Reexamining the ideal depth of endotracheal tube in neonates

Utilizing nasal-tragus length to estimate optimal endotracheal tube depth in neonates: A prospective randomized control study

BACKGROUND

Determination of the optimal depth of endotracheal tube insertion in neonates is challenging. Various formulae have been proposed and are being commonly used for this purpose. There is no single formula that is ideal or can be applied across different populations.

AIM

To compare weight and nasal-tragus length-based formulae as a guide to endotracheal tube insertion depth in term neonates undergoing surgery. Ther primary objective of the study was to determine the position of the endotracheal tube using either weight-based or nasal-tragus length-based formulae and the secondary objective was to determine the incidence of repositioning of the endotracheal tube.

METHODS

A total of 120 full term neonates were divided into two groups with 60 neonates each (group N = NTL + 1 cm and group W = Weight + 6 cm). Endotracheal tube was inserted according to the pre-calculated value and fixed. A neonatal flexible fiberoptic bronchoscope was used to confirm the position of the endotracheal tube tip by measuring its distance from the carina. Repositioning was done if the distance from carina to endotracheal tube tip was less than 20 mm. Chi-squared and Mann-Whitney tests were used for the analysis.

RESULTS

The mean distance measured from carina to endotracheal tube tip in group N was 9.41 ± 6.65 mm and in group W was 3.21 ± 3.45 mm (p value = <.001). A higher incidence of optimal endotracheal tube placement was observed in group N which led to repositioning in 88.3% of neonates in group N and 100% in the group W (53/60 and 60/60, respectively, p value < .05).

CONCLUSION

Based on the results from the studied sample, NTL +1 cm formula is a better predictor than Weight + 6 cm formula to determine endotracheal tube insertion depth in term Indian neonates.

Determining Carina and Clavicular Distance-Dependent Positioning of Endotracheal Tube in Critically Ill Patients: An Artificial Intelligence-Based Approach

Early and accurate prediction of endotracheal tube (ETT) location is pivotal for critically ill patients. Automatic and timely detection of faulty ETT locations from chest X-ray images may avert patients' morbidity and mortality. Therefore, we designed convolutional neural network (CNN)-based algorithms to evaluate ETT position appropriateness relative to four detected key points, including tracheal tube end, carina, and left/right clavicular heads on chest radiographs. We estimated distances from the tube end to tracheal carina and the midpoint of clavicular heads. A DenseNet121 encoder transformed images into embedding features, and a CNN-based decoder generated the probability distributions. Based on four sets of tube-to-carina distance-dependent parameters (i.e., (i) 30-70 mm, (ii) 30-60 mm, (iii) 20-60 mm, and (iv) 20-55 mm), corresponding models were generated, and their accuracy was evaluated through the predicted L1 distance to ground-truth coordinates. Based on tube-to-carina and tube-to-clavicle distances, the highest sensitivity, and specificity of 92.85% and 84.62% respectively, were revealed for 20-55 mm. This implies that tube-to-carina distance between 20 and 55 mm is optimal for an AI-based key point appropriateness detection system and is empirically comparable to physicians' consensus.

Tracheal Length Measurement in Intubated Neonates to Guide the Design and Use of Endotracheal Tube Glottic Depth Markings

Background: Data on neonatal tracheal length are needed to inform the standardization of safety features for endotracheal tubes (ETTs) such as glottic depth markings. Laryngotracheal airway measurements are available from digital imaging in infants and children but not in neonates. We aimed to determine the tracheal length (TL) of intubated preterm and term neonates. Methods: An observational study was performed on 57 neonates of 22–42 weeks’ gestation and <1 week of age. Two clinicians independently reviewed 153 digital chest radiographs to determine the carina position and TL. TL was measured from carina to mid-C4 (cricoid level). We analyzed interrater agreement (within 0.5 vertebral levels) on the position of the carina and TL. TL was plotted as a function of gestational age and weight, using graphical and regression analyses. Results: Carina position ranged from T3 to T5.5, with an interrater agreement of 95%. On image pairs concordant for carina position, TL determinations were virtually identical between readers (mean difference 0.1 mm, 95% CI −0.5–0.6 mm). Average mid-tracheal length overlies the body of T1. In infants aged less than 32 weeks’ gestation, the mid-trachea lies <20 mm from the carina or the larynx. TL linearly correlates with gestational age, but correlation with birthweight best fits a segmented regression with a node at 1 kg. Conclusions: The functional length of the laryngotracheal airway can be reliably measured in sick neonates. It correlates well with gestational age and birthweight, and this information can inform the redesign of ETT markings to promote the safer use of these devices.

Weight Is More Accurate than Gestational Age When Estimating the Optimal Endotracheal Tube Depth in Neonates

Determining the optimal endotracheal tube (ETT) depth in neonates remains challenging for neonatologists. The guideline for optimal ETT depth is based on the patients’ weight or gestational age. However, there is a discrepancy in the suggested ETT depth between these two parameters. The aim of this retrospective study was to compare the recommended weight-based and age-based formulas for optimal ETT depth and obtain the optimal reference before intubation. Participants were assigned to group 1 if the recommended ETT insertion depth based on weight was concordant with the recommended depth based on gestational age, and to group 2 if the weight and age-based depth recommendations were discordant. After exclusion, 180 patients were included in the analysis. Results indicated that the predicted ETT depth suggested by age required more adjustment than by weight (p < 0.05). Furthermore, the required adjustment in the weight-based formula was smaller than the age-based formula (p < 0.05). Multivariate linear regression analysis revealed that weight was the key factor affecting the optimal depth (p < 0.001). These results imply that when there is a discrepancy in ETT depth between the weight-based and age-based recommendation, the weight-based one will be more accurate than the age-based one.

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.

Decreasing radiographs in neonates through targeted quality improvement interventions

OBJECTIVE

Our aim was to decrease radiograph use for monitoring placement of peripherally inserted central catheters (PICC) and endotracheal tubes (ETT) in neonates admitted to the neonatal intensive care unit (NICU) by 20% from November 2017 to November 2018.

STUDY DESIGN

We carried out three Plan-Do-Study-Act (PDSA) cycles: (1) implementation of a radiograph protocol emphasizing ideal patient positioning, standard radiograph views and frequency, (2) standardizing ETT depth using the NRP guidelines, and (3) implementation of an institution specific ETT depth guideline.

RESULTS

The pre-intervention radiographs per PICC day was 0.86 versus a post-intervention value of 0.46 (P = 0.004). The pre-intervention radiographs per ETT day was 1.45 versus a post-intervention value of 1.07 (P = 0.002).

CONCLUSIONS

Our multidisciplinary NICU team performed a QI project, which resulted in more than a 20% decrease in the number of radiographs used for monitoring placement of PICCs and ETTs.