The concordance of ultrasound technique versus X-ray to confirm endotracheal tube position in neonates : preliminary results

Position du problème et objectif(s) de l’étude

In neonates, the risk of selective bronchial intubation is higher due to the shorter length of the trachea, potentially causing harm or even fatality. While X-ray is the gold standard for confirming endotracheal tube (ETT) placement, it involves radiation and is time-consuming. Our study aims to compare ultrasound to X-ray in confirming proper ETT placement.

Matériel et méthodes

After obtaining institutional research ethics approval, we conducted a prospective observational monocentric study, including all intubated neonates, admitted in our neonatal intensive care unit (NICU). In all patients enrolled, the ETT was secured using the formula (ETT size * 3, gum to tip). ETT position was confirmed by auscultation, observing symmetrical chest wall movement and End-Tidal CO2 detector. The time of ETT insertion was recorded, and simultaneous calls were made to the radiography technician and for the ultrasound machine. On radiography, the correct position of the ETT was confirmed by visualizing its tip at the level of the 1st or 2nd thoracic vertebra. Bedside ultrasound was performed by a 7th-semester or more anesthesia-critical care resident trained with a 1-hour course in thoracic and upper abdomen ultrasound imaging, under the direct supervision of the anesthesia-critical care attending. We studied pleural sliding and the direction of diaphragmatic excursion. Diaphragmatic sonography was performed using the Sonosite M-Turbo with a 10 to 5 MHz convex transducer. The primary scanning window was the subxiphoid area, with alternatives in the lower lateral chest. M-mode was used to assess diaphragmatic motion relative to ETT position. After that, the ETT was classified as: 1-Tracheal: pleural sliding and bilateral caudal diaphragmatic movement 2-Selective: pleural sliding and ipsilateral caudal movement 3-Esophageal: absence of pleural sliding and diaphragmatic movement Absence of the sliding lung sign, which could also indicate pneumothorax, atelectasis, or pulmonary consolidation, required further investigation. The primary endpoint of the study was the concordance between the two examinations. The study also recorded the duration of ultrasound and X-ray completion, as well as the incidence of bradycardia and desaturation during handling for both exams.

Résultats & Discussion

Ten neonates were included during the study period, with a sex ratio of 0.8, a gestational age ranging between 33 and 39 weeks, a post-gestational age ranging between 34 and 40 weeks and weight ranging between 1672 and 2916 g.

Table I Concordance between Chest Xray and sonography for ETT placement

	Proper ETT position	Selective ETT position	Oesophageal ETT position
Lung ultrasound	10	0	0
Chest Xray	10	0	0

The median duration needed to perform the ultrasound (5 minutes, interquartile range of 1 minute) was significantly lower than the median duration needed to obtain a chest X-ray (30 minutes, interquartile range of 40 minutes), p = 0,0014.

Conclusion

Bedside ultrasound examination looks to be as effective as chest X-ray in confirming proper ETT placement in intubated neonates admitted in NICU. A larger sample size is needed to confirm these results.

Auteurs

Sandra BOUHSASS, Ahmed BEN SLIMENE, Mohamed Khalifa KNANI, Seif MBAREK, Marwan BAAZOUG, Emna KHAMMERI, Ahmed MEKNI, Rym KAROUI, Mehdi TRIFA - (1)Hôpital D'enfants Béchir Hamza De Tunis, Tunis, Tunisie