Efficacy of modified Tochen's formula for optimum endotracheal tube placement in low birth weight neonates: an RCT

Randomised trial estimating length of endotracheal tube insertion using gestational age or nasal-tragus length in newborns: a study protocol

INTRODUCTION

Endotracheal tube (ETT) insertion depth estimation is important for optimal placement of ETT tip and balanced ventilation of the lungs. Various methods are available to determine the ETT insertion depth. The Neonatal Resuscitation Programme recommends the gestational age and nasal-tragus length (NTL) methods for estimating ETT insertion depth during cardiopulmonary resuscitation. However, the prospective data comparing these two methods is lacking.

METHODS AND ANALYSIS

This is an open-label multi-centre randomised controlled trial, where gestational age and NTL methods will be used to determine the initial ETT insertion depth in term and preterm infants that are less than 28 days old, requiring oral intubation in the delivery room or neonatal intensive care unit (NICU).

SITES AND SAMPLE SIZE

The trial is aimed to recruit 454 infants over 3 years across tertiary level NICUs.

OUTCOMES

The primary outcome includes an optimally positioned ETT, defined as an ETT tip between the upper border of the first thoracic vertebra and the lower border of the second thoracic vertebra. The outcome is assessed by a paediatric radiologist, who will be masked to the group assignment. Secondary outcomes are malpositioned ETT tips, pneumothorax, ETT repositioning, chronic lung disease, invasive ventilation days, and death.

ANALYSIS

Data will be analysed using the intention-to-treat principle. The primary and categorical secondary outcomes will be compared using the χ² test. Adjusted risk ratios of outcomes will be calculated along with 95% CIs through multivariable logistic regression analysis, including covariates deemed biologically to influence the outcomes.

ETHICS AND DISSEMINATION

The study has been approved by the PNU Research Ethics Board (20-0148) and the respective ethical review boards of the participating centres. The results will be disseminated through conference meetings, social media platforms, and publications in scientific journals.

TRIAL REGISTRATION NUMBER

NCT04393337.

Methods for Estimating Endotracheal Tube Insertion Depth in Neonates: A Systematic Review and Meta-Analysis

OBJECTIVE

To systematically review the methods for estimating endotracheal tube (ETT) insertion depth in neonates.

STUDY DESIGN

Medline, Embase, Cochrane Central, and Cumulative Index to Nursing and Allied Health Literature databases searched for randomized clinical trials (RCTs). RCTs comparing two or more different methods to estimate ETT insertion depth were included. Two co-authors independently extracted the data and assessed the risk of bias. The primary outcome includes the proportion of optimally placed ETT tips identified on chest X-ray.

RESULTS

Eight RCTs evaluating seven different estimation methods were included. Trials varied defining the optimal position of the ETT tip. Overall, the percentage of optimal position ranged from 8.8 to 93%. The weight, gestation nomogram, and vocal cord estimation methods resulted in malpositioning of ETT tips in more than half of infants ≤30 weeks' gestational age. The rates of optimal ETT tip placement with the digital palpation method differ between moderately (83-93%; two RCTs) and extremely (47%; one RCT) preterm infants. Meta-analysis showed no difference between weight-based and digital palpation methods (relative risk = 0.88; 95% confidence interval = 0.75-1.04; three RCTs; participants = 205; I ² = 0%; quality of evidence, low).

CONCLUSION

Commonly used estimation methods for ETT tip placement are inaccurate and unreliable. Further research is required to improve the accuracy of estimation methods and also to identify the usefulness of the digital palpation method in large clinical trials.

Is Nasal Septum-Tragus Length Measurement Appropriate for Endotracheal Tube Intubation Depth in Neonates? A Randomized Controlled Study

OBJECTIVE

Endotracheal intubation is a frequent procedure performed in neonates with respiratory distress. Clinicians use different methods to estimate the intubation insertion depth, but, unfortunately, the improper insertion results are very high. In this study, we aimed to compare the two different methods (Tochen's formula = weight in kilograms + 6 cm; and nasal septum-tragus length [NTL] + 1 cm) used to determine the endotracheal tube (ETT) insertion depth.

STUDY DESIGN

Infants who had intubation indications were enrolled in this study. The intubation tube was fixed using the Tochen formula (Tochen group) or the NTL + 1 cm formula (NTL group). After intubation, the chest radiograph was evaluated (above T1, proper place, and below T2).

RESULTS

A total of 167 infants (22-42 weeks of gestational age) were included in the study. The proper tube placement rate in both groups was similar (32.4 vs. 30.4% for infants < 34 weeks of gestational age and 56.8 vs. 45.0% in infants > 34 weeks of gestational age). The ETT was frequently placed below T2 at a higher rate in infants with a gestational age of <34 weeks, especially in the NTL group (46% in the Tochen group and 60.7% in the NTL group).

