CONCLUSION: The average value derived from radiograph-based estimation is less than the corresponding average value from age-related formula. There is a significant difference between age-related formula-based estimation and actual tracheostomy tube inserted. Since the range of differences between the two estimation methods is high, these results imply that the bias or the difference between measures from the two methods is not consistent, with the two methods exhibiting very poor agreement.