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ETT Size & Depth

Endotracheal tube (ETT) size and insertion depth estimation based on age and weight. Correct sizing prevents airway trauma and ensures effective ventilation.

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Formulas

Uncuffed ETT = (Age/4) + 4

Cuffed ETT = (Age/4) + 3.5

Depth (oral) = ETT size × 3

Depth (nasal) = ETT size × 3 + 2

Neonatal ETT Reference

WeightETT Size (mm)Depth at Lip (cm)
<1 kg2.56.5-7
1-2 kg3.07-8
2-3 kg3.0-3.58-9
>3 kg3.59-10

Pediatric ETT Reference by Age

AgeUncuffed (mm)Cuffed (mm)Oral Depth (cm)
Premature2.5-3.0N/A6-9
Full-term neonate3.0-3.5N/A9-10.5
6 months3.53.010.5
1 year4.03.512
2 years4.54.013.5
4 years5.04.515
6 years5.55.016.5
8 years6.05.518
10 years6.56.019.5
12 years7.06.521
14 years7.57.022.5

References

  • Walsh BK. Neonatal and Pediatric Respiratory Care, 5th Edition.
  • Luten R, Broselow JA. Color-coded pediatric resuscitation tape.
  • AHA/AAP Neonatal Resuscitation Program (NRP), 8th Edition.