Comparison of Two Modified Nasal-Tragus Length Methods for Estimating Orotracheal Tube Depth in Thai Neonates: A Randomized Controlled Trial
In brief
Two neonatal tube-depth methods place 49% to 61% of tubes in target zone
In a randomized trial of 83 Thai neonates, the two methods had similar accuracy, with 49% of tubes in the target zone using the table and 61% using the formula; the difference was not statistically significant. Short-term respiratory complications also did not differ, so neither method proved superior and radiographic confirmation remains essential.
- Journal
- Neonatology (Q1)
- Published
- 10 October 2026
- Study design
- Randomized controlled trial
- Evidence level
- Level 1, High (CEBM 1b)
- Authors
- Sopitsakarn Jaimuang, Wipawee Morakote, Varangthip Khuwuthayakorn, Shanika Kosarat, Maillika Pomrop, Satit Manopunya
- PMID
- 42858280
- DOI
- 10.1159/neo/adsag020
Why clinicians should know about it
- Picked for Neonatology (top studies of the week, 11 October 2026): RCT comparing two NTL methods for optimal ETT placement
Abstract
INTRODUCTION: Various recommendations have been proposed to estimate the proper orotracheal tube insertion depth (Pro-depth). This study aimed to compare the performance of two modified nasal-tragus length (NTL)-based methods-the NTL-based table (T-method) and a modified NTL-based formula (F-method: NTL + 1 cm for NTL ≤ 6.5 cm and NTL + 0.5 cm for NTL > 6.5 cm)-for estimating Pro-depth in Thai neonates. METHODS: In this randomized controlled trial, Thai neonates undergoing orotracheal intubation were assigned to either method. Estimated insertion depth was compared with radiographically determined Pro-depth. Accuracy and short-term respiratory complications, including bronchial intubation, atelectasis, and unplanned extubation, were compared between groups. RESULTS: Thirty-nine and forty-four neonates were allocated to the T-method and F-method groups, respectively. Both methods demonstrated strong correlations with Pro-depth (r = .87 vs .92, p = 0.305). The T-method slightly underestimated depth, whereas the F-method slightly overestimated depth (-0.03 ± 0.65 cm vs 0.11 ± 0.62 cm, p = .314). The F-method showed a higher rate of optimal ETT placement within the mid-intrathoracic target zone (49% vs 61%, p = .247), with no significant difference in short-term respiratory complications. CONCLUSION: Both modified NTL-based methods demonstrated comparable accuracy and safety in Thai neonates. The F-method showed a trend toward improved optimal positioning within the mid-intrathoracic trachea, although the difference did not reach statistical significance. Radiographic confirmation remains essential to minimize the risk of clinically significant complications.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.