Supplementary Material for: Ultrasound for Endotracheal Tube Tip Position in Term and Preterm Infants

<b><i>Background and Objective:</i></b> Placing an endotracheal tube (ETT) in neonates is challenging and currently requires timely radiographic confirmation of correct tip placement. The objective was to establish the reliability of ultrasound (US) for assessing ETT position in the neonatal intensive care unit (NICU), time needed to do so, and patients’ tolerance. <b><i>Methods:</i></b> A prospective study on 71 newborns admitted to our NICU whose ETT placement was evaluated with US (ETT-echo) and confirmed on chest X-rays (CXR). Data were collected by 3 operators (2 neonatologists and a resident in pediatrics). The right pulmonary artery (RPA) was used as a landmark for US. The distance between the tip of the ETT and the upper margin of the RPA was measured using US and compared with the distance between the tube’s tip and the carina on the CXR. <b><i>Results:</i></b> Seventy-one intubated newborns were included in the study (<i>n</i> = 34 &lt; 1,000 g, <i>n</i> = 18 1,000–2,000 g, <i>n</i> = 19 &gt; 2,000 g). Statistical analysis (Bland-Altman plot and Lin’s concordance correlation coefficient) showed an excellent consistency between ETT positions identified on US and chest X-ray. The 2 measures (ETT-echo and CXR) were extremely concordant both in the whole sample and in the subgroups. Minimal changes in patients’ vital signs were infrequently observed during US, confirming the tolerability of ETT-echo. The mean time to perform US was 3.2 min (range 1–13). <b><i>Conclusions:</i></b> ETT-echo seems to be a rapid, tolerable, and highly reliable method worth further investigating for future routine use in neonatology with a view to reducing radiation exposure.

**背景与目的：** 对新生儿实施气管插管（endotracheal tube, ETT）操作具有挑战性，目前需及时通过影像学检查确认插管尖端位置是否正确。本研究旨在评估超声（ultrasound, US）在新生儿重症监护病房（neonatal intensive care unit, NICU）中用于评估气管插管位置的可靠性、操作所需时长以及患儿的耐受度。**方法：** 本研究为前瞻性研究，纳入我院新生儿重症监护病房收治的71例新生儿，均采用超声（ultrasound, US，下称ETT-echo评估法）评估气管插管位置，并通过胸部X线（chest X-rays, CXR）确认插管位置。研究由3名操作者完成，包括2名新生儿科医师及1名儿科住院医师。以右肺动脉（right pulmonary artery, RPA）作为超声定位的解剖标志，通过超声测量气管插管尖端与右肺动脉上缘之间的距离，并与胸部X线中气管插管尖端与气管隆突之间的距离进行对比。**结果：** 本研究共纳入71例接受气管插管的新生儿，其中出生体重<1000g者34例，1000~2000g者18例，>2000g者19例。统计分析采用Bland-Altman图（Bland-Altman plot）与Lin一致性相关系数（Lin’s concordance correlation coefficient），结果显示超声评估与胸部X线检测的气管插管位置具有极佳的一致性；无论在全样本还是各亚组中，两种检测方法的结果均高度一致。超声操作过程中仅极少观察到患儿生命体征出现轻微变化，证实了ETT-echo评估法的良好耐受性。超声操作的平均时长为3.2分钟（范围1~13分钟）。**结论：** ETT-echo评估法是一种快速、耐受良好且可靠性极高的气管插管位置评估方法，值得进一步研究以推广至新生儿科临床常规应用，从而减少辐射暴露。