ETT Size for Uncuffed Tube

Used for pediatric airway management when choosing an appropriately sized uncuffed tube in children. Size is generally estimated by (age/4) + 4 (mm internal diameter). Useful when a larger air leak is acceptable, in settings avoiding cuff‑related mucosal pressure, or when tube changes are expected. Clinically helps ensure adequate ventilation, minimizes airway trauma, and reduces risk of post‑extubation edema.

Use (age/4 + 4 mm) as a starting point, but choose the smallest tube that gives an adequate leak to reduce subglottic injury risk. ERC 2025 cautions that age formulas are unreliable; confirm with leak testing and have adjacent sizes ready 1 [Level I evidence]. Avoid oversized tubes because larger IDs increase airway complications in children 2 [Level I evidence]. Aim for a slight leak at ≤25 cmH2O.