摘要目的:研究新生儿脐静脉置管（umbilical vein catheterization，UVC）对门静脉血流的影响，以及门静脉血流变化与胃肠道并发症的关系。方法:本研究为前瞻性研究。选取甘肃省妇幼保健院新生儿科2019年3月至2021年3月收治的行UVC且一次置管成功的新生儿作为研究对象。UVC成功定义为脐导管通过静脉导管达到下腔静脉与右心房入口处。于UVC前、后床旁超声测量门静脉血流速度（portal vein blood flow velocity，PBFVe）。比较UVC后至脐导管拔除前出现与未出现胃肠道并发症的患儿组内及组间UVC前后PBFVe及其下降百分比的差异。应用logistic回归分析和受试者工作特征（receiver operating characteristic，ROC）曲线分析UVC后出现胃肠道并发症的危险因素和预测价值。结果:共91例新生儿纳入本研究，包括并发症组37例和非并发症组54例。并发症组UVC前PBFVe与非并发症组比较，差异无统计学意义，UVC后PBFVe小于非并发症组（ t=－2.98， P=0.004），PBFVe下降百分比大于非并发症组［（22.5±6.0）%与（12.6±4.9）%， t=8.65， P<0.001］。并发症组及非并发症组组内比较，UVC后PBFVe均低于UVC前［并发症组分别为（11.3±1.8）与（14.7±2.4）cm/s， t=－16.92；非并发症组分别为（12.4±1.7）与（14.2±1.8）cm/s， t=－17.62； P值均<0.001］。多因素logistic回归分析显示，出生体重是出现胃肠道并发症的保护因素（ OR=0.294，95% CI：0.089~0.974， P=0.045），PBFVe下降百分比是出现胃肠道并发症的危险因素（ OR=1.478，95% CI：1.249~1.749， P<0.001）。UVC后PBFVe下降百分比预测出现胃肠道并发症的ROC曲线下面积为0.919（95% CI：0.843~0.966， P<0.001），界值为16.9%，对应的灵敏度和特异度分别为89.2%和85.2%。 结论:UVC可使PBFVe降低。PBFVe下降越多，出现胃肠道并发症的可能性越大。

abstractsObjective:To explore the effect of umbilical vein catheterization (UVC) on portal vein blood flow velocity (PBFVe) and its relationship with gastrointestinal (GI) complications in neonates.Methods:A prospective study was conducted on neonates with indications for UVC and achieving one-time successful catheterization at Gansu Provincial Women and Child-care Hospital from March 2019 to March 2021. Successful UVC was defined as the umbilical catheter reaching the entrance of the inferior vena cava and right atrium through the ductus venosus. PBFVe was measured by bedside ultrasound before and after UVC. All subjects were divided into two groups as those with GI complications anytime from insertion to withdrawal (complication group), and those with no GI complications (no complication group) to compare the PBFVe value before UVC and the percentage of decrease in PBFVe after UVC. Multivariate logistic regression analysis and receiver operating characteristic (ROC) curve were used to analyze the risk factors of GI complications and the predictive value of the percentage of decrease in PBFVe after UVC.Results:Of 91 subjects included, 59.3% (54/91) had no GI complications, and 40.7% (37/91) had. After UVC, PBFVe was decreased than before in neonates both with and without GI complications [(11.3±1.8) vs (14.7±2.4) cm/s; (12.4±1.7) vs (14.2±1.8) cm/s, t=－16.92 and－17.62, respectively, both P<0.05]. PBFVe before UVC were similar between the two groups. However, the complications group had a lower PBFVe after UVC ( t=－2.98, P=0.004) and a higher percentage of decrease in PBFVe [(22.5±6.0)% vs (12.6±4.9)%, t=8.65, P<0.001] when compared with the no complications group. Multivariate logistic regression analysis showed that the body weight was the protector of GI complications ( OR=0.294, 95% CI:0.089-0.974, P=0.045), and the percentage of decrease in PBFVe was the risk factor ( OR=1.478, 95% CI:1.249-1.749, P<0.001). The area under the curve of the percentage of decrease in PBFVe for predicting GI complications was 0.919 (95% CI:0.843-0.966, P<0.001). The cut-off value was 16.9% with a sensitivity of 89.2% and a specificity of 85.2%. Conclusions:UVC can reduce the PBFVe of neonates. The more the PBFVe decreases, the greater the possibility of GI complications.