Supplementary Material for: A Multicenter Lung Ultrasound Study on Transient Tachypnea of the Neonate

Background and Aim: Discordant results that demand clarification have been published on diagnostic lung ultrasound (LUS) signs of transient tachypnea of the neonate (TTN) in previous cross-sectional, single-center studies. This work was conducted to correlate clinical and imaging data in a longitudinal and multicenter fashion. Methods: Neonates with a gestational age of 34–40 weeks and presenting with TTN underwent a first LUS scan at 60–180 min of life. LUS scans were repeated every 6–12 h if signs of respiratory distress persisted. Images were qualitatively described and a LUS aeration score was calculated. Clinical data were collected during respiratory distress. Results: We enrolled 65 TTN patients. Thirty-one (47.6%) had a sharp echogenicity increase in the lower lung fields (the “double lung point” or DLP sign). On admission, there was no significant difference between patients with and without DLP in Silverman scores (4 ± 1.5 vs. 4 ± 2.1; p = 0.9) or LUS scores (7.6 ± 2.6 vs. 5.6 ± 3.8; p = 0.12); PaO2/FiO2 (249 ± 93 vs. 252 ± 125; p = 0.91). All initial LUS scans (performed at the onset of distress) and 99.5% of all scans showed a regular pleural line with no consolidation, with only 1 neonate showing consolidation in the follow-up scans. The Silverman and LUS scores were significantly correlated (rho = 0.27; p = 0.02). Conclusion: A regular pleural line with no consolidation is a consistent finding in TTN. The presence of a DLP is not essential for the LUS diagnosis of TTN. A semi-quantitative LUS score correlates well with the clinical course and could be useful in monitoring changes in lung aeration during TTN.

背景与目的：既往横断面单中心研究中，针对新生儿暂时性呼吸增快症（transient tachypnea of the neonate, TTN）的诊断性肺超声（lung ultrasound, LUS）征象已发表诸多结论相悖的结果，亟需进一步澄清。本研究旨在以多中心、纵向研究设计，关联临床与影像数据。方法：纳入胎龄34~40周、确诊为TTN的新生儿，于出生后60~180分钟行首次LUS扫描。若患儿仍存在呼吸窘迫征象，则每6~12小时重复行LUS扫描。对超声图像进行定性描述，并计算LUS通气评分。同时收集呼吸窘迫发作期间的临床资料。结果：本研究共纳入65例TTN患儿。其中31例（47.6%）于肺下野出现锐利的回声增强表现，即“双肺点”（double lung point, DLP）征象。入院时，存在DLP征象与无DLP征象的患儿，其Silverman评分（4±1.5 vs 4±2.1；p=0.9）、LUS评分（7.6±2.6 vs 5.6±3.8；p=0.12）及动脉血氧分压/吸入氧浓度比值（PaO2/FiO2）（249±93 vs 252±125；p=0.91）均无显著统计学差异。所有首次扫描（于呼吸窘迫起病时实施）及99.5%的随访扫描均显示胸膜线规则且无肺实变，仅1例患儿在随访扫描中出现肺实变。Silverman评分与LUS评分呈显著相关（rho=0.27；p=0.02）。结论：胸膜线规则且无肺实变是TTN患儿的一致性影像学表现。双肺点征象并非TTN的LUS诊断必备条件。半定量LUS通气评分与临床病程具有良好相关性，可用于监测TTN患儿的肺通气动态变化。