pediatric_ett_size: Pediatric Endotracheal Tube (ETT) Size Calculator

In cliot: Clinical Indices and Outcomes Tools

Pediatric Endotracheal Tube (ETT) Size Calculator

Description

Calculates the recommended internal diameter (ID) for uncuffed and cuffed endotracheal tubes for pediatric patients based on age. Also estimates the depth of insertion. This function typically uses the Cole formula for children older than 1 year.

Usage

pediatric_ett_size(age_years)

Arguments

age_years

Numeric. Age of the child in years.

Details

The standard formulas used for children \ge 1 year are:

• Uncuffed Size (mm ID): (Age / 4) + 4

• Cuffed Size (mm ID): (Age / 4) + 3.5

• Depth (cm): (Age / 2) + 12

For infants (< 1 year), fixed sizes (3.5mm uncuffed for <6mo, 4.0mm for 6mo-1yr) are generally recommended.

Value

A list containing:

Uncuffed_ETT_Size_mm	Recommended internal diameter for an uncuffed tube.
Cuffed_ETT_Size_mm	Recommended internal diameter for a cuffed tube.
Depth_of_Insertion_cm	Estimated depth of insertion at the lip.

References

Cole F. Pediatric formulas for the anesthesiologist. AMA J Dis Child. 1957;94(6):672-673. Standard PALS Guidelines (AHA).

Examples

# Example 1: 4-year-old child
# Uncuffed: 4/4 + 4 = 5.0 mm
# Cuffed: 4/4 + 3.5 = 4.5 mm
# Depth: 4/2 + 12 = 14 cm
pediatric_ett_size(4)

# Example 2: 8-year-old child
# Uncuffed: 8/4 + 4 = 6.0 mm
# Cuffed: 8/4 + 3.5 = 5.5 mm
# Depth: 8/2 + 12 = 16 cm
pediatric_ett_size(8)

cliot documentation built on Dec. 1, 2025, 1:06 a.m.