Comparisons and Refinements of Neonatal Oro-Tracheal Intubation Length Estimation Methods in Taiwanese Neonates

Objective: This study aimed to evaluate the efficacy of Tochen's formula [TF, body weight (kg) plus 6 cm], nasal septum to ear tragus length (NTL) + 1 cm, and Neonatal Resuscitation Program gestational age (NRP-GA) and body weight (NRP-BW)-based intubation table in estimating the oro-tracheal intubation length, and to improve the estimation efficacy using anthropometric measurements in Taiwanese neonates. Study design: This was a prospective observational study conducted at a neonatal intensive care unit in Taipei, Taiwan. One hundred intubated neonates were enrolled. The estimated intubation depth was defined as being mid-tracheal concordant if it placed the endotracheal tip between the upper border of the first and the lower border of the second thoracic vertebra. A linear regression model was used to analyze the relationships between mid-tracheal depth and body weight (BW), NTL and gestational age (GA), and to revise the NRP intubation tables using our results. Results: Overall, 56% of the neonates were born at a GA ≤ 28 weeks and 48% had a BW ≤ 1,000 g. The overall mid-tracheal concordance rates for TF, NTL + 1 cm, NRP-GA, and NRP-BW estimations were 51.0, 57.0, 15.0, and 14.0%, and in the infants with a BW ≤ 1,000 g 56.3, 56.3, 8.3, and 8.3%, respectively. Our revisions of the NRP intubation tables based on the anthropometric measurements of our participants improved the efficacy of BW, GA, and NTL estimations to 63, 44, and 61%, respectively. Conclusion: TF and NTL + 1 cm were more reliable than NRP intubation tables in predicting the neonatal mid-tracheal length in neonates of all BW and GA. Considering morphological differences secondary to ethnicity, we recommend using these tailored recommendations during neonatal resuscitation in Asian neonates.