Pediatric Ventilator Tubing Size Recommendations
For pediatric patients, cuffed endotracheal tubes are recommended in most circumstances, with specific size formulas based on age and weight. 1
Endotracheal Tube Size Selection
Cuffed Endotracheal Tubes
- For infants ≥3.5 kg and <1 year of age: 3.0 mm internal diameter (ID) 2, 1
- For children between 1-2 years of age: 3.5 mm ID 2, 1
- For children >2 years of age: Use formula ID (mm) = (age in years/4) + 3.5 2
Uncuffed Endotracheal Tubes
- For infants up to 1 year: 3.5 mm ID 2
- For children 1-2 years: 4.0 mm ID 2
- For children >2 years: Use formula ID (mm) = (age in years/4) + 4 2, 1
Preparation for Intubation
- Always have tubes with ID 0.5 mm smaller and 0.5 mm larger than the estimated size available 2
- If resistance is met during intubation, use a tube 0.5 mm smaller 2
- If there's a large glottic air leak after intubation, consider replacing with a tube 0.5 mm larger or switching to a cuffed tube of the same size 2
Advantages of Cuffed ETTs
- Preferred in circumstances such as poor lung compliance, high airway resistance, or large glottic air leak 2, 1
- Associated with higher likelihood of correct tube size selection and lower reintubation rates 2
- May decrease risk of aspiration 2, 1
- If using cuffed tubes, monitor cuff inflation pressure and limit according to manufacturer's instructions (usually <20-25 cm H₂O) 2
Alternative Methods for Tube Size Selection
- Length-based resuscitation tapes are helpful and more accurate than age-based formulas for children up to approximately 35 kg 2
- The traditional age-based formula may not be accurate for all children, with studies showing it applies to only about 53.5% of patients in some populations 3
- Having three sizes available before intubation is recommended due to individual variations 3
Verification of Proper Placement
- Use both clinical assessment and confirmatory devices to verify tube placement 2
- Look for bilateral chest movement and listen for equal breath sounds over both lung fields 2
- Listen for absence of gastric insufflation sounds 2
- Check for exhaled CO₂ 2
- Continuous waveform capnography is the most reliable method for verifying proper placement 1
Common Pitfalls and Caveats
- Using too small an ETT can increase the risk of inadequate ventilation, air leakage, and aspiration 4
- Using too large an ETT may cause serious complications including airway damage, post-intubation croup, and subglottic stenosis 4
- Age-based formulas are not always accurate and may need adjustment based on the individual patient 4, 3
- Replacement of a functional endotracheal tube carries risks and should be performed in an appropriate setting by experienced personnel 2
- Different populations may require adjustments to standard formulas, as demonstrated in studies of Japanese children 3