What size tracheal tube is used for newborn intubation?

Endotracheal Tube Size for Newborn Intubation

For newborn intubation, a 3.0 mm internal diameter (ID) cuffed tracheal tube should be used for infants weighing ≥3.5 kg and less than 1 year of age. 1

Recommended Tracheal Tube Sizes for Newborns

• For newborns weighing ≥3.5 kg, use a 3.0 mm ID cuffed tracheal tube 1
• If using an uncuffed tube for newborns, a 3.5 mm ID tube is appropriate 2
• Have tubes 0.5 mm smaller and 0.5 mm larger than the estimated size available during intubation 2
• Recent evidence suggests that for smaller newborns (1000-1199g), a 2.5 mm tube may be associated with fewer adverse events than the standard 3.0 mm recommendation 3

Tube Selection Considerations

• Both cuffed and uncuffed tracheal tubes are acceptable for newborn intubation 1, 2
• Cuffed tubes may be preferable in certain circumstances such as poor lung compliance, high airway resistance, or large glottic air leak 1, 2
• If using cuffed tubes, monitor cuff pressure and keep it below 25 cm H2O to prevent airway damage 1, 2
• The 3.0 mm tube size recommendation is based on multiple prospective studies including LOE 2 prospective randomized multicenter studies 1

Proper Tube Placement

• Depth of insertion (cm at lip) = weight in kg + 6 cm 2
• Alternatively, depth can be estimated as 3 times the internal diameter of the tube 2, 4
• The tube should be inserted to approximately 50-55% of tracheal length 4
• Verify proper tube placement using multiple methods including:
  • Bilateral chest movement 2
  • Equal breath sounds over both lung fields 2
  • Absence of gastric insufflation sounds 2
  • End-tidal CO2 detection 2

Troubleshooting

• If the tracheal tube meets resistance during insertion, use a tube with an ID 0.5 mm smaller 1, 2
• If there is no leak around the tube with the cuff deflated, reintubation with a tube ID 0.5 mm smaller may be beneficial when the patient is stable 1
• Be aware that smaller tubes (2.5 mm) have significantly higher resistance, which may increase work of breathing in spontaneously breathing infants 5

Clinical Considerations

• A very small ETT increases the risk of inadequate ventilation, air leakage, and aspiration, while a very large ETT may cause airway damage, post-intubation croup, and subglottic stenosis 6
• Recent research suggests that for some weight categories, tubes 0.5 mm smaller than standard recommendations may be associated with fewer adverse events during intubation, including less severe oxygen desaturation 3
• Remember the "DOPE" mnemonic if a patient's condition deteriorates after intubation: Displacement, Obstruction, Pneumothorax, Equipment failure 2

The evidence strongly supports using a 3.0 mm ID cuffed tracheal tube for newborn intubation in infants weighing ≥3.5 kg, based on multiple high-quality studies and international guidelines. This recommendation balances the need for adequate ventilation while minimizing the risk of airway trauma.