Pediatric Endotracheal Tube Size
Estimates endotracheal tube internal diameter from the child age.
When to use
Initial endotracheal tube estimate in children aged 1 to 18 years, before confirmation by laryngoscopy.
Pearls and pitfalls
- The formula estimates internal diameter in millimeters and does not replace choice guided by glottic view.
- The uncuffed version uses age/4 + 4; the cuffed version uses age/4 + 3.5.
- Have a tube half a size above and below available during intubation.
- The formula does not apply to neonates, who use weight and gestational age tables.
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Formula
Uncuffed ETT (mm) = age/4 + 4; cuffed ETT (mm) = age/4 + 3.5.
Evidence
Estimate incorporated into pediatric advanced life support guidelines, based on the relation between age and airway diameter.
References
- Topjian AA, Raymond TT, Atkins D, et al. Part 4: Pediatric Basic and Advanced Life Support: 2020 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2020;142(18_suppl_2):S469-S523. doi:10.1161/CIR.0000000000000901
Frequently asked questions
What is Pediatric Endotracheal Tube Size?
Estimates endotracheal tube internal diameter from the child age. Initial endotracheal tube estimate in children aged 1 to 18 years, before confirmation by laryngoscopy.
How is the result calculated?
Uncuffed ETT (mm) = age/4 + 4; cuffed ETT (mm) = age/4 + 3.5.
How should the result be interpreted?
Estimate incorporated into pediatric advanced life support guidelines, based on the relation between age and airway diameter.
What are the sources?
Topjian AA, Raymond TT, Atkins D, et al. Part 4: Pediatric Basic and Advanced Life Support: 2020 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2020;142(18_suppl_2):S469-S523.