The Oro-Helical Length Accurately Predicts Endotracheal Tube Insertion Depth in Neonates

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.

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.

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.