What are the guidelines for selecting and managing an endotracheal tube (ETT) in pediatric patients?

Endotracheal Tube Selection and Management in Pediatric Patients

Both cuffed and uncuffed endotracheal tubes are acceptable for pediatric intubation, but cuffed tubes offer significant advantages including higher likelihood of correct size selection, lower reintubation rates, and no increased risk of complications when cuff pressure is properly monitored below 20-25 cm H2O. 1

Tube Size Selection by Age

Infants Under 1 Year

• Cuffed tube: 3.0 mm ID 1, 2
• Uncuffed tube: 3.5 mm ID 1, 2

Children 1-2 Years

• Cuffed tube: 3.5 mm ID 1, 2
• Uncuffed tube: 4.0 mm ID 1, 2

Children Over 2 Years

• Cuffed tube: 3.5 + (age/4) mm ID 1, 2
• Uncuffed tube: 4 + (age/4) mm ID 1, 2

When to Strongly Favor Cuffed Tubes

Cuffed endotracheal tubes are particularly beneficial (Class IIa, LOE B) in the following clinical scenarios: 1, 2

• Poor lung compliance 1, 2
• High airway resistance 1, 2
• Large glottic air leak 1, 2
• Risk of aspiration 1, 2

The American Heart Association guidelines support both tube types equally (Class IIa, LOE C), but evidence demonstrates cuffed tubes achieve better first-pass success rates without increased perioperative complications in intensive care settings. 1

Depth of Insertion

Use the formula: weight in kg + 6 cm at the lip 2

• Alternative method: 3 times the internal diameter of the tube 2
• Maintain head in neutral position after securing; neck flexion advances the tube deeper while extension withdraws it 2

Critical Preparation Steps

Always have tubes 0.5 mm smaller AND 0.5 mm larger available at the bedside before intubation 1, 2

Length-based resuscitation tapes are superior to age-based formulas for children up to 35 kg, providing more accurate size estimates than traditional calculations 1, 2, 3. Research validates that length-based selection achieves 77% accuracy for correct tube size compared to only 47% for age-based formulas. 3

Troubleshooting During Intubation

• If resistance is met during tube passage: use a tube 0.5 mm smaller 1, 2
• If large glottic air leak interferes with ventilation after placement: replace with a tube 0.5 mm larger OR switch to a cuffed tube of the same size 1, 2
• Tube replacement carries significant risks and should only be performed by experienced personnel in appropriate settings 1, 2

Laryngoscope Blade Selection

For infants under 1 year: use a straight blade (Miller size 1) 2

• Straight blades provide superior visualization by directly lifting the epiglottis 2

Mandatory Verification of Tube Placement (Class I, LOE B)

Use multiple methods simultaneously: 1, 2

• Bilateral chest movement 1, 2
• Equal breath sounds over both axillae 2
• Absence of gastric insufflation sounds 1, 2
• Exhaled CO2 monitoring 1, 2
• Pulse oximetry if perfusing rhythm present 2
• Direct laryngoscopy to visualize tube between vocal cords if uncertain 2
• Chest x-ray in hospital settings to confirm midtracheal position 2

Cuff Pressure Management

When using cuffed tubes, continuously monitor cuff inflation pressure and maintain below 20-25 cm H2O per manufacturer instructions 1, 2. This is critical to prevent tracheal mucosal damage. 1 The risk of complications with properly managed cuffed tubes is no greater than uncuffed tubes in intensive care settings. 1

Common Pitfalls: The DOPE Mnemonic

If patient condition deteriorates after intubation, immediately assess: 2

• Displacement 2
• Obstruction 2
• Pneumothorax 2
• Equipment failure 2

Alternative Sizing Methods

While ultrasound measurement of subglottic diameter shows promise in research settings for predicting appropriate tube size 4, 5, the guideline-recommended approach using age-based formulas or length-based tapes remains the standard for emergency and routine intubation 1, 2. Ultrasound may reduce reintubation attempts but requires additional time and expertise. 4