WIP 48 - Is Oro-Helical Length a Better Predictor of Ideal Endotracheal Tube Depth Than the Naso-Tragal Length or Gestational Age-Based Table?

Poster Number: WIP 48
Publication Number: WIP 48.2600

Background: Endotracheal (ETT) malposition is common in the neonatal intensive care unit (NICU) and can result in morbidity or death. To minimize ETT malposition, the Neonatal Resuscitation Program (NRP) recommended either the distance in centimeters from the nasal septum to the ear tragus plus 1 (NTL formula) or the gestational age-based (GA) table in the 8th edition of the NRP textbook. While a previous study has shown significant variation between the ideal ETT depth and NTL in the Asian population, a randomized study did not see any significant difference between the GA table and the 7-8-9 rule. Oro-helical length (OHL), the distance in centimeters between the angle of the mouth and the ipsilateral ear tragus, has been shown in a study to be a better predictor of ETT depth than the 7-8-9 rule in infants weighing ≤1500g. By comparing the predicted insertion depths using the OHL, the NTL, and the GA table with the ideal ETT location, we hypothesized that the OHL is a better predictor of the ideal ETT depth in neonates weighing ≤1500g.

Objective: This study aims to determine which of the available ETT depth prediction methods (OHL, NTL, and GA table) better predict the ideal ETT depth in neonates weighing ≤1500g.

Design/Methods: This is an ongoing prospective observational study approved by the Stony Brook IRB. Using the postintubation CXR on each neonate, we compared 3 insertion depths (the NTL depth, GA table depth, and the OHL depth) with the ideal ETT depth in neonates weighing ≤1500g. We defined ETT malposition as any measurement ≥0.5cm above the upper border of T1 or below the lower border of T2 on the CXR. We expected that the discrepancy between the OHL depth and the ideal ETT depth is 0.5cm less than between the NTL depth or the GA table depth and the ideal ETT depth. Based on the repeated measures of the ANOVA model, 50 neonates would provide >99% statistical power to detect the difference. Statistical analysis will be performed using SAS v9.4 (SAS Institute, Cary, NC), and significance level set at < 0.05. Expected timeline for completion of this study is March 2024.