Formula of Park et al for Predicting the Appropriate Uncuffed Endotracheal Tube Size for a Child 3 to 6 Years Old

 

Patient selection: 3 to 6 years old not excluded (based on small size for age, history of airway surgery, or abnormal air leak around the tube).

 

Endotracheal tube: uncuffed (plain). Targeted air leak around the tube was 10-30 cm H2O.

 

Study: chest radiograph to include neck

 

Measurement: inner tracheal diameter at C7 in millimeter

 

external diameter of the endotracheal tube in mm =

= (0.3 * (tracheal diameter)) + 3

 

Performance:

• This method was less likely to underestimate th actual tracheal size when compared to age-related estimates.

 

Limitations:

• The radiograph needs to be standardized to minimize variation in magnification.