Prospective assessment of guidelines for determining appropriate depth of endotracheal tube placement in children

Pediatr Crit Care Med. 2005 Sep;6(5):519-22. doi: 10.1097/01.pcc.0000165802.32383.9e.


Objective: To determine whether multiplying the internal diameter of the endotracheal tube (ETT) by 3 (3x ETT size) is a reliable method for determining correct depth of oral ETT placement in the pediatric population.

Design: Prospective, observational.

Setting: University-affiliated, 12-bed pediatric intensive care unit.

Patients: Orally intubated pediatric intensive care unit patients of < or =12 yrs of age.

Interventions: Demographics, ETT size, and depth of ETT placement measured from the lip were obtained. Correct placement, defined as the tip of the ETT below the thoracic inlet and > or =0.5 cm above the carina, was determined by chest radiograph.

Measurements and main results: Suggested ETT size based on the Pediatric Advanced Life Support (PALS) age-based formula and the Broselow tape-length-based guidelines were determined. A total of 174 of 226 ETTs (77%) were correctly positioned. If practitioners utilized the 3x ETT size for the actual tubes chosen, 170 of 226 (75%) would have been accurately placed. More accurate were the 3x PALS-based ETT size (81%) and 3x Broselow-suggested ETT size (85%). The use of the Broselow ETTs to determine the depth would have led to a significantly improved ETT position (p = .009) compared with the actual ETT.

Conclusion: The commonly used formula of 3x tube size for ETT depth in children results in 15-25% malpositioned tubes. Practitioners can improve the reliability of this formula by utilizing the recommended ETT size as suggested by the Broselow tape. A more reliable method is necessary to avoid ETT malposition.

Publication types

  • Evaluation Study

MeSH terms

  • Age Factors
  • Body Height
  • Child
  • Child, Preschool
  • Critical Care*
  • Guideline Adherence
  • Humans
  • Infant
  • Infant, Newborn
  • Intubation, Intratracheal / standards*
  • Practice Guidelines as Topic*
  • Prospective Studies
  • Radiography
  • Reproducibility of Results
  • Trachea / diagnostic imaging