Objective: To determine whether multiplying the internal diameter of the endotracheal tube (ETT) by 3 (3× 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 ≤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 ≥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 3× ETT size for the actual tubes chosen, 170 of 226 (75%) would have been accurately placed. More accurate were the 3× PALS–based ETT size (81%) and 3× 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 3× 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.
From the Department of Pediatrics, Division of Nursing (LMP, RKG, JAR, TRB), Division of Pediatric Critical Care Medicine (NJT), and Department of Health Evaluation Sciences (NJT), Penn State Children's Hospital, Pennsylvania State University College of Medicine, Hershey, PA; the Department of Critical Care Medicine and Pediatrics, Children's Hospital of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA (RAO); and the Department of Pediatrics, Division of Pediatric Critical Care Medicine (CLR), University of Maryland, Baltimore, MD.