CONCLUSION

The NTL + 1 cm formula led to a higher rate of ETT placement below T2, especially in infants with a birth weight of <1,500 g. Therefore, more studies are needed to determine the optimal ETT insertion depth.

'Lip-to-Tip' study: comparison of three methods to determine optimal insertion length of endotracheal tube in neonates

The aim of this prospective observational study was to compare the incidence of endotracheal tube (ETT) malposition using weight-based (Tochen), gestation-based (Kempley), and nasotragal length (NTL) methods in deceased neonates and fresh stillbirths. We enrolled deceased neonates and fresh stillbirths within 2 ± 1 h of death or delivery, respectively; without hydrops, tracheostomy or major congenital anomalies affecting face, neck, or thorax. Each enrolled subject was intubated orotracheally, with lip-to-tip distance determined by three methods in random succession. Chest X-ray was acquired after each insertion. The primary outcome was proportion of malpositioned ETTs on chest X-ray (defined as ETT tip not lying between upper border of T1 and lower border of T2 vertebrae), assessed by two experts masked to the methods used. The proportion of malpositioned tubes was not significantly different with any of the three methods: (weight 27/50 (54%), gestation 35/50 (70%), and NTL 35/50 (70%), p value 0.055). The malpositioned tubes were too far in (87/150; 58%) than too far out (10/150; 6.7%).Conclusions: None of the currently recommended methods accurately predicts optimal ETT length in neonates. There is an urgent need for newer bedside modalities for estimating ETT position in neonates. What is known? • NRP guidelines recommend gestation-based and nasotragal length (NTL) methods to estimate initial ETT depth in neonates. Weight-based (Tochen) method is still widely used in neonatal units for ETT depth estimation. Evidence till date has not proven superiority of one method over the other. What is new? • All three methods for ETT depth estimation (Tochen, gestation-based, and NTL) resulted in high rates of ETT malposition in neonates. Formulae, devised from this study based on linear regression models, did not perform well for estimation of optimal ETT position.

New Formula for Nasal Endotracheal Intubation in Extremely Low-Birth Weight Infants in the Emergency Transport Setting: The "Genoa Formula"

OBJECTIVE

The purpose of this study was to find a predictive equation for estimating the optimal nasal endotracheal tube insertion depth in extremely low-birth weight infants (ELBWs) requiring invasive ventilation in the critical care interfacility transport setting.

METHODS

We retrospectively calculated the optimal tube insertion depth in a cohort of neonates ≤ 1,000 g born at our neonatal intensive care unit and nasally intubated within the first 24 hours of life from January 2019 to May 2020.

RESULTS

A total of 75 ELBW infants were included, with a median gestational age of 26.6 weeks (range, 22.1-32.6 weeks) and a median birth weight of 780 g (range, 410-990 g). The linear regression of the estimated optimal endotracheal tube insertion depth showed a good correlation when plotted against weight (R² = 0.491); thus, a new weight-based formula was obtained.

CONCLUSION

The proposed weight-based formula (the "Genoa formula") may help in predicting optimal insertion depths for nasal intubation in ELBW neonates, especially when a prompt radiologic confirmation of the tube position is not available, as during neonatal critical care transport.

Randomised trial of estimating oral endotracheal tube insertion depth in newborns using suprasternal palpation of the tip or weight

BACKGROUND

Endotracheal tube (ETT) tip position is determined on chest X-ray (CXR) and should lie between the upper border of the first thoracic vertebra (T1) and the lower border of second thoracic vertebra (T2). Infant weight is commonly used to estimate how far the ETT should be inserted but frequently results in malpositioned ETT tips. Palpation of the ETT tip at the suprasternal notch has been recommended as an alternative.

OBJECTIVE

To determine whether estimating ETT insertion depth using suprasternal palpation of the ETT tip rather than weight results in more correctly positioned ETT tips.

DESIGN

Single-centre randomised controlled trial.

SETTING

Level III neonatal intensive care unit (NICU) at a university maternity hospital.

PATIENTS

Newborn infants without congenital anomalies intubated in the NICU.

INTERVENTIONS

Participants were randomised to have ETT insertion depth estimated using palpation of the ETT tip at the suprasternal notch or weight [insertion depth (cm)=6 + wt (kg)].

MAIN OUTCOME MEASURE

Correct ETT position, that is, between the upper border of T1 and lower border of T2 on CXR, determined by one consultant paediatric radiologist masked to group assignment.

RESULTS

There was no difference in the proportion of correctly placed ETT tips between the groups (suprasternal palpation 27/58 (47%) vs weight 23/60 (38%), p=0.456). Most incorrectly positioned ETTs were too low (56/68 (82%)).

CONCLUSION

Estimating ETT insertion depth using suprasternal palpation did not result in more correctly positioned ETTs.

TRIAL REGISTRATION NUMBER

ISRCTN13570106.

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.