Do age-based formulae predict the appropriate endotracheal tube sizes in Japanese children?

Area of Science:

• Pediatric Anesthesiology
• Airway Management
• Clinical Pediatrics

Background:

• Age-based formulas are commonly used to determine endotracheal tube (ETT) size in pediatric patients.
• Existing formulas rely on outdated data primarily from Western populations.
• The applicability of these formulas to diverse pediatric populations remains a concern.

Purpose of the Study:

• To evaluate the accuracy of established age-based formulas for predicting endotracheal tube (ETT) size in Japanese children.
• To assess the effectiveness of current ETT sizing guidelines in a contemporary Japanese pediatric cohort.

Main Methods:

• Retrospective review of 1301 children aged 0-8 years who underwent oral intubation.
• Data collected included patient age and the internal diameter (ID) of the endotracheal tube (ETT) used.
• Analysis focused on comparing actual ETT sizes with those predicted by age-based formulas.

Main Results:

• For infants under 2 years, specific ETT IDs were most common: 3.0 mm (<1 month), 3.5 mm (1-4 months), 4.0 mm (5-17 months), and 4.5 mm (18-23 months).
• The formula ID (mm) = [age in years + 16]/4 showed applicability in children aged 2-8 years.
• This formula accurately predicted ETT size in only 53.5% of the overall study population.

Conclusions:

• The age-based formula ID (mm) = [age in years + 16]/4 is partially applicable to Japanese children.
• Despite formula applicability, a recommendation is made to have three ETT sizes readily available prior to intubation.
• This approach ensures preparedness for variations in airway anatomy and facilitates successful pediatric endotracheal intubation